Communicating vessels

Hence: if, then

LECTURE 3

Hydrodynamics

Examines the laws governing the movement of liquids.

Basic concepts:

1.Volume flow V = v cf S

2.Mass flow M = r v cf S

3.Average speed v with p =

Hydraulic channel radius r guide =, P - wetted perimeter

Equivalent diameter: d e = 4r guide

Flow regimes

1. Laminar - fluid layers move parallel to each other without acceleration or uniformly accelerated.

2. Turbulent - the layers are mixed, vortices and pulsations are observed.

Figure 2.4 - Distribution Figure 2.5 - To the equation of velocities of continuity

Reynolds criterion:

Re =

Re cr = 2320

v max = (p 1 -p 2) v r = v max ()

Continuity equation

V = v cf S = const

The volumetric flow rate through any section of the liquid flow is constant.

Euler's equations of motion

- acceleration

M - force causing movement m = rdV

Figure 2.6 - To the equations of motion of Euler

The elementary volume is affected by the forces of pressure and gravity:

In equilibrium we equate to the forces causing movement. After conversion:

(1)

Bernoulli equation

Adding and differentiating (1), we obtain the Bernoulli equation for an ideal fluid (without friction):

Figure 2.7 - To the Bernoulli equation

In accordance with Figure 2.7, taking into account the head losses to overcome friction forces, you can write:

(for real liquid)

where, is the total head Н

Z 2- geometric head

Static (piezometric) head

High-speed (dynamic) head

h - head loss. It is caused by friction. Head loss coefficients along the length of the pipeline:

laminar, turbulent

Hydraulic resistance (friction and places of origin):

1. Inlet and reducer 4. Pipe rotation

2. Large volume vessel 5. Gates, taps

3. Constriction, expansion

The energetic meaning of the Bernoulli equation:

H is the total energy;

Z - potential energy;

- specific kinetic energy

Basics of hydrodynamic similarity

1. Geometric similarity

2. Hydrodynamic similarity - similar are the fields of physical quantities characterizing the phenomenon

Newton's criterion;

; Ne m- model, Ne n- nature.

Froude's criterion:, - the ratio of the force of gravity and inertia;

Euler's criterion:, - ratio of pressure force and inertia;

Gallileo's criterion:, - the ratio of the force of viscous friction and gravity;

Grashof's criterion:, - ratio of viscous friction force and lifting force;

Homochronism criterion: - unsteady character of movement.

Calculation of pipe diameters

Important when designing

Volumetric flow equation: ... From here the diameter is determined:

1¸3 m / s (for dripping liquids)

8 - 15 m / s (gas, air at low pressure)

15 - 20 m / s (gas, air at high pressure)

20 - 30 m / s (saturated steam)

30 - 50 m / s (superheated steam)

LECTURE 4

Leakage of liquid

We use the Bernoulli equation. First, we investigate the outflow at a constant level:

H and - overpressure in meters of water column.

To obtain jets, nozzles are used ( l/ d = 3¸5)

1 - Cylindrical (j u = 0.8), 2 - Conical: A - tapering (j u = 0.9–0.95, for a long-range jet), B - expanding (j u = 0.5–0.55 , for high flow rate at low kinetic energy), 3 - Conoidal (j = 0.97).

Figure 2.9 - Nozzles

Jet force:

On a flat wall: F = rVu

On a convex wall: F = rVu (1 - Cos a)

On a concave wall: F = 2rVu

Basics of rheology

Non-Newtonian liquids (3 main groups):

1. The shear rate depends on the direction and does not depend on the duration of exposure - viscous:

a) Bingham s> s cr - coefficient of plastic viscosity (thick suspensions, pastes);

b) pseudoplastic small values ​​s cr - apparent viscosity h k, which decreases with increasing velocity gradient (suspensions with asymmetric particles);

c) dilated - h k grows with an increase in the velocity gradient (suspensions with a large amount of solid phase);

a) thixotropic - shear stress decreases over time (the structure is destroyed);

b) rheopectic - shear stress grows over time.

3. Viscoelastic (Maxwellian) - flow when stress is applied, and after removal, partially restore the shape (dough).

When calculating pipelines, the volumetric flow is determined:

where M is the mass flow rate, kg / s.

Then - the diameter:

LECTURE 5

Hydromachines

Technological processes require mixing, pumping, supply and removal of liquids and gases.

For liquids - pumps;

For gases - compressor machines.

Determination of the head created by the pump

Figure 2.10 - Determination of the required pump head

H g - the height of the geometric rise of the liquid. Also called full pressure;

H n - discharge height;

Н в - suction head.

H gsv - hydraulic resistance in the suction pipeline;

N gsn - hydraulic resistance in the injection pipeline.

If the pressure in the tanks is different:

The theoretical suction lift can be equal to atmospheric pressure, but is highly dependent on temperature (boiling).

So at t = 0 o C ® H B = 9 m, and at t = 65 o C ® H B = 0

Pumps are divided into:

1) piston (plunger): single and double-acting, multi-piston

Figure 2.11 - Plunger pump

Double action

2) centrifugal: single and multistage - for mixing low-viscosity liquids. It must be filled before starting, therefore it is installed below the liquid level (Figure 2.12)

B - Screw pump C - Jet pump

A - Diaphragm pump

Figure 2.14 - Pumps

2.Compressor machines

They are used to move gases and are divided depending on the ratio of pressures at the outlet Р 2 and inlet Р 1 into:

1) fans: R 2 / R 1< 1,1

2) gas blowers: R 2 / R 1< 3

3) compressors: P 2 / P 1> 3

BRIEF SUMMARY OF THE MODULE

The food industry meets the needs of the population for food products. In terms of size, it produces about a fifth of the gross industrial output in Belarus. The food industry employs about 9% of the country's total industrial production assets.

The great importance of the food industry is also evidenced by the fact that its products make up more than 90% of all food consumed by the population.

The food industry includes many different industries. With all the variety of technology, all these industries are united, first of all, by the common purpose of their products. The most important branches of the food industry are: flour milling, cereals, bakery, sugar, confectionery, meat, fish, canning, butter, cheese, tea and coffee, winemaking, brewing, etc.

The food industry is characterized by an extremely wide distribution. Its wide distribution is facilitated by the great variety and prevalence of its raw materials. However, its individual industries differ greatly from each other in terms of their location, and in this respect the food industry can be divided into three groups of industries.

One group is made up of industries that process non-transportable (or low-transportable) raw materials (sugar beet, fruit processing industry, wine, distillery industry). These industries are located in areas where raw materials are produced.

Another group is made up of industries that process transportable raw materials and produce low-transportable or perishable products (bakery, some confectionery, pharmaceutical, brewing industries, etc.), they are located in areas of product consumption.

The third group includes industries that can be located in both commodity and consumer areas (depending on the circumstances).

The didactic module "Basic technological processes of food production" is designed for independent study by students of economic specialties of a number of issues of organizing technological processes of bakery production, meat and milk processing. Studying this topic, they should get a clear understanding of the technical and economic indicators of the efficiency of food production technologies.

THEMATIC PLAN

1.Bakery technology.

2.Technology of meat and meat products.

3.Milk processing technology.

1. TECHNOLOGY OF BAKERY PRODUCTION

The production process of bread and bakery products consists of 6 stages:

1.reception and storage of raw materials;

2.preparation for launching into production;

3.dough preparation;

4. cutting the dough;

5. baking;

6.storage of baked products and sending them to the retail network.

Acceptance and storage of raw materials covers the period of acceptance, transfer to warehouses, subsequent storage of all types of main and additional raw materials entering the bakery industry. The main raw materials include flour, water, yeast and salt, and the additional raw materials include sugar, fatty products, eggs and other types of raw materials.

Each batch of raw materials is analyzed for compliance with their standards for the production of certain types of bakery products.

Preparation of raw materials for start-up consists in the fact that on the basis of the data of analyzes of individual batches of flour available at the bakery, laboratory staff establish a mixture of individual batches of flour that is expedient from the point of view of the baking properties. Mixing of flour of individual batches is carried out in flour mixers, from which the mixture is sent to the control sifter and to the storage hopper, from which, as required, it will be fed for dough preparation.

Water is stored in containers - tanks of cold and hot water, from which it enters the dispensers, providing the required temperature for making the dough.

The salt is preliminarily dissolved in water, the solution is filtered, brought to the required concentration and sent to prepare the dough.

Pressed yeast is preliminarily crushed and mixed with water into a suspension in a mixer, then it is fed to prepare the dough.

Dough preparation. With the safe method, dough preparation consists of the following processes:

Dosing of raw materials. Appropriate dosing devices measure and send the required quantities of flour, water at a given temperature, yeast suspension, salt and sugar solution to the mixer bowl.

Kneading the dough. After filling the bowl with the necessary components, turn on the kneading machine and knead the dough. The kneading should provide a homogeneous dough in terms of physical and mechanical composition.

Fermentation and kneading of the dough. In the kneaded dough, an alcoholic fermentation process occurs, caused by yeast. Carbon dioxide released during fermentation loosens the dough, due to which it increases in volume.

To improve the physical and mechanical properties, the dough is subjected to one or more kneading during fermentation. The kneading consists in the fact that the dough in the bowl is re-mixed for 1 - 3 minutes. During kneading, excess carbon dioxide is mechanically removed from the dough.

The total fermentation time of the dough is 2-4 hours. After fermentation, the bowl with the finished dough is turned with the help of the dezherodzhikat in the position at which the dough is unloaded into the hopper - dough release, located under the dough dividing machine.

Dough cutting. The division of the dough into pieces is carried out on a dough divider. Pieces of dough from the dividing machine enter the dough rounder, then undergo several operations to form the desired shape of the bakery product. After this, the dough pieces undergo final adjustment at tº 35 - 40º and humidity 80 - 85% for 30 - 55 minutes. in a special cell. The correct determination of the optimal duration of the final adjustment has a great impact on the quality of baked goods. Insufficient detuning duration reduces the volume of products, rupture of the upper crust, excessive detuning leads to vagueness of products.

Bakery. Baking of dough pieces of bread weighing 500-700g. takes place in the baking chamber of a baking oven at a temperature of 240-280º for 20-24 minutes.

Storage of baked products and sending them to the retail network. Baked bakery products are sent to the bakery, where they are placed in trays, which are loaded into vehicles and transported to the distribution network.

There are standards for bakery products by which their quality is determined. Deviations from these standards can be caused by a number of defects and diseases in the bread. Defects in bread can be caused by the quality of flour and deviations from the optimal modes of certain technological processes of bread production, storage and transportation.

Defects in bread caused by the quality of flour include:

Foreign smell

Crunching teeth due to the presence of sand in the flour.

Bitter taste.

Chaff stickiness if flour is ground from sprouted or frosty grains.

Bread defects in case of improper technological processes include:

1. Incorrect preparation of the dough.

2. Incorrect cutting of the dough (rasterizing).

3. Incorrect baking (too short or too long baking time).

The most common bread diseases are potato disease and mold.

Bread potato disease is expressed in the fact that the crumb of bread under the influence of microorganisms that cause this disease becomes viscous and acquires an unpleasant odor. The causative agents of this disease are spore microorganisms that are found in any flour. The concentration of these microorganisms and the baking temperature of the bread play an important role.

Bread mold is caused by mold fungi and their spores on the already baked bread.

2. TECHNOLOGY OF MEAT AND MEAT PRODUCTS

To accept a batch of livestock by live weight, it is sorted into age groups and body condition categories in accordance with the standards for livestock. Cattle and young animals are divided into three categories: higher, medium and below average. The same classification applies to small ruminants. Pigs are categorized as fat, bacon, meat and skinny. Poultry and rabbits are divided into 3 categories: 1, 2 and custom.

To create the necessary conditions for preparing animals for slaughter at the meat processing plants, workshops for the pre-slaughter maintenance of livestock and poultry have been created. Preparation of animals and poultry for slaughter consists in emptying their gastrointestinal tract, cleaning and washing. To free the gastrointestinal tract, feeding of cattle stops in 24 hours, pigs - 12 hours, poultry - 8 hours. Drinking animals and poultry is not limited.

After pre-slaughter aging, the animals go to the initial processing to obtain meat carcasses. The technological process of slaughtering cattle and cutting carcasses is carried out in the following sequence: stunning, exsanguination and collection of food blood, separation of the head and limbs, removal of the skin, removal of internal organs, sawing the carcass into two half carcasses.

There are several methods of stunning: electric shock, mechanical stress, chemical anesthesia. The main method in meat processing plants is electric current.

After stunning with the help of a winch or an elevator, the animals are delivered to the slaughterhouse, where the carotid artery is initially cut, the esophagus is closed with a clamp. Then the blood is collected (closed and open systems). After bleeding, the skin is removed from the carcass, then the head and limbs are removed. Extraction of internal organs must be done immediately after slaughter, no later than 30 minutes. without damaging the gastrointestinal tract. After removing the internal organs, the carcasses are cut into two halves. These half carcasses go for sale or processing.

Sausage products are products prepared on the basis of minced meat with salt, spices and additives with or without heat treatment. Salted products are products prepared from raw materials with an intact or coarsely ground structure.

Depending on the raw materials and processing methods, the following types of sausages are distinguished: boiled, semi-smoked, smoked, stuffed, blood sausages, etc. etc.

Over the next years, scientists and specialists from different countries are conducting research on the creation of combined meat products that combine traditional consumer properties when using proteins of various origins.

The solution to the problem of creating full-fledged combined meat products must be linked to the development of a new direction in food technology - the design of food products.

Canned food is meat products packed in airtight containers and sterilized or pasteurized by heating. According to the types of raw materials, canned food is divided in natural juice, with sauces and jelly.

According to the purpose, canned food is divided into snack bars, first course, second course, semi-finished products.

According to the method of preparation before use, canned food is divided into those used without heat treatment, used in a heated state, in a chilled state.

By the duration of the shelf life, canned food is distinguished for long-term storage (3-5 years) and snack bars.

One of the main tasks of the meat industry technologists is the creation of waste-free technologies for processing raw materials. This can be achieved by improving the existing technological schemes with the rational use of the stock of raw materials, technological equipment, vehicles.

3. MILK PROCESSING TECHNOLOGY

The main condition for obtaining high-quality dairy products is compliance with sanitary and hygienic rules during milking and primary processing of milk, as well as the conditions for feeding and keeping animals. Particular attention should be paid to cleaning the udder and milk equipment. Mechanical processing of milk includes cleaning from mechanical impurities and contaminants of biological origin, separation.

Milk purification from mechanical impurities can be carried out using pressure filtration through a cotton cloth. The most perfect method is the use of separators - milk purifiers, in which, under the action of centrifugal force, milk and mechanical impurities are separated. For mechanical processing of milk, in addition to centrifugal milk purifiers, separators are used - cream separators, universal separators.

Heat treatment is an important and indispensable operation in the technological process of the production of dairy products. The main purpose of heating is to render the product microbiologically harmless and, in combination with cooling, to prevent spoilage during storage.

In the dairy industry, two main types of heat treatment of milk by heating are widely used - pasteurization and sterilization.

Heat treatment of milk at temperatures below the boiling point is called pasteurization. The purpose of pasteurization is the destruction of vegetative forms of microorganisms in milk. In practice, the most common short-term pasteurization (74-76 ° C, 20 sec.) Milk passes through heated plates.

Sterilization is understood as heat treatment of milk at temperatures above 100 ° C in order to completely destroy the vegetative forms of bacteria and their spores. Sterilized milk takes on a boiling flavor.

In practice, the following sterilization modes are used: I - sterilization in bottles at a temperature of 103-108 ° C for 14-18 minutes, II - sterilization in bottles and sterilizers at a temperature of 117-120 ° C, III - instant sterilization at a temperature of 140-142 ° C with a spill in paper bags.

After pasteurization, the milk is immediately cooled to different temperatures, depending on the technological process of producing the finished product.

Pasteurized milk is produced in small packaging, as well as in tanks.

It is produced according to the following technological scheme: acceptance of raw materials - qualitative assessment - milk purification (at 35-40 ° C), cooling pasteurization (74-76 ° C) cooling (4-6 ° C), container preparation - sealing and labeling - storage. The shelf life of pasteurized milk at a temperature of 8 ° C is no more than 20 hours from the date of release. The quality of pasteurized milk is controlled according to the following parameters: temperature, acidity, fat content, smell and taste.

The process of production of pasteurized milk is carried out according to two basic schemes: with one and two-stage sterilization mode. In a one-stage sterilization mode, milk is heat treated once - before or after bottling. In this case, the first option is better. Technological scheme: acceptance of raw materials - qualitative assessment - cleaning - heating (75-80 ° C) - sterilization (135-150 ° C) - cooling (15-20 ° C) preparation of containers, bottling - quality control.

A more stable product is obtained with two-stage sterilization. With this method, milk is sterilized twice: before bottling (in flow) and after bottling (in bottles).

Baked milk - pasteurized milk with prolonged heat treatment (heating for 3-4 hours, 95-99 ° C).

Milk with fillers: coffee, cocoa, fruit and berry juices.

Fortified milk with the addition of vitamins A, D, C.

Cream: fat content - 8, 10, 20, 35%

Lactic acid products include: yogurt of various types, fermented baked milk, kefir, kumis, yogurt and other drinks. A common feature of all lactic acid products is fermentation that occurs when milk is fermented with pure cultures of lactic acid bacteria.

There are two groups of fermented milk drinks: obtained only as a result of lactic acid fermentation and with mixed fermentation - lactic acid and alcoholic.

Group 1 includes yogurt, fermented baked milk.

Group 2 - kefir, koumiss.

There are two ways to make fermented milk drinks: tank and heat-resistant. The first method includes: fermenting milk in tanks - stirring - cooling in tanks - maturation - filling into bottles or bags. The second method consists of the following operations: bottling - labeling - cooling - maturation in a refrigerating chamber.

Curd is obtained by fermenting milk with lactic acid bacteria with subsequent removal of whey. There are cottage cheese from pasteurized milk, intended for direct consumption and the production of various curd products, as well as from unpasteurized milk, used for the production of various processed and other cheeses that undergo heat treatment.

Depending on the fat content, cottage cheese is divided into fat (18% fat), semi-fat (9%) and low-fat. Curd is produced by acidic and rennet-acidic methods. According to the first method, a curd in milk is formed as a result of lactic acid fermentation, however, with this method of fermentation of fatty milk, the curd gives off whey poorly. Therefore, in this way, only fat-free cottage cheese is obtained. Fatty and semi-fatty cottage cheese is made by the rennet-acid method ...

Sour cream is produced by fermenting pasteurized cream. Sour cream is produced with a fat content of 10% (dietary), 20, 25, 30, 36 and 40% (amateur).

The fermented cream is mixed, packaged, cooled to + 5-8 ° and left to ripen for 24-48 hours.

Ice cream is produced by freezing and whipping milk or fruit and berry mixtures in an assortment of more than 50 items. The name of the ice cream depends on the composition, flavoring and aroma additives. Despite the significant variety of assortment, ice cream production is carried out according to the technological process: acceptance of raw materials - preparation of raw materials - preparation of a mixture - pasteurization (68 ° С, 30 minutes) - homogenization of the mixture (whipping) - cooling (2-6 ° С) - freezing (freezing ) - packaging and hardening (further cooling) - storage (18-25 ° С).

FEDERAL EDUCATION AGENCY

VLADIVOSTOK STATE UNIVERSITY OF ECONOMY AND SERVICE

COLLEGE OF SERVICE AND DESIGN

"Equipment for public catering establishments"

for specialties 260502.51

"Technology of Public Catering Products",

050501.52 vocational training specialization

"Technology of public catering products"

Vladivostok 2008

Lecture number 6. Dough and cream making machines

Lecture number 7. Weighing equipment

Lecture number 8. Checkout machines

Lecture number 9. Basics of heat engineering. Heat generating devices

Lecture number 10. Cooking equipment

Lecture number 11. Frying and baking equipment

Lecture number 12. Cooking and frying and hot water equipment. Electric cookers

Lecture number 13. Food dispensing equipment. Food warmers

Lecture number 14. Refrigeration fundamentals. Compressors

Lecture number 15. Commercial refrigeration equipment. Cameras and cabinets

refrigeration

Lecture number 16. Occupational Safety and Health. Legal framework for labor protection

Bibliography

Lecture number 1. Introduction. Equipment classification

At the present stage, public catering will occupy a predominant place in comparison with meals at home. In this regard, there is a need for further mechanization and automation of production processes, as the main factor in the growth of labor productivity. Domestic industry creates a large number of different machines for the needs of public catering enterprises. Every year, new, more modern machines and equipment are mastered and introduced, providing mechanization and automation of labor-intensive processes in production.

New machines and equipment are being created and mastered, which will work in automatic mode without human intervention.

Currently, one of the most important tasks in the country is a radical reform to accelerate scientific and technological progress in the national economy.

In public catering, it is especially acute; in enterprises, the vast majority of production processes are still performed manually. There are many types of work that employ a large number of low-skilled workers. Therefore, a radical restructuring in this area of ​​production presupposes the need for extensive industrialization of production processes, the massive introduction of industrial methods of preparation and delivery of products to consumers.

Such organization of production in public catering will allow not only to use new high-performance equipment, but also to use it more efficiently. Consumers will also benefit - time costs are reduced, the culture of service is increased, and public catering workers - due to mechanization and automation of production, manual labor costs are sharply reduced, production productivity is increased and sanitary conditions are improved.

The introduction of new technology and progressive organization of production makes it possible to significantly increase the economic efficiency of public catering enterprises by increasing labor productivity, reducing the consumption of raw materials and energy.

Scientific and technological progress in public catering consists not only in the development and improvement of the tools of labor used, in the creation of new, more efficient technical means, but also unthinkable without a corresponding improvement in technology and organization of production, the introduction of new methods of labor and management.

Improvement of technology should ensure not only an increase in labor productivity and its facilitation, but also a decrease in labor costs per unit of output when new machines and mechanisms are used. In other words, a new technique will only be effective if the expenditure of social labor on its creation and use requires less labor saved by the use of this new technique. In the final analysis, the economic essence of improving machines and mechanisms lies in reducing the cost per unit of output produced with the help of new technology.

To accelerate the pace of scientific and technological progress in public catering, it is of great importance to improve heating devices, which make it possible to intensify the processes of heat treatment of raw materials through the use of new heating methods, automatic maintenance of preset modes, and programming of the thermal process.

In the production of heating equipment in our country over the past twenty years there have been fundamental changes that can be called technological restructuring. It can be divided into three periods. The first consisted of a shift from solid fuel equipment to gas and electrical equipment. At the second stage, there was a transition from universal equipment (for example, a kitchen stove) to sectional equipment, each type of which is designed to perform separate operations for heat treatment of products. The third period is currently taking place. It consists in the production and implementation of equipment using new methods of heat treatment of products, dry steam or convective heating.

For the development of thermal equipment, the most promising direction is the creation of new devices:

With new types of thermal processing of products (combined heating, processing of products with dry steam and convective heating);

With automatic regulation and programming of the thermal process;

With continuous action for cooking and frying food (transfer automatic machines);

With devices and devices that mechanize the processes of turning and mixing products (cooking kettles with a mechanical stirrer).

Unification and standardization of technological equipment can significantly reduce its nomenclature and reduce material consumption and also create real prerequisites for reducing the labor intensity of products.

To improve the technical level of public catering enterprises, increase labor productivity and improve the organization of public services, it is important to improve the distribution equipment, the introduction of high-performance conveyor lines for the acquisition and implementation of complex meals. A new direction for improving dispensing equipment is the creation of self-service counters, including mobile food warmers, counters, cabinets and other types of dispensing equipment that meet sanitary and environmental standards.

Improvement of technological processes in public catering will be effective only if their implementation is carried out on a new technical basis. At the same time, new technology should be created in three directions. The main thing is the development and mastering of technology that meets the modern level of development of science. Work must constantly be carried out to create fundamentally new types of technology. Along with this, great attention should be paid to the modernization of the existing technological equipment.

An important means of accelerating scientific and technological progress in public catering is the timely modernization of equipment, replacement of obsolete equipment with modern technology that is not inferior in quality, reliability, metal consumption and energy consumption to the best achievements of science.

The low efficiency of the introduction of new technology is often associated with the imperfection of the design solutions of certain types of machines. The quality and reliability of the equipment used are still not high enough.

Thus, the developer and creator of new technology is tasked with significantly improving the weight of the most important technical and economic parameters of machines, equipment and various mechanisms in public catering:

Creation of machines and devices operating on the basis of electrophysical methods of heat treatment of food products (infrared rays and microwave heating and their use with traditional methods);

Development of means of complex mechanization and automation of production processes for specialized and highly specialized public catering enterprises (pancakes, dumplings, pies, etc.);

Improving the quality of manufactured equipment - reliability, durability and maintainability, and having standard unified units and parts.

Creation of high-performance universal machines and mechanisms, convenient for their use both individually and as part of mechanized or automated production lines.

The solution of these tasks will make it possible to intensify production processes at public catering enterprises, significantly improve the quality of products and reduce their cost.

Further expansion of the network of public catering establishments and an increase in their technical equipment requires the maintenance personnel to improve technical literacy, special knowledge and professional development.

Classification of machines

Depending on the purpose and type of processed products, catering machines can be divided into several groups.

1. Machines for processing vegetables and potatoes - cleaning, sorting, washing, cutting, rubbing, etc.

2. Machines for processing meat and fish - meat grinders, meat mixers, meat rippers, cutlet molding machines, etc.

3. Machines for processing flour and toast - sifters, kneaders, whippers, etc.

4. Machines for slicing bread and gastronomic products - bread slicers, sausage slicers, butter dividers, etc.

5. Universal drives - with a set of replaceable executive machines.

6. Machines for washing hearth dishes and appliances.

7. Hoisting-and-transport machines.

The machine consists of three main mechanisms: motor, transmission and executive, as well as control, regulation, protection and blocking mechanisms.

The motor mechanisms are mainly AC squirrel-cage motors (closed, asynchronous, three-phase or single-phase). DC electric motors are used to operate in dining cars and ships.

The transmission mechanism serves to implement the relationship between the motor and executive mechanisms. Together, the motor and transmission mechanisms are called the drive of the machines.

The actuator determines the purpose and name of the machines. Its design depends on the structure of the working cycle and the nature of the technological process, as well as the type and physical and mechanical properties of the product being processed: The actuator includes a working chamber with loading and unloading devices, as well as tools for mechanical processing of products.

With the help of control mechanisms, start, stop and control over the operation of the machine are carried out. The control mechanisms are designed to adjust the machine, and the protection and interlocking mechanisms are designed to protect the machine from damage and emergency shutdown.

All machines used in trade and public catering enterprises can be classified according to the structure of the working cycle, the degree of mechanization and automation of processes, and according to their functional characteristics.

By the structure of the working cycle, machines are distinguished, of periodic and continuous action. In batch-type machines and mechanisms, the product is processed for a certain time, called the processing time, and then removed from the working chamber. After loading a new portion of the product, the process is repeated. In continuous machines, the processes of loading, handling and unloading the product take place simultaneously and continuously.

According to the degree of mechanization and automation, machines are distinguished non-automatic, semi-automatic and automatic. In non-automatic machines, loading, unloading, control and auxiliary technological operations are performed by the operator. In semi-automatic machines, the main technological operations are performed by the machine; only transport, control and some auxiliary processes remain manual. In automatic machines, all technological and auxiliary processes are carried out by the machine.

On a functional basis, machines and mechanisms of trade and public catering enterprises are subdivided into a number of groups due to their purpose: machines for separating bulk food products; machines for washing vegetables and tableware; machines for cleaning products from external integuments; machines for grinding products; machines for mixing products; pressure processing machines; weighing devices and cash registers; lifting and transporting equipment.

Lecture number 2. General information about machines and mechanisms

A machine is a collection of mechanisms that perform a specific job or transform one type of energy into another. Depending on the purpose, machines are distinguished - engines and working machines.

Depending on the purpose, working machines can perform certain work to change the shape, size, properties and state of objects of labor. The objects of labor in public catering enterprises are food products that undergo various technological processing - cleaning, grinding, whipping, stirring, shaping, etc.

According to the degree of automation and mechanization of the technological processes performed, machines are distinguished non-automatic, semi-automatic, automatic. In non-automatic machines, loading, unloading, control and auxiliary technological operations are performed by a cook assigned to this machine. In semi-automatic machines, the main technological operations are carried out by the machine, only transport, control and some auxiliary processes remain manual. In automatic machines, the technological and auxiliary processes are carried out by the machine. They are used as part of flow and flow-mechanized lines and completely replace human labor.

Basic requirements for machines and mechanisms.

Machines and mechanisms must meet the requirements of advanced technology for processing raw materials and products.

For this, it is necessary that the structural, kinematic and hydraulic parameters of the equipment provide optimal modes of technological processes and high technical and economic indicators. These parameters are: specific energy consumption, specific metal consumption, specific material consumption, specific water consumption, the area occupied by the equipment, etc., that is, the parameters of the machine, referred to the unit of productivity.

The design must ensure high reliability and durability of the machine, quick replacement of worn out and faulty working bodies, tools, assemblies and parts. The design must be technologically advanced, that is, in the process of manufacturing and operating the machine, minimal funds are spent. It is necessary that machines and mechanisms meet the requirements of safety measures and industrial sanitation (machines are grounded; working bodies, tools and transmission elements are covered with casings, covers, safety rings, linings or enclosed in housings; the design of many machines includes various interlocking devices and elements that provide turning them off when the fences are raised).

Manufactured machines are increasingly required to meet the requirements of production aesthetics. The correct proportions of the machines, the simplicity of their shape, the convenient arrangement of the controls, loading and unloading devices, and pleasant coloring contribute to an increase in labor productivity and the creation of a safe working environment.

When creating modern machines and mechanisms, they strive to standardize and unify units, parts and components, which makes it possible to reduce the range of spare parts and facilitate repair work.

Working bodies and tools of machines and mechanisms must have high wear resistance. Rapidly rotating machine parts and components must be balanced to eliminate wear on bearings, shafts and housing parts.

Materials used in the manufacture of machines and mechanisms.

The parts that make up the machines are subjected to different loads, which is taken into account when choosing materials. The parts of the bodies (beds, racks, etc.) account for up to 75% of the mass of all parts of the machine, and although they experience insignificant loads, the parts must meet the requirements for strength and rigidity. The body parts are cast from gray cast iron or aluminum and welded from carbon steel grades StZ and St5. The use of welded caps and casings provides great savings in metals. To reduce the mass of portable machines and mechanisms, parts of their bodies are made of aluminum alloys by casting or injection molding. In some cases, body parts can be made of reinforced plastics or fiberglass.

Shafts, gears, rods, axles, pins are under the greatest stress. Materials for their manufacture are carbon and stainless steels. Most often, steels of grades 45, 50, 40X, 65G, 15, 20X are used.

Gears, pulleys, cogwheels, flywheels are made from cast iron, steel, aluminum alloys, as well as from plastics, textolite, plastics, nylon, etc.

Knives and grinders of meat grinders are made of tool steel, as well as high-chromium cast iron of the X28 brand. Materials used for the production of tools and working chambers should not corrode as a result of contact with products, in addition, they should be easily cleaned of product residues and not destroyed by detergents.

The choice of the brand and method of heat treatment of the material is determined by calculating its strength or stiffness, taking into account technological, operational and economic requirements.

Marking of machines and mechanisms.

Currently, the marking of machines and mechanisms is carried out according to industry instructions, which establish a single order of designations, mandatory for all organizations and enterprises of trade and public catering.

The designation is based on a mixed alphanumeric system.

The left part of the designation - alphabetic - consists of three to four letters. The first letter corresponds to the name of the product (P - drive, M - machine, etc.), the second - to the purpose of the product (U - universal, O - cleaning, K - combined, V - whipping, T - dough mixing , M - washing, I - grinding), the third letter corresponds to the name of the type of energy or the main technological process (E - electric, O - vegetable, M - meat, V - vibration), etc.

The right part of the designation - digital--: serves as an indicator of the main parameter of the product (productivity, working chamber capacity, etc.) and is separated from the left part with a hyphen. The main parameters of the products are indicated by the upper (maximum) limit. If the machine is produced in a modernized version, after its main parameter, a code is put down indicating the modernization (M, Ml, M2, etc.).

Examples of machine marking: MOK-250 - a machine for peeling potatoes and root tubers with a capacity of 250 kg / h; MMU-1000 - universal washing machine with a capacity of 1000 plates / h; MIM-500 - a machine for grinding meat with a capacity of 500 kg / h.

Lecture number 3. Machine parts. Electric actuators

Main parts and machine parts

Modern machines consist of a large number of parts for various purposes. Connecting to each other, the parts form nodes. The main units of any machine used in public catering establishments are: bed, body, working chamber, working bodies, transmission mechanism and engine.

Bed - serves for the installation and assembly of all machine components. It is usually made cast or welded and has holes for fixing the machine in the workplace. Machine body - designed to accommodate the internal parts of the machine - working chamber, transmission mechanism, etc. Sometimes the bed and body are manufactured as one piece.

Working chamber - a place in the machine where the product is processed by the working bodies.

Working bodies are units and parts of machines that directly affect food products during their processing.

Transmission mechanism - transfers movement from the motor shaft to the working body of the machine, while providing the required speed and direction of movement. As a rule, an electric motor is used as the engine of the machine.

Understanding gears

A transmission is a mechanical device that transfers rotary motion from the shaft of the electric motor to the shaft of the working bodies. At the same time, the gears allow you to change the speed of rotation of the shaft, the direction of movement to the opposite and transform one type of movement into another.

In mechanical transmissions, the shaft with the parts that transmit the rotation purchased on it is called the driving shaft, and the shaft with the rotation parts is called the driven shaft.

All mechanical transmissions can be divided into belt, gear, worm, chain and frictional.

Gears is a mechanism consisting of 2 gears interlocked with each other. These transmissions are widely used in the transmission mechanisms of machines.

Depending on the design and arrangement of the gears, gears are classified into cylindrical, bevel and planetary. According to the method of teeth engagement, gear drives are divided into gears with external and internal gearing.

Depending on the location of the teeth, the wheels are divided into flat-toothed, helical and chevron. To transmit a complex rotational motion, a planetary gear mechanism is used (Fig. 1-2pap), in which one gear wheel is stationary, the other performs double rotation: around its axis and around the axis of a stationary wheel (whipping machine).

Belt transmission - carried out by means of two pulleys fixed on the drive and driven shafts, and a belt put on these pulleys. Rotation from one shaft to another is transmitted by friction between the pulley and the belt.

The belt in cross-section can have the shape of a rectangle - flat belt transmission, trapezium - V-belt transmission, circle - round-belt transmission. Belts are made of leather or cotton and rubberized fabric. Normal operation depends on correct belt tension. The belt drive is quiet in operation, simple in design and protects the machine from damage in case of jamming, as the belt will slip. At catering establishments, V-belt transmission is widely used, which is used in potato peelers, meat grinders, refrigeration units, etc.

A worm gear is used to transfer motion between shafts with intersecting axes. It consists of a screw with a special thread (worm) and a gear with teeth of the corresponding shape. These transmissions are compact, quiet and significantly reduce shaft speed.

The chain transmission consists of 2 sprockets fixed on the shafts and an articulated flexible chain, which is put on the sprockets and serves to connect them. These transmissions are used in mechanisms and machines with large distances between shafts and parallel arrangement of their axes. Chain drives provide a constant gear ratio and, in comparison with a belt drive, allow the transmission of high power, in addition, several shafts can be driven by one chain. The disadvantages of the chain drive include the high cost of maintenance, the complexity of manufacture and noise during operation.

The friction gear consists of 2 rollers mounted on shafts and pressed against one another. Rotation from the driving roller is transferred to the driven roller due to the frictional force.

When transferring rotation between parallel shafts, cylindrical gears are used, between intersecting shafts - bevel gears.

These transmissions are simple in design, silent in operation and self-protection from overloads, however, they have some disadvantages: low efficiency - 80-90%, inconsistent gear ratio and increased wear of the rollers.

The crank mechanism is designed to convert rotary motion into reciprocating motion of the working tool. It consists of a crankshaft, connecting rod and piston. As the crankshaft rotates, the connecting rod inserts the piston to move reciprocally. This mechanism is used in refrigeration compressors.

The concept of electric drives

An electric drive is a machine device used to propel a machine. It consists of an electric motor, a transmission mechanism and a control panel. At catering establishments, the most common are motors designed for a voltage of 380/220 V. This means that the same motor can operate on an alternating current network with a frequency of 50 Hz and with a voltage of 380 or 220 V, it is only necessary to correctly connect its windings stator. Connecting them with a "triangle", the engine is connected to a 220 V mains, connected by a star to a 380 V mains.

Universal drives have been widely used, which can alternately drive various installed replaceable working mechanisms - a meat mixer, a meat grinder, whipped, etc. The use of universal drives in stop stops is very beneficial. This is explained by the fact that shiftable working machines work in canteens for no more than an hour and therefore have a very low utilization rate. In such cases, it is impractical to install an electric drive to each machine due to the increase in its cost and occupied area. Currently, the industry produces 2 types of universal drives: general-purpose, which are used in several workshops, and special-purpose, which are used only in one workshop, for example, in a butcher. Universal small-sized drives UMM-PR with an AC electric motor, UMM-PS with a DC electric motor, which are used in transport (ships and restaurant cars), also belong to the universal halts of general purpose. All universal actuators are identified by letter designations. The first letter P denotes the drive, the second is the name of the workshop: M - meat, X - cold, G - hot, U - universal, for the cold workshop PX-0.6, for the hot workshop PG-0.6 and for meat shop PM-1.1. For general-purpose drives: PU-0.6 and P-11, replaceable mechanisms are installed, which have letter designations: the first letter M is a replaceable mechanism, the second M is a meat grinder, B is a whipping mechanism, O is a vegetable cutting mechanism.

Universal drives

At enterprises of a society of a different kind, along with machines designed to perform one particular operation, universal drives with a set of interchangeable mechanisms are used that perform a number of operations for processing products.

Universal drives are used mainly in small catering establishments, in meat, vegetable and confectionery shops.

A universal drive is a device consisting of an electric motor with a gearbox and having a device for variable connection of various replaceable mechanisms. It consists of an electric motor with a gearbox, on which removable mechanisms of various purposes can be fixed and alternately operated: a meat grinder, a beater, a vegetable cutter, a meat looser and other machines. From here the drive got its name - "universal".

The use of universal drives significantly increases labor productivity, reduces capital costs, increases the efficiency of equipment, etc.

At present, the industry produces universal drives P-11 and PU-0.6 for various workshops, as well as drives for special purposes P-1.1 for a relatively small range of products.

For work in small canteens, as well as in the galleys of river and sea vessels, universal small-sized drives UMM-PS or UMM-PR are used. The power source of these drives the layout be alternating (AC) or direct (PS) current.

The universal general-purpose drive PU-0.6 is produced as a two-speed drive with a shaft speed of 170 and 1400 rpm and a single-speed drive with a speed of 170 rpm and an engine power of 0.6 kW. It has a set of interchangeable mechanisms (Table 1), which can be used in small enterprises where there is no workshop.

At large catering establishments, where there is a workshop division, specialized universal drives are used:

The PM-1.1 drive specialized for the meat and fish shop is produced in a single-speed or two-speed version, with a shaft speed of 170 or 1400 rpm and an engine power of 1.1 kW. It has a set of replaceable actuators that can only be used in meat and fish shops of enterprises.

The PKh-0.6 drive is specialized for cold shops. Consists of a single-speed P-0.6 drive and a set of replaceable actuators that can be used in cold shops.

The PG-0.6 drive, specialized for hot shops, consists of a full-speed P-0.6 drive and a set of replaceable actuators that can be used in hot shops.

The P-P universal drive consists of a two-stage gear reducer, a two-speed motor. The rotational speed of the drive shaft of the drive is PO and 330 rpm. On the throat of the drive there is a handle with a cam for attaching replaceable actuators. The electric motor speed switch, start button and gesh relay return button are mounted on the control panel.

All manufactured drives and replaceable mechanisms for them have alphabetic and numeric designations.

The letter P - denotes the word drive, Y - universal, M - butcher shop, X - cold shop, G - hot shop. The numbers following the letters indicate the nominal power of the drive motor in kilowatts.

Replaceable mechanisms (MO. Complemented to universal or specialized drives have a specific serial number.

Number 2 - meat grinder, 3 - juicer, 4 - beater, 5 - potato peeler, 6 - ice cream maker, 7 - wiping mechanism, 8 - meat mixer, 9 - cutter, 10 - vegetable cutter, 11 - cart or stand for drive, 12 - grinding mechanism, 13 - device for cleaning knives and forks, 14 - sausage cutter, 15 - bone cutter, 16 - sharpener, 17 - fish cleaner, IS - mechanism for figured cutting of vegetables, 19 - ripper meat, 20 - a mechanism for beating, 21 - a cutlet-forming mechanism, 22 - a mechanism for cutting boiled vegetables, 24 - a sifter, 25 - a mechanism for mixing salads and vinaigrettes, 27 - a mechanism for cutting fresh vegetables, 28 - a mechanism for cutting raw vegetables in cubes.

The figure following the sequential number of the mechanism shows the value of the average productivity. In addition, some interchangeable mechanisms are identified by two or more numbers. For example, MS-4-7-8-20. This designation testifies to the multipurpose purpose of the mechanism: 4 - whip the product, 7 - wipe the product, 8 - stir the minced meat, 20 - the capacity of the tank.

Operating and safety regulations for universal drives

The preparation for the operation of the universal drive is carried out by the chef assigned to this machine, who, before starting work, must comply with the safety requirements and observe labor safety when working with the machine.

That is why, before starting work, the correctness of the installation of the universal drive, the serviceability of the replaceable mechanism and the correctness of its assembly and fastening with the help of clamping screws are checked. When installing the body of the replaceable mechanism in the throat of the drive, check that the end of the working shaft of the mechanism fits into the socket of the drive shaft of the gearbox of the universal drive. The presence of protective devices, grounding or grounding is checked.

After making sure that the replaceable mechanism and drive are in good working order, a test run is carried out at idle speed. The drive should run with little noise. In the event of a malfunction, the drive is stopped and the cause of the malfunction is rectified. It is allowed to adjust the rotation speed during operation only if there is a variator in the design of the machines.

The cooked products should be loaded into the interchangeable mechanisms only after turning on the universal drive, the only exception is the whipping mechanism, in which the products are first loaded into the container and then the universal drive is turned on.

During operation, it is forbidden to overload the interchangeable mechanism with products, as this leads to deterioration of the quality or damage to the products, as well as to the breakdown of the machine. Particular attention must be paid to strict adherence to safety rules when working with a universal drive, because negligence leads to personal injury.

Inspection of the universal drive and the installed replaceable mechanism, as well as troubleshooting, is allowed only after turning off the electric motor of the universal drive and stopping it completely.

After the end of the work, the universal drive is turned off and disconnected from the mains. Only then can the replaceable mechanism be removed for disassembly, rinsing and drying.

Preventive and current repairs of the universal drive and replaceable mechanisms are carried out by special workers in accordance with the concluded contract.

Lecture number 4. Vegetable processing machines

General information.

At the enterprises there are several ways of peeling vegetables from the skin: alkaline, steam, combined, thermal and mechanical. In the alkaline method, potatoes and other vegetables are preheated in water, and then treated with an alkaline solution heated to 100 ° C, which softens the surface layer of tubers. Then, in a drum washer, the tubers are cleaned of the outer layer and washed from the alkali. In the steam method, the potatoes are treated with steam under a pressure of 0.6 0.7 MPa for 1-2 minutes, then enters a roller washing machine, where the softened layer is removed from the tubers. With the combined method, the potatoes are first treated with a 10% caustic soda solution at a temperature of 75-80 ° C for 5-6 minutes, then with steam for 1-2 minutes. After that, the potatoes go to the washers, usually of the drum type.

In the thermal method, vegetables are fired in a cylindrical oven with a rotating cylindrical rotor and reach a penetration depth of no more than 1.5 mm. The vegetables are then cleaned in a washer-cleaner. Duration of heat treatment for onions 3-4 sec, for carrots 5-7 sec, for potatoes 10-12 sec. Another cleaning method is mechanical.

Equipment for chopping and cutting vegetables.

Vegetable cutting machines are: disc, rotary, punched and combined.

The table-top machine MPO-200 is used for cutting raw vegetables into slices, slices, strips, cubes. The drive of the machine consists of an electric motor and a V-belt transmission. The working chamber is made in the form of a cylinder with windows for loading vegetables. The machine is supplied with a circular cutter, two grating discs and two combination blades. The circular knife is used for cutting vegetables into slices and shredding cabbage, combined - vegetables in cubes with a section of 3 x 3 and 10 x 10 mm.

Classification.

Machines for grinding raw materials can be conditionally divided into two groups: machines that provide coarse grinding of raw materials and machines that provide fine grinding. Modern machines for coarse grinding are: roller, knife, hammer, crushers - separators for grapes, crushers - seed separators for tomatoes. Machines for cutting raw materials exist with fixed knives, with rotating circular knives; combined machines for cutting vegetables into cubes. For fine grinding of raw materials and separation of seeds, rubbing machines are used, as well as homogenizers, colloid mills, disintegrators, micronor, cutter, etc.

Vegetable cutter

Has two horizontal shafts rotating in opposite directions. Shaft 1 rotates the drum, into the inner cavity of which the raw material enters. Shaft 2 drives disc knives, the number of revolutions of which is five times the number of revolutions of the drum. The raw material entering the drum, under the action of centrifugal force, is thrown by the blade to the stationary cylindrical body and is fed under the influence of circular knives and a stationary flat knife. The blade shape ensures product jamming during cutting. Therefore, the raw material is cut in two planes into cubes and removed from the machine along the chute. In the same root cutter, after modernization, the main improvement is the use of a device that imparts an oscillatory motion to the flat knife in a plane perpendicular to the cutting edge, which improves the cutting quality.

The performance of the machine can be determined by the formula:

where n is the number of drum revolutions per minute; D is the diameter of the casing in which the drum is located, in m; h is the height of the product cut with a horizontal knife; ? - width of the drum blade, m; p is the volumetric mass of the product, kg / m3; ? - the utilization rate of the cutting tool (? = 0.3? = 0.4).

The machine for cutting eggplants and zucchini into circles cuts off the ends of the fruit together with the stalk and inflorescence and cuts them into circles with a set of circular knives; the thickness of the circles is determined by the spacers,.

Rubbing machines

Rubbing is not only a grinding process, but also a separation process, i.e. separation of the mass of fruit and vegetable raw materials from seeds, seeds and peels on sieves with a mesh diameter of 0.8-5.0 mm. Finishing is an additional grinding of the rubbed mass by passing it through a sieve with apertures of 0.4-0.6 mm in diameter.

The basic designs of rubbing machines differ in the interaction of the sieve and scouring devices. It is based on the following signs: the mesh drum is stationary, whips are moving, "inverse" rubbing machines in which the sieve moves, and the whips are stationary, and whipless. In them, the sieve makes a complex rotational movement around its own axis and planetary. By the number of stages: one-stage, two-stage, three-stage, two twin machines. Screen design: conical and cylindrical; sectional and by hole diameters. By the design of the whip devices: flat; wire, etc. By loading devices: auger, in combination with a paddle device, loading through a pipe.

The single-stage wiping machine consists of a frame, a drive shaft mounted in 2 bearings with a screw, a blade and a scourge device, a loading hopper and a drive with a V-belt transmission.

The operation of the machine is based on the forceful action of the whips on the processed product, forcing it through the sieve and due to centrifugal force. The working machine is also regulated by changing the angle between the axis of the shaft and the whips, changing the gap between the sieve and the whips and the diameter of the sieve holes. The rubbed mass is discharged through the pallets, and the waste from the cylinder is discharged through the chute.

Lecture number 5. Machines for processing meat and fish

Classification

For the processing of meat and fish, machines are used: meat grinders, meat looters, meat mixers, fish-cleaning and fish-cutting machines, cutlet-forming, stuffing and filling machines, for cutting gastronomic products, bone cutters.

Meat processing machines.

Meat grinder

Meat grinders and tops are designed for coarse grinding of raw materials.

At the enterprises, meat grinders MIM-82 with a capacity of 250 kg / h and MIM-105 with a capacity of 400 kg / h are widely used.

The MIM-82 meat grinder is a table-top machine, consisting of a body, a processing chamber, a loading device, auger, working bodies, and a drive mechanism. The working chamber of the machine on the inner surface has screw grooves, which improve the supply of meat and prevent it from rotating with the auger. On the upper part of the body there is a loading device with a safety ring, which excludes the possibility of hands access to the auger, and a pusher.

The meat grinder is equipped with three grates with holes 3, 5, 9 mm, a scoring grate and two double-sided knives.

When assembled, the knives and grates are tightly pressed against each other using a thrust ring and a pressure nut.

Inside the working chamber there is a screw with a variable pitch of turns, which decreases towards the cutting mechanism. Thanks to this design of the single-threaded worm-working auger, the product is compacted, which makes it easier to cut with knives and push through the grates. When assembled, the knives and grates are tightly pressed against each other using a thrust ring and a pressure nut. The auger is used to grip meat and feed it to knives and grates. The installed grids remain stationary in the working chamber, and the knives rotate with the auger.

The first is the scoring grid, which has three bridges with sharpened edges outward. The second is a double-sided knife with counterclockwise cutting edges. The third is a large lattice on either side. Next, a second double-sided knife, a fine grate, a thrust ring and a pressure nut are installed. The diameter of the grinders of the grinder 82; 105; 120; 160; 200 mm. Working bodies: knives and grates MIM-105 are similar to those of MIM-82, only the diameter of the working chamber (diameter of the grating) is 23 mm larger.

In the 632-M grinder with a capacity of 400 kg / h, the processing chamber is a cylindrical body cavity with guiding ribs and grooves that improve product feed. In addition, they prevent the product from spinning with the working auger.

The principle of operation of meat grinders (tops) is the same. Product entering the cutting zone, i.e. between the rotating cross-shaped knives and stationary grates, it is crushed to a degree corresponding to the diameter of the holes of the last grating.

The MP-160 spinning top with a capacity of 3000 kg / h with a cutting mechanism diameter of 160 mm differs from the 632-M by the presence of two parallel augers in the processing chamber: a receiving and a working screw.

The grinder K6-FVZP-200 has a capacity of 4500 kg / h and a cutting mechanism diameter of 200 mm.

Meat mixers and meat looseners

Meat shop machines and mechanisms include: MRM-15 meat looser with a capacity of 1800 pcs / h, mechanisms for loosening meat MRP11-1 (1500 pcs / h) and MS19-140 (1400 pcs / h); mechanism for loosening meat for beef stroganoff MBP11-1 (100 pcs / h); meat mixer MS8-150 and MVP11-1 (150 kg / h); grinding mechanism MS 12-15 and a mechanism for grinding fragile products MIP 11-1 (15 kg / h); fish cleaning machine RO-1M and bone cutter.

Meat mixers are designed for mixing minced meat and its components into a homogeneous mass and saturating it with air.

Meat mixer MS-150 consists of an aluminum cylindrical body, cast at the same time with the feed hopper. A shaft is inserted inside the working chamber, on which there are blades set at an angle of 3000. When the working shaft rotates, the blades evenly mix the minced meat with the components.

In the FMM-300 minced meat mixer, the kneading trough with a capacity of 300 l has a thermal jacket for heating the product while stirring it. Inside the trough there are working bodies in the form of two Z-shaped helical blades, which rotate at different speeds (67 and 57 rpm) towards each other.

In a mince mixer with a detachable bowl, during operation, the bowl continuously rotates around the axis of the lower worm wheel, and the cam mixer also rotates and ensures uniform mixing of the product.

Two-blade stuffing mixers with a tilting bowl with a capacity of 340 and 650 liters consist of two kneading blades rotating towards each other at different speeds (47.6 and 37.4 rpm) and two drives, the first of which drives the kneading blades, and the second - overturns the bowl.

The MRM-15 meat looser is designed for loosening the surface of rump steaks, schnitzels, etc. before frying them. The working bodies of the meat looser are disc cutters with distance washers between them, located on the shafts and rotating towards each other during operation.

The carriage also has two combs between the cutters, which prevent the meat from winding on the cutters. A piece of meat, passing between the cutters, is notched from both sides with teeth, while the fibers are destroyed and the surface increases.

Fish processing machines.

Fish cleaning and fish processing machines

RO-1M machine is designed for cleaning fish from scales. The working tool of the fish cleaning machine, the scraper, is made of stainless steel in the form of a cutter with longitudinal grooves, sharpened on one side.

The rotating scraper has a protective cover to protect against accidental touching of hands and scattering of scales. The scraper is driven by a flexible shaft consisting of a rubber hose with a steel cable inside.

There are equipment for sorting fish, for orienting and loading fish and fish processing machines.

If sieves are used for sorting fish, then this is a mechanical process. The sieve is the working body of the machine and is a plane made of wires, threads, plates, as well as movable and fixed rods.

The technical methods of partial orientation of the fish are different. The most widespread are the inclined, and especially the widespread oscillating plane.

Partial orientation of fish, when all of them after orientation are positioned head first, is sufficient for loading into stringing machines, for example, in the line "Sprats in oil". Full orientation of the fish is required to load and operate the fish cutting machines. For example, all fish located head first should lie on their backs or, conversely, with their backs up and, finally, rest their snout against some kind of bar.

When developing the designs of fish-cutting machines, it is necessary in the future:

1) Reduce the nomenclature of names at the expense of universality.

2) Increase productivity by mechanizing loading fish into cassettes of fish-cutting machines.

This requires a universal cutting machine for medium fish.

Universal machine ...........

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Lecture notes

At the rate "General technology of food production and industry" in the direction 6.090220 "Engineering mechanics"

Topic 1. General information about nutrition, nutritional value of food products, about the composition and properties of food raw materials.

1.1 Subject and content of the course "General technology of food production and industry."

The classification of an enterprise of the agro-industrial complex of Ukraine for the primary processing of vegetable and animal raw materials and fish (the first group of enterprises) and the production of various food products on its basis (the second group of enterprises) is given. A list of questions is given that are included in the course program: general information about food products, characteristics of raw materials of plant and animal origin, microbiology of food preservation, principles of preserving raw materials and products from spoilage. In addition, the technology of preserving all types of the listed raw materials with cold will be considered, including cooling methods, the use of a modified gas atmosphere (MTA), freezing methods. With regard to the processing of fish raw materials, methods of salting, drying, smoking, the production of canned food and fish meal will be studied.

The section "Technology of raw materials preservation" will consider methods of preparing semi-finished products for preservation for all types of raw materials: vegetable, animal origin and fish.

1.2 Chemical composition of raw materials of vegetable, animal origin, fish.

Vegetable raw materials.

It differs in great variety. So the fluctuation in the moisture content in the raw material is from 14 to 90 percent or more, and in this regard, it is customary to divide it into separate groups: cereals, vegetables, fruits, berries. Vegetables, in turn, are subdivided into vegetative forms, tuberous plants, stem plants, fruits, and fruits - into pome fruits and stone fruits.

The main constituent of dry matter of plant raw materials are carbohydrates, their amount in most cases reaches 70-75%, with a sharp fluctuation in the native state from 2% (cucumbers) to 65% (legume seeds) and 70-80% (cereals).

In addition, aroma-forming substances, organic acids, mineral elements, pigments, vitamins are included in the composition of tissues of plant raw materials, which determines their nutritional value.

Chemical composition of milk,%: moisture - 85-88, lipids 3-5, protein - 3-4, lactone -5, minerals -0.7, vitamins of group B, as well as A, D, E. Milk protein is characterized by high nutritional value, competes with meat protein.

The chemical composition of the meat of warm-blooded animals,%:

Beef: moisture - 70-75, lipids - 4-8, protein - 20-22, minerals - 1-1.5.

Poultry: moisture - 65-70, lipids - 9-11, protein - 20-23, minerals - 1-1.5.

Pork: moisture - 70-75, lipids - 4-7, protein - 19-20, minerals - 1-1.5.

Lamb: moisture - 72-74, lipids - 5-6, protein - 20, minerals - 1-1.5.

Proteins contain a complete set of essential amino acids and therefore nutritionally complete. Proteins of muscle tissue are divided into water-soluble, contractile and insoluble, the latter include collagen and elastin. The muscles of animals contain water-soluble vitamins.

Chicken eggs. The ratio of yolk to protein is 1: 3. The egg white contains,%: moisture - 87-89, lipids - 0.03, protein - 9-10, minerals - 0.5. The yolk, respectively, contains: 48; 32; 15; 1.1. Egg whites are recognized as more nutritious, even in comparison with animal muscle proteins.

The chemical composition of fish tissues,%: moisture - 56-90, lipids - 2-35, protein - 10-26, minerals - 1-1.5. According to the content of fat and protein, they are divided into 4 groups, respectively. The composition of muscle proteins contains more non-protein nitrogenous substances than proteins of warm-blooded animals, fats are more unsaturated and therefore are in a liquid state at room temperature, in warm-blooded animals - in a solid state.

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