Classification of household refrigerators

Modern household refrigerators and freezers are complex household appliances that operate in specific conditions - in residential (kitchen) premises, therefore they are subject to high demands: operation in automatic mode; minimum noise level; high level of reliability; complete safety of operation; possible small overall dimensions with a certain useful capacity, low cost and low operating costs.

By type of refrigeration machine, household refrigerators are classified as compressor (cooled by a compressor refrigeration machine), absorption (cooled by an absorption refrigeration machine) and semiconductor (cooled by semiconductor batteries), and freezers - compressor and absorption.

Compressor refrigerators make up a significant share in the range of household refrigeration equipment - over 90%.

Based on the installation method, refrigerators are divided into floor-standing, wall-mounted and built-in.

Floor-standing refrigerators, installed on the floor of a room, are the most widespread type of refrigerators both in our country and abroad. Among them are models made in the form of a table; their height is the same as kitchen tables- 850 mm, and on top there is a serving surface made of a special type of plastic for placing kitchen utensils and products. Wall-mounted refrigerators, suspended from the wall of the room, do not take up floor space, which is important for small apartments

Built-in refrigerators are devices that are part of the design of a furniture unit and are enclosed in a common shell with it. The block can be a kitchen or living room, such as a sideboard and a bar.

According to climatic design, refrigerators are divided into products of versions U and T. The first refrigerators are intended for use in areas with a temperate climate, i.e. in an area where the average of the annual absolute maximum air temperatures does not exceed 40 ° C, and the average of the minimums is below - 45 ° C. Products of execution U, used in residential premises, must provide the required parameters at an ambient temperature of 10 to 35 ° C GOST 16317-70 “Household Electric Refrigerators” provides for a narrower range of climatic factors: 16-32° C. Typically, for products of execution U, the upper limit value is taken to be 40° C.

Refrigerators of the T version are used in areas with a tropical climate, which include the Near and Middle East, India, Indonesia, Vietnam, a significant part of Africa and Latin America, Cuba, the southeast and far west of the United States and several other areas. In Russia, tropical-style refrigerators are manufactured for export to these countries. For products of design T, used in residential premises, the maximum and operating values ​​of ambient temperatures are the same: from 10 to 45 ° C; The International Organization for Standardization (ISO) and CMEA have established a temperature range from 18 to 43°C. Refrigerators in tropical design are subject to increased requirements regarding the materials used, protective coatings, grounding, cabinet sealing and automation partings.

Based on functionality, refrigerators for storing fresh food and fresh and frozen food are distinguished. Appliances for storing fresh food do not have a low-temperature compartment. They are produced in small quantities in some countries. The possibility of storing frozen products is ensured only if the temperature in the low-temperature compartment is maintained no higher than - 6°C; The lower the temperature in the compartment, the longer the shelf life.

In accordance with international and domestic standards, it is customary to divide refrigerators into three categories: for short-term (several days) storage of frozen food - a temperature not higher than - 6 ° C; for medium-term storage (up to two weeks) - temperature no higher than - 12°C; for long-term storage (up to three months) - temperature no higher than - 18°C. Refrigerators are marked accordingly with one, two or three stars. Models with two and three stars are called two-temperature. In the USA, Canada and Australia, star marking is not used. According to the standards of these countries, two-temperature refrigerators must provide a temperature in the low-temperature compartment no higher than - 15 ° C.

By design, two-temperature refrigerators are single-chamber, double-chamber and multi-chamber. In two-chamber rooms there is a heat-insulating partition between the low-temperature and positive compartments; Each compartment is equipped with a separate door. Multi-chamber refrigerators have several (at least three) chambers with separate doors for storing various products.

Air circulation in the chambers can be carried out naturally either using a fan or in combination: in a low-temperature chamber using a forced method, and in a positive chamber using a natural method.

Refrigerators with natural air circulation in the chamber may have one (conventional design) or two evaporators (crying evaporator design).

In models with natural air circulation, the low-temperature chamber is located at the top; in refrigerators with forced circulation it can also be placed at the bottom or next to the plus.

Refrigerators also differ in the method of defrosting the evaporator: they use manual, semi-automatic and automatic defrosting (partially or completely). In the first method, the consumer himself determines the moment of the beginning and end of the process, and also manually removes melt water. With semi-automatic - the consumer determines only the beginning of defrosting, the end of the process is automatic; melt water is removed manually or automatically through drainage system. Defrosting is automatic if the process is controlled and melt water is removed without the participation of the consumer.

Partially automatic defrosting is the automatic defrosting of one of the two cooling surfaces. For example, the positive compartment evaporator is defrosted automatically every cycle, while the low temperature compartment evaporator is defrosted manually every few months. Fully automatic defrosting is the automatic defrosting of all cooling surfaces.

The defrosting process can be fully automated only in refrigerators with forced air circulation; in other designs, use automatic system defrosting (due to its frequent operation) would lead to spoilage of frozen food.

Three methods are used to heat the evaporator during defrosting: with ambient air; hot freon steam supplied by the compressor to the evaporator, bypassing the condenser; electric heater. When defrosting manually, natural heating with ambient air is used, when defrosting semi-automatically and partially automatically, all three types of heating are used. Natural heating of the evaporator in the case of partially automatic defrosting occurs during the non-operating part of each cycle. With fully automatic defrosting, intensive heating of the evaporator with hot freon steam or an electric heater is used.

The adopted cooling system, i.e. the presence of one or two evaporators, natural or forced air circulation, largely determines the operational and design features refrigerators. Therefore, later in this chapter we will consider (as the main types) single-evaporator refrigerators, including two-temperature, dual-evaporator refrigerators, as well as forced-air refrigerators.

According to GOST 16317-87, household refrigerators are divided according to the method of obtaining cold into:

compression (K); absorption (A);

by installation method:

floor-standing cabinet type (W); apole table type (C);

by number of cameras on:

single-chamber; two-chamber (D); three-chamber (T).

Two chamber refrigerators have a heat-insulating partition between the LTO and the plus compartment.

Based on their ability to operate at maximum ambient temperatures, refrigerators are divided into classes:

UHL - not higher than 32 0 C;

T - not higher than 43 0 C.

The chambers of refrigeration appliances are divided into:

storage chamber fresh vegetables and fruits;

refrigeration chamber for cooling and storing chilled products;

low-temperature chamber for storing frozen foods (NTK);

a freezer for freezing and storing frozen foods (MK);

a universal chamber for storing food in fresh, chilled or frozen condition.

Single-chamber refrigerators are divided into:

according to the availability of scientific and technical information on:

single-chamber with NTO;

single-chamber without NTO;

by temperature in NTO at:

with a temperature not higher than -6 0 C;

with a temperature not higher than -12 0 C;

with a temperature not higher than -18 0 C.

The temperature in the NTO is not higher than - 6 0 C ensures short-term storage for several days, not higher than - 12 0 C for two weeks and not higher than - 18 0 C for three months.

Household electrical appliances Refrigerators and freezers are used for storing chilled and frozen foods. Household refrigerators are designed for storing fresh and frozen food and preparing small quantities edible ice.

Refrigerators used for freezing food and storing it for a long time are called freezers. These devices can be used for making edible ice, cooling and dispensing drinks, and quick freezing food products in order to reduce their losses, for freezing and storing frozen ready meals, semi-finished products, vegetable mixtures, etc.

Classification of refrigerators:

By purpose: refrigerators, freezers, refrigerator-freezers.

By installation method: floor-standing cabinet type, floor-standing table type, built-in.

By number of chambers: 1, 2 and 3 chambers.

According to the degree of comfort: regular and superior comfort.

According to the method of evaporator defrosting: refrigerators with natural evaporator tapping, semi-automatic and automatic.

According to the temperature: in the low-temperature compartment (LTC) no higher than -6°C, food can be stored for no more than a week; with a temperature not exceeding 12°C, frozen foods can be stored from two weeks to a month; with a temperature not exceeding 18°C, from 3 months to a year of storage; freezer.

Based on the method of producing cold, refrigerators are divided into compression, absorption, and thermoelectric.

1) Compression refrigerators occupy 90% of the refrigerator market. There are one-, two-, and multi-chamber. Such refrigerators are produced as combination refrigerators, such as refrigerators and freezers. In a compression refrigerator, the refrigerant is:

a) freon 12 (“Sviyaga”) freezer temperature -6°C;

b) freon-701, temperature is -12-18°C freezer.

They have a large freezer volume, the volume of the cold chamber is 120-450 dm 3, and they do not consume large number energy.

Ergonomic properties- ease of use, degree of comfort, the strength of shelves, pallets, dimensions, light and sound alarms are important.

Aesthetic properties of the refrigerator- This color scheme, proportionality of the forms of the refrigeration cabinet, location of the chambers, expressiveness of brand marks.

The range of refrigerators entering the trade includes a large number of models of different designs, from various manufacturers: “Atlanta” (Belarus), “Stinol”, “Nord”, “Biryusa” (Russia), “Arston” (Italy), etc.

2) Absorption refrigerators- Ammonia is a refrigerant that is heated by electric current or gas.

Absorption refrigerators are simple in design, silent, but have disadvantages: small food storage volumes, high energy consumption. The capacity is 80-300 dm3. The assortment is represented by domestic models “Rime”, “Morozko”, as well as more expensive imported “Electrolux” (Sweden), etc.

Negative feature - there is no thermostat, no time relay, they consume a lot of energy.

3) Thermoelectric refrigerators- there is no refrigerant. His role is played by electric current. They are safer. Heat is collected and dissipated outside by a thermopile. The refrigerator does not freeze, but cools. The temperature is from +3 to +8C. The range of Russian-made refrigerators includes such brands as “Chaika”, “Voronezh”, “Krokha”, etc.

Quality requirements.

Refrigerators must meet the requirements of the standard in terms of technical and operational indicators. Domestic refrigerators must provide the required temperature in the refrigerator compartment and low-temperature compartment. The noise level should not exceed 45 dB at a distance of 1 m from the housing. Refrigerators should be stored in packaged form in closed areas with natural ventilation at a relative humidity of no higher than 80%.

Refrigerators are transported in the working position (vertically), securely fastened to prevent possible impacts and movements inside the vehicle.

They have a warranty period of 2-3 years.

The set of refrigeration units that provide conditions for continuous refrigeration processing and on the way from the places of their procurement to the places of consumption is called a cold chain. The cold chain is made up of links, the combination of which may vary depending on the type of raw material. The individual links in the chain are as follows: for processing the product and storing it at the manufacturing plant or plantation; for local and long-distance transportation; refrigerators for various purposes, including commercial refrigeration equipment and.

Usually a refrigerator- this is an industrial enterprise (or its workshop), in the premises of which, with the help of a refrigeration unit, certain modes necessary for the processing and storage of perishable products are maintained. The refrigerator consists of a technological building and a compressor workshop with an attached equipment department.

Refrigerators are classified depending on their purpose, type of stored products, capacity and number of floors. Depending on their purpose, refrigerators are divided into the following main ones: procurement, production, forwarding, distribution, transshipment, trade and household. In addition, refrigerators are divided into stationary and transport. Refrigeration is divided into rail, sea, river and road.

Procurement refrigerators are intended for procurement of products in rural areas or directly on plantations. They have refrigeration units high power; The storage capacity of such refrigerators is less than the capacity of the chambers. Pre-cooling stations, mostly mobile, also belong to the procurement category.

Industrial refrigerators are part of food enterprises: meat and poultry plants, dairy and canning plants. Almost all manufactured products are refrigerated, so industrial refrigerators equipped with powerful devices for cooling and freezing.

Forwarding refrigerators provide cargo operations on rail, water and air lines.

Distribution (multi-purpose, basic) refrigerators are designed to uniformly supply cities and industrial centers with seasonal food throughout the year, as well as to create a reserve supply of food. These refrigerators are characterized by large storage capacity and low performance of cooling and freezing devices. In the event that distribution refrigerators have production workshops (packing oil, solid carbon dioxide, semi-finished products, culinary), such enterprises are called refrigeration plants.

Transfer refrigerators designed for temporary storage of products when transferring them from one part of the refrigeration chain to another. These refrigerators are characterized by a large load area. To carry out external cargo operations, special cargo platforms for road and rail transport are installed on the two longitudinal sides of the refrigerator.

Trading is used for short-term storage of products in retail chains, restaurants, canteens (). These refrigerators are small in capacity. The water chamber can store several different types of food.

Household refrigerators serve for short-term storage of food at home and for producing small amounts of ice. They are the last link in a continuous cold chain. The above classification of refrigerators is conditional. Depending on the range of stored goods, there are universal and specialized refrigerators.

In universal refrigerators They store mixed cargo (meat, fish, fruits, canned food, etc.), in specialized ones they store the same type. Depending on the capacity, refrigerators are conventionally classified into large, medium and small. Large refrigerators have a capacity of over 3000 tons (these include universal, distribution, and specialized refrigerators). The capacity of medium-sized refrigerators ranges from 1000 to 3000 tons (they can be universal or specialized). The capacity of small refrigerators does not exceed 1000 tons. Depending on the number of floors, there are single-deck and multi-deck refrigerators.

By design, refrigerators are classified as industrial buildings. Their characteristic feature is that the chambers maintain low temperatures at high temperatures. Changes in temperature and relative cause a gradual weakening of the structure of building and insulating materials. Materials for refrigerator structures are selected taking into account the capital of the building. The building capital of refrigerators is divided into four classes: Class I includes buildings with a service life of over 100 years, Class II - from 50 to 100 years, Class III - from 25 to 50 years, Class IV - from 5 to 25 years.

The capital class is taken depending on the capacity of the refrigerator. Refrigerators with a capacity of 701 tons or more belong to class II, from 250 to 700 tons to class III, and up to 250 tons to class IV. If the building capital of refrigerators corresponds to classes II and III, the frame structures are made of reinforced concrete.

The operation of refrigerators is based on the artificial removal of heat from the internal space into environment.

I. By the method of heat transfer from the refrigerator to the environment. Household refrigerators are divided into:

Compression (K);

Absorption-diffusion (A);

Thermoelectric (TE);

Magnetic (M).

In compression and absorption-diffusion refrigerators, heat from the refrigerator cabinet is removed into the environment using a special working substance - refrigerant (in compression refrigerators - freon gas , in absorption-diffusion - a solution of ammonia with hydrogen), which, as it circulates through a closed system refrigeration unit changes its state of aggregation, passing from liquid to gaseous and back to liquid.

The process of transition from a liquid to a gaseous state (the process of evaporation or boiling) takes place inside the refrigerator and is accompanied by the absorption of heat.

In compression refrigerators, the movement of the refrigerant (freon - 12, less often freon - 22, another name is freon - 12, 22) is caused by the operation of the electric motor and compressor (a complex unit designed to compress and increase the temperature of the refrigerant vapor).

The refrigerant under pressure caused by the operation of the electric motor enters the compressor, where it is compressed and heated. The heated vapor enters the condenser, the temperature of which is lower than the temperature of the refrigerant. In the condenser, due to the temperature difference, condensation occurs (steam into liquid). The refrigerant then enters the evaporator through a narrow capillary tube. Since the evaporator channels are much larger than the diameter of the capillary tube, a pressure drop and boiling of the refrigerant occur in it. Turning into vapor, the refrigerant absorbs heat in the refrigerator compartment and the temperature decreases. Then the vaporous freon is sucked from the evaporator by the compressor and the whole cycle is repeated. The condenser is cooled by ambient air.

The design of the refrigerating chamber of compression refrigerators allows you to create different temperature conditions in individual places. In a regular refrigerator compartment the temperature is maintained from +2 to + 10 o C, in some types -0 o C, in the freezer compartment from -6 to -24 o C (quick freezing), in the low-temperature compartment pre-frozen products are stored.

[ Foreign-made compression refrigerators may have additional temperature compartments (“wine cellar”, ice maker, etc.). ]

Refrigerators can be defrosted in the usual way or using special systems (No-Frost, Frost-Free, etc.).

Appliances with the No-Frost system defrost automatically due to the fact that air is distributed throughout the refrigerator using special fans. However, this system creates:

1) increased level noise and constant air circulation;

2) dries food.

In refrigerators with a “crying” evaporator, the latter is located in the refrigerator compartment. When the compressor is running, freezing occurs, and when it stops, thawing occurs due to the heat generated by the products. Moisture is removed through special channels.

Refrigerators with the Frost-Free system use both a “crying” evaporator and a No-Frost system.

Range of compression refrigerators:

1) domestic – Stinol-205 (107;110) – Novolipetsk Iron and Steel Works; Atlant – 355-0 (151-01); Nord – 233 (226; 234) – Belarus and Ukraine.

2) foreign – Bosch KGS 3202; Siemens KGE 3501; Indesit GC 2322 W; Ariston - 216; Sharp RFSJ-55; Samsung SR-V-43.

In contrast to compression refrigerators, absorption-diffusion refrigerators do not have an electric motor with a compressor, so the device operates silently. The movement of the refrigerant (a solution of ammonia with hydrogen) is carried out due to heating (electric, gas, etc.).

Cooling of the chamber is achieved, as in compression refrigerators, by absorbing heat from it by boiling liquid ammonia in the evaporator.

The freezer compartment of such refrigerators maintains a temperature of about -5 o C.

Absorption refrigerators are small in size, operate silently, consume a small amount of electricity, and are relatively cheap.

The assortment is represented by devices of domestic production (Iney, Morozko), as well as foreign companies - Whirpool, Electrolux, etc.

The production of cold in thermoelectric refrigerators is based on the Peltier effect, and refrigerators also do not have a refrigerant. The Peltier effect is that when DC through dissimilar semiconductors (i.e. materials with different conductivities - exp: selenium with bismuth, tellurium with antimony) a temperature difference is created at the places of their junctions (connections); one semiconductor is heated (it is located outside the refrigerator), and the other is cooled by the same amount (it is located inside the refrigerator).

The temperature inside the refrigerator is up to +5 o C.

Thermoelectric refrigerators consume a lot of electricity and have a high price. They are used primarily as car refrigerators.

Assortment: Chaika, Voronezh, Krokha, etc.

II. According to climatic version:

1) (up to 40 o C) refrigerators for temperate climates (U);

2) (up to 45 o C) for tropical (T).

III. By number of refrigeration chambers:

Single chamber;

Two-chamber;

Three-chamber;

Multi-chamber.

IV. According to the temperature regime in the low-temperature compartment:

1) up to -6 o C;

2) from -6 to -12 o C;

3) from -12 to -18 o C;

4) from -18 to -24 o C.

V. At the installation location:

1) floor-mounted in the form of a cabinet (W);

2) floor in the form of a table (C);

3) built-in desktop (H);

4) block-built (B);

5) portable.

VI. By difficulty group – from 0 to 5.

VII. By comfort level:

1) refrigerators with ordinary comfort;

2) with increased comfort (automatic defrosting; automatic door closing (if not closed at an angle of up to 10 o), light indication of the operating mode, device for cooling and dispensing drinks, computer control and monitoring system, clock-timer, sound alarm open door etc.).

VIII. According to the internal volume of the chamber:

In the marking of refrigerators, the total volume in liters is indicated by numbers separated by a fraction, the numerator is the total volume, the denominator is the volume of the low-temperature mode.

IX. Based on materials of manufacture: metal, plastic, etc.

X. By the nature of the coating and finishing.

XI. By model: model number – two digits, modification number – a digit separated by a hyphen).

Refrigerator markings contain:

1) brand – Stinol;

2) difficulty group (0-5);

3) model serial number (two digits);

4) serial number of the modification (digit separated by a hyphen);

5) type of refrigeration device (compression);

6) number of cameras;

7) total volume;

8) nature of installation (floor-standing in the form of a cabinet);

9) standard number;

10) temperature in the lower temperature compartment.

In foreign models of refrigerators, the level of energy consumption is indicated, which is reflected in the letters: A, B and C - very economical, D - economical, E, F and G - with high energy consumption.

Refrigerated structures, or refrigerators, are specially equipped industrial buildings with a refrigeration compressor unit that provides them with temperature and humidity conditions that correspond to technological standards for the storage or production of food products.

In refrigerators they support reduced temperature air (from +4 to -30 °C) and high relative humidity (80 - 95%). To create and maintain such parameters, they are built without windows, they have a powerful thermal insulation roofs, external and internal fences, doors, are equipped with equipment for cooling the premises and devices to prevent freezing of the soil at the base of the building.

Classification of refrigerators by purpose. The following types of refrigerators are distinguished by purpose: procurement, production, distribution, basic, for storing vegetables and fruits, food depots, ports, transshipment, retail and catering enterprises, mixed-use.

Procurement refrigerators built in areas where perishable food products are stored. They are intended for initial refrigeration treatment, short-term storage and preparation of prepared products for transportation to retail establishments or distribution refrigerators and other types of refrigerators.

Industrial refrigerators - an integral part of food enterprises (meat processing plants, fish processing plants, canning plants, dairies, etc.). They provide refrigeration for production processes. They are used for cooling, freezing and storing raw materials and finished products.

Distribution refrigerators are intended for the creation and storage of reserve, seasonal, current and insurance stocks of perishable raw materials and finished products, ensuring the rhythm of production of food industries and a uniform supply of food products to the population throughout the year.

Distribution refrigerators can be universal or specialized depending on the range of goods stored. Distribution refrigerators, especially those with a capacity of 7,000 to 20,000 tons, may include workshops for the production of ice cream or frozen food products (berries, etc.), dry and water ice, oil packaging, production of semi-finished products. Such refrigerators are called cold storage facilities.

Basic refrigerators designed for long-term storage of reserves of perishable products (state reserve). These refrigerators are built in places that are remote from settlements and reliably protected.

Refrigerators for storing vegetables and fruits can be independent enterprises or be part of fruit and vegetable and food bases. They are located in rural areas, playing the role of procurement, or in places of consumption (in cities, towns).

Refrigerators for food stores designed to serve the retail chain of small towns. They receive food products from production and distribution refrigerators.

Port refrigerators used for storing food products transported by water. They carry out transshipment of food products from refrigerated ships to railway and road transport and vice versa, which is why they are classified as transport and forwarding.

Transfer refrigerators are designed for short-term storage of goods when transferring them from one type of transport to another, for example from rail to road and vice versa.

Refrigerators for retail and catering establishments are intended for storing stocks of products that are sold by enterprises within several days.

Mixed-use refrigerators perform several functions. For example, industrial and port refrigerators in large cities can simultaneously perform distribution functions. And port refrigerators in fishing ports can serve as industrial refrigerators in fish processing plants.

Classification of refrigerators by cargo capacity. Based on cargo capacity, refrigerators are divided into small (up to 100 tons), small (up to 300 tons), medium (up to 500 tons), large (up to 10,000 tons) and extra-large (over 10,000 tons).

The carrying capacity (capacity) of refrigerators is expressed in tons of conventional cargo. Meat in half carcasses is taken as a conditional load, having a volumetric mass of 0.35 t/m 3 when placed on the floor in a stack or when placed on overhead tracks, a load of 0.25 t per 1 m of track (excluding distribution tracks and switches). Depending on the nature of the cargo, its packaging and stowage, the calculated volumetric mass of the cargo may be more or less than indicated. The conditional cargo capacity of the refrigerator is determined by the formula

E x = E k.o + E k.z + E k.p,

Where E k.o And E k.z- conditional cargo capacity of all storage rooms for refrigerated and frozen cargo, respectively, t; E k.p - conditional cargo capacity of all chilled meat storage chambers equipped with overhead tracks, tons;

E k.o= 0,35 V year; E k.z = 0,35 V g.z; E k.p= 0.25L,

Where V year, V g.z– cargo volume of storage chambers for refrigerated and frozen cargo, respectively, m 3 ; L- load length of overhead tracks, m.

Conditional cargo capacity can be converted into actual (for a specific cargo) by dividing it by the conversion factor. Thus, the conversion factor, for example, for eggs in cardboard boxes is taken equal to 1.35, for butter in cardboard boxes - 0.44.

When determining the cargo capacity of a refrigerator, cooling and freezing chambers, refrigerated rooms not intended for food storage (expeditions, storage chambers, loading and unloading rooms, ice storage facilities), as well as uncooled rooms (utility rooms, corridors, lobbies, elevator shafts and staircases) are not taken into account ).

The cooled building volume of the refrigerator chamber, m3, is determined by the formula

Vc = FH,

Where F- chamber floor area, m2; N - chamber height from floor to ceiling, m.

Cargo volume of the chamber V g, less construction:

V g = F g H g< V c ,

Where F g - area of ​​the chamber floor on which the load is laid, m 2 ; N g- cargo height of the room, m;

F g = F - ∑ f,

Where ∑f - total area floors occupied by columns, passages and driveways, refrigeration equipment, m 2 ;

H g = H – h,

Where h- distance from the top of the stack to the ceiling or beams, cooling devices and air ducts (0.2 - 0.3 m).

The load capacity of distribution refrigerators is established on the basis of annual freight turnover. The distribution refrigerators available in our country are designed for a freight turnover rate of 4-6 per year.

In the refrigerator of meat processing plants, the capacity of the chambers for storing frozen meat must correspond to the 40-60-shift capacity of the meat production plant, and the storage chambers for chilled meat must correspond to a two-day production supply. The carrying capacity of a refrigerator at a city dairy plant is assumed to be equal to the 10-15 shift production volume of products to be stored.

Refrigerators with a cargo capacity of up to 700 tons belong to class I, over 700 tons - to class II of building capital with a service life of 50-100 years, from 250 to 700 tons - to class III with a service life of 25 - 50 years, less than 250 tons - to IV class with a service life of 5 - 25 years.

The main load-bearing structures of buildings of classes II and III are made of reinforced concrete or steel.

Refrigerator buildings - single-story and multi-story; sometimes they have a basement floor.

In single-story refrigerators, where there is no need for floor-by-floor vertical movement of cargo, it becomes possible to increase the spans of the building's load-bearing structures to 24 - 30 m (compared to a grid of columns of 6 · 6 m in multi-story refrigerators), two to three times the payload on the floors due to their location on the ground, which allows you to store cargo at a greater height (10 - 20 m). However, single-story refrigerators are characterized by increased heat inflows through external fences compared to multi-story ones (by 20 - 40%), especially through the roof, the surface of which can account for up to 70% of the entire surface of their external fences.

For multi-storey refrigerators, the issue of protecting the soil at the base of the building from freezing is easier to solve. They occupy a smaller area, and the heat inflow through the roof in the overall balance of heat input into them is less than in one-story buildings.

The space-planning solution and the number of refrigeration chambers for one purpose or another (cargo capacity structure) should allow the introduction of advanced technology for refrigeration processing and storage of food products, organizing rational cargo flows in the building, achieving a high level of mechanization of loading and unloading and transport and storage operations, minimal heat inflows and cold consumption.

In Russia, refrigerators with a cargo capacity of over 4000 tons are mainly equipped with chambers with a cargo capacity of more than 400 tons (over 90%). The load capacity of frozen food storage chambers (-20 °C) of distribution refrigerators is 50 - 70%, chilled food storage chambers (+4...-3 °C) - 20 - 35%, universal (0...-20 °C ) - 10-15%, freezing chambers (-30°C) - 0.5-1%. The sizes of the chambers are different. For example, in single-story refrigerators, chambers for storing frozen foods have an area of ​​300-600 m2, and chambers for storing chilled foods have an area of ​​up to 300 m2. In multi-storey refrigerators, the chamber area is larger - up to 1000 m2.

Cameras with the same temperature conditions form blocks (compartments) horizontally (on floors) and vertically (in a building). In the basement there are chambers with a temperature not lower than -3 0 C so that the ground under the floor does not freeze.

Multi-storey refrigerators are built with a width of up to 40 m, single-storey ones - 24 - 72 m. The length of the refrigerator is determined mainly by the front of loading and unloading operations, i.e. the length of railway and automobile platforms, which depends on the capacity of the refrigerator and cargo turnover. For refrigerators with a capacity of over 3000 tons, the length of the railway platform must be at least 120 m, i.e. sufficient to unload a 5-car refrigerated section.

For cooling meat, up to 3 chambers are used, for freezing - 5 - 7, for storing chilled meat - 1 - 2 (area 200 - 300 m2), frozen meat - 3 - 4 (area 300 - 1000 m2). Depending on the need, universal chambers (from 1 to 3) are used for refrigeration processing and storage.

With the establishment of market relations in our country, the operating conditions for refrigeration enterprises provided for in the projects changed, primarily distribution refrigerators designed and built during the period of planned distribution economy and intended for the one-time long-term storage of food products in large quantities.

Due to the increase in cargo turnover caused by a reduction in the shelf life of goods, their irregular arrival, and small consignments of goods, the use of existing refrigerator capacities does not exceed 25 - 35%, while previously it reached 100%. There was a need for small capacity cells that could be rented by small trading companies. It is necessary to redesign existing refrigeration chambers, which will increase the load rate of refrigerators, reduce the cost of cargo turnover, and increase profits.

The creation of refrigeration chambers with a capacity of 100 tons based on the refrigeration capacities of existing distribution refrigerators makes it possible to increase the number of refrigerated volumes and the efficiency of their use.

In Fig. 14 shows a diagram of the restructured refrigeration chamber.

Rice. 14. Restructured cold room:

1 - thermal insulation fencing; 2, 9 - side guards; 3 - air cooler;

4 - movable partition; 5- wall batteries; 6- monorail tracks;

7 - doors; 8 - seal made of elastic material; 10 - autonomous compartments

When creating new refrigerators, it is rational to arrange them in the form of modules of various cargo capacities, adapted both for cold processing of goods and for their storage.

As an example in Fig. Figure 15 shows the layout of the refrigeration chamber module for cooling, freezing and storing half-carcasses with a capacity of 6 tons/day of cold processing and 80 tons of storage.

Such modules can also be used on existing production and distribution refrigerators when receiving small batches of meat for cooling and freezing carcasses and their subsequent storage in refrigeration chambers, as well as for storing meat with short sales periods. These modules can also be installed in remote areas where transport communications are not developed to ensure supplies to the local population.

Let's give technical specifications refrigeration modules with freezing capacity 1; 3 and 6 tons of meat per day (Table 1).

Unlike existing refrigerators, the frames of which are made of prefabricated reinforced concrete structures with multilayer enclosing walls made of bricks or reinforced concrete panels with thermal insulation, the frame of the modules is made of metal frames, profiled iron and pipe racks, and the walls are made of thermally insulated polyurethane foam sandwich panels. . This design allows the module to be transported disassembled railway and road transport.

Refrigeration is provided by 4 refrigeration machines with air-cooled condensers, which allow you to regulate the temperature by turning off individual units depending on the load of the chambers and the outside temperature. The maximum power consumption at a temperature in the chambers is -3°C 1.2 kW.