Refrigeration basically includes a number of cold rooms for storing materials that are able to cool, freeze and store any perishable materials.

There are certain general infrastructure conditions that must be taken into account for the cold storage to be successful.

Choosing easy access roads such as road and train, areas with good mechanical resistance and water level problems, good sources of drinking water and electrical industries and water and sewage facilities are among the factors that should be considered for the establishment of a cold storage facility. Also, the preparation and presence of local workers (industrial people, skilled workers for the protection sector, general workers) are among the things that should be investigated. Although cold storage is basically a place where products are kept for a while, in addition to where there are machine rooms.

 

Obviously, the presence of complementary spaces in the cold room is mandatory, which includes:

Office, laboratory, public services (toilets and washrooms), additional rooms, shop and cold storage for packaged materials.

Other services may also be seen in the field of cold storage, such as cutting, deboning, salting, production of meat products, packaging and sales. Before dealing with cold storage plans, it is important to define specific health and practical issues, which are definitely related to warehouse products, cold storage conditions, environment, energy and work personnel. A guide published in 1976 for the storage of frozen products contained a valuable list of work steps and the use of given designs.

 

General classification of cold storage practical programs

The general form of the practical programs of the cold store (production, cold and cooling sizes, frozen and freezing stores, cutting, deboning, packaging, storage and daily transfers) including the total capacity, number, size of the rooms, cooling system and equipment storage and transportation. transfer and access to the facilities, the location of these different parts depends on the conditions of the selected cooling system, they should be aware of the sizes they want to place the cold rooms, but they should note that these rooms should not be exposed to direct sunlight and should He placed them in a completely shaded place.

To choose the warehouse environment, they should choose open and wide spaces as much as possible, which of course is an additional issue, that is, they have issues such as transportation, parking, or maybe they want to develop there in the future. It is said that the selected land should 6 to 10 times the desired base should be selected, in this case it is enough. Of course, there are general tendencies that want to build cold storages individually, and they do this because they think that the wider the environment, the greater the loss of heat.

Individual cold storages have several advantages:

Less accumulation, column strength and capacity can be increased.

The building can be built in soils with low resistance.

Also, the internal mechanical transfer becomes easier, which helps the manufacturers of high-height warehouses to reduce their costs with machines known as lift trucks.

It is better that the height of the rooms is high so that the mechanical equipment of the warehouse or the mechanical equipment for packing the goods that are not stored may not face problems during the work. In fact, frozen meat carcasses that cannot be stored occupy the height of cold storage rooms so that they have to be hung by rails. Cooling, slicing, and slicing are done by special machines that are specially designed for cold storage without storage. The length and width of these places are chosen by the overall size of the machines that are going to be used in them, and how they are used, for example, to hang them from the ceiling, or to use them through the ground and lift trucks, which are the number of rooms and the size of the basic elements. Transfer is also effective in this case.

It is not useful for us to build a cold storage building with small rooms, especially for meat products.

Heating appliances are not very accurate tools to use for several rooms.

The accuracy of measuring devices and adjusting the internal conditions of the rooms is always very different from the cold room conditions for different products.

This is especially true for frozen produce.

Cooling different types of meat such as muscle, thigh, etc. can be kept in one place.

Because these parts do not differ much in terms of the air temperature required for spoiling.

Frozen meats have fewer problems.

A warehouse for cold storage products usually has more compartments and is often lower in height than a warehouse for frozen goods. The plan that was given in the early stages for the construction of these large and small rooms suffered a high economic cost to build several doors and separating walls, which rejected this plan. The presence of control and cooling equipment simplifies and reduces the investment costs and transportation, and the existence of large rooms enables proper temperature and humidity control, as well as the optimal use of space for storage. Only in most special situations, it is better to design the cold storage building with more than 5 to 6 rooms.

The warehouse capacity depends entirely on the amount of products given for storage.

If the capacity of the rooms is full, surely the products should be arranged and stored with more density and pressure.

Several factors must be considered in the mortuary.

The overall capacity is a space that includes the roof, floor, walls and space of the building.

The main capacity is the total capacity in which the product can be stored, which includes other spaces. Not only the cold room space, but any space where the product can be placed, whether it is cold or stored normally, which includes columns, coolers, pipes and channels, and air purifiers.

The density of the cold store depends on the net capacity of the cold store, which is calculated in terms of Kg/m³ (kilograms per cubic meter), but generally and usually it also depends on the main capacity of the cold store. The indicator that shows how the cold storage is designed in terms of responsibility and economy is the main capacity, which is divided by the total capacity, which should be between 5% and 10%. Similarly, the main capacity is about 50% more than the net capacity, and the capacity of the main areas is about 25% more than the specific areas. The extent of the occupied environment is relative. Between the normal quality of the product in the cold store at the moment of delivery and the ability to keep that product equally on the scale of exploitation, the average amount of space occupied by the product in a delivered period is taken, which is usually one year, but it can also be one month.

Management Cold storage function

The operation of the cold store should be said to meet the cold storage requirements of the products, which includes:

The rules of loading, protection and hygiene, as well as the maintenance and continuity of cold storage equipment.

The type of loading depends on the type of cold room, whether it is for products stored in early stages or for frozen or chilled pieces. The basic maintenance that takes place in slaughterhouses depends on the speed of the slaughterhouse, which itself has been recognized as depending on the size of the meat to be divided into several pieces. To prevent the door from being open all the time, the hot air of the slaughterhouse, which is harmful to the environment and materials, is moved out every half hour.

The movement of the carcasses inside the cold store should be designed so that the wet and warm meat all meet the air coming out of the cold carcass environment. Therefore, the ceiling rails are installed in such a way that they rotate the carcass according to the air circulation in the environment without disturbing or obstructing it. Sometimes it is recommended to keep the entire capacity of the barns between the small rooms. kills and the capacity has increased enough, or when the killing reaches 40 a day, in which case the above is recommended.

The working method is that the carcasses are transferred from tunnels to mechanical machines, which after being cut into smaller parts, are returned to the cold storage rooms, and these meat cutting devices are completely emptied and cleaned before and after work for the next time. Usually, cut carcasses are kept in refrigerators. The morgue rooms should be equal in capacity to the rooms for cut carcasses.

For fresh meats that want to enter the market quickly and be consumed, it is no longer necessary to take them to the section of sliced meats with a temperature of 7, it is enough to keep them at a temperature of 2. The capacity of the cold room to store the carcasses hanging on the hook depends on the space of the rails, as well as the height and size of the carcasses and maybe their weight. In Figure 3 and 4, you can see the details of the carcass loading and storage plans.

The meat is usually frozen as a whole carcass or cut into small and medium-sized halves, which are used for large animals. Changing the location of the meats from the frozen rooms to the tunnels as in the case above is also possible, although when there is a large order. Of course, frozen meats are not kept hanging from the ceiling to the ground, but they are cut into pieces and divided into small pieces, packed and sent.

 

Air circulation and industrial cold storage

Although cold rooms are sometimes completely filled with air, for example, 6 to 7 hours for the initial stages of cutting rooms, so sometimes parts of the cold room must be filled with air, although the air circulation must be done correctly and to keep this air circulation in parts When the materials are arranged in an orderly manner, the air should circulate in such a way that it passes directly between the materials, or there should be a cooling device such as a cooler near these parts where the materials are piled up. The fans should operate in such a way that they stop automatically when the freezing system is running and only start when the systems are off. Usually, 2-speed fans are used to circulate the air in these environments. Storage should be done in a way that allows air to pass easily through the ceiling, floor and walls.

The general shape of the plan of using current wheels is that they must create a main door between the kept elements, which is about 5 to 10 cm between the wheels. 15 to 20 cm away from the wall and 40 to 60 cm away from the shelves. The entrance of lift trucks depends on the type of car, but in general it is about 2.15 to 3 meters. The circulation of the internal air of the cold storage is measured by the air speed between the empty areas of the cold storage and also the air capacity of the cold storage, which is the number of times the incoming air compared to the total internal capacity of an empty cold storage, how much it cools in one hour. It is said for cold stores than for tunnels.

تغییر هوا همان جایگزیی هوای درونی سردخانه با هوای تمیز بیرون است، كه از بدبو شدن و تغییر حالت دادن فراورده‌ها در سردخانه جلوگیری می‌كند. این جابه‌جایی هوا صرفاً برای بخش انجماد سردخانه بكار نمی‌رود كه بوی بد ندهند بلكه بیشتر در اتاقهای برش گوشت استفاده می‌شود كه هوای بیرون بیاید و جایگزین بوی بد داخلی شود كه این هوای ورودی هیچگونه ناخالصی ندارد و هوای داخلی نیز توسط فیلترهای صاف‌كنندة هوا به بیرون رانده می‌‌شوند. علت اینكه هوای داخلی را از سردخانه بیرون می‌فرستند این است كه از طرفی برای شرایط سردخانه لازم است و از طرف دیگر موجب خسارت می‌شود. هوای ورودی باید سرد و خشك باشد و رطوبت‌زدایی شده باشد سپس وارد سردخانه شود و بلافاصله وارد كولرها شود.

محاسبة ظرفیت هوای مورد نیاز گفته شده برای كاهش خرابی فراورده ها و حفاظت آنها امكان‌پذیر است، اما در كل این مقدار باید بطور مساوی چیزی حدود 5 بار برای ظرفیت هر اتاق باشد البته برای كاهش 99 درصدی هوای مانده در سردخانه (البته چنین ادعا می‌شود كه اگر ظرفیت كمتر از 8 تا 10 بار باشد مطمئناً پوشش دادن فراورده‌ها ناقص انجام می‌شود) تغییر دادن هوا ممكن است از طریق باز كردن در اتاقهای سردخانه صورت بگیرد اما این روش پرزحمت است كه می‌توان توسط روش مكانیكی كنترلی این كار را به آسانی انجام داد.

برای اتاقهای بزرگ بیش از 1000 مترمربع لازم است كه از پنكه‌های مخصوص اینكار استفاده كرد تا بتواند به راحتی هوای درون را به بیرون و هوای ورودی را از كولرها عبور دهد. در ادامه اینكه بیشتر اوقات در سردخانه باز است و تغییرات هوا با رفت‌ و آمدها نیز صورت می‌گیرد. اگرچه این تغییرات گاهی مفید است، اما می‌دانیم وقتی در به صورت طولانی باز بماند و محصولی وجود داشته باشد كه احتیاج به هوای زیاد نداشته باشد این امر باعث خسارت می‌شود و باید از رخداد چنین اتفاقی جلوگیری كنند.

 

Evacuating cold storage rooms

When the products are taken out from the cold storage rooms, there is a risk of atmospheric moisture being compressed and concentrated on the surface of the chilled product, which may wet them and provide the basis for the creation of bacteria. This can damage or spoil the materials of the refrigerator, which sometimes cannot be seen in cases packed in cartons and boxes. This air compression occurs when the temperature of the air around the product is higher than the air on the surface of the refrigerator. Considering this point, it is necessary to take several precautionary measures in advance, such as using anti-heating agents, anti-humidity agents that keep the air dry quickly, covering the products with a tent, and finally using cold storage materials that include materials from Prevents the effects of air humidity.

 

Cleaning and disinfection of the cold room

The cold storages installed for sliced meats and the cold storage of these products must be a completely hygienic environment and free from any kind of germs and bacteria. The following instructions are specific things that must be followed:

• Any germs and dirt in the cold storage room should be removed immediately.
• Every time the rooms are empty or after air conditioning at low temperature, the ceilings and walls should be washed with hot water and cleaning materials, and after cleaning, we drain the water and disinfect with special works.
• Once every 4 months, we clean the cargo wheels and all the equipment in the cold storage.
• Twice a year, for about 48 hours, we disinfect the cold room cutting rooms and the ice products rooms that are empty.
• Before storing animal products in cold rooms that include aromatic fruits and vegetables, we first remove the smell with anti-odor materials, we store the materials there where they use more salt to remove this smell. Sanitation should be observed even after the material is frozen during transportation and separation. Especially in the case of very long transfers, the equipment must be cleaned and disinfected every day.

 

There is a very common and clear system for the transfer of meat.

The first method is for carcasses or large pieces of meat that are kept in cold storage.

Meats are hung from the ceiling by rails that can be pushed by hand or moved by special machines. Another method that is very common is a repeating system that is specific to cold storages with a high loading capacity. This second method is the use of a lift truck that is used to move different forms of meat, which, of course, sometimes uses cargo wheels for smaller pieces of animal carcasses.

Internal transportation should be related to everything that is stored and stored there.

When the pieces and also the frozen pieces in the cold room are taken to the slaughter area, rails are installed in them, and the height of the roof and doors are according to those rails. The general design of these cold room rooms is made according to the convenience of the rails and that the air circulation covers everyone well. The way of working and design of these rails is such that it should allow the control to be done easily and not prevent the transfers as much as possible.

The number of rails and their position in the cold room are known for the pieces of meat, which are usually short, and depend on the capacity of the cold room. In cold storage rooms for cargo wheels and things like this, it depends on the model of the cargo wheel, which itself has different sizes and dimensions, how much it can bear the load, and this size difference may depend on the difference in the distances of the entrances.
Cargo wheels made of different materials should be standard, the most common one being 0.80 x 1000 x 1020. Its length or shortness depends on us, which can be 5 cm more or less. The width of the shelves depends on the width of the entrances and the length of the cargo wheels, the width of the corridors depends on the lift trucks, and the depth of the cargo wheels depends on the circumference of the shelves.

The depth of cold storage wheels is 3 to 4 wheels for long rotation and 7 wheels for short rotation.

Multi-layer boxes may be used in cycles, the number of layers is determined by the authorities and depends on the shape of the cargo, how they are easier to carry. 5 to 6 layers are common and sometimes it can reach 7.

We said that the number of layers usually depends on the car carrying the load and the lift truck that wants to carry it.

2 and 4 wheels are usually suitable for heavy loads, but for large items with short turns, 5 wheels are usually used.

In order to avoid any problems for the boxes, we fix them with accessories so that no change in its shape occurs and it is easy to transport by lift truck. And it is noteworthy that sometimes everywhere is filled with materials and products, even the corridors at this time, the use of moving rails is valuable, although it is very expensive.

Of course, most of them tend to use automatic storage or collecting systems with direct computer monitoring of material and warehouse control. Obviously, these services require a large investment. There are also powerful electric forklift trucks that run on gas or gasoline, each of which has advantages and disadvantages. Gasoline machines can be dangerous, so they are not recommended for testing meat products in cold storage, while the risk of using gas machines is less and because they are faster than gasoline machines, electric machines need to have their batteries charged throughout the week. to be charged, or to change its batteries, while if we want to use this car for a long time, it will run out of charge soon.

Mechanical transmission refers to machines that can be turned on and off by our own hands, which is suitable for the mentioned cases of these machines, automatic transmission is seen in all types of modern machines. Certain machines are used in the cold storage environment, which they choose according to the lack of space that they sometimes encounter, rotating and collecting machines are among these, whose prices are 2 or 4 times higher than normal machines sometimes. They use special belts for internal transportation, which is much cheaper than cars. which, due to the rails in the ceiling, can easily be transferred without having any contact with each other.

 

Product storage plans in cold storage

The division of the cold storage and its specific patterns are determined by the related factors during the work and the process they have ahead of them, here are some points that are worth mentioning: Fresh is received there and sent to the control room, which has a temperature between 8 and 12 degrees Celsius, a storage and transfer room, which has a temperature of about 2 to 4 degrees Celsius, and one or more cold rooms that are installed to store and keep the products cold. These rooms are divided into rooms for cutting and hanging meat at a temperature between 8 and 12 degrees Celsius.

The packing room and the sales room, both of which have a low temperature of about 5 to 7.

For freezing and packing, there are tunnels whose temperature is -30 to -45 degrees, as well as cold storage rooms whose temperature is adjusted according to its contents, and the general needs are car rooms, offices, dressing rooms, and washrooms. The most important thing in the design of the cold store is to avoid leaving extra space, so there should be a place for workers and employees if they say it is not necessary.

Cold stores require the existence of a holding room and a cutting and freezing room.

Corridors are minimized.

The use of a large waiting room with normal air temperature between the warehouse and the surrounding environment is now obsolete. But it is interesting that in hot and humid areas they avoid compressing the products. Looking at the machine room, we understand that it is an important place to be installed as close as possible to the cold room, especially next to the cooling equipment, which is still one of the issues with which we hope to develop these designs in the future. And that the rooms should have easy access to the outside.

The width of the corridors depends on the normal traffic. If there is a lot of traffic, the width of the corridors should be equal to the traffic of two-way cars, which may be one-way. The width of the corridor is from 2 meters one way to 60.3 meters both ways, which of course depends on the width of the car. It is also possible to travel and load between rows 1 to 3 of the tunnels. But sometimes when the work is heavy and busy and there may be traffic between the devices, several of them must stop until it is quiet, and in some cases, one-way corridors are difficult to travel, so it is recommended to make them wider.

It shows us some basic measurements regarding the use of different types of lift trucks. The doors are also not ineffective in transportation, the shape and size of the cars and the width of the transportation corridors, the door should be large enough so that they can easily carry out these trips and entry and exit. The door width for cars is about 1.80 to 2.10, while carcasses on wheels need 2.50 to 2.80, while there are corridors that are not wide enough to turn 90 degrees.

The height of the doors is related to the loading height. In normal cars, cargo wheels are from 2.20 to 2.80 meters, up to 3.30 meters in long loading cars. One of the advantages of tall doors is that warm humid air is discharged and balanced when the door is open. For the transportation of carcasses, the height clearly indicates that it should be such that the rails move easily.

The doors should be a means of separating the walls from each other.

Most of them use electric doors so that they are closed immediately after loading and transportation. This electrical system is very important and useful because according to what we said, damage is done proportionally with the entry and exit of air. Although there are many ways to open the door, the most commonly used model in the cold room is the horizontal system. In order for the doors to be opened and closed quickly, a mechanical door system must be used, which uses an opening key to open the door and a key to close it. It opens and closes.

Every time the door is opened, it also causes the internal air to move. When the door is opened, all the moisture and heat go out of the refrigerator, considering that the increase in cold should not be high. To reduce these air changes, they use transparent flexible plastic doors, which are called transparent doors or air protection doors. These two types are resistant and will not break even when traffic or transportation is heavy. Some of the predictions made in the plan, which will reduce these weather changes, is to minimize the number of doors and it is better to use one-way transportation and not in such a way that the doors are facing each other two by two and the air move

The air system also includes powerful blowers that are usually installed on top of the door to keep the air vertically and horizontally, the type of blower depends on the size of the door. For example, for 2-meter doors, the wind speed should be m³/h, and for 4-meter doors, it should be around m³/h. And the type of hot and cold wind also depends on the climate of the cold room and corridors. Of course, the amount of sufficient air that has been detected is about 60 to 70 percent.

 

Loading docks from cold storage

The loading docks make it easy to move and transfer cargo wheels from the cold storage and transfer equipment and machinery.

Therefore, most warehouses are equipped with these docks for unloading and loading materials and equipment based on the type of road or train transportation. For road transport, the problem is that the height of the docks must be the same as the height of the cargo, which is about 1.40 for cars, but about 60 cm less for vans. Although the average height after and before loading is different. Of course, it is better to use lift trucks when we have to match the loading level with the height of the vehicle.

The surface of the car and the dock are somehow related.

Loading for transport by train requires a standard height.

The loading height should be such that it allows easy transportation so that the items and packages are loaded well.

Again, this depends on the type of cold storage.

In this way, downloads are usually covered.

Sometimes they are covered by tents and sometimes they are covered by walls and doors. The selection of open and closed loading depends on the weather and the type of transportation system. In closed loading, the loading space must be cool, and we use this method when the humidity and air temperature are high, or when the goods have been stored too much in the open environment, in such cases, the rules are completely different from the cold storage conditions, any delay When transferring goods from the car to the cold storage room, open loading should be minimized compared to closed loading.

The loading system with the cold storage must be accompanied by equipment such as a strong cooling system.

The insulation of the roofs should be such that it prevents the passage of heat and spoilage of materials.

The height of the awnings is chosen in relation to the height of the warehouse doors, and as in the picture above, a shoe for the doors is installed in the upper part of the door, which opens the door and causes the air to circulate. When 2 current wheels enter the cold store at the same time.

In this case, the loading height depends on the roof of the loaded cargo. Cold loading rooms must be fully equipped.

When the cars pass through the doors during loading, the air temperature will surely decrease, which, similar to what we have said so far, will ensure that the mechanism is not compromised and the air movement will be done well. Some of these loadings are sometimes for domestic use and slaughterhouses, and some are sent to the review room for direct control and preparation for transportation operations. As mentioned, battery changes may also occur, which will cause interruptions and traffic in internal transportation, in such cases, it is not recommended to use the gas system. When the temperature of the cooled outdoor air is exactly the same as the temperature of the warm air for the workers, it is necessary to immediately change the air to the initial state.

 

Possibilities of cold storage

Another method of covering the loaded cargo is to put them inside the chambers, for which good insulation of the roof is essential when the air temperature during loading is lowered in a closed environment.

 

from the morgue

The transportation of chilled or frozen meat products should be under the control and supervision of the appropriate air temperature so that no bacteria and microbes or spoilage occur in them until the time of delivery of the cargo to the destination. The means of transportation are divided into 3 groups. Roofed, refrigerator and mechanical refrigerators.

Roofed devices are used only for short distances and for a short period of time when there is no need to open and close the door. Two types 2 and 3 are used for long distances and for materials such as ice, solid carbon dioxide, eustatic mixtures with large weights that are directly marketed. They also use these machines for liquid nitrogen in long distances.

Due to the fact that the weight of slivers containing liquid nitrogen is very heavy, only machines with mechanical refrigerators are able to move these materials for a long time. The insulation of the car roof should be thick enough to prevent heat from entering without reducing the loading space. In hot countries, they have strengthened this insulation in such a way that they have brought the heat transfer coefficient below 0.4 w/m³.

To reduce the transfer time, it is recommended to use fast vehicles in high traffic areas. The size of the entrance yard of the loading area depends on the amount of traffic and the size of the cars, but it should be at least 35 meters wide so that when the traffic increases, the cars can easily line up for loading.

Cars with roof rails are used to transport carcasses.

The rails should be standard so that the carcasses can be easily transferred from the cold storage to the car.