اواپراتور پوسته و لوله (Shell and Tube) چیست؟
Shell and tube evaporator is one of the most popular types of evaporator. As mentioned earlier, the evaporator is a heat exchanger that causes the delay of fluids. The shell and tube evaporator mechanism is such that a low pressure fluid flows inside the evaporator coils. Another fluid (gas or liquid) with a higher temperature moves around these coils. (flowing) due to this temperature difference, heat transfer occurs between the two fluids and the low pressure fluid evaporates due to heat absorption from the external fluid.
کاربرد اواپراتور پوسته و لوله
Evaporator has 2 different uses in industries.
- The first application is the evaporation of the fluid introduced into the evaporator coils. In this case, the low-pressure fluid evaporates by receiving heat from the external fluid, which has a higher temperature.
- The next application is cooling. In this way, the temperature difference between the fluid inside the coil and the hot fluid outside the coil causes the internal fluid to absorb heat from the hot fluid and as a result, the external fluid cools.
مشخصات اواپراتور پوسته و لوله بارد صنعت
One of the products of Bared Sanat production group is the Shell and Tube evaporator, the entire design and production process of this evaporator is done inside the complex.
The following items can be mentioned among the features of Sanat shell and bared tube evaporator.
- Shell material from ST37
- Baffles are made of PTFE
- Tube sheet made of ST37 material
- Bending U-shaped pipes with a bending machine instead of welding
- Connecting the flange to the shell body through welding
- Production in different capacities according to the customer’s order
- 12-month warranty of Baredsanat company
Bared Sanat shell and tube evaporators are produced in different capacities. So far, many groups have purchased their required evaporators from Baredsanat, which have been used for various purposes, including the manufacture of chillers.
The table below shows the technical specifications of Baredsanat shell and tube evaporator.
قیمت اواپراتور پوسته و لوله
The price of the evaporator generally depends on many factors, including its capacity, the type of evaporator, the type of refrigerant, the circuit, the type of coils and internal components, the quality of construction, etc., and it is cheaper compared to the plate and fan evaporator.
Baredsanat is capable of producing shell and tube evaporators in various capacities. You can talk to Baredsanat sales experts to get accurate and up-to-date prices.
طرز کار اواپراتور به عنوان تبخیر کننده
Evaporator is used as a vaporizer in various industries such as food, chemical, etc.
In general, when the fluid pressure is low, the fluid evaporates at a much lower temperature. In the evaporator with this application, the fluid enters the coils of the evaporator with a low pressure equal to the atmospheric pressure or slightly more. Inside the evaporator chamber and outside the coils, another fluid (gas or water) with a higher temperature flows with the help of a fan. Due to this temperature difference and the indirect connection of these two fluids, heat transfer is done and the fluid inside the coil is absorbed by the heat, evaporates and leaves the evaporator in the form of steam.
طرز کار اواپراتور در سیکل سرمایش
Evaporators play an important role in refrigeration systems. In this application, the function of the evaporator is cooling. The liquid refrigerant in the refrigeration cycle enters the expansion valve after the condenser. In the expansion valve, the pressure and temperature of the refrigerant decreases and the refrigerant is prepared to enter the evaporator. Then the refrigerant fluid enters the evaporator coils at a pressure lower than atmospheric pressure. Hot fluid (air or water) also flows outside the coils with the help of a fan or pump. In this order, due to the temperature difference between the refrigerant and the hot fluid, heat exchange is done and the refrigerant absorbs the heat of the external fluid and vaporizes. As a result of this heat exchange, the external fluid is cooled.
If the cooled fluid is air, this evaporator is part of the refrigeration system or air conditioners. Otherwise, if the cooled fluid is water, the evaporator is part of a chiller. Among the uses of the evaporator in the refrigeration system are:
Chiller evaporator
One of the most widely used and popular cooling systems in air conditioning are chillers, which are divided into two types, compression and absorption. Chillers need two heat exchangers for cooling, one of which is the evaporator and the other is the condenser. The cold water coming out of the chiller, which is transferred to the fan coil and air conditioners inside the building through pumping and causes the air temperature of the building to decrease, is cooled in the evaporator.
Cold room evaporator
Cold stores are used to keep food cool and frozen and are divided into two categories below zero and above zero. Cold storages have four main components; Condenser, compressor, evaporator and expansion valve. In subzero cold stores, the evaporator cools the temperature down to -45 degrees Celsius, which are used to freeze food such as vegetables and meat. Cold rooms above zero are usually used to store fruits that do not need to be frozen.
Freezing tunnel evaporator
If you need to freeze food quickly, the freezing tunnel is one of the best choices. In the freezing tunnel, the temperature of the food decreases rapidly with the passage of cold air (using fans). The speed of doing this is very important to maintain the quality and appearance of the food. Freezing tunnels are usually produced in two types, linear and spiral, in both models, equipment similar to cold storage equipment, including an evaporator, is used.
انواع اواپراتور
Evaporators are divided into different types based on the design structure, external fluid flow arrangement, operating conditions, and refrigerant type. The most common type of classification is based on the structure.
اواپراتور پوسته و لوله
The shell and tube evaporator is actually the shell and tube heat exchanger that was discussed in a separate article. This product consists of a shell and a number of coils, which are connected to the sheet tube and placed inside the shell. Refrigerant flows inside the coils and hot fluid flows inside the shell and around the coils. This evaporator is mostly used in the refrigeration industry. There are different types of shell and tube evaporators, which include:
Shell and Tube Flooded Evaporator
In the evaporator, the refrigerant flows inside the shell and the hot fluid flows inside the coils. As shown in the picture below, in the lower evaporator (flooded evaporator), tubes are placed in only 50% of the lower space of the evaporator and 50% of the upper volume of the shell is empty of tubes. The volume of the liquid refrigerant is such that it covers the entire space around the coils and the pipes are submerged in the refrigerant. For this reason, this model is also called flooded evaporator.
By receiving the heat of the fluid inside the tube, the refrigerant is vaporized and placed on the surface of the liquid refrigerant and in the upper space of the evaporator, which is empty of pipes. Finally, it is discharged by the steam outlets installed on the top of the evaporator.
Fewer tubes are used in wet evaporators, and because of this, the construction cost is reduced. Due to the fact that the pipes are immersed in the liquid refrigerant and the pipe surface is in complete contact with the refrigerant, the heat transfer capacity is higher in this type.
Shell and Tube Dry Expansion Evaporator
In the dry expansion evaporator, the refrigerant flows in the tubes and the fluid flows in the shell. The liquid refrigerant experiences a pressure drop when passing through the expansion valve. As you know, in fluids with a pressure drop, the evaporation temperature decreases and the liquid fluid changes phase at a lower temperature and becomes vapor. With the pressure drop of the liquid refrigerant in the expansion valve, part of the refrigerant turns into vapor upon entering the pipes. Further, while passing through the pipe, by receiving heat from the hot fluid inside the shell, a larger volume of refrigerant turns into gas, and the volume of liquid refrigerant naturally decreases. Therefore, the surface of the pipes is in contact with refrigerant vapors, not liquid refrigerant droplets, and for this reason, this evaporator is called dry expansion type.
The amount of use of the dry expansion evaporator is higher than the wet evaporator; Although the evaporator is superior to its competitor in terms of consumption costs and heat transfer rate. The reason for the lower production of the evaporator compared to the dry evaporator is the special technology used in this evaporator (to separate the cycle oil from the refrigerant), that many manufacturing companies do not have this technology.
Baredsanat is able to provide both types of flood and dry expansion evaporator according to the needs of you dear customers and with the best quality.
