VRcooler is a technology manufacturer engaged in the R&D, production and sales of medicine, chemical, health care products and food machinery. The various forms of steam heat exchangers designed and produced by the company are sold well throughout the country, and the quality of the products has been well received by users.
The following mainly introduces the choice of heating media and coolant for the steam heat exchanger.
In the process of heating or cooling the material, the steam heat exchanger needs to consider the selection of the heating agent and the coolant according to the production situation. Generally speaking, it is the selection of the heat source and the cold source. There are many media that can be used as a heating agent and a coolant. For example, the heating agents commonly used in tubular heat exchangers are saturated steam, flue gas and hot water. Commonly used coolants are water, air and nitrogen. When selecting heating agents and coolants, the main considerations are these aspects: convenient source, sufficient temperature, low price, safety and environmental protection.
First, the heating agent commonly used in steam heat exchangers
1. Saturated water vapor. Saturated water vapor is one of the most widely used heating agents. Due to the high coefficient of heat transfer film when saturated water vapor condenses, the pressure of the steam can be changed to accurately adjust the heating temperature. However, if the saturated steam temperature exceeds 180 ° C, a high pressure is required. Generally only used when the heating temperature is below 180 °C;
2, Smoke. The flue gas obtained by fuel combustion has a very high temperature of 700-1000 ° C, which is suitable for heating that needs to reach a high temperature. The disadvantage of heating with flue gas is lower specific heat, difficulty in control, and low coefficient of heat transfer film. In addition to the above two commonly used heating agents, hot air can be used as a heating agent in combination with the specific conditions of the factory. Hot water can also be used as a heating agent.
Second, the coolant commonly used in steam heat exchangers. Water and air are the most commonly used coolants, which can be taken directly from nature without special processing. Compared with water and air, the specific heat of water is high, and the coefficient of heat transfer film is also high. However, the acquisition and use of air is more convenient than water, and should be selected according to local conditions. Water and air as coolants are subject to local temperature limits, and the typical cooling temperature is 10 to 25 °C. If it is to be cooled to a lower temperature, a cryogen should be applied. Commonly used cryogens are frozen brine and other solutions.
The following is a special introduction to some of the maintenance knowledge of heat exchangers in winter:
1. It should be noted that the steam heat exchanger is checked regularly for normal operation, temperature control and pressure control are normal, and the operating parameters of the unit should be recorded frequently;
2. When the vehicle is out of service in winter, the heat exchanger inlet and outlet shall be cut off and the water in the unit piping shall be drained to prevent freezing and cracking;
3. Pay attention to the maintenance and cleaning of the steam heat exchanger unit, especially the temperature control valve, water pump and electric control cabinet, keep it clean and dry;
4. After the unit has been running for a period of time, when there is insufficient heat transfer and the pressure difference between the inlet and outlet of the heat exchanger is significantly increased, the plate heat exchanger should be considered.
It is hoped that the majority of steam heat exchanger users, according to the working environment and production conditions, choose the appropriate steam heat exchanger heating agent and coolant.