After a period of time, it is very important to clean the shell and tube heat exchanger. Why should we clean the shell and tube heat exchanger? Generally, due to the long-term use of pipe in the industry, there will be various dust and sediment adhesion, which leads to the decrease of heat exchange efficiency, increased cost in disguise, and serious service life and loss of shell and tube heat exchanger.

1. how to generate dirt in the tubular heat exchanger

Shell and tube heat exchanger cleaning, i.e. tube exchanger cleaning. Because of the wide application of shell and tube heat exchanger in industry, industrial heat exchanger is mainly used for equipment cooling and has a large water consumption. At the same time, cooling tower is often set to save water to make the cooling water circulating. The cooling water is continuously used in the circulation system. Due to the rise of water temperature, the change of water flow speed and the evaporation of water, the concentration of various inorganic ions and organic substances, the cooling tower and cold pool are exposed to sunlight outside, the wind blows rain, the entry of dust and sundries, and the comprehensive effect of various factors such as equipment structure and materials, The problems of sediment attachment, equipment corrosion and microbial growth, and the plugging of pipeline caused by slime fouling will be more serious than that of DC system. The fouling of heat exchanger is an important problem that can not be avoided by industrial enterprises.

2. damage to the fouling of shell and tube heat exchanger

Shell and tube heat exchanger is not concerned about it in industry after purchase, but it has many advantages in proper maintenance and cleaning. In the process, a lot of fouling, such as coking, oil dirt, scale, sediment, corrosion products, polymer, fungi, algae, slime, etc., will be produced in the equipment and pipeline line. The resulting fouling will reduce the heat transfer coefficient of the equipment, reduce the circulation area of the pipe or increase the flow resistance, increase the consumption of energy and materials, and the efficiency will decrease obviously, When the fouling corrosion is especially serious, the process will be interrupted, and the device system will be shut down, which will cause various economic losses directly, and even may cause malignant accidents. In the scientific development, it is almost impossible to completely avoid the generation of dirt. Therefore, cleaning of the equipment such as shell and tube heat exchanger becomes industry, Especially in petrochemical and thermal power plant is an indispensable important link

3. cleaning is beneficial to improve heat exchange efficiency

After the shell and tube heat exchanger or pipe is running for a period of time, the surface will often be covered with a layer of dirt, which is generally compact and hard, and the thermal conductivity is very small.

The efficiency of fouling is amazing. If the organic ions and dust are not attached importance, other problems may be inevitable.

The thermal resistance of dirt is 50-100 times of that of low carbon steel and 200-400 times of copper. So the effect of fouling on heat exchange effect is very big. After the scaling of heat transfer equipment, it will inevitably affect the heat transfer, make the medium that should be cooled can not be properly cooled, the heating medium can not get proper heating, the heat transfer efficiency will decrease, the consumption of heating steam or electric energy will be increased, and the cost will be directly increased, and the * * and normal operation of the equipment will be affected. Therefore, the heat exchange equipment should be cleaned regularly to remove dirt and improve its heat exchange efficiency.

In conclusion, the cleaning of shell and tube heat exchanger not only brings about the longer service life of the heat exchanger, but also reduces the cost and expenses. It is important to ensure that the heat exchange efficiency of the shell and tube heat exchanger can be fully exerted. Therefore, cleaning of the tube and shell heat exchanger after a period of use is a serious problem.

Cleaning is necessary. What else needs our master's attention in the process of cleaning?

Cleaning of tube and shell heat exchanger cleaning of tube and shell heat exchanger pay attention to the compact and compact parts of heat exchanger * * dismantle the heat exchanger. It is possible that the metal gasket or metal plate is damaged due to the tight assembling of heat exchanger, and leakage problems may occur if the assembled heat exchanger is not compact and tight. The leakage of medium between metal plates is caused. Besides brine cooling, the continuous casting equipment often has internal leakage, which increases the cost of removing brine and a large amount of loss of spare parts of shell and tube heat exchanger, which also increases the maintenance cost of heat exchange equipment.

For cleaning and fine cleaning of tubular heat exchanger, it is noted that the high energy-saving heat exchange coefficient is very easy to scale. In the cleaning of the tube heat exchanger, the cold and hot medium flows through the respective channels through the adjacent heat exchange plates, and the middle is heat exchange through a thin heat exchange plate. Therefore, it is effective energy saving, high heat exchange coefficient and easy to scale; Meanwhile, the inner circulation aperture of the tubular heat exchanger is small, and the cross-section of the internal channel becomes smaller or blocked after scaling, which results in the reduction of heat exchange efficiency of the tubular heat exchanger, which will affect the normal operation and the heat exchange equipment * *. Therefore, the shell and tube heat exchanger shall be cleaned periodically to remove the dirt to ensure the effective heat exchange efficiency of the tubular heat exchanger and the normal operation of the heat exchanger, This can also promote the rapid development of the company.

If the shell and tube heat exchanger is frequently disassembled during cleaning, the hanging concave at both ends of the metal plate will be deformed. The deformation at the concave will cause the asymmetry between the metal plates, which will make the metal plate very easy to deform. When the water flows through the shell and tube heat exchanger, the change of water flow velocity will be affected, Thus, the fouling and corrosion of shell and tube heat exchanger is intensified. The shell and tube heat exchanger is a heat exchanger which is made of thin metal plate (usually stainless steel) and then laminated with sealing rubber.

For the shell and tube heat exchanger, the former mainly disintegrates the tube heat exchanger, and then remoulds the fouling layer on the heat exchange surface by piece manually. This method can only be used when the tube heat exchanger is completely separated from the system. The clamping size of the tube heat exchanger is required to be higher when reassembling, mainly composed of heat transfer piece, sealant pad, clamping bolt, pressing plate, whole machine frame and other parts.

The cooling surface of tubular heat exchanger is industrial water, and the turbidity of water source of Yellow River is greatly changed. Therefore, the cooling efficiency of tubular heat exchanger is reduced, which affects the temperature drop of cooling water of equipment. The phenomenon of stopping pouring frequently occurs, which causes significant and economic losses, Cleaning of the tube heat exchanger is an important work in the management of continuous casting equipment. For the above reasons, we have to disassemble the tubular heat exchanger to clean the mud dirt when the casting machine stops pouring. Because of the short interval time, the mechanical cleaning method is to disassemble the tube heat exchanger and clean one piece by one, and find various problems in the cleaning process.