On the importance of plate type closed filter in chemical industry!

Plate type closed filter is widely used in chemical industry, no matter whether its production scale and production process are complex or not, there are two procedures: one is mainly chemical reaction, which is usually carried out in the reactor, such as cracking furnace for petroleum cracking, synthesis tower for ammonia synthesis, reactor for polymer polymerization, etc., because of the same chemical reaction properties, There are great differences in reactors: the other is mainly based on physical changes. The plate type closed filter is usually a process completed by using operating equipment (or machinery), such as fluid transportation, heat transfer, crystallization, drying and other operations used in fertilizer, dye production and sugar production, pharmaceutical production - each operation process is called unit operation. In chemical production, such operations often provide conditions such as temperature, pressure and concentration to maintain normal chemical reaction, which are collectively referred to as chemical unit operation process. Geothermal tail water recharge is an important and necessary means to maintain the balanced utilization of geothermal resources. The technical requirements of geothermal tail water reinjection are to prevent the bubbles produced in reinjection from affecting the reinjection speed, and to prevent physical and chemical blockage in the process of reinjection.

In the process of atmospheric distillation, it should be noted that the heat source of flammable liquid distillation should not be open fire, but it is safer to use water vapor or superheated water vapor for heating. For distillation of corrosive liquid, it is necessary to prevent the tower wall and tray from corrosion, resulting in the escape of flammable liquid or vapor, and combustion in case of open fire or burning furnace wall. For the liquid with low spontaneous ignition point in distillation, attention shall be paid to the sealing of distillation system to prevent spontaneous combustion of air due to high temperature leakage. For the distillation system with high temperature, it is necessary to prevent the cooling water from leaking into the tower suddenly, which will make the water vaporize rapidly, and the pressure in the tower will increase suddenly, and the material will be rushed out or explode. Before start-up, the condensate in the tower and steam pipeline shall be emptied and then used. In the process of atmospheric distillation, attention should also be paid to prevent the pipeline and valve from being blocked by the condensation of substances with higher freezing point, resulting in the increase of pressure in the tower and causing explosion. When heating the high boiling point materials (such as phthalic anhydride) of Yan fraction with direct fire, the plate type closed filter should prevent the resin oil with low self ignition point from self ignition when encountering air. At the same time, it should be prevented from drying, coking and scaling of residues, causing local overheating and fire explosion. Oil coke and residue should be removed frequently. The cooling water or chilled salt water of the condensation system shall not be interrupted, otherwise, the escape of the uncondensed flammable vapor will increase the temperature of the local absorption system, or the escape will ignite in case of an open fire. Chemical plugging is due to the change of physicochemical state or the chemical reaction between reinjection water and geothermal water to produce precipitation (mainly silica or calcium carbonate, etc.), thus reducing the reinjection capacity of the well. In high temperature geothermal field, the chemical component concentration of geothermal water increases, temperature and pressure decrease, which may form supersaturated solution and precipitate.

According to the pressure adopted, the plate type closed filter evaporation can be atmospheric pressure evaporation, pressurized evaporation and reduced pressure Yanfa (vacuum evaporation). According to the utilization times of heat needed for evaporation, it can be divided into single effect evaporation and multi effect evaporation. Attention shall be paid to the following problems in the evaporation process:

The selection of evaporator should consider the properties of Yanfa solution, such as viscosity, foaming, corrosiveness, heat sensitivity, and whether it is easy to scale and crystallize.

In the evaporation operation, it is inevitable that there is scaling on the inner wall of the tube, especially when dealing with the materials easy to crystallize and corrode, the heat transfer will decrease. In these evaporation operations, on the one hand, regular stop cleaning and descaling should be carried out; on the other hand, the structure of the evaporator should be improved. For example, the heating pipe of the evaporator should be processed more smoothly, so that the dirt is not easy to generate. Even if it is generated, it is easy to clean, so as to improve the speed of solution circulation, so as to reduce the speed of dirt generation.

The physical plugging of the plate type closed filter is mainly due to the suspended particles in the water, which are attached to the wall of the reinjection well or enter into the cracks of the thermal storage under the effect of the reinjection pressure and affect the reinjection ability. In order to avoid or reduce the physical blockage, the suspended matter in the water can be removed by filtration, and then it can be reinjected.