Features of chemical centrifugal pump:
The pump is a kind of machine for liquid transportation. The chemical centrifugal pump is one of them. The impeller makes the liquid flowing through the impeller centrifugally, and increases the mechanical energy of the liquid to carry out liquid transportation. It is a machine for increasing the energy of the liquid. Due to the special requirements of the chemical production pump, the chemical centrifugal pump has the following characteristics compared with other centrifugal pumps:
(1) It can adapt to chemical process needs in the chemical production, not only to transport liquid materials and provide the necessary pressure for process requirements, but also to ensure the amount of material to be transported. In certain chemical unit operations, the pump flow and head are required. Stable, keep the pump running efficiently and reliably.
(2) The medium transported by the corrosion-resistant chemical pump, including raw materials and reaction intermediates, is often a corrosive medium. This requires proper and reasonable material selection of the pump to ensure safe, stable and long-life operation of the pump.
(3) High-temperature medium for high temperature and low temperature chemical pump transportation, there are process liquid materials, and there are also heat transfer liquids required and generated by the reaction process. For example: condensate pump, boiler feed pump, heat transfer oil pump. There are many types of cryogenic media delivered by chemical pumps, such as liquid oxygen, liquid nitrogen, methane, etc. The low temperature operating temperature of the pump is mostly at 20~10 °C. Regardless of the chemical pump that delivers high or low temperature, the material selection and structure must be appropriate, and there must be sufficient strength. The parts of the designed and manufactured pump can be affected by thermal shock resistance, thermal expansion, cold deformation, cold brittleness and the like.
(4) Wear resistance and erosion resistance Because the chemical pump delivers suspended solid particles in the flow, and the impeller and cavity of the pump also work at high pressure and high flow rate, the surface protective layer of the pump parts is destroyed, and its life is better. Short, so it is necessary to improve the wear resistance and erosion resistance of the chemical pump. This requires the pump material to be made of wear-resistant manganese steel, ceramics, cast iron, etc., and the use of erosion-resistant titanium and manganese steel.
(5) Operational reliability The reliable operation of the chemical pump includes two meanings: one is that the long-cycle operation does not fail; the other is that the various parameters are stable during operation. The reliability of operation is critical to chemical production. If the pump fails frequently, it will not only cause frequent production stoppages, but also affect production and economic benefits, and sometimes it may cause accidents in the chemical system. The fluctuation of the speed of the chemical pump will cause the fluctuation of the flow rate and the pressure of the pump outlet, so that the chemical production can not be carried out normally or the reaction in the system is affected, the material can not be balanced, which not only causes waste, but also causes the product quality to drop or the product to be scrapped.
(6) Non-leakage or less leakage The medium delivered by chemical pump is mostly flammable, explosive, toxic and harmful liquid. Once it leaks, it will seriously pollute the environment, endangering personal safety and physical and mental health of employees, and is even less suitable for leak-free factories and To clean the requirements of civilized factories, it is necessary to ensure that the chemical pump does not leak during operation, adopt new technology and new materials on the seal of the pump, operate according to the regulations, and maintain high quality.
(7) A liquid capable of transporting a critical state liquid in a critical state tends to vaporize when the temperature rises or the pressure decreases. Chemical pumps sometimes transport critical liquids. Once the liquid is vaporized in the pump, it is prone to cavitation damage, which requires the pump to have high cavitation resistance. At the same time, the vaporization of the liquid may cause frictional bonding of the static and dynamic parts of the pump, which requires the gap to be larger. In order to prevent mechanical seals, packing seals, labyrinth seals, and the like from being destroyed by dry friction due to vaporization of the liquid, such chemical pumps must have a structure that sufficiently removes gas generated in the pump.
The pump for conveying critical state liquid can use materials with better self-lubricating properties such as polytetrafluoroethylene and graphite. For the shaft seal structure, in addition to the packing seal, a double-end mechanical seal or a labyrinth seal can be used. When the double-face mechanical seal is used, the cavity between the end faces is filled with the sealed liquid; when the labyrinth seal is used, the seal gas having a certain pressure can be introduced from the outside. When the sealing liquid or the sealing gas leaks into the pump, it should be possible to pump the medium, and it is harmless if it leaks into the atmosphere. For example, when liquid helium is transported in a critical state, methanol can be used as a sealing liquid in the cavity of the double-face mechanical seal; when liquid hydrocarbons that are easily vaporized are transported, nitrogen gas can be introduced into the labyrinth seal.
Make Up Kits,Piercing Kits,Professional Tattoo Kits
Danyang Trading Co., Ltd. , http://www.gdtattoomachine.com