High-temperature medium transport on the pump structure, materials and auxiliary systems put forward higher requirements, the following talk about different temperature changes on the cooling requirements and the company applies to the pump: 1. For temperatures below 120 ℃ medium, usually not Set a special cooling system, use more of their own medium to lubricate and cool. DFL (W) H chemical pump, DFL (W) PH shield chemical pump (class H should be used for shielded motor over 90 ℃); DFCZ common type and IH chemical pump can make the temperature Up to 140 ℃ ~ 160 ℃; IHF lined with fluorine pump up to a maximum temperature of 200 ℃; only CQB ordinary magnetic pump temperature does not exceed 100 ℃. It is worth mentioning that for the easy-to-crystallize or media containing particles should be equipped with a sealing surface flushing pipe (design have left interface). 2. For media above 120 ° C and within 300 ° C, a cooling chamber is normally to be provided on the pump cover, and the seal chamber is also to be filled with coolant (to be fitted with a double-ended mechanical seal). When coolant is not allowed to penetrate the medium , It should be taken after the cooling medium itself access (through a simple heat exchanger). The company has DFCZ chemical process pump, GRG high temperature pipeline pump and HPK hot water circulation pump (under development) to choose from, the other CQB-G high temperature magnetic pump can be used within 280 ℃ high temperature medium 3. For more than 300 ℃ High-temperature medium, not only need to cool the pump head part, the suspension bearing chamber should also be equipped with cooling system, the pump structure is generally the central support form, the mechanical seal is best to use metal bellows type, but the price is high (the price is normal mechanical seal 10 Multiple). There are currently DFAY centrifugal pump temperature can reach 420 ℃ (under development). Sealing problems No leakage is the eternal pursuit of chemical equipment, it is this requirement contributed to the growing use of magnetic pumps and shielded pumps. However, there is still a long way to go without leakage, such as the life span of the magnetic pump isolation sleeve and shielding pump shielding sleeve, the material pitting problem, the reliability of static sealing, and the like. Now on the sealing of some of the basic situation is briefly described as follows: 1. Seal For the static seal, seal and seal are usually only two forms, and O-ring seal again the most widely used; for the dynamic seal, chemical Pumps rarely use packing seals, mainly mechanical seals, mechanical seals have a single end and double end, balanced and unbalanced points, balanced for high pressure medium seal (usually refers to the pressure greater than 1.0MPa), double End machine seal is mainly used for high temperature, easy to crystallize, viscosity, containing particles and toxic volatile medium, double seal should be injected into the sealed chamber isolation fluid, the pressure is generally higher than the media pressure 0.07 ~ 0.1MPa. 2. Sealing material Chemical pump static sealing materials generally use fluorine rubber, special circumstances only use PTFE material; mechanical seal ring static material configuration is more critical, not cemented carbide on the best cemented carbide, the price is high On the one hand, the difference between the two is not unreasonable hardness, so it is best to distinguish between media characteristics (Note: The American Petroleum Institute API 610 Eighth Edition of the mechanical seal and piping system configuration in Appendix D in more detail The viscosity of the medium has a great effect on the performance of the pump. When the viscosity increases, the lift curve of the pump drops, the lift and flow rate of the best condition decrease, and the power rises accordingly. Therefore, the efficiency reduce. General parameters on the sample are the performance of the transport of water, when the transport of viscous media should be converted (different viscosity correction factor can be found in the relevant conversion chart). For the viscosity of pulp, paste and viscous liquid delivery, the proposed selection of screw pump, the company DFGG single screw pump medium viscosity up to 1000000cst.
