The reasonable selection of slurry pumps is one of the key factors to improve the service life of the pump. the reasonable selection of slurry pumps includes the reasonable selection of pump type, performance parameters, material of overflow parts, seal type and transmission mode, etc. several main aspects from All Pump Machinery industrial pumps company.
1、The choice of slurry pumps pump type
Centrifugal slurry pumps of many types, according to the nature of the slurry body to choose different types of pumps, to Warman pump, for example, weight concentration of 30% below the low abrasive slurry can choose L type pump; high concentration of strong abrasive slurry pumps can choose AH type pump; when the liquid surface height changes more and need to invade the liquid work, should be selected SP (SPR), KZJL type pump.
When the need for high head conveying. Choose ZGB type, KZJ type or HH type pump.
2、The choice of slurry pumps performance parameters
After the pump type is determined, the head and flow rate are the basis for selecting the size of the pump specification and whether to connect in series. Transport high concentration of strong abrasive slurry, generally do not choose the highest number of pump revolutions nmax (the highest number of revolutions in the performance curve of a variety of revolutions), choose the number of revolutions for about 3/4nmax is more appropriate.
When the selected pump in 3/4 nmax, the flow rate is appropriate and the head can not reach, multiple pumps can be used in series form. For Warman pump, different slurry, flow range should also be limited; for high concentration of strong abrasive slurry, the flow should be selected to pump the highest efficiency corresponding to the flow of 40% to 80% range; for concentration of low abrasive slurry, the flow should be selected to pump the highest efficiency corresponding to the flow of 40% to 100% range. Generally do not choose in the highest efficiency corresponding to the flow of 100% ~ 120% range.
3、The head margin of slurry pumps
slurry transfer pump in the process of operation, due to the wear and tear of overflow parts pump performance decreases, until finally can not meet the requirements of the working conditions. In order to make the pump can run for a long time in the vicinity of the rated working conditions, usually in the selection of pumps to increase a head margin. The general margin is 10% of the rated head.
4、Slurry pumps overflow parts material selection
Slurry pumps overflow parts can be selected from a wide range of materials, according to the physical (particle composition, particle size, shape, hardness, concentration), chemical (acid, alkali, oil) characteristics of the transported slurry.
Metal wear-resistant material hard nickel 1# has better anti-abrasive properties for coarse particles; hard nickel 4# has anti-abrasive properties close to hard nickel 1#, but has better anti-abrasive properties for large particles, high stress impact slurry, and higher price than hard nickel 1#; chromium 27 wear-resistant cast iron has similar anti-abrasive properties to hard nickel 1#, and has better corrosion resistance as far as alkaline mixture is concerned, and higher price than hard nickel 1#.
Cr15Mo3 is currently recognized as an excellent anti-abrasive material in the world, with macro hardness up to 650-750 Brinell hardness, and has better anti-abrasive performance for coarse-grained strongly abrasive slurry, but the price is higher and more brittle.
There are more varieties of rubber materials, which are mainly suitable for fine particles without sharp edges. Natural rubber is suitable for conveying weak acids. Weak alkaline slurry, large abrasive particle size and its speed within a certain range, natural rubber is more durable than other metal or rubber elastic materials. Neoprene is not as good as natural rubber, but the temperature is below 200 ℃, in the oil slurry has excellent anti-abrasive properties.
In slurry pumps material application, rubber with its excellent wear resistance, corrosion resistance, anti-cavitation performance has been rapid development, especially the application in power plants flue gas desulfurization conditions is particularly ideal, the service life of up to five years.
5、Slurry pumps shaft seal type selection
Slurry pumps mainly have packing seals, secondary impeller seals and mechanical seals and other shaft seal forms.
Vice impeller seal is generally used under the backflow work, high pipe pressure should be less than 10% of the pump outlet pressure, this shaft seal type does not add shaft seal water, but the use of vice impeller seal will increase power consumption, generally about 5% of the rated power.
Packing seal need to add shaft seal water, and ensure sufficient water pressure and water, shaft seal water pressure is equal to slurry pumps export pressure plus 35Kpa. mechanical seal need to add shaft seal water, good sealing, no leakage.
6、The transmission mode of slurry pumps
The transmission mode of slurry pumps are V-shaped v-belt transmission, flexible coupling transmission, gearbox transmission, hydraulic coupling transmission, frequency drive device, silicon controlled speed regulation.
Among them, elastic coupling and V-v-belt are cheap, easy to disassemble and install, should be given priority to use. However, V-ribbon will increase the power consumption by 5%.