Selection & Use Guide of Slurry Pumps
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 pump includes a reasonable selection of pump type, performance parameters, the material of overflow parts, sealing type, and transmission mode.
How to Reasonable Select Slurry Pump?
1. Selection of pump type
There are many types of centrifugal slurry pumps, and different types of pumps should be selected according to the properties of slurry. Taking Warman pump as an example, L-type pump can be selected for low abrasion slurry with weight concentration less than 30%; Ah type pump can be selected for high concentration and strong abrasion slurry pump; Sp (SPR) and kzjl pumps shall be selected when the liquid level changes greatly and needs to work under the liquid. When high lift conveying is required. ZGB, kzj or HH pumps are selected.
2. Selection of performance parameters
After the pump type is determined, the head and flow are the basis for selecting the pump specification and whether it is connected in series. For the transportation of high concentration and strong abrasive slag slurry, the maximum rotation number nmax of the pump (the maximum rotation number of multiple revolutions in the performance curve) is generally not selected, and the rotation number of about 3 / 4nmax is more appropriate. When the selected pump is at 3 / 4 nmax, the flow is appropriate and the head cannot be reached. Multiple pumps can be connected in series. For Warman pump, the flow range of different slurry should also be limited; For the slag slurry with high concentration and strong abrasion, the flow shall be within 40-80% of the flow corresponding to the maximum efficiency of the pump; For low concentration abrasive slag slurry, the flow shall be within 40% – 100% of the flow corresponding to the highest efficiency of the pump. Generally, it is not selected in the range of 100% – 120% of the flow corresponding to the highest efficiency.
3. Selection of the material of overflow parts
The selected slurry pump shall ensure good operation stability and safe and reliable operation. So the selected pump shall select the performance corresponding to a short section of the curve after using a certain point on a flow and head curve. If the change of flow is large and the change of head or pressure is small, the steep drop performance curve should be selected; If the change of head or pressure head is required to be large and the change of flow is small, the steep drop performance curve shall be selected. The pump has good cavitation resistance.
4. Selection of sealing type
Selection of shaft seal type slurry pump mainly includes packing seal, auxiliary impeller seal and mechanical seal.
The auxiliary impeller seal is generally used under backflow operation, and the upper pipe pressure should be less than 10% of the pump outlet pressure. This type of shaft seal does not add shaft seal water, but the use of an auxiliary impeller seal reduces the power consumption, which is generally about 5% of the rated power. Shaft seal water shall be added to the packing seal, and sufficient water pressure and water volume shall be ensured. The water pressure of the shaft seal is equal to the pump outlet pressure plus 35kpa The mechanical seal needs to add shaft seal water, with good sealing performance and no leakage.
5. Selection of transmission mode
The transmission modes of slurry pump include V-shaped triangular belt transmission, elastic coupling transmission, gear reducer transmission, hydraulic coupling transmission, variable frequency drive device, and thyristor speed regulation. Among them, elastic coupling and V-shaped V-belt are cheap and easy to disassemble, so they should be preferred. However, the V-belt will increase the power consumption by 5%.
Other Selection or Use of Slurry Pump
- According to the user’s on-site working conditions, determine whether to use the horizontal slurry pump or the vertical slurry pump. The horizontal slurry pump is suitable for working conditions with certain pressure at the inlet, and the vertical slurry pump is suitable for working conditions such as the pool at the customer’s site.
- According to the acidity and alkalinity of the customer’s slurry, judge what material to use. Acid can be made of A49, cr30, or natural rubber.
- According to the flow and head parameters provided by the user, after increasing the surplus, select the appropriate slurry pump according to the hydraulic performance curve of the slurry pump, and calculate the motor power.
- It is up to the customer to determine the sealing method. There are three sealing methods: packing seal, pressure relief cover, auxiliary impeller seal, and mechanical seal.
- After calculating the motor power and slurry pump type, it is also necessary to confirm the size of site space and transmission mode with the user and provide the installation drawings to the customer.
- Inform the customer of precautions when starting the pump. Such as:
First, never reverse. Viewed from the pump inlet, the impeller turns counterclockwise. Second, if a mechanical seal is used, cooling water must be added before starting the pump.
- Inform the customer of possible problems and solutions during the use of the pump.
Walker pump is a professional industrial pump manufacturer in China. It focuses on supply technology supports and industry-level solutions for various ultra heavy duty applications. The main pump products include slurry pumps, dredge pumps, sand & gravel pumps, submersible pump, froth slurry pumps, vertical pumps, centrifugal water pumps, etc., If you are looking for such pumps, please contact us.