Piston pump WDPP
The piston pump WDPP is evolution in pumping highly viscous masses such as bottom ash or dense slurry. The description of pump is two or more cylinders working together in sequence. Control valves on media side and driving medium side. Driving medium is clean water. Piston cylinders can be horizontal, vertical or inclined position. Cylinder orientation is selected according to pumped medium to reach maximum reliability and lifetime of pump components. If medium is very polluted then cylinder will be designed vertical.
Compared to many other piston pumps using hydraulic oil as driving fluid this pump has a lot of advantages using water as driving medium.
The pump WDPP works similarly as a double-piston pump or a three-piston pump. Once one cylinder is being filled under low pressure with slurry, from the other cylinder slurry is discharged into the delivery piping under high pressure. In case of a pump with three cylinders, the third cylinder waits for starting the discharge after having been filled with slurry. In case of a pump with more than three cylinders, the filling or discharging process proceeds simultaneously. Unlike conventional piston pump using hydraulic oil, the pump WDPP is not provided - besides the main cylinders - with any other cylinders interconnected with piston rod. Pressure of driving water is directly transferred through a single piston to the pumped slurry and due to that, it is possible to provide for backwash of the piston sealing by driving medium.
The valves (driving medium and driven medium side) are controlled so that no pressure pulsations occur in the pump delivery piping.
Figure 1: Operating scheme horizontal
Figure 2: Operating scheme vertical
Advantages of the pump WDPP compared to some other types of piston pumps:
Lower purchase costs
Lower operating costs
High hydraulic efficiency (electric energy saving)
High lifetime of the main cylinder parts of the pump
Low maintenance costs (costs of cones and seats of valves on the slurry side, piston sealings, costs of driving medium components)
Environmentally safe driving medium (water)
Health friendly driving medium (drinking water) – suitable for food industry
Lower demands on purity of driving medium
Considerably lower purchase costs of driving medium (filtered industrial water)
Simpler elements of driving medium
Low requirements on build-up area
Lower pressure pulsations in delivery piping (in case of using centrifugal pump for driving medium or in case of using special source of driving medium)
Simple cleaning (possibility of using the driving medium for flushing the piston sealing and valves on the slurry side)
Possibility of using high-pressure driving medium (water) for directly flushing the slurry delivery piping
Possible installation of only one big source of driving medium for more in parallel working pumps (pumping into one pipeline)
Possible customization to individual requirements.
Applications of pump WDPP:
Power engineering
Dense Slurry transportation
Fly Ash or Bottom Ash hydraulic transportation
Coal hydraulic transportation
Ore mining
Ores hydraulic transportation
Slurry transportation
Ore processing
Paper industry
Pumping of paper pulp
Waste-water treatment plants
Pumping of sludge
Pumping of sludge to filter presses
Building industry
Pumping of concrete
Food industry
Pumping of high-viscous food masses
Desalination
Pressure energy recovery
Specification of the WDPP pump:
Number of cylinders: 1, 2, 3 or 4
Position of cylinders: vertical / horizontal / inclined
Pressure class of pump: PN16 to PN320
Material of cylinder (internal surface): chrome / stainless steel / rubber / other…
Material of valves and piping (discharge): steel / stainless steel / other…
Operated main valves: Hydraulic (oil) / Hydraulic (water) / Pneumatic
Driving medium:
The source of driving medium consists of a storage tank, booster pump, filtration and high-pressure pump or pumps. For high-pressure pump can be used a centrifugal pump for clean medium or slightly polluted medium and/or plunger pump.
The source of driving medium should be located as close as possible to the WDPP pump, in dependence of local conditions.
The source of driving medium should be designed in dependence on particular application (flow, pressure, temperature, driving medium, etc.) and on the basis of customer´s requirements.
Figure 3: Driving medium source scheme