LPP-T Pumps Gypsym Slurry to Pickling Process
Raahe Steelworks in Finland has drastically cut down maintenance costs and lengthened maintenance intervals after replacing a conventional progressive cavity pump with a Larox peristaltic pump (LPP-T40) in their abrasive gypsum slurry application. The replaced progressive cavity (mono) pump had required changing of its rubber stator and stainless steel rotor every 1 to 2 weeks.
|
Process Conditions
|
|
Specific Gravity
|
1.3
|
|
Solids Content
|
30%
|
|
Temperature
|
30oC
|
|
Medium
|
Abrasive pickling slurry
|
Larox Pump in the Process
The hose is the only wearing part of the Larox peristaltic pump (LPP-T). Less than an hour is required to maintain the pump and the payback time is only a few weeks. The cost of ownership in this part of the process is drastically lower than before.
In the Raahe Steelworks process, pickling acid flushing water is fed to a thickener and neutralized. The thickened slurry is very abrasive causing high wear on pumps especially in high pressure solutions like the filter feed.
The LPP-T40 operates as an underflow pump and transfers the slurry from the thickener to a vertical plate pressure filter five meters above the pump. The total length of the discharge line is 10 meters.
Operating in cycles, the pump keeps the filter tank pressure between 5 and 8 bar (g). The pump starts when the pressure decreases to 5 bar during the filtration process and stops once the pressure reaches 8 bar (g) in the filter feed line simultaneously pressurizing the in-line pressure accumulator. The maximum flow of the pump is 3 m3/h at a speed of 41 rpm. The LPP-T is equipped with a 2.2 kW helical bevel geared motor.
|
|
