There are three main types of pumps that are used for slurry pumping:
- Horizontal slurry pumps
- Vertical slurry pumps
- Submersible slurry pumps
Horizontal slurry pumps
Horizontal slurry pumps are often called dry mounted because the hydraulic end and the drive unit are located outside the sump. It is the most common type of slurry pump and they are available for a wide range of head and flow conditions and material options.
These types of pumps normally use standardized electrical motors and seals. In plants where there is a risk of flooding, there can be reasons for replacing a dry-mounted horizontal pump with a submersible, slurry pump.
Vertical slurry pumps
Vertical Slurry Pumps can be subdivided into two main groups:
- Tank pumps
- Cantilever sump pumps
Tank pumps are considered dry installed pumps. The sump is incorporated in the pump. The open sump and vertical inlet prevent air blocking and give smooth operation. There are no submerged bearings or shaft seals, but quite a long shaft overhang from lower bearing to the impeller.
Cantilever sump pumps are considered semi-dry installed, as the hydraulic end is lowered into the slurry, but the drive unit and support structure are dry installed. Similar to tank pumps, there are no submerged bearings or shaft seals, but a long shaft overhang.
These types of pumps are mounted with a base plate over the sump. Cantilever pumps have a number of disadvantages which make them suitable for replacement with submersible pumps:
- Long distance between motor and hydraulics makes the pump bulky to handle.
- Limited access to the sump. Problems with sediment build-up can occur when used in sumps deeper than 2 m (6 ft.).
- Not waterproof - flooding will damage the motor.
- High noise level.