How to Choose a Sludge Pump

Do you need to pump out contaminated water or other liquids that could damage a regular pump? In such cases, a sludge pump will help you. It is specifically designed to handle liquids with mechanical particle admixtures. But how do you choose the right sludge pump for different purposes?

When to Use Sludge Pumps

Sludge pumps are suitable for more demanding pumping of waste, sludge, and sewage water. These pumps are ideal for stationary installation, for example, in a pumping pit, or they can be used as portable pumping units for lowering groundwater levels, draining drainage pits, pumping water from collection pits of surface water with inflow from roof gutters, shafts, tunnels, etc., pumping water from ponds and reservoirs, pumping waste water containing fibrous admixtures from laundries and industrial facilities, pumping sewage water from septic tanks. The pumps are also suitable during floods, flooded basements, precisely because of their ability to pump heavily contaminated water containing solid particles. 

A sludge pump is therefore an essential piece of equipment, especially if you are not connected to a sewer system. However, it is also appreciated by owners of all family homes, where sludge pumps find use in various tasks and in maintaining the house and its surroundings.

Sludge Pumps for Contaminated Water

Even ordinary water must be pumped with a sludge pump if it contains mechanical particle admixtures. Typically, this includes water from a contaminated well or borehole, or water from flooded areas after floods and heavy rains. Sand, mud, and other impurities would quickly clog and irreparably damage a regular pump. 

A sludge pump is also suitable for draining water from ornamental ponds, contaminated pools, or tanks with utility and rainwater.

Sludge Pumps for Septic Tanks or Cesspools

A powerful sludge pump is also useful for draining a cesspool, septic tank, or pit. These pumps can easily handle sewage in buildings not connected to a sewer system. Submersible sludge pump for septic tanks with a grinder is also suitable for buildings where toilets are used by a larger number of people, such as restaurants and guesthouses. The grinder can handle flushed fabrics or sanitary items. Sludge pumps for septic tanks are made from durable materials that withstand aggressive environments.  

In some cases, even the most powerful sludge pump may not be able to efficiently drain the contents of a septic tank or cesspool, especially if it involves greater depths or volumes of waste. In such situations, we recommend contacting experts in the field of pumping and waste water removal, such as the company Herčík a Kříž. They offer not only professional services but also have the necessary equipment and experience for safe and effective waste removal from septic tanks and cesspools.

Sewage Pumps

The most common application of sewage pumps is their installation in a basement bathroom. Since the waste pit is often below the level of the house, pumps are needed to pump water and sewage out of the building. Once you have a pit or sewage shaft dug in the basement, the installation of a sewage pump is very similar to that of a sludge pump. The main difference is that you will need additional piping from your basement for removing gases and odours.

Sewage pumps are designed to switch on less frequently but have greater torque and power to pump water with impurities and solid materials. 

How a Sludge Pump Works

Compared to regular submersible pumps, sludge pumps have a more robust construction and can pump liquids containing fibrous and solid mechanical impurities, with their suction basket easily removable and cleanable without special tools. They are typically supplied with a float switch that ensures maintaining the desired water level. For excessively contaminated sludge water, pumps with an integrated cutting device must be used. Pump variants with the autoadapt function have all sensors integrated in the pump, eliminating the need to purchase a float switch and control units. The pump adapts to the current conditions in the pit. Lower power sludge pumps are usually in single-phase design /230V/, while higher power pumps require a three-phase design /3x400V/.

Criteria for Choosing a Sludge Pump

Sludge pumps are either surface or submersible. Accordingly, their use, construction, and installation differ. A surface sludge pump can be used if it can be placed on a dry surface above the level of the pumped water. Submersible sludge pumps can be placed directly in the water, up to the depth specified by the manufacturer.

The main point when choosing a sludge pump is to correctly select the size and power of the pump. Power is sometimes given in horsepower, with most being 0.5 – 1 horsepower.

Sludge pumps can have electric or petrol engines. Electric ones are quieter and cheaper to operate, but not everywhere has access to electricity. For such cases, petrol pumps are available. In the case of electric engines, ensure the pump has a sufficiently long and well-insulated power cable.

Flow rate should be based on the amount of waste water you need to pump, expressed in litres per hour. Generally, sludge pumps can pump 20,000-30,000 litres per hour. However, flow rate decreases with discharge height, so keep in mind that the deeper the space being drained, the lower the pumping speed will be.

Suction depth is an important parameter for surface pumps and indicates from what depth the pump can draw water. A similar parameter for submersible pumps is the so-called submersion depth. Discharge height tells you how high the pump can push the drawn water.

For a sludge pump, also check the maximum size of particles that can be sucked. Pumps should have protective screens to prevent larger particles from entering the mechanism. But what to do if larger particles need to be sucked? For such situations, sludge pumps with grinders or cutting devices are available on the market.

The price of a sludge pump depends on its power and other parameters. If you need to pump water from greater depths (more than about 8 metres) or in volumes for which the flow rate of regular pumps is insufficient, it is better to entrust this task to professionals. Commonly available sludge pumps would either not handle such work or the cost of the pump would be higher than the cost of professional intervention.  

BRANDS

In our e-shop, we offer quality sludge pumps from reputable manufacturers: Danish Grundfos and German Wilo.