Slurry Pumps – Engineering Requirements

Slurry is not like other liquids, mainly because it usually contains solids of varying sizes, so slurry pumps need to be specially designed and constructed to cope with these challenges. Tramspread has nearly 30 years of experience in supplying high performance pumps to agricultural businesses throughout East Anglia (as well as its own contracting business) so we know firsthand the physical demands made on pumps which are used for slurry spreading. Here we take a look at these special requirements and how our range of pumps deals with them.

Why are Slurry Pumps Needed?
First, we need to understand why slurry cannot be moved around using manual processes (e.g. using gravity based pouring, tipping or syphoning methods) and why ordinary water pumps are unsuitable for the job.

Quantity – The sheer volume of slurry involved means that manual methods are simply impractical in terms of the time and manpower that would be required to achieve. Since slurry is composed mainly of water, the weight involved for just a few cubic metres of material is immense. In addition, slurry may need to be moved multiple times between cow or pig shed, storage tanks or transport tankers, before finally being applied to the land.

Consistency – Slurry varies greatly in consistency and can contain a variety of different non-liquid materials including partially digested food, faecal solids, bedding straw or other plant matter, and even grit. Trying to use a regular water pump would result in frequent blockages and breakdowns, if it worked at all.

Viscosity – Even if the solids have been mixed to a very even consistency, the resulting slurry will still be highly viscous compared to water. To keep the slurry moving at a reasonable flow rate through the pump and connected pipework, requires much greater power than needed for pumping equivalent quantities of water.

Even Application – Regardless of the challenges of moving slurry around between animal quarters to storage facilities, a pump is essential at the point of application to the land. Manual methods of slurry application are uneven and can result in patchy fertilisation and lengthen the wait time required before slurry treated land can be grazed by livestock. Even distribution is only made feasible by using a pump to deliver slurry at a consistent rate to the applicator nozzles.

 

Special Engineering Requirements for Slurry Pumps
All these qualities of slurry translate into specific engineering requirements for slurry pumps.

High Capacity – A slurry pump needs to be able to transfer large volumes of highly viscous liquids quickly. The capacity of a pump is directly related to the input power provided by either an external source either a tractor, a direct coupled engine, or an electric motor. Using a tractor driven pump is advantageous when the tractor is going to be present in any case but an engine or electrically driven pump may be preferable in situations where the slurry is simply being moved from one location to another or when the tractor is required elsewhere.

High Build Quality – The internal forces within a high powered pump can be very great, so the required output of the pump needs to be matched with an extremely high build quality to withstand these forces.

Built in Cutters – Solids and fibres within the slurry are the chief source of potential breakdowns, so slurry pumps need to be designed to proactively deal with them as part of their operation. This is achieved with the use of a built in cutter within the pump which reduces solids down to a manageable size, enabling them to pass through the pump without causing a blockage. Cutting within the pump is also essential when feeding through to smaller tubing e.g. umbilical applicators, where slurry must be fine enough to prevent blockages. Slurry pumps are typically engineered to deal with a specific percentage of solids.

Slurry Pumps Supplied by Tramspread
Tramspread supply a range of pumps engineered to meet the heavy duty demands of slurry movement and application. Our range includes:

Tractor Driven Pumps – We supply the Bauer Magnum SX1000 and the Bauer Magnum SM540. The SX1000 is a tractor driven pump, requiring 150hp input which can transfer up to 300m3 of liquid per hour, and includes a built in cutter. The SM540 is also tractor driven, with a lower output and power requirement than the SX1000 but is built to the same quality.

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Engine Driven Pumps – The Bauer SX2000 pump directly coupled to a 170hp engine is mounted on a trailer complete with wheels and road lighting for easy transport to where it is needed (and also has a capacity of up to 300mᵌ per hour).

Long Shaft Pumps – We supply Bauer long shaft pumps which include a stirring nozzle. These pumps are ideal for transferring slurry between pits over short distances and can deal with extremely high levels of solids. Transfer rate is 20-240 cubic metres per hour depending on input power and viscosity of the slurry. It is available in two versions, LE (electric drive) or LP (tractor driven).

Submersible Pumps – The Bauer submersible motor pump is available with or without a built in cutter and can pump between 20-120m3 per hour.

Positive Displacement Pumps – We supply Vogelsang pumps which are available in a range of different versions to match your specific needs. They are capable of pumping up to 1000m3 per hour at up to 16 bar and are self priming.

Slurry Pumps – View our range of slurry pumps here.