Although slurry separators are not new, they certainly seem to be the in-thing right now and
there is plenty of choice. Here is our pick of what is available on the UK market.
Expanding herd sizes, impending legislation on slurry storage, the need to upgrade ageing facilities or simply the availability of funding can lead farms to consider making changes to their slurry handling equipment. Slurry separators are worth investigation as they can increase storage capacity by 15-25% and improve the ease of slurry handling, pumping and mixing. Material pumped into the separator is mechanically ‘squeezed’ to give two or more products: a liquid fraction and a solid material.
There are also benefits when using the separated products including improved management of applications and nutrient levels. The liquid fraction is the main source of nitrogen and offers improved infiltration to the soil and reduced leaf contamination, the latter extending application periods. Livestock can be returned much earlier to grassland due to increased penetration of liquid into the soil.
Separated liquids should not require mixing before application and can be spread via irrigation, injection or dribble bar.
The solid material which holds the larger proportion of phosphate and potash is stackable and easier to store and offers improved nutrient management. It can also be composted and is easier to transport.
Separating the slurry and resulting easier application of the fraction can also reduce the volumes that need to be stored.
Another benefit is the opportunity to produce ‘green bedding’ recycling the fibres in the material for animal bedding.
Terry Baker of Tramspread comments on the practical benefits for storage and application: “Removing solids from slurry makes in-store management easier, especially if the slurry store is covered. This offers increased application output from both tankers and umbilical systems. Reduced friction in umbilical hoses allows for longer pumping distances and reduces wear on the pump, hose and applicator, and saves fuel too. The more uniform product aids even flow from applicators giving an accurate application to the crop, helping to maximise the efficiency of nutrient use and minimise environmental impact.”
Slurry separators may be fixed installations where the separator is mounted on a gantry so that the dry material can be stockpiled below or mobile systems with the separator working across more than one location.
Fixed or mobile?
While there is plenty of interest from contractors in running a mobile separator service, the reality is that multiple machines would be needed to handle the workload, comments Bauer Group’s, Rob Jackson.
“We’re finding that for our best-selling size of separator, which can process 30m³ of slurry per hour, the most popular option is to choose a ‘plug and play’ unit and move it to where it is needed on the farm. There’s no need for a platform, as it can be placed on the floor so there’s no site work involved. It also works well for tenant farmers who could sell the equipment on at the end of their term.”
He suggests that bigger contractors who could justify a 150m³/hr machine to separate from big lagoons could attract some business.
“We have seen this in Northern Ireland where farms are looking to clear full stores in November or December ahead of the winter, but the downside is that you are busy for six to eight weeks and then the work tails off.”
Rob comments that another common scenario is for farms to use a contractor with a mobile separator to find out if the process works for them and then purchase their own system.
FUNDING
DEFRA has indicated that grants from the Farming Equipment and Technology Fund, which includes slurry equipment, will be available once again in 2025. In the 2024 round, grants were offered for both fixed and mobile separators.
Types of separator
Different separation mechanisms lend themselves to specific bedding and management systems, and to the desired end result.
Screen Separation
Slurry is pressed against a screen made up of specified pore sizes that allow only particles of a certain size to pass through. The most common designs are stationary screens mounted on an incline, vibrating screens and rotating screens.
The Evolution rotary screen separator is made from stainless steel for reliability and ease of maintenance. For use on bedding such as straw, sand, shavings etc, it has low energy consumption and is available in three sizes.
Distributor: CE Projects
GEA offers Sloped Screen separators said to offer low-cost operation from their simple design without moving parts. With a choice of sizes up to 2.42m x 3.62m (designated 8ftx12ft) to process manure from 60-300 cows per hour, the stainless steel separators have progressive wedge wire screen openings which allow liquid to pass through the upper portion while captured solids are dewatered on the bottom portion of the screen.
To increase dry matter, a downstream stand-alone roller press system can be fitted, capable of processing manure from 90-300 cows per hour, and of bringing moisture levels down to 80%.
The sloped screen separator is typically installed on a platform approximately 4.0m above a concrete dry pad. Liquid enters the separator through a centre mid-level intake that distributes the flush liquid into an even flow across the top screen panel. The liquid gravity-flows over the openings and the wet fibre slides off the sloped screen and is compressed between a rubber roller and a stainless steel screen roller before it falls on the pad underneath.
Liquid is ejected through the 203mm gravity discharge for further treatment.
GEA offers a choice of control panels including a sequencer panel to control additional moisture management operations.
Distributor: GEA
Sperrin roller press separators are said to be ideal for sand laden slurry, with liquid squeezed between rubber coated rollers to a rotating screen.
Fibre then falls from the front of the separator and the liquid is dropped into the bottom of the separator, then into a 110mm pipe which leads to storage. This design offers the low running costs of a 1.5 kw motor and can be run at variable speed, processing 30m³/hour. Dry matter of 25-30% can be achieved.
Distributor: Stamford Agricultural Services (SAS)
Press Separation
Mechanical pressure is applied to the slurry material by either roller, belt, screw or filter presses, allowing the liquid to pass through a filter or screen while the solids are retained. This approach can achieve a high level of dewatering, producing pressed, solid material.
Bauer
A three-model range of farm slurry separators from Bauer caters for static installations and mobile applications with the separator working across more than one location.
All use a screw press mechanism, comprising a heavy-duty ‘floating’ auger to avoid the stresses that can be created in a fixed auger design and have an automatic pressure control system regulating slurry inflow. Initial liquid extraction is via gravity before the screw compresses fibrous material against outlet doors, equipped with adjustable weights. Liquid is forced out through slotted screens, with a choice of four slot widths from 0.25-1mm.
Together with the adjustable outlet restrictor weights, the choice of screens enables users to create the optimum set-up for the volume, type and dry matter of the incoming material, throughput relative to the volume of slurry produced, and the dry matter target.
The ‘baby’ of the range, the Bauer S300, combines a 300mm long screw with a 120mm diameter screen to separate up to 16m³/hr of slurry into liquid and solids, the latter with a dry matter content of around 32%, or up to 36% at a lower throughput.
Its size and weight means the S300 does not need a heavy-duty gantry if used as a static unit. However, Bauer also offers a ‘Plug & Play’ version which comes mounted on a galvanised steel platform – together with a pump and automatic control panel – with pallet fork slots in three sides enabling it to be moved on-site or loaded on to a trailer and taken to a different location.
These mobile versions have a fully enclosed frame for the pump, pipework and automatic control system, and pallet fork slots to mount the unit on a trailer.
“These systems are easy to use and maintain,” explains, Rob Jackson of Bauer. “As they are floor based, you do need an elevator to take away the solids.”
A new Plug & Play Elevator version lifts the separator 4.3m into the air using a parallel lift structure for discharge options – such as a trailer or spreader, or into a large loader bucket. The lift system is formed by the slurry intake and separated dirty water pipes, so there no separate pipes adding weight.
Like Bauer’s current mobile unit, the Plug & Play Elevator is seen as a solution for large farms with more than one dairy unit and duplicate slurry storage and handling facilities, only with greater flexibility in terms of how the solids are managed.
“You don’t need a separate conveyor for the Elevator models so it’s more convenient, but they are a more costly choice,” comments Rob Jackson.
Distributor: Bauer Group
Börger
The Börger Bioselect RC is an energy-efficient, compact screw press separator with capacities up to 150m³/hr. Said to be the largest mobile single slurry separator on the market, the RC150 is mounted on a trailer with its own generator and integrated washdown system for easy use in any farm situation.
A straightforward installation process—simply connecting pipes and power—ensures quick deployment. The separator produces a loose solid fraction with up to 38% dry solids (DS) content, facilitating easy further processing. Users can adjust the DS content manually or automatically, enhancing operational flexibility.
Sequentially positioned drainage and press channels protect the filter unit, while the rotating clearing auger avoids contact with the screen, minimizing abrasive wear and extending component lifespan.
An intelligent control system makes it easy to adjust machine parameters to suit each farm’s specific material and needs, and distributor Slurryquip suggests that this has made the Borger Bioselect RC a popular choice with contractors.
Distributor: Slurryquip
EYS
Features of the EYS screw press separator from Storth Machinery include a tungsten face hardened screw and stainless steel screen in a range of sizes with simple mechanical weights for dry matter adjustment. There is an observation hatch to see inside the separator and a plug sensor is an option to control solid plugs.
Storth control panels can operate the separator system manually or automatically, based on either time or slurry level. Separator controls can be individually programmed to suit each farm system and slurry type, sequencing the mixer, pump and separator engagement.
Separator capacities are from 6-30m³/hr (cow slurry) and 12-52m³/hr (pig slurry) and all models incorporate the Top Box feed system and overflow pipework to improve agitation. Slurry is transferred throughout the machine via quick release Vacupress hoses.
By mounting the separator 3.0m high, solid material is stackable to 3.0m and with a discharge height of 3.3m, the separated liquid can potentially be fed to its final storage destination without the requirement of an additional pump. For those with longer distances to final storage, a Storth-EYS dry run pump is employed.
Designed as a simple solution, the entry level FarmerPlus Mobile has a main frame constructed of fully galvanised box, standing with a compact footprint of 2.6m x 2.1m. Powered using a three-phase supply, Storth’s control panel offers the same tested functionality as standard separators, with power connected via a four- pin 63Amp connector male/female plug & play socket. There’s a choice of long shaft, submersible or positive displacement (PD) feed pumps.
The Contractor Mobile Separator features a built-in self-priming positive displacement (PD) feeding pump, supplied via a hose from the slurry reception pit. An output dry run pump sends the separated liquid on its way. Separated solids slip down a stainless-steel chute directly to the discharge conveyor, designed to prevent material bridging. The conveyor can be opened or closed easily by hand and locked by the hinges, it comes with a hand pump to adjust working height.
Distributor: Storth Machinery.
Fan Separator
PSS de-watering machines from Fan Separator include 11 screw press models, capable of throughputs from up to 16 to 150m3/hr, for scheduled or continuous operation.
Flagship of the range is the new Fan PSS 8, featuring a 2.2m long heavy-duty screw supported on bearings at both ends and operating within a 400mm diameter ‘floating’ double screen assembly. With a maximum throughput of 65m³/hr, the Fan PSS 8 is aimed at large dairy farms and biogas operations.
The oscillator unit on all Fan PSS separators sets up a vibration in the machine’s intake section to keep thick slurry in its most viscous state to maintain a smooth flow as it passes into the screw compression housing. At the outlet, compression pressure and therefore the amount of liquid extracted, is regulated by ‘barn doors’ with adjustable weights that enable users to fine tune the performance of the machine.
Liquid is forced out through precision-manufactured screens with a choice of slot widths from 0.1-2mm to suit different materials and the end result required.
Five versions of the Fan separators – from the PSS 1.1-300 to the PSS 3.2-780 – can be mounted on a fully-enclosed frame housing a pump, all pipework and an automatic control system. Equipped with pallet fork slots, the complete unit can be mounted on a flat-bed trailer for use as a mobile unit.
Fan also offers a Plug & Play Elevator version.
Distributor: Bauer Group
The Sepcom screw press separator, manufactured by Wam Group, It works through a combination of gravity and mechanical compression using a screw conveyor and a screen. Augers are made from a wear-resistant SINT polymer, and the screens are designed for durability and self-cleaning, reducing maintenance requirements and downtime.
Sepcom separators are modular, allowing for customisation and easy adaptation to different applications and throughput requirements.
The machine separates by gravity and mechanical compression. It is designed to separate the liquid phase from the solids. Capable of processing up to 35m³/hour, it has energy consumption of 4.0kw and can produce dry matter of 28-30%.
Stamford Agricultural Services (SAS) also offers a tripe mobile separator unit using Sepcom separators, which can be pto driven from a tractor or a generator or three-phase supply and is capable of processing up to 100m³/hour. The company comments that it has proved highly popular for multi-site use and comes with a built-in pump and conveyor for easy stacking.
Sepcom is distributed by Greencrop and Stamford Agricultural Services (SAS) in the UK.
Stallkamp offers two basic ranges: the PSS and PSG. Both are screw type separators, which use an armoured auger to press the material against a fine screen, the liquid passing through whilst the solid continues its passage through the machine to be ejected, with the screen constantly cleaned by the screw.
Dry matter content of the finished solid is controlled by adjusting the counter pressure at the discharge end. This results in quicker operation, since a plug doesn’t have to be built-up from the material being separated, says Tramspread.
Both ranges are offered as standalone fixed machines or as mobile units, either free-standing or trailer mounted.
All are suitable for use with pig and cow slurry, including the production of green bedding material, separating digestate produced by AD plants, and also for industrial applications such as dealing with food waste and distillery mash. Other options include an integrated chopping system to protect the pumps when dealing with more variable slurry.
The PSS 2.2-400 is a compact design suited for smaller throughputs. It features a stainless-steel housing with inlet chamber and side cleanout, stainless steel armoured press screw, stainless steel sieve section and a 2.2kW drive motor. It is available as a mobile unit consisting of the basic PSS 2.2-400 separator, choice of supply pump, 0.83m³ feed hopper, a pressure measuring unit and an advanced electronic control system. Typical performance ranges from 16m³/hr with 4% dry matter pig slurry to produce a 30% dry matter solid, down to around 6m³/hr to process 8% dry matter cow manure to the same standard.
PSS 4-500 and 5.5-500 models are larger, higher performance separators using the same basic design, with a stainless-steel press screw with tungsten carbine plating and 4.0 or 5.5kW drive motor. The hydraulically pressurised ball-head can be easily pivoted for maintenance making it particularly user-friendly.
Mobile units are available with the option of rotary lobe supply and discharge pumps, 0.85m³ feed hopper and 0.85m³ liquid tank. Typical throughput is 15 to 20m³/hr, for example performance of 16m³/hr with 7% DM digestate to increase dry matter to 30%.
Heavier duty PSG 4-600, 5.5-600 and 5.5-750 models have a cast iron housing, reversible stainless steel press screw and stainless-steel solids outlet with sleeplessly adjustable flaps to control dry matter content. The PSG series offers higher throughput, simple control and low energy consumption. Motors of 4.0 or 5.5kW are used.
A mobile unit consisting of a PSG 5.5-600 with 5.5kW drive motor, progressive cavity pumps for supply and removal, feed hopper, reception tank and control panel is also offered. Typical throughput is 15 to 20m³/hr, although around 22m³/hr working in 7% dry matter digestate to produce 30% dry matter solid material is achievable.
Distributor: Tramspread
Vogelsang offers a trailer mounted mobile separator, the XSplit, designed to be lighter than previous versions and benefiting from a low ride height which makes it easier to tow.
Mounted on Vogelsang’s Pro Frame, the XSplit weighs in at 3.1 tonnes and sits low to the ground for better stability and balance during transport and operation.
Redesigned in 2024, the separator has been purpose-built as a mobile unit. This means it retains all the benefits of the XSplit such as the rubber disc sealing system for the chamber and the sectional screen but is better suited to mobile use.
The gearbox is positioned at the dry end of the separator and there is easy adjustment of the dry matter content. The screw press mechanism and sieve are both easy to access for servicing requirements and there is a high-quality elastomer sealing disc.
Four 15cm cleaning ports and the large end cover improve access to the interior of the XSplit. This significantly reduces the time required for service and maintenance work. Throughput is up to 50m³/hr and produces dry matter up to 40%.
Distributor: Vogelsang UK
Other press-type separators
GEA’s Xpress roller press separator can be used individually or stacked – a single roller will achieve between 24-28% dry matter and a stacked system can achieve 35%+ dry matter.
The Xpress’s rotation pulls in a steady stream of material from the integrated regulator tank or dewatered material from a sloped screen or vertical dewaterer – the latter specified to remove excess liquid before the roller press treatment for higher capacities.
Fibre material is squeezed between an upper rubber roller and a lower stainless steel screen to remove moisture. The extracted liquid is diverted from the fibre material via openings in the screen roller. The process is repeated two or three times depending on the capacity or dry matter rate targeted. Pressure is applied to the fibre with an air bag system to provide uniform material compression across the roll.
Constructed from grade 304 stainless steel, the Xpress uses a rubber roller made of small individual sections bolted together to provide easy rotation and replacement of the roller sections, when needed. Each steel roller and transition chute has an integrated rinsing system.
The regulator tank, with three-level sonar, regulates the amount of manure that is transferred into the XPress, to ensure proper separation. A stainless steel chute with spray bar transitions the fibre to the next roller press.
A laser level sensor provides accurate readings of the level of solids in the hopper to prevent overloading. The laser allows the rollers to run at a lower RPM during normal operation. When the level of solids is high, the speed of the roller will increase for a short time and then return to the lower speed. In case of extreme solids build up, the laser will stop the feed pump, reducing the risk of overflow.
When used in stacked formation, a ‘step down’ concept allows increased pressure at each step for optimal moisture removal.
Equipment stands, side and three-side decks, as well as steps, are offered with all Xpress configurations for maintenance.
Distributor: GEA
The Groundhog mechanical separator uses rotary brushes to press slurry through screens. Material is pumped to the separator inlet weir box and flows on to the first perforated screen where it is slowly brushed the full length of the screen to remove most of the liquid. It is then presented to the second screen where remaining fibre is pressed and brushed the full length of the perforated screen to ensure the maximum amount of liquid is removed.
A ‘super dry’ version double presses the solids in the second stage to give dry solids of 26-30%.
A ‘cam-lock’ system makes for quick screen changes, and the design is said to be low maintenance even on sand bedding systems.
Distributor: Pollution Control
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