Screw Press Solid-Liquid Separator

A screw press solid liquid separator is a mechanical dewatering unit that removes water from manure, biogas slurry, food waste, and other high-moisture organic materials. It separates the incoming stream into a drier solid fraction and a liquid fraction, which can then be processed separately into solid and liquid organic fertilizer.

LANE Machinery supplies screw press dewatering machines with processing capacities from 5 to 25 m3/h, SS304 or SS316L material-contact parts, V-shaped wedge wire screens, adjustable outlet pressure, and PLC-ready control. The separator can be supplied as a single unit or integrated into a complete organic or liquid fertilizer production line.

Product Overview

The LANE screw press solid-liquid separator is built for continuous operation in farms, biogas plants, food processing facilities, and fertilizer plants. It uses a rotating screw inside a wedge wire screen basket. As the screw moves the material forward, the available volume decreases, pressure increases, and water is forced through the screen openings.

The machine is designed for materials with high moisture content and moderate solids levels, where gravity screens alone cannot produce a dry enough solid fraction. The dewatered solids are easier to transport, compost, dry, or granulate, and the separated liquid can be reused in liquid fertilizer production, biogas processing, or irrigation after treatment.

Typical processed materials include:

• Cow, pig, chicken, sheep, and duck manure.
• Biogas slurry and digestate.
• Food and vegetable processing waste.
• Slaughterhouse waste and organic sludge.
• Fermentation broth and organic liquid fertilizer feed.
• Fruit, vegetable, and crop waste slurries.

Features and Advantages

High solids capture with low energy use

• Screw compression removes water mechanically without high heat.
• The wedge wire screen captures fine particles while allowing liquid to pass.
• LANE’s published liquid fertilizer processing guidance cites more than 90 percent solids removal for its high-performance separators.
• The machine can reduce manure moisture from about 80 percent to roughly 40 to 60 percent, depending on the feedstock and outlet setting.

Durable screw and screen design

• Screw, shaft, and spiral blades are made of thickened SS304 stainless steel.
• Wear-resistant manganese alloy is available on high-wear screw sections.
• The V-shaped wedge wire screen resists clogging and keeps its gap stable.
• Lantern ring and seal components are selected for abrasive, fibrous material.

Adjustable dewatering performance

• The outlet counter-pressure device controls moisture in the discharged solids.
• Screen gap can be selected from 0.5 mm to 1.0 mm depending on material.
• Screw speed and feed flow can be matched to plant capacity.
• The operator can adjust the machine between runs without replacing major parts.

Continuous operation

• The machine is designed for 24-hour production in seasonal and year-round plants.
• A non-clogging feed system reduces stoppages from fibrous material.
• Liquid and solid outlets run continuously without batch cycling.
• Control cabinet includes start, stop, overload, and alarm functions.

Corrosion-resistant construction

• SS304 is standard for material-contact parts.
• SS316L is available for aggressive chloride, acid, and fertilizer chemistry.
• Polished surfaces reduce residue build-up and simplify cleaning.
• Material certificates are available for traceability.

Line integration and automation

• The separator can be connected to collection tanks, transfer pumps, and conveyors.
• Optional PLC control automates start, stop, and alarm sequences.
• The liquid outlet can feed filtration, storage, or fermentation tanks.
• The solid outlet can feed crushing, mixing, or composting equipment.

Working Principle

The working principle of the screw press solid-liquid separator combines conveying, filtration, and compression.

1. Slurry is pumped or gravity-fed into the inlet of the separator.
2. The screw rotates inside the wedge wire screen basket and moves the material forward.
3. Liquid passes through the screen openings by gravity and pressure.
4. As the screw continues, the cavity volume decreases and pressure on the material rises.
5. Additional water is squeezed out through the screen.
6. The dewatered solids reach the outlet, where a counter-pressure device controls final moisture.
7. The liquid fraction is collected in the liquid outlet, and the solid fraction exits separately.

The separated liquid can be processed into liquid organic fertilizer, returned to a biogas plant, or treated for reuse. The dewatered solids are suitable for composting, blending with bulking agents, or drying before granulation.

Application in an Organic Fertilizer Production Line

The screw press separator is the moisture-reduction stage between raw material collection and biological processing:

Raw material collection -> Screw press solid liquid separator -> Liquid fraction -> Filtration and fermentation -> Liquid organic fertilizer
                                                                  -> Solid fraction -> Mixing and composting -> Granulation -> Solid organic fertilizer

In this configuration:

• The separator removes excess water before composting, which cuts drying energy later.
• The liquid fraction becomes feed for liquid organic fertilizer production.
• The solid fraction becomes feed for solid organic fertilizer production.
• One waste stream can support two product lines without overloading the dryer.

LANE supplies the screw press separator as a single unit or as part of a complete organic fertilizer production line with crushing, mixing, composting, granulation, drying, screening, and packaging systems.

Application Scope

• Livestock and poultry manure from farms and feedlots.
• Biogas slurry and anaerobic digestate.
• Food processing and vegetable waste.
• Slaughterhouse waste and organic sludge.
• Fermentation broth and organic liquid fertilizer feed.
• Agricultural and crop waste slurries.
• Environmental and waste-to-fertilizer projects.

Technical Specifications

The table shows standard configurations. LANE confirms capacity, screen gap, motor power, and automation level with the actual feedstock before delivery.

Quality, Standards, and Certification

LANE manufactures screw press solid-liquid separators under an ISO 9001 quality management system and can supply CE-certified equipment with material certificates for stainless steel screws, screens, and housings.

The machine is designed for corrosive, abrasive organic materials, with material selection reviewed against the feedstock. For fertilizer products exported to the European Union, the final product must meet Regulation (EU) 2019/1009 and any applicable animal by-product rules under Regulation (EC) No 1069/2009. LANE’s machine and line design support clean changeover, batch traceability, and quality control. We recommend independent certification of the final fertilizer product by the relevant authority.

Why Choose LANE Machinery

Henan Lane Heavy Industry Machinery Technology Co., Ltd. is a fertilizer equipment manufacturer with more than 20 years of engineering experience. LANE has delivered equipment and production lines to clients in more than 50 countries and supplied machines for a 100,000 tons per year national fertilizer project in Africa.

LANE provides one-stop service from machine selection and plant layout to overseas installation, commissioning, operator training, remote video guidance, and after-sales support. For organic fertilizer projects, our engineers review the feedstock, solids content, moisture, and target products, then recommend the correct screw press model, screen gap, pump, and line configuration.

Frequently Asked Questions

What is a screw press solid liquid separator used for?

It separates high-moisture organic slurry into a drier solid fraction and a liquid fraction. Common applications include manure, biogas slurry, food waste, sludge, and fermentation broth.

How does a screw press separator work?

A rotating screw moves material through a wedge wire screen basket. The space around the screw decreases, pressure increases, and water is forced through the screen. A counter-pressure device at the outlet controls the final moisture of the solids.

What moisture content can the separator achieve?

The discharged solids typically reach 40 to 60 percent moisture, depending on the feedstock, screen gap, and outlet pressure setting. LANE adjusts the machine to match the downstream composting or drying process.

What is the difference between a screw press and an inclined screen separator?

An inclined screen separator handles large volumes of low-solids slurry quickly and is cost effective for manure and biogas slurry. A screw press is better for higher-solids material and finer dewatering. LANE offers both and can combine them in one system.

Can the separator process biogas slurry?

Yes. Screw press separators are commonly used for biogas slurry and digestate because they handle fibrous material and produce a drier solid fraction than gravity screens.

How much energy does the machine use?

Standard models use 5.5 to 22 kW depending on capacity. Because the process is mechanical rather than thermal, it consumes far less energy than drying the same material.

What maintenance does a screw press separator need?

Routine checks include the screen, screw, bearings, seals, pump, and control cabinet. The wedge wire screen reduces clogging, and the wear-resistant screw design extends service life. Spare parts and overseas support are available.

What is the warranty?

LANE provides a five-year warranty, spare parts support, and overseas installation and commissioning services.

Get a Quote for Your Screw Press Solid-Liquid Separator

Tell LANE your feedstock, solids content, moisture, processing capacity, and downstream process. Our engineering team will recommend the correct screw press model, screen gap, pump, and line integration, then provide a technical data sheet and quotation.