Single Screw Press Manufacturer & Suppliers in Sweden

Sweden has historically been at the global forefront of environmental standards, sustainable biorefinery engineering, and high-efficiency paper and pulp processing. Under the overarching framework of the Swedish Environmental Protection Agency (Naturvårdsverket) and national sustainability goals, industries from Gothenburg to Sundsvall are continuously pressured to minimize landfill waste, optimize thermal efficiency, and reduce liquid content in industrial byproducts. A central mechanical pillar in this process is the Single Screw Press.

A single screw press is a slow-rotating mechanical device designed to continually squeeze slurry to separate water or process liquids from solid fibers. Designed for heavy-duty dewatering, our systems play a major role in separating water from organic digestate, paper mill sludge, food waste, and chemical slurries. Standard municipal and industrial processes require high-dryness cakes to lower transport costs and improve performance in incineration boilers. By upgrading from traditional belt presses or decanter centrifuges to Jiangsu Zongheng’s advanced single screw press configurations, Swedish operators achieve substantial energy savings and lower chemical flocculant consumption.

The Sweden Mechanical Dewatering Paradigm: Challenges and Trends

Sweden’s cold winter temperatures and strict environmental water discharge limits present distinct operational challenges for chemical, bio-gas, and municipal processing plants. High energy costs on the Nord Pool grid make electricity-intensive machinery like high-speed centrifuges less viable for continuous dewatering applications. This economic reality has led to a major transition towards low-RPM, high-torque single screw presses, which consume up to 85% less energy. Furthermore, the rising demand for biogas (biometan) production utilizes screw presses to effectively separate organic digestate, creating a highly dry solid fraction for composting and a liquid fraction rich in nitrogen for local agricultural application.

The single screw press operation relies on a simple yet highly effective mechanical concept: continuous volumetric compression. The system consists of a slowly rotating tapered screw shaft wrapped in flights, placed inside a cylindrical wedge-wire or perforated screen basket. As the slurry enters the feed inlet, the mechanical screw conveys the material forward. Crucially, the pitch of the screw decreases and the shaft diameter increases progressively towards the discharge end. This spatial reduction generates high compressive pressures, forcing the liquid through the screen matrix while retaining the solids inside.

To control the final dryness of the cake, a pneumatically or hydraulically loaded backpressure cone is positioned at the cake discharge outlet. By adjusting the resistance of this cone, operators can precisely tune the moisture profile of the discharged cake. A continuous internal or external spray wash system clears the screen apertures from clogging, ensuring consistent liquid filtration and continuous throughput without downtime.

1. Pulp & Paper Sludge De-watering

In Sweden's forestry and paper sector (especially mills in Värmland and Norrland), large volumes of primary and biological sludge require processing daily. Traditional belt filters struggle to reach the dryness levels required for efficient fluidized bed incineration. The Zongheng Single Screw Press is engineered to process fibrous pulp rejects and biological mixtures, increasing cake dryness to 40%–50% DS. This reduces the energy required for thermal destruction, turning waste management into a net-positive energy asset.

2. Biogas Digestate Fractionation

Swedish biogas production utilizes municipal wastewater sludge, food waste, and agricultural manures. Post-digestion, the remaining digestate must be separated. Integrating our screw press allows plants to separate the liquid fraction (ideal for chemical-free farm fertilizer) from the highly dry solid fraction (used for soil conditioning). This step reduces shipping volumes and storage requirements, optimizing logistics across the municipality.

3. Food Processing & Potato Starch Extraction

In southern regions like Skåne, agricultural starch refining generates organic fibrous waste. Operating under strict hygiene standards, our stainless steel single screw presses dewater fibrous waste to minimize spoilage and fermentation. Combined with our Starch Washing Cyclones, our systems provide food plants with a complete processing solution.

Purchasing large-scale dewatering equipment requires close coordination. Jiangsu Zongheng ensures high transparency through standard quality milestones:

• Material Slurry Assessment: Send a sample analysis report of your process slurry. Our engineering laboratory determines the required polymer dosage, feed concentration, and screw torque requirements.
• CAD Integration Check: We provide detailed drawings showing nozzle connections, motor locations, and dimensions to ensure compatibility with your plant layout.
• ASME Certified Manufacturing: During fabrication, we perform non-destructive testing on welds and structural parts, documenting all material certifications.
• Factory Acceptance Testing (FAT): We verify alignment, hydraulic function, and control automation. Video FAT is supported for engineers unable to visit Yixing.
• Delivery and Commissioning Support: We supply comprehensive documentation and operation manuals. Our field engineering team can support local Swedish contractors during site assembly and commissioning.