CASE STUDY
Municipal Wastewater Treatment & Biogas Energy
Salzburg Sewage Treatment Plant, Austria
Pumps for Used Frying Fat: An Eccentric Screw Solution
Waste-to-Energy Digestion • Salzburg, Austria • Equipment: Lutz B70V50.1 eccentric screw pump
Project Details
- Client: Salzburg Sewage Treatment Plant Operator
- Industry: Municipal Wastewater Treatment & Biogas Energy
- Location: Salzburg, Austria
- Project Type: Organic Waste-to-Energy Digestion Feed Systems
- Equipment: Lutz B70V50.1 Eccentric Screw Pump (progressing cavity, with heating collar integration)
- Capacity: Up to 3,000 L/hour at 8 bar, media up to 100,000 mPas
- Solution Partner: Water Treatment Supply
Project Overview
A municipal wastewater treatment facility in Salzburg, Austria, set out to enhance its sustainable biogas production by feeding high-energy used frying fat directly into an integrated digestion tower. Sourced from commercial deep fryers — processing chips, schnitzel and fish — the organic fat arrives at the facility in bulk drums and transit containers.
To manage this process efficiently, the operator needed an industrial dosing pump solution capable of emptying deep containers and transferring thick materials safely into the treatment stream, without risking mechanical clogging or unexpected facility downtime.
Developing a reliable wastewater treatment dosing system for recycled organic fats presents intense technical challenges. Standard hydraulic pumps lack the torque and clearance required to manage heavy food waste. Without a specialised viscous fluid transfer apparatus, the facility faced constant maintenance blockages, accelerated gear wear, and excessive repair costs during waste reclamation cycles.
The Challenge
Pump Highly Viscous and Sticky Media
The system had to move deep-frying fat that thickens rapidly into a dense, resinous paste at low temperatures.
Pass Suspended Solids Safely
Bulk fluids contain abrasive food residues, carbonised organic particles, and solid fragments of varying size.
Prevent Internal Resinous Deposition
Oxidation byproducts cling to internal pump walls, seize moving components, and drive operational power draw sharply upward.
Withstand Aggressive Chemical Corrosion
High-molecular organic acids produced during fat degradation cause severe pitting and failure on standard metallic alloys.
Our Solution
Lutz Pumpen supplied a heavy-duty progressing cavity pumping assembly designed specifically to clear high-viscosity industrial fluids and sludge streams. Following rigorous on-site pumping trials, facility engineers selected the Lutz B70V50.1 eccentric screw pump.
This high-torque progressing cavity pump conveys extremely viscous media up to 100,000 mPas, delivering steady, low-shear volumetric throughput of up to 3,000 litres per hour against discharge backpressures up to 8 bar.
Why the Lutz B70V50.1?
High-Torque Progressing Cavity Design
Conveys extremely viscous media up to 100,000 mPas with steady, low-shear throughput — where standard hydraulic pumps simply stall.
1200 mm Nominal Immersion Length
The extended immersion tube reaches the absolute bottom of deep shipping drums and bulk storage tanks, leaving no wasted residual material.
Premium Stainless Steel Fluid End
All fluid-end structural housings and internal mechanical components are high-grade stainless steel, for absolute resistance to oxidation products and corrosive organic acids.
Installation Configuration
The Lutz B70V50.1 is mounted vertically as a heavy-duty drum evacuation station directly adjacent to the reception deck of the digestion tower. To optimise the flow characteristics of the incoming frying fat and minimise line drag, the operator fitted the staging containers with specialised heating collars.
This thermal integration pre-liquefies the resinous outermost layers of the fat before extraction. The pump then smoothly draws the material out, passing any food solids directly into the pressurised feed lines of the active anaerobic digestion tower. The pump’s modular engineering lets maintenance technicians access internal wearing joints quickly, supporting efficient wastewater treatment automation routines.
Equipment Configuration
| Specification | Detail |
|---|---|
| Product | Lutz B70V50.1 eccentric screw pump (progressing cavity) |
| Maximum Viscosity | Up to 100,000 mPas |
| Throughput | Up to 3,000 litres per hour |
| Discharge Pressure | Up to 8 bar backpressure |
| Immersion Length | 1200 mm nominal — reaches the bottom of deep drums and bulk tanks |
| Materials | Premium high-grade stainless steel fluid-end housings and internals |
| Thermal Integration | Heating collars on staging containers to pre-liquefy resinous fat layers |
| Fluid Handled | Used deep-frying fat with abrasive food residues and carbonised solids |
Results & Impact
The installation established a dependable route from bulk drum to digestion tower — turning a waste stream that used to block pumps into a steady, high-energy feedstock for the plant’s biogas operation.
Continuous Heavy Media Processing
A reliable method for pumping highly viscous, sticky frying fats up to 100,000 mPas directly into the biomass loop.
Corrosion & Wear Resistance
Internal pitting and chemical damage eliminated by using robust, high-grade stainless steel components throughout the fluid path.
Optimised Digestion Throughput
Automated, continuous delivery capacity of up to 3,000 litres per hour at an operating delivery pressure of 8 bar.
Minimised Maintenance Downtime
Routine upkeep simplified through a modular pump layout, backed by a 24-hour rapid spare parts supply programme.
Enhanced Waste-to-Energy Efficiency
The municipal plant can now recycle thick food waste into clean biogas, advancing its sustainable energy goals.
Before & After Comparison
| Parameter | Before Implementation | After Implementation |
|---|---|---|
| High-Viscosity Handling | Severe pump stalling and line blockages | Smooth, continuous transfer up to 100,000 mPas |
| Solid Particle Tolerance | Food residues caused rapid wear and seal failure | Industrial screw drive passes carbon and food solids safely |
| Corrosion Resistance | Oxidation products damaged metallic pump components | Stainless steel construction resists organic acid pitting |
| Container Evacuation Efficiency | Incomplete drainage and wasted material residuals | Complete tank drainage via an extended 1200 mm immersion tube |
| Maintenance Turnaround | Long downtime waiting for custom replacement parts | Fast, modular component swaps with 24-hour parts support |
Customer Benefits
Reliable High-Viscosity Transfer
The B70V50.1 handles dense, sticky, solid-laden frying oils easily, providing steady flow rates without losing suction efficiency.
Industrial-Grade Component Lifespan
Heavy-duty stainless steel components protect against corrosive organic compounds, ensuring a long operational life in harsh wastewater settings.
Maximum System Uptime
A modular, easy-to-service pump design combined with a rapid 24-hour parts supply chain keeps plant operations running with minimal interruption.
Looking for Precision Dosing Solutions for Your Application?
Water Treatment Supply provides advanced chemical feed systems, wastewater disinfection systems, high-capacity chlorine dosing loops, and specialised industrial pumps engineered to thrive in demanding operational environments.
If you are moving viscous, abrasive or chemically aggressive media, our team can help you specify a pump built to survive it.