Screw pumps

Screw pumps – design and principle of operation

The screw pump is an advanced development of the Archimedes screw concept, which acts as an extremely efficient positive displacement device. The mechanism is based on a metal rotor working inside a rubber stator, which creates precise chambers that transport the liquid.

VACUUBRAND solutions go one step further by offering non-contact screw operation that almost completely eliminates friction and provides a number of technical benefits:

• no pulsation and foaming of the medium,
• perfectly stable flow without pressure spikes,
• dry operation without the risk of wear of components,
• the possibility of obtaining an extremely deep vacuum,
• safe transport of sensitive substances,
• maintaining full continuity of the jet.

Types of screw pumps and differences in construction

The key distinguishing feature of screw pumps is the number of impellers used. Single-screw  models efficiently pump thick liquids, while multi-screw  variants provide powerful suction. Precision spindles create sealed chambers inside the device, which guarantees high efficiency of the entire system.

Modern designs offer a number of significant operational advantages:

• versatility from single-sided to deep-sea versions,
• modular architecture facilitating fast service,
• innovative seals to extend the life of the machine,
• effective reduction of the risk of costly failures,
• Maintenance is made easy thanks to a well-thought-out design.

Sterile processes are dominated by oil-free VACUU· PURE. They work completely dry, eliminating the risk of contamination of the substance. They generate a high final vacuum and are ATEX certified, making them ideal for drying, coating or packaging. It is a modern and clean alternative to traditional helical pumps.

Low pulsation and transport of viscous media

The use of screw technology guarantees an extremely stable flow, which effectively eliminates the risk of harmful shear stresses. Thanks to the gentle treatment of liquids, the structure of sensitive emulsions and suspensions remains intact.

These devices can easily handle the transport of extremely dense substances, maintaining high performance even in the case of plastics.

• flow stabilization to protect the product structure,
• the ability to transport high viscosity media,
• excellent self-priming properties of the device,
• precise dosing thanks to rotation control,
• integrated heating jacket to prevent consolidation,
• Protecting the line from costly downtime.

Precise speed control enables rigorous dosing of ingredients, which is crucial for maintaining recipe parameters. In situations where the product tends to concentrate quickly, the integrated heating jacket comes to the rescue. By maintaining a constant temperature inside the chamber, it eliminates the risk of blockages, protecting the system from failures and ensuring full continuity of production processes.

Construction materials and durability of screw pumps

The service life of screw pumps is primarily determined by the class of materials used. The use of appropriate alloys and elastomers allows for perfect adaptation of the device to the specifics of the pressed medium, using such components as:

• stainless steel AISI 304,
• acid-resistant version 316L,
• EPDM elastomers,
• durable NBR,
• chemically resistant

In industries that require special sterility, such as pharmaceuticals or food production, sanitary models that comply with  stringent FDA and EHEDG standards are crucial. Their design fully supports CIP systems, which allows for instant and effective cleaning of the inside of the mechanism without the need for troublesome disassembly of components.

On the other hand, the VACUUBRAND  brand technology is based on non-contact operation of the spindles, which virtually eliminates friction and mechanical wear of parts. Thanks to completely oil-free operation, users not only benefit from the guarantee of the highest process cleanliness, but also measurably lower service and operating costs.

The use of screw pumps in industry and installations

Screw pumps are extremely durable devices designed to operate in the harshest operating conditions. In the food and chemical industries, they are valued for  their high precision and ability to transport media without compromising their delicate structure. In the municipal sector, their special design effectively prevents blockages, which is crucial when pumping dense sludge and sludge in wastewater treatment plants.

The versatility of these devices makes them widely used in many areas:

• precise dosing of food raw materials,
• safe transport of aggressive chemicals,
• pumping of dense sewage sludge,
• maintaining the continuity of lubrication of industrial machines,
• drawing water from deep water intakes,
• powering efficient irrigation systems for fields and gardens.

Deep sea models are distinguished  by their resistance to the abrasive effects of sand, which makes them an ideal solution for groundwater extraction. The use of hermetic motors significantly extends their service life, ensuring trouble-free and efficient operation for many years.

Screw and rotor pumps – comparison of parameters

The selection of the right device depends on the density and parameters of the liquid to be pumped. Rotor models  work well with clean water, but their efficiency decreases as the medium thickens. The presence of sand has an abrasive effect, which leads to rapid wear of components.

In difficult conditions, screw pumps perform much better, which retain constant power regardless of the viscosity of the substance. Their design provides:

• maintaining stable work efficiency ,
• much quieter operation of the system,
• a significant reduction in energy costs,
• no risk of hydraulic impacts,
• high abrasion resistance,
• ensuring a constant operating pressure .

Screw solutions dominate demanding industrial processes. They guarantee maximum durability, which makes them indispensable for the most difficult technical tasks.