Flexible Screw Covneyors


Spiroflow’s Flexible Screw Conveyors are just that – flexible!  Flexible screw conveyors can convey in any direction – from horizontal to vertical, routed around fixed obstacles and equipment, and from one room to another. Additionally, flexible conveyors are ideal for lifting materials from bag dump stations or storage bins. They can convey products at ceiling height to feed a line of processing or packaging machines – as multiple discharge points can be placed along horizontal sections.

Flexible Screw Conveyors constantly remix material through the action of the rotating spiral – effectively eliminating the risk of product segregation. These conveyors are also an extremely cost effective method of conveying dry bulk solids and ingredients!

Flexible Screw Conveyors are called by many different names, including a flexible auger, flexible screw conveyor, flex conveyor, flexible spiral conveyor, helix or helical conveyor.


Continuous Mixing & Blending with Flexible Screw Conveyors

Thorough mixing is achieved over a short length of material flow with Spiroflow’s Inline Twin Screw (ITS) continuous proportional blender. It is steplessly adjustable for any blend ratio and is designed for use with any free free-flowing, granular, flake or pelleted materials. Accuracy of the Spiroflow ITS is to 2%, depending on material and application, making it suitable for a wide range of uses in the food, chemical, building products and other process industries specifications.


The Spiroflow ITS incorporates a novel principle in that the feed of the secondary ingredient is introduced directly into the center of the flow of the primary ingredient. The unit has two rotating spiral type conveyors of different diameters. The steel tube of the smaller conveyor is located within the spiral of the other. As the diagram shows, the tube of the smaller conveyor extends beyond the inlet hopper of the larger conveyor. This ensures that the flow of the minor ingredient is introduced into the primary one at the optimum point for thorough mixing. Stratification of different ingredients, which occurs with other types of mixer, is avoided by the unique design of the Spiroflow ITS due to its mechanical action.

Output Rates

Spiroflow ITS blenders are made up of standard sized Spiroflow rotating spiral conveyors and can be designed for any required throughput up to a maximum of 10 tph.


Food & Pharmaceutical Applications

Hygienic versions of the Spiroflow ITS with quick release connectors for ease of disassembly and cleaning are available for use in the food, chemical and pharmaceutical industries.


Versatility of installation and the ability to deal with the widest range of material particle sizes, bulk densities, and flow properties puts Spiroflow at the leading edge of flexible screw conveyor technology. Flexible screw conveyors, or auger conveyors, are often the lowest cost means of transferring dry bulk solids from one point to another.

The rotating flexible screw conveyor spiral, centralized within the conveying tube, gently moves material without degrading it. Its unique action also eliminates the risk of mixed product separation.


The simplicity of operation is the key element in the Spiroflow flexible spiral conveying system. The electric motor driven spiral, the only moving part, rotates within a sealed tube, moving the materials along by its Archimedean screw action. This design simplicity eliminates the need for additional operating equipment such as filters or bearings – all adding up to a system that’s hygienic, easy to clean, low on installation and maintenance costs and high on efficiency and performance.


The Spiroflow flexible screw conveyor is totally sealed during operation. Because air isn’t used as a conveying medium, there’s no risk of dust contamination or humidity from the atmosphere, a critical factor when used in food and pharmaceutical applications. Additionally, dust can cause airborne contamination of other products and also pose a threat to the working environment.


The simplicity of the Spiroflow flexible screw conveyor system makes cleaning a simple operation. The electric motor may be reversed to empty the conveyor of residual material. It can then be flushed out with water or cleaning solution. If necessary, the spiral can be quickly removed from the tube, and optional quick release connectors enable rapid dismantling and reassembly to minimize downtime.


A robust inner spiral is the only moving part of a Spiroflow flexible screw conveyor which ensures trouble-free operation.

We offer heavy-duty screw conveyors with Ultra High Molecular Weight Polyethylene (UHMWPE) tubes for abrasive or high bulk density materials.

For the most abrasive metals, aggregates and materials such as glass cullet, we offer our RHINOVEYOR Flexible Screw Conveyor which has an abrasion resistant rubber conveying tube in addition to a heavy-duty spiral. Tests and operational experience have confirmed that our RHINOVEYOR conveying tubes have a significantly longer life than standard UHMWPE plastic tubes in aggressive applications.

The action of the Spiroflow flexible screw conveyor ensures the material is being constantly remixed. This is particularly important when feeding premixed product to packaging and tablet machinery.



Because of their versatility and ability to handle a wide range of particle sizes, bulk densities, and flow properties, Spiroflow flexible screw conveyors are installed around the world in a multitude of industries.


Hygienic ingredients handling is a fundamental benefit of Spiroflow equipment, designed to satisfy the stringent sanitary demands of the food and allied industries.

Water Treatment

Spiroflow supplies efficient dosing equipment for hydrated lime, activated carbon, and other chemicals used in water treatment.

Minerals & Ceramics

No bulk handling tasks are more arduous than in minerals and ceramics. Spiroflow equipment is robustly built to meet the most exacting demands.


Spiroflow’s long experience within the chemicals industry ensures the safe handling and accurate metering of these often hazardous materials.

Plastics Rubbers

Spiroflow solids handling equipment is widely chosen to ensure efficient feeding of molding, extrusion and mixing machinery in the volume manufacturing sectors.


Accuracy, hygiene, and consistent feeding are prime requirements in the pharmaceutical field.


Flexible screw conveyors, or auger conveyors, can be utilized in a number of different configurations.  Here is a sampling of configurations we see regularly:

Feeding Filling Machinery

Horizontal Outlet for Restricted Headroom

Conveying from Hopper to Process

Controlled Feeding & Dosing from Bulk Bags

Multi-Infeed Conveyor

Loading Silos

Filling Bulk Bags

Mobile Conveyors


Standard Construction & Components:

Electrical Requirements:

Pneumatic Requirements

Inlets, Outlets & Feeding

Spiral Profiles & Tube Selection

For most applications, the standard round spiral is suitable, combining strength and flexibility. Flat section spirals are recommended for certain light or aerated products.The Proscrew beveled profile is used for conveying difficult materials such as iron oxide. The semi-rigid construction enables steep conveying angles to be achieved without bends.

The Centre Core is used for very light materials that fluidize readily and for conveyors inclined more than 60°. They are also used to prevent flooding/overfeeding of certain solids in short or horizontal conveyors.All spirals are heat treated to provide strength and long life. Heavy duty spirals are also available for certain high density or aggressive materials.

Flexible screw conveyor tubes are available in UHMWPE, carbon steel (mild steel), 304 stainless steel or the industry’s only ‘Rhinoveyor’ rubber tubing (used when conveying abrasive material).


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