Dynaflow Drag Chain Conveyors


The Dynaflow Tubular Drag Chain Conveyor is a mechanical drag conveyor system operating within the confines of a pipe. We call it the Problem Solver in a Pipe!

Spiroflow’s Dynaflow® tubular drag conveyors are structural mechanical drag chain conveyors operating within the confines of a pipe. In this conveyor, discs connected by articulated metal links (chains) move material within the pipe making it ideal for ultra-heavy-duty applications. The discs are made from a variety of materials including steel and cast iron. Dynaflow drag chain conveyors are suitable for applications with temperatures up to 420°F / 216°C.



Our Dynaflow drag chain conveyors are ‘Problem Solvers in a Pipeline.’

A structural drag chain conveyor is designed for ultra-heavy-duty applications. The conveyor moves at a slower rate than other drag conveyors but it can handle a wide range of often difficult to convey products.

The conveyor provides gentle handling and low material degradation. It is also totally enclosed and dust-free.

With this system, a series of straight and curved pipes are coupled to housings in a layout designed for your specific site and application requirements. The conveyor forms a circuit where the product can enter and exit through multiple chutes. When the drag chain conveyor is in motion, the discs drag material through the circuit which is driven by a sprocket at one end. More sprockets can be added to the circuit to provide frictionless direction changes and/or reduce the system load.


Our Dynaflow Link & Pin Driven Tubular Drag Conveyor is an ultra-heavy-duty structural mechanical drag conveyor system operating within the confines of a pipe.  The discs that move material along the pipe are connected by heavy duty articulated metal links.  This means that they are well suited to the most arduous of applications.  The discs can be made from a variety of materials including steel and cast iron.  This enables our drag chain conveyors to operate at temperatures up to 420°F (216°C).

All conveying takes place in a totally sealed structural system, which ensures the dust-free transfer of material.

Structural drag chain conveyors can transfer dry, moist, fragile, cohesive, abrasive, hot, hygroscopic or sludge-like materials.  We call it ‘the problem solver in a pipe’ for its ability to transfer difficult materials.

Material is fed into the pockets formed between the discs within the conveying pipe. The chain and discs gently move through the enclosed circuit pulling the material along until it reaches the outlet.  This type of gentle conveying action minimizes product degradation and also maintains blends.

Dynaflow conveyors require very low maintenance. We suggest making it a point to check the conveyor’s housings for wear every month. This type of conveyor is built to last a long, long time.

Structural drag chain conveyors can operate in three (3) planes.  This layout flexibility enables our engineers to design complex circuits which eliminates transfer points while using a single drive.

As a worldwide industry leader in mechanical conveying, Spiroflow is unique in that we offer three types of drag conveyors – Dynaflow drag conveyors as well as Chainflow and Cableflow conveyors.   Our engineers will carefully assess your application needs so that you can count on your conveyor to run 24/7/365.

The drag chain conveyor can accommodate applications with multiple outlets so that one conveyor can deliver material to multiple points.  Multiple inlets are possible as long as only one is operational at a time.

No matter how great the volume, structural drag conveyors are very energy efficient especially when compared to pneumatic conveying systems.  Users benefit by their minimal power requirements and associated energy savings.

Convey over long distances with maximum straight-line lengths of up to 200 ft. (60 m) per conveyor and link multiple conveyors for longer distances.

Enjoy the operational flexibility to stop and start under load, and run empty with most materials.  You can also flood or meter feed the conveyor based on your product flow characteristics.

Depending on the size of the drag chain conveyor you can maximize your use with a mobile design available for multiple in-plant applications or freight car and truck loading.

With structural drag conveyors, no additional air is added to convey material so there is no excess air at the outlet to filter for dust.  Any material that is not ejected at the outlet is simply carried around the enclosed system until it is ejected at the next outlet.



Because tubular drag conveyors can operate in three (3) planes there is an endless number of layout options.  Our engineers will evaluate your application requirements and site restrictions to determine the optimal layout. Typical circuits include the layouts below, however, this is by no means a complete list.


Our Dynaflow Drag Chain conveyor is offered in four sizes.  Our engineers will access your application needs and recommend the optimal configuration and options.

Standard Construction & Components:

  • Structural Schedule 40 Pipe: Carbon Steel (can be upgraded to stainless steel)
  • Chain: Sealed pin, link & pin or dropped forged chain
  • Discs: UHMWPE or cast iron
  • Flanges: Carbon (mild) steel
  • Drive Assembly
  • Manual Chain Tensioner

Electrical Requirements:

  • 1 – 30 hp / 0.74 – 22.1 kW Motor
  • The motor is sized to each application.

Inlets, Outlets & Feeding

  • Multiple inlets & outlets are allowed.
  • The material can be metered or flood fed depending on the product.
  • Variable conveying rates


Spiroflow’s Dynaflow structural drag chain conveyor is designed to achieve gentle handling and low material degradation.   A series of straight and curved pipes coupled to housings form a circuit where the product can enter and exit through pipe mounted chutes.  Conveying is achieved when material enters the space between the discs that is contained within the circuit.  The chain and discs are dragged through the circuit by a drive motor. Changes in direction are accomplished with pipe bends and/or 90°/180° idler housing assemblies.

Straight Pipe Sections

Curved Sections

Pipe Flange

Chain & Disc

Drive Motor

Inspection Opening

Corner Housing

Inlet Housing

Chain Vibrator


Dynaflow Structural Drag Conveyors can operate at rates up to 50 ft./min / 15m/min depending on material characteristics & layout. Capacities are typically up to 10 ft3/min. / 0.28 m3/min.

The capacity charts below allow you to roughly estimate the size of the conveyor and the speed based on the throughput requirements in cubic feet/minute or cubic liters/minute. The horizontal lines represent the velocity at which your product will pass through the conveyor. The vertical lines indicate the volumetric throughput rate in liters per minute. The diagonal lines are the sizes of the conveyors available.

But don’t think you have to figure out which drag conveyor will work best for your application.  Our sales engineers can do that for you!

Tubular Drag Conveyor Capacity Charts

How to Use the Capacity Charts

  • Based on your material’s bulk density, calculate the required conveying rate in feet/minute or liters/minute. Locate the amount required on the horizontal scale.
  • Move up the vertical line and note where it intersects with one or more diagonal lines. Each intersection point indicates a possible conveyor size.
  • From each intersection point, move left horizontally all the way to the vertical scale, indicating the conveyor cable speed.

There are many factors that enter into the tubular conveyor selection process. Beyond the mechanical selection described above, we carefully consider the physical characteristics of the material to be conveyed and the equipment duty cycle.

Tubular Drag Conveyor Selection Guidelines

  • The Dynaflow drag conveyor can operate at speeds up to 50 ft./min (15 m/min).
  • Smaller conveyor sizes and faster speeds are usually selected when the material is free-flowing and non-abrasive and/or the equipment duty cycle is low.
  • Future capacity requirements should be considered. It may be prudent to install a larger conveyor now at a lower speed. You can increase the speed later to accommodate a higher capacity. This can be done with the use of a variable frequency drive or gearing change.
  • Surges and uneven feed conditions should be considered. Surge hoppers may provide more constant feeding and may enable the use of a smaller conveyor.

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