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® 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 conveyors are suitable for applications with temperatures up to 420°F / 216°C.


  • Ultra-heavy-duty conveying
  • Gentle handling of fragile materials
  • Maintain blends
  • Totally enclosed for dust & contamination-free handling
  • Layout versatility with 3 plane circuits
  • Multiple inlets & multiple outlets
  • Conveying capacities up to 10 ft3/min. / 0.28 m3/min.
  • Convey straight-line lengths of up to 200 ft. / 60m per conveyor and link multiple conveyors for longer distances
  • Low energy consumption


How It Works

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 them to operate at temperatures up to 420°F (216°C).

Our Dynaflow 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 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.


Totally Enclosed, Dust-free, Contamination-free Handling

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

Gentle Product Handling & Maintaining Blends

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.

Operates in Multiple Planes

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.

Multiple Inlets & Outlets

The 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.

Operational Flexibility

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 conveyor you can maximize your use with a mobile design available for multiple in-plant applications or freight car and truck loading.

Conveys a Wide Range of Materials

Structural drag 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.

Minimal Maintenance

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.

24/7/365 Reliability

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.

Low Energy Consumption

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.

No Filters or Cyclones

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.


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

ModelTube SizeCapacity* Up To
* Throughput rates vary depending on the bulk density and flow characteristics as well as the layout of the conveyor.
DF33” / 75mm1.5 ft3/min / 0.042 m3/min
DF44” / 100mm2.5 ft3/min / 0.070 m3/min
DF66" / 150mm7 ft3/min / 0.198 m3/min
DF88" / 200mm10 ft3/min / 0.283 m3/min


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

Check out our Conveyor Comparison Chart

This document compares our conveyor offerings based on application suitability, configurations, specifications, options & cleanability. Our engineers will assess your application needs & recommend the optimal conveyor system.


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.

Cableflow Cable Drag Conveyor Typical Circuits


Check out our Conveyor Comparison Chart

This document compares our conveyor offerings based on application suitability, configurations, specifications, options & cleanability. Our engineers will assess your application needs & recommend the optimal conveyor system.


Dynaflow Chain Drag Conveyor Components


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.

Standard Components
Conveyor PipingStraight Pipe Sections & Bends
Our engineers will recommend the pipe sections and bends based on your application and layout requirements.

Seamless carbon (mild) steel or 304 stainless steel pipe make up the layout in accordance with a general arrangement drawing. Pipes can be upgraded to 316 stainless steel.

Pipe bends are available in a range of angles of deflection: 5-15°, 16-30°, 31-45°, 46-75° or 76-90°.

Flanges connect adjacent sections of pipe as required.
Disc & Chain AssemblyOur engineers will recommend the optimal disc & chain assembly for your application.

  • Sealed pin Chain, black neoprene or white nitrile seals, UHMWPE flights
  • Link & pin chain, steel washers & UHMWPE flights
  • Drop forged chain with cast iron flights
Drive Motor2-7.5 hp / 1.5-5.6 kW
Motor selected based on application requirements.
Screw: 580 rpm
Controls: Motor starter, controls by customer or see options.
Drive Housing AssemblyThe Drive Housing Assembly is a combination drive and take-up assembly designed to operate the conveyor chain at a constant velocity. The components include:

  • A motor directly coupled to a hollow shaft style gear reducer which is mounted directly to the conveyor head shaft
  • Conveyor drive sprocket
  • Gear reducer mounted on a slide plate base with side mounted guide rails
  • Screw type take-up
  • Removable drive guard
Conveyor Drive MotorA 1 - 30 hp / .74 – 22.4 kW motor is selected based on application requirements.
Optional explosion proof drive motors are available.
Idler HousingRequired dependent on layout. The combination 90° or 180° idler and take-up assembly includes a fabricated housing with a removable bottom cover, externally mounted bearings, and an idler shaft with a conveyor chain sprocket.

All components are mounted on a common slide plate base with pressure plate style clamps.
Inlet Housing AssemblyA flanged inlet housing assembly is welded to the pipe assembly and includes an integral conveyor chain guide.
Open Discharge AssemblyAn open style flanged discharge assembly is fitted to the pipe assembly and includes an integral conveyor chain guide.
High Temperature Chain AssemblyA high-temperature chain assembly utilizing Hytrel discs is available for conveying materials up to 482°F / 250°C.
Conveyor PipingThe conveyor piping can be upgraded to 304 stainless steel.
FlangesThe flanges can be upgraded to stainless steel.
Motor Load MonitorAn electric shear pin (Motor Load Monitor) is used to monitor the amp draw on the drive motor. If motor load spikes the system will E-Stop preventing damage.
Inlet CoverA gasketed and bolted inlet cover comes with a round inlet collar.
Air Actuated Discharge GateThe Air Actuated Discharge Gate is a clam shell type gate valve. It is equipped with a solenoid valve to actuate the gate open and closed to direct material flow.
Flanged Discharge HopperThis gasketed & bolted cover comes complete with a round inlet collar.
Pipe Valve TransitionThe pipe discharge transition is located below the discharge assembly/gate.

It is designed to capture the discharged material and its dust and to direct the flow to a flanged discharge opening.
Housing Discharge TransitionThe discharge housing transition is gasketed and bolted to the bottom flange of the drive/discharge assembly.

It is designed to capture the discharged material and its dust and to direct the flow to a flanged discharge opening.
Additional Pipe Mounted InletsMultiple pipe mounted inlets can be mounted in the conveying circuit
Additional Pipe Mounted OutletsMultiple pipe mounted outlets can be mounted in the conveying circuit.
Chain VibratorAn unbalanced load type chain vibrator assembly is available with an electric motor mounted on an adjustable take-up base.

The vibrator spring plate is made of spring grade steel.

It includes a polyurethane bellows around the entry point of the conveyor housing to form a dust seal.

It is mounted at the product discharge point and is provided with a drive guard.
Inspection PortInspection openings are easily removable with bolted top covers.
ControlsComplete controls are available with or without a VFD.

Check out our Conveyor Comparison Chart

This document compares our conveyor offerings based on application suitability, configurations, specifications, options & cleanability. Our engineers will assess your application needs & recommend the optimal conveyor system.


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 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 speed.

There are many factors that enter into the structural 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.

Structural Drag Conveyor Selection Guidelines

  • The Dynaflow 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.


Application Suitability
Layout Constraints
(Single Conveyor)
Maximum total length 400 ft. / 120m including return leg
200 ft. out & 200 ft. return / 60m out & 60m return
Longer distances require multiple units feeding each other
MaintenancePeriodic only
Very low maintenance
Energy ConsumptionMedium energy consumption
Dust Control/Air DisplacementMechanically dust tight, enclosed loop system
No systems filters required
Residual MaterialLow deposits
DegradationVery low conveying speed up to 50 ft./min / 15 m/min
Low abrasion gentle conveying
Fragile ProductsIdeal for fragile materials
Maintaining BlendsIdeal for maintaining blends
Hygroscopic MaterialsSuitable
Moist MaterialsSuitable
Cohesive MaterialsSuitable
Hot MaterialsExcellent
Handles material temperatures up to 420°F (216°C)
SlurriesRecommend material test
Fine ParticlesFine particles are suitable for conveying
Some powders such as cement and TiO2 should be avoided due to product build up and higher drag factors
Running EmptyCan be run empty for extended periods
Starting & StoppingCan be started & stopped under load
Operates in three planes

Check out our Conveyor Comparison Chart

This document compares our conveyor offerings based on application suitability, configurations, specifications, options & cleanability. Our engineers will assess your application needs & recommend the optimal conveyor system.


Dynaflow drag chain conveyors can gently transport a multitude of materials that often are considered difficult to convey.  They should be considered when transporting hot, moist, cohesive or hygroscopic materials that range from fine powders to sludges.  Here is a list of materials generally considered for this type of conveyor.  Our engineers will carefully assess the properties of your material and likely perform a material test to ensure your drag chain conveyor performs exactly to your expectations.


  • Acetylene Black Powder
  • Activated Carbon
  • Adipic Acid
  • Alum
  • Ammonium Nitrate
  • Antimony Oxide
  • Benzoic Acid
  • Bismuth Oxide
  • Black Oxide
  • Calcium Carbonate
  • Calcium Hypochlorite
  • Calcium Zinc Stearate
  • Calcium Oxide
  • Carbon Black
  • Carbon Chips
  • Catalyst Crystal
  • Caustic Soda
  • Cellulose
  • Chlorendic Anhydride
  • Copper Oxide Scale
  • Fly Ash-Lime
  • Fumeric Acid
  • Graphite Powder
  • Hefnium Hydroxide
  • Hexamine, Granular
  • Irganox
  • Iron Oxide
  • Isophthalic Acid
  • Lead Oxide
  • Lime, Hydrated
  • Magnesium Chilis
  • Magnesium Fluoride
  • Magnetic Oxide
  • Molybdenum
  • Monosodium Phosphate
  • Paraformaldehyde Flake
  • Pentaerythritol
  • Phosphorus Pentasulfide
  • Phthalic Acid
  • Phthalic Anhydride
  • Silica Dust Fines
  • Soda Ash
  • Sodium Bicarbonate
  • Sodium Disulfate
  • Sodium Hydroxide
  • Sodium Phosphate
  • Sodium Tripolyphosphate
  • Stearic Acid
  • Terephthalic Acid
  • Titanium Dioxide
  • Titanox
  • Uranium Oxide
  • Uranium Salts
  • Uranium Tetraflouride
  • Urea
  • Zirconium Oxide


  • Bone Meal
  • Fertilizer Powder
  • Fertilizer
  • Grains
  • Grass Killer, Powdered
  • Herbicide
  • Insecticide Powder
  • Lime Powder
  • Paunch Manure
  • Pesticide

Animal Feed

  • Animal Feed

Building Materials

  • Asbestos
  • Carpet Fines
  • Cement Powder
  • Sawdust
  • Wood Chips
  • Wood Pellets


  • Canola Seed Hulls & Fines
  • Coffee Beans
  • Coffee Chaff
  • Coffee, Ground
  • Coffee, Instant
  • Corn Meal
  • Graham, Ground
  • Malt
  • Mustard
  • Peanuts, Shelled
  • Rice Hulls
  • Rice
  • Spent Grain
  • Spent Hops
  • Spices
  • Starch
  • Sugar, Powdered
  • Tea

Minerals & Mining

  • Bentonite Clay
  • Ceramic Clay
  • Coal Briquettes
  • Coal Dust, fines
  • Copper Chromate
  • Copper Powder
  • Copper Sulfate
  • Diatomaceous Earth
  • Epsom Salt
  • Ferrous Sulfate
  • Graphite
  • Green Salts
  • Iron Oxide
  • Iron Sulfate
  • Kaolin Clay
  • Lead Oxide
  • Lead Slag
  • Lime
  • Mercuric Oxide
  • Metal Chips
  • Metal Powder
  • Metallurgic Coke
  • Mica
  • Phosphate Ore
  • Powdered Metal
  • Red Lead
  • Sulfur
  • Talc
  • Tile Clay
  • Zinc Ore

Plastics & Rubber

  • Bisphenol
  • Mylar Flake
  • PET
  • Phenolic Resin
  • Plastic Flake
  • PVC Compounding Powder
  • PVC Powder
  • Resin
  • Vinsol Resin

Paints, Pigments & Coatings

  • Paint Flake
  • Paint Sludge


  • Baghouse Dust
  • Biomass
  • Detergent
  • Digested Wood Knots
  • Filter Cake Flock
  • Grinding Sludge
  • Mill Scale
  • Paper Pulp
  • Petroleum Coke
  • Phosphate Sludge
  • Plastisol Sludge
  • Scale
  • Sewage Grit
  • Sewage Sludge


Structural Drag Chain Conveyor Buyer's Guide