Tubular Drag Conveyors

Versatility Meets Durability in Hapman Tubular Drag Conveyors.

Convey product in a completely sealed system. The sprocket drive in our tubular drag conveyors slowly pulls a heavy-duty chain through a fully enclosed pipe. As the chain moves your material through the pipe there is no chance for dusting, explosions or contamination issues.

Use less energy than other conveyors. The low-horsepower motor produces the slow, steady drag that cuts your energy costs when conveying powders or bulk solids.

Move challenging materials. Our tubular drag conveyors handle high-moisture ingredients and abrasive, blended, friable, easy-to-compact or smear products without compromising quality or efficiency.

One conveyor does the work of several. A modular design means we can configure our tubular drag conveyors to move your product vertically, horizontally, at any angle and around corners. Need more than one inlet/outlet in your bulk material handling process? Add as many as you need.

The Tubular Drag Operation

The fundamental operation of tubular drag conveyors involves a chain with flights that pull material through a sealed pipe circuit. They operate at high torque/low speed, and their capacity is determined by the diameter of the flight and the speed at which the chain assembly can be pulled through the pipe. Tubular Drag Conveyors are sealed to upstream and downstream equipment by a hard flange or a flexible sleeve. The layout of these conveyors allows for pipe bends, multiple inlet and discharge points, and routing through multiple planes and in any direction.

All of our tubular drag conveyors are customized to fit the specific bulk material handling needs of your application and facility.

• Dust-free operation. Tubular Drag Conveyors feature completely sealed construction that confines bulk materials within the equipment. You convey materials in any direction – horizontally, vertically, at any angle and around corners – without dusting, odors, contamination, or spillage.
• Convey up to 50 cfm (1.416 cmm). A sprocket drive pulls a chain through a stationary outer casing. Flights attached at regular intervals along the chain convey material from inlet points to discharge points.
• Longer life from chain than steel cable. Chain is less prone to fatigue, wear and stretch than steel cable. As individual parts on the chain wear out, you can replace them at a much lower cost and time expense than replacing the entire steel cable in other conveyors.
• Work day-in, day-out with minimal chain wear. A heavy-duty chain allows you to start, stop and operate our conveyors under load all day long.
• Discharge 100% of your product. Hapman’s exclusive, self-cleaning discharge gate is rounded to the shape of the pipe. Unlike flat gates in other conveyors, there is no place for your product to get trapped.
• Minimal maintenance required. The automatic chain take-up idler in our Tubular Drag Conveyors makes adjustments as the chain stretches so you don’t have to do regular manual tightening.
• Eliminate multiple conveyors with multiple inlets/outlets. We can install numerous inlets and/or discharge points into a single tubular drag conveyor, allowing you to add ingredients and discharge product all along the way. Tubular construction lets you reconfigure your design as your floor layout or process needs change.
• Reduced energy usage. A low-horsepower, electric motor drives material for hundreds of feet.

Hapman’s custom-built tubular drag conveying systems move some of the toughest products up to hundreds of feet: from hardened steel shot to bacon grease waste, from fishmeal and bones to explosive materials. Our expert consultants and engineers can spec out and build a system based on your specific bulk material handling needs. Paths are virtually limitless and multiple inlets and outlets are possible with our Tubular Drag Conveyors.

In addition to optimum conveying, our sealed Tubular Drag Conveyors offer:

• Process efficiency
• Increased worker safety from clean, dust-free operation
• Excellent material integrity with minimal degradation / segregation
• Low energy consumption
• Minimal maintenance requirements
• Brush box cleaning
• Discharge gate
• Auto-tensioner

Improve product flow when you install mechanical vibration. An offset weight and hammer system taps on the tops of flights to dislodge material.

Fully discharge material with Hapman’s exclusive, self-cleaning discharge gates. Unlike flat gates in other conveyors, ours are rounded to the shape of the pipe so there is no place for your product to become trapped.

Detailed Options

Brush Box

Discharge Gate

Hapman Auto Tensioner

The chart below represents the optimum convey rate for most materials based on average capacity in cubic feet/minute and pipe size. Actual capacities vary depending on the material type, its abrasiveness and flow character.

Pipe Casing Diameter & Material Options
3 in (76 mm) to 12 in (300 mm) diameter
Carbon steel
Stainless steel

Chain Material Options
Carbon steel
Stainless steel

Circular Flights
Cast iron
Ductile iron
Nylon
Stainless steel
UHMW polyethylene
Tivar® H.O.T. premium UHMW polyethylene
Custom

Maximum Conveyance Distance
85 ft vertically (26 m)
400 ft horizontally (122 m)

Maximum Conveyance Speed
Convey up to 50 cfm (1.416 cmm)

Chain vs. Cable – Which Conveying Type Works Best?

During your evaluation of tubular drag conveyors to determine the best match your bulk material handling needs, you will need to assess the cable vs. chain comparison. While every application has different requirements and measurements for value, we present some of the most common differences between the two conveying types for your review.

Tubular Conveyor Chain vs. Cable Comparison

The importance of choosing the right conveyor chain and flight assembly.

You never have to worry about selecting the correct chain and flight assembly for your bulk material handling application. We will work with you to determine the equipment that best suits your specific needs. We do not believe in a one-size-fits-all approach to conveying material.

As confirmed by our more than 70 years of experience and our testing of over 2,600 distinct materials, mechanical conveying is most effective when the right combination of chain type and flight material is applied to the characteristics of the conveyed material. That’s why we offer the most comprehensive array of chain and flight options in the industry to provide you the best conveying equipment for your application. The options range from:

• Sealed pin
• Universal sealed pin
• Drop-forged or rivetless chain
• Round link

Flight material options range from UHMW polyethylene, glass reinforced polyethylene, cast steel, and iron. Each is engineered for exceptional conveying properties when evaluating bulk density, temperature, and other handling and material characteristics.

• Cast iron
• Ductile iron
• Nylon
• Stainless steel
• UHMW polyethylene
• Tivar® H.O.T. premium UHMW polyethylene

The most common chain and flight assembly is the sealed pin with UHMW polyethylene flights. This configuration of chain type and flight material provides the longest life for the flight and least maintenance for the chain in most material conveying applications. The sealed pin chain is engineered specifically for moving dry material of various size and bulk density. The main advantages are:

• The sealed pin keeps gritty, abrasive material out of the chain knuckle, reducing the need for frequent maintenance and significantly extending the life of the chain.
• UHUMW is cost-effective, lightweight, has excellent release properties, is low cost, and has a high wear resistance coupled with a low friction/drag. Each of these properties provides optimum conveying with low horsepower for reduced energy consumption.

Product Brochures
Product Brochure: Tubular Drag Conveyors

Application Review
Application Review: Food Processor Replaces Aeromechanical Conveyor with Hapman Tubular Drag System Eliminating Contamination, Clogging, Jamming & Shutdowns
Application Review: Biotech Lab Handling Dirty Mice Bedding From Cages with Cleaning Disposal System
Application Review: Portable Bulk Bag Unloading – Chemical Company Charging Hoppers with Limestone Combining with Helix^® Flexible Screw Conveyor
Application Review: Tubular Drag Conveying System – Mining Operation Handles and Conveys Ammonium Nitrate Reducing Degradation
Application Review: Tubular Drag Conveying System – Tire Manufacturer with Dust-Free Multiple Inlet System Handling Carbon Black

Case Studies
Case Study: A Manufacturer of Explosives Seeks to Safely and Effectively Off-Load Railcars of Corrosive Bulk Material
Case Study: Human Health Benefits, Operational Efficiencies, Increased Productivity, Cost Improvements
Case Study: The Genentech South San Francisco Campus Achieves Cost Savings and Operating Efficiency By Applying the Right Waste Bedding Handling System
Case Study: Tubular Drag Conveying Technology – A Cost-Effective and Energy Saving Alternative to Pneumatic Conveying
Case Study: Stillwater Mining Improves Smelting Efficiency and Yield, Eliminates Dust with Tubular Drag Conveyor
Case Study: Fiber By-Products Reduces Maintenance, Dust and Reprocessing of End Product with Tubular Drag Conveyor
Case Study: The University of California San Francisco, Laboratory Animal Resource Center (LARC) Finds Significant Cost Savings in Effective Handling of Waste Bedding Material
Case Study: Uniformed Services University Health Science Center for Laboratory Animal Medicine Overcomes a Severe Bedding Handling Challenge
Case Study: Aluminum Casting Company Leverages Custom-Built Hapman Equipment to Create a Cleaner, Quieter Foundry

Tech Briefs
Tech Brief: Selecting A Conveyor for Effectively Moving Bulk Materials
Tech Brief: The Evaluation of Tubular Drag Conveyor Types
Tech Brief: Tubular Drag Technology for the Conveyance of Powder and Bulk Solids
Tech Brief: Tubular Drag Conveying – A Cost-Effective, Energy-Saving Alternative to Pneumatic Conveying

White Papers
White Paper: The Case for Engineered Chains Over Round-Link Chains