Using Advanced Rotary Tube Internals to Improve Thermal Processes

Related Vendors

DÜPERTHAL Sicherheitstechnik GmbH & Co. KG

TURCK GmbH

EDL Anlagenbau Gesellschaft mbH

Harper International

Controlling the Gas Flow Ensures Product Quality

Contact of the process off-gas(es) with the final product, depending of the reaction, can hinder product quality. This is common when off-gassing moisture and trying to prevent the vapor from condensing on the dry reacted product. In some cases, off-gas contact with the raw feed material can also hinder processing. If this is an issue, strategic placement of a solid core helical flight or Archimedes screw may be the solution. The helical flight or Archimedes screw can create enough of a barrier preventing unfavorable gas migration.

Gallery

Gallery with 6 images

Rotary Furnaces also Provide Efficient Material Flow

A rotary furnace is not only a great piece of thermal equipment for powder processing, but also for large agglomerates or irregularly shaped materials. Without internal flights in the rotary tube these irregularly shaped materials and agglomerates may segregate themselves due to the tumbling flow through the tube. This phenomenal can be controlled with the use of an Archimedes screw that is continuous throughout the entire tube length. In this case, the rotary tube angle does not play as large of a role in determining the residence time of the material but rather the pitch of the flight paired with the tube rotation will determine the exact residence time.

In many cases, when processing in the rotary, a short section of a helical flight is installed at the entrance of the tube. This is done to ensure that material does not build up at the entrance causing the material to spill forward into the entrance chamber or worse, cause material to plug up the tube.

Current Processing – What Thermal Processes Can Do

As an industry leader in custom thermal processing equipment, Harper International has recently paired up with U.S. Demil in a successful effort to design a rotary tube furnace utilized in the demilitarization of excess, obsolete and unserviceable munitions, done so for safety and environmental purposes.

One of the key features that made this project successful was the specific design for tube internals. This particular design had to take considerations for the controlled migration of material through the tube while acting as a containment preventing chain reactions due to rapid exothermic reactions, controlling gas flow through the reaction area and most significantly forcing a specified key reaction location within the rotary tube. Functional tube internals can improve processing efficiency and product quality, but may make the difference between success and failure.

* The author works as application engineer for Harper Int.: Tel. +1-17-16684-7400

(ID:39583350)