Indirect-Fired Rotary Process Furnaces
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What Is an Indirect-Fired Rotary Process Furnace?
An indirect-fired rotary process furnace heats the outside of a rotating alloy processor tube, keeping the process material separate from burner combustion gases. This arrangement allows the material atmosphere and evolved process gases to be managed independently for compatible drying, calcination, pyrolysis and other controlled thermal-treatment duties.
The terms rotary process furnace and indirect-fired rotary kiln can describe closely related equipment. This page documents processor-tube components, an example HiTemp configuration and typical supply considerations. For the broader application overview, see HiTemp indirect-fired rotary kilns.
HiTemp Rotary Process Furnace System Overview
The example processor-tube system shown on this page uses three principal sections. For the illustrated carbon-processing application, the material-contact surface is a one-quarter-inch 304 stainless-steel alloy cylinder installed inside a refractory-lined outer shell. Final tube alloy, thickness and construction must be selected for the project temperature, atmosphere, material chemistry and mechanical duty. Stationary feed and discharge sections can use inert-gas-purged seals to limit oxygen entry.
All high-temperature stainless steel contact surfaces have flanged connections for the feed, stack and an optional powered-screw discharge.
Typical Included Components
- Inlet Stationary System with Feed/Discharge Pipe
- Piping for Gas Testing
- Hopper and Screw to feed material
- Gas Vent Port
- Rotary Drive System Motor(s)
- Full Control System with Sensors
Example System Specifications
The following dimensions and burner arrangement describe the configuration shown and are not universal specifications for every HiTemp system:
- Reaction Tube inner diameter - 36 inches (91.5 cm)
- Reaction Tube inner length - 192 inches (488 cm)
- Approximate Outer Shell width - 60 inches (152.5 cm)
- Approximate Outer Shell length - 216 inches (549 cm)
- Gas-fired Burners - 3 Midco J121-3-G
HiTemp System Components
System components can be custom-built to match the customer’s process parameters and specifications. The contract should identify whether blowers, controls and installation items are supplied by HiTemp, purchased locally or furnished by others.
HiTemp can provide recommendations for building and site plans at the customer’s plant. Available drawing formats may include DWG or DXF, as defined in the project scope.
Rotary Feeder and Discharge Screw Tube
The feeder tube is constructed from a high-temperature alloy selected for the application. A double-block arrangement can be considered to limit air leakage during material feeding.
Main Rotary Chamber, Secondary Chamber and Stack
The assembly can include support rings, support wheels and bearings, seals, drive motor and gearing, shell stabilizer, stationary sections and a discharge hopper. The required secondary treatment and off-gas equipment depend on the process and applicable emissions requirements.
System Options
- Powered screw discharge
On-Site Storage
Equipment awaiting installation should be stored under cover in a dry, frost-free and pest-free environment within the limits specified in the project documentation. Incorrect storage can damage electrical, mechanical or refractory components.
System Shipping and Delivery
HiTemp can coordinate shipment of contracted components, parts and documentation to the installation site. Freight charges and delivery responsibilities are defined separately in the applicable quotation or contract.
Unless the contract states otherwise, shipping terms are FOB origin.
Installation and System Commissioning
HiTemp can provide an operating engineer to assist with site design, installation, commissioning, startup and training of operating and maintenance personnel. The duration, responsibilities and deliverables are defined in the project scope.
Travel and per diem expenses may be charged separately as specified in the contract.
Warranty and Maintenance
The example supply terms describe a twelve-month limited warranty from the date of delivery for defects in material or workmanship. Exclusions can include inadequate servicing, normal wear, accident, misuse and events outside the manufacturer’s control. The executed contract and warranty document govern the coverage for each project.
Operating and Maintenance Manuals
Electronic and printed operating and maintenance documentation can include component manuals, startup procedures, operating instructions, scheduled maintenance and troubleshooting information. Project files may be updated during installation and startup. Where included, an on-site computer can provide access to wiring information, component documentation and PLC programs for real-time monitoring.
System Support
HiTemp provides ongoing technical support for installed equipment. Included and chargeable support services are defined by the applicable contract and service requirements.
Equipment and Site Work Not Typically Included
- Concrete foundations or building work
- Covering structures or buildings
- Crane hire for off-loading system components
- Chimneys and erection work at installation site
- Supply and installation of materials for wiring between incinerator control panel and site electrical supply
- Any site work other than specified in system contract
Indirect-Fired Rotary Process Furnace Questions
How Is a Rotary Process Furnace Different from an Indirect-Fired Rotary Kiln?
The terms can describe closely related equipment. On the HiTemp website, this page documents processor-tube components, an example configuration and typical supply scope, while the indirect-fired rotary kiln page provides the broader application and operating overview.
What Information Is Needed to Specify an Indirect-Fired Rotary Process Furnace?
Useful starting information includes feed composition and particle size, throughput, inlet and target moisture, required temperature and residence time, process atmosphere, evolved-gas composition, materials compatibility, utilities, emissions controls and installation requirements.
For Additional Information
Please visit our Downloads page, or contact us directly using the Contact Form to discuss your system needs.
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Indirect-Fired Rotary Process Furnace Gallery
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