Calciner Rotary Kiln

Industrial Calciner Rotary Kiln Application

The industrial calciner refractory furnace or oven is an indirect rotary kiln used to remove moisture in the production process of materials and products like cement, lime, and gypsum. The calciner rotary kiln, or indirect kiln, is a rotating drum inside an externally-heated furnace that can reach temperatures as high as 3000°F that must be tightly controlled to remain even across the surface of the drum.

In these applications, very large supply fans pull clean, ambient air into the hot rotating drum where it moves across the material that enters from the opposite end. The air draws the moisture out of the material, leaving the converted powder, or clinker in the case of cement, to exit through a product outlet at the bottom. The rotary kiln also has one or more exhaust fan/s, which pull out the gas and/or water vapor before it goes through various other potential applications for dust or pollution control including oxidizers, bag houses, cyclones, or others.

Your industrial calciner application environment and airflow will determine your process fan specifications. Scroll or hyperlink down to find Application Featured Products, Case Studies, and further application details as follows:

Primary Industries for Calciners

Many varied industries use calciner in their processes. The indirect rotary kiln is a prominent application in these and other industries:

  • Cement
  • Infrastructure
  • Building Materials
  • Lime/Limestone
  • Gypsum
  • Process Metallurgy
  • Food Processing
  • Pharmaceuticals

Calciner Fan Selection & Specification

Because the fan supplies clean ambient air into the calciner drum, high-efficiency models with backward inclined or backward curved impellers are optimal. The fan size and design depends on airflow. There are just a few models that we use depending on the specific application.

Industrial Fan Designs Commonly Used for Calciner Rotary Kilns

Fan Arrangements, Accessories, & Design

Fan Arrangements indicate how the motors mount to and drive the fans. On the calciner fan, the motor size determines the arrangement, typically an Arrangement 1 belt-drive motor up to about 250HP. When the motor gets bigger than about 250HP, which is common, we would use an Arrangement 8 direct-drive motor.

These are the arrangement options:

Arrangement 1 – Belt Drive with an overhung impeller. The fan and motor mount separately to a unitary base.

Arrangement 8 – Direct Drive with an overhung impeller. The fan shaft is directly coupled to the motor shaft with a flexible coupling.

When it comes to design and accessories, it’s all about protecting and optimizing operations, maintenance, and life of the fan and bearings. On the rotary kiln, there is an additional complication of calculating how to dry the material. If you’re not careful, you could end up too close to the maximum and still needing more speed. Because of that, we tend to recommend designing with a 15% performance margin in rotary kilns and dryers to leave a little wiggle room.

In industrial calciner applications, we often recommend:

  • Airflow Meter to measure the energy transfer in the fan
  • Inlet Box if space is tight for the ductwork
  • Inlet Filter to ensure the airstream is clean
  • Flexible Coupling Drive to reduce belt pull on the bearings and related maintenance
  • Vibration isolators to help maintain supply fan balance
  • Vibration, and temperature sensors to monitor bearing and fan health and prevent unplanned outages.
  • Split Housing for easier maintenance access to the fan wheel and shaft.
  • Proper installation and maintenance to ensure safe startup and operations

Talk with Our Application Engineers

If you feel overwhelmed by all this information, don’t despair! We have a team of application engineers who are happy to talk with you and select the best fan for your application. You can call 715-365-3267, email [email protected], or send us your information, and one of our engineers will connect with you.

Content Related to Rotary Kiln Applications

Here are related posts and case studies that might be of interest as you think about your application.