Hollow Flight Thermal Processor for Cooling Activated Carbon

General Description

Activated carbon is used in thousands of applications for filtration and absorption. Air/water purification, solvent recovery, and sewerage treatment are just a few of the industries that use activated carbon daily.

The media is created by pyrolyzing a carbonaceous substance, such as nutshells, coal, wood, or peat without oxygen to make carbon char. The char is treated to develop an interconnected series of pores inside the carbon. The great surface area of this internal pore network results in an extremely large surface area ideal for adsorption and holding organic chemicals.

A major activated carbon producer developed an innovative process to create its product more effectively and efficiently than traditional kiln and oven methods. KWS had already provided a highly engineered screw conveyor to hold activated carbon at 1,800-degrees F. Now, KWS designed and manufactured a thermal processor to cool from 1,800-degrees F to below 250-degrees F. Cooling activated carbon below 250-degrees F allows the producer to eliminate the need for high-temperature components on the downstream equipment, adding significant cost savings to the overall process.

Design Parameters

1. Product Type: Activated Carbon
2. Product Inlet Temperature: 1,800-degrees F
3. Product Outlet Temperature: 250-degrees F
4. Material Density: 25 to 35 Lbs. per Cubic Foot
5. Conveyor System Capacity: 80 Cubic Feet per Hour
6. Duty: Continuous

KWS Advantages

Engineers at KWS designed a thermal processor based on required volumetric capacity and heat load to fit within limited space constraints. The KWS Hollow Flight Screw Processor provides a path for cooling media to ¬flow through the full length of the thermal processor, utilizing every available square inch of heat transfer area. The center pipe of the screw also provides surface area for heat transfer. Heat transfer efficiency was maximized, and substantial cooling provided in an overall footprint of less than 33 feet.

KWS Special Features

The KWS thermal processor was designed in strict accordance with the ASME Boiler and Pressure Vessel Code. Special plate, pipe, and sheet steel alloys were used to meet the demands of the activated carbon temperatures as well as the internal pressures of the cooling medium within the processor’s cooling jacket and hollow flight screw. As an ASME-certified pressure vessel manufacturer, KWS provided an ASME code stamp for the trough jacket and hollow flight screw prior to shipment.

KWS utilized a slider base pedestal trough end to protect the end bearing from contamination and allow for thermal expansion. Expansion and contraction are common in every high-temperature application and occur axially along the length of the screw and trough. The KWS slider base trough end is designed for thermal expansion and can account for axial expansion up to 4 inches.