The Contact Column Drying, Heating & Cooling Process
The column is designed as a mass flow vessel giving uniform residence time and even thermal treatment to all of the solids as they pass over the heat exchange surface (tubes and/or plates) that are suspended cross-current to the flow of material. A small counter-current flow of air can be passed, as required, through a gas distribution cone and up through the material. This adds a convective component to increase the overall process efficiency and provide a smooth running operation. Internal heating elements containing heat transfer fluid (steam, hot water, hot oil) are located in the upper section of the column. Vertical baffles are installed in the vessel below the heating plates and above the sweep gas distributor. In some cooling applications, the heat transferred to the cooling medium can be utilized elsewhere in the plant.
The Contact Column unit provides high heat transfer rates in a simple, compact, and space-saving design. Minimal, if any air handling equipment is required (achieving extremely low operating costs) and with exception to the feed and discharge conveyors and the water recirculation pump, the Column Processor has no moving parts. The result is a reliable, ecological and economical solution to processing bulk solids.
Capacities range from pilot plant scale up to 100 tons / hour for key applications including:
- Salt
- Sugars
- Fertilizers
- Metal Powders
- Sand
- Polymers
Features
- Long residence time possible
- Plug flow
- Indirect heat transfer tubes and/or plates
- Low airflows or even none in some contact systems
- Optional cassette arrangement
- Few moving parts
Benefits
- Ideal for diffusion controlled processes to produce low moistures or to purge volatiles
- Homogeneous product
- Enables drying, heating or cooling duties
- Provides heat transfer liquid flexibility
- No or minimal air handling equipment required
- Reliable system requiring minimal maintenance
Process Flow Diagram
