Therma-Flite Holo-Scru® thermal desorption systems are turn-key, and include all necessary components to:
• Hold and meter feed stock into the desorption chamber
• Provide an airlock to the inlet and discharge of the unit
• Cool the material exiting the desorption chamber
• Condense volatiles for collection
The feed system may be customized, but the standard system includes a feed screw with loading trough, or for applications when feed storage is required, a feed hopper with integrated live bottom. For low viscosity sludges, such as drill cuttings containing diesel and water, a positive displacement pump is used to feed the unit. Feed stock is discharged from the feed screw into a double knife-gate airlock. The airlock cycles to allow feed to enter the airlock chamber while maintaining a seal to the desorption chamber. For added safety, the airlock includes optional fittings for a nitrogen or CO2 purge which can be used to insure any air remaining in the airlock is displaced prior to the airlock cycling, and discharging the feedstock into the desorption chamber.
The heart of the system, the desorption unit, includes intermeshed Holo-Scru® rotors. In this chamber, feed stock is heated under a slight negative pressure in a sealed, anaerobic environment; heating is indirect. Thermal fluid is circulated throughout the Holo-Scru® rotors and outer jacket of the desorption chamber. The proprietary Holo-Scru® dual rotor design is self-clearing and feed stock which might otherwise bake on to the rotors, is easily removed. Different mixing programs may be set in the Programmable Logic Controller (PLC) which will increase the heat transfer into the feed stock.
A variety of heat transfer fluids may be used to heat product up to 850-degrees Fahrenheit. A second stage system can be incorporate to heat the product to above 1200-degrees Fahrenheit. Most feed stocks may be de-volatilized to less than .05% remaining hydrocarbons. As the heated solids exit the desorption chamber, they pass through a second airlock and into a cooling screw conveyor. In the cooling screw, solids are indirectly cooled by circulating water through the jacketed wall of the screw. The temperature is further reduced by direct-contact quench cooling via atomizing sprays along the top of the cooling screw housing. The vapors exit the unit into a Venturi-effect, multi-stage condenser. Cooled and filtered condensate is used as the condensing fluid. The Venturi-effect condenser is highly-efficient with less than .01% hydrocarbons remaining in the non-condensable stream. The non-condensable stream is released through a duct to the air intake on the diesel generator providing the unit’s electrical power.
• Maximum product temperature: 900-degrees Fahrenheit
• Maximum operating pressure: 350 psi
• Maximum operating vacuum: 50 millitorr
Single-stage desorption unit