70' Indirect Fire Thermal Desorption System for Tire Pyrolysis -
The 70' Indirect Thermal Distortion Unit was purpose build for tire pyrolysis and is capable of processing up to 80 ton of tires per day. The system distills the tires in an oxygen deficient environment where tire chips are heated without burning to extract high quality oil, gas, carbon and steel.
A 20 lb tire yields approximately 5 to 9 lbs of carbon, 1.5 to 2.5 gallons of fuel oil, more than 50,000 BTUs of gas and around 2 to 3 lbs of scrap steel. Amounts recovered depend on the type of tire and operating conditions.
Process Description
Initially material is prepared in material preparation unit where lime and oil are added to tire chips. Material preparation is batch operated process. The material is placed in a live bottom feeder by a chain conveyor. The live bottom feeder measures the quantity of material that is fed in to a feed transfer conveyor. The feed transfer conveyor is an inclined tubular screw conveyor that transfers the material from the live bottom feeder to the feed injection conveyor. The feed injection conveyor is a special tubular screw conveyor with a pair of external bearings and a cantilever drive shaft. It is designed so that the conveyed material forms a seal to keep air out of the process. The feed injection conveyor feeds the material into the indirect fired rotary kiln.
The kiln is an externally heated rotating CORTEN steel cylinder. Hoods are mounted at each end to seal out air and to attach the material feed and removal systems. The solid material is conveyed through the kiln by its rotation and slope. The kiln shell is heated by the hot gases passing over its outside. The hot metal of the kiln shell then heats the solids as they contact it. Special seals on the discharge hood and feed injection conveyor prevent air from entering the kiln. By eliminating oxygen inside the kiln, the reaction is limited to the vaporization of the water and hydrocarbons. The gases vaporized in the kiln are sent to the direct contact quench/scrubber.
The quench scrubber cools, condenses and cleans the gases. The gases that condense below operating temperature of the quench scrubber and the particulate are captured in the scrubbing media (oil). Oil is also recovered and mixed with the scrubbing oil. The recovered oil in the scrubbers is cleaned by filters to remove suspended solids and increase oil quality. The recovered oil is then transferred to storage tanks, to be supplied by client.
The remains are processed through a mist eliminator and the clean gases are collected by a gas compressor (3 stage compressor can be added to process which will separate the gasses further for storage) and can be used as a fuel to heat the kiln and/or stored for processing.
A process induced draft fan draws the products of combustion from the kiln combustion chamber through the kiln plenum. This heats the kiln and its contents and cools the gases. The cooled combustion gases are then sent to the atmosphere through the induced draft fan.
A water cooled screw conveyor collects solids as they are discharged from the kiln. It is designed so that the conveyed solids form a seal to prevent air from entering the process. The steel is removed from the carbon by a magnetic separator. The carbon is conveyed by a bucket elevator to a baghouse where the carbon can be bagged in 1 ton mega bags.