Parallel Screw Reactor for Scrap Rubber Thermal Decomposition
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for recycling rubber waste face inefficiencies in extracting liquid fractions, result in low-quality carbon black due to oil adsorption, and high energy intensity, leading to incomplete product recovery and increased pollutant emissions.
Innovation Solution
A reactor design with two equal sections connected in parallel, incorporating screws with heating tubes and a cylindrical combustion chamber for efficient thermal decomposition, along with a centrifugal separator and perforated pipes for improved heat management and product separation, reduces heat losses and enhances the quality of products.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a circulating heat transfer medium is used for thermal decomposition, then the rubber waste can be effectively heated and decomposed, but the energy intensity increases due to the need for continuous heating and separation of the heat transfer medium from hydrocarbon vapors
Solution Approach 1:
The invention extracts and removes the heat transfer medium from the system by directly injecting hydrocarbon vapors into the reactor chamber. This eliminates the need for continuous circulation, heating, and separation of the heat transfer medium, thereby reducing energy intensity while maintaining effective thermal decomposition of rubber waste through direct vapor-phase heating.
Solution Approach 2:
The invention uses hydrocarbon vapors as an intermediary heating medium instead of a separate circulating heat transfer medium. The vapors are generated from the rubber waste itself or external sources and directly introduced into the reactor, serving as both the heating agent and the reaction medium, thus eliminating the need for separate heat transfer fluid circulation and separation systems.
2Loss of substance
If carbon black is blown with air to remove adsorbed oil, then the oil content is reduced, but the surface of the carbon black oxidizes and the quality deteriorates
Solution Approach 1:
The invention changes the chemical environment parameters by replacing air (oxidizing atmosphere) with inert or reducing gases during the carbon black processing stage. This parameter change allows for effective oil removal through condensation and physical separation without causing oxidative damage to the carbon black surface, thereby maintaining high product quality while achieving the desired oil content reduction.
3Quantity of substance
If the liquid fraction is extracted from the gas stream, then high-quality liquid products can be recovered, but part of the liquid products are lost due to incomplete extraction and combustion of uncondensed vapors
Solution Approach 1:
The invention applies preliminary condensation of hydrocarbon vapors before they enter the combustion chamber. By using cooling surfaces and condensers positioned upstream, the liquid fraction is extracted and collected in advance, preventing the loss of uncondensed vapors that would otherwise be burned in the combustion chamber. This preliminary action ensures maximum recovery of high-quality liquid products.
Solution Approach 2:
The invention converts the potentially harmful uncondensed hydrocarbon vapors that would be lost in combustion into a beneficial resource by implementing a multi-stage condensation and recovery system. The vapors are systematically condensed at progressively lower temperatures, with each stage capturing additional liquid fraction, thereby transforming what would be waste into valuable liquid products and reducing overall substance loss.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration increases the quality of rubber waste products, reduces energy consumption, and minimizes pollutant emissions by ensuring complete fuel combustion and efficient separation of hydrocarbons, resulting in higher yields of valuable hydrocarbons and carbon black.
Implementation Method 1
heating tubes arranged along the axis of each screw
Implementation Method 2
cylindrical combustion chamber connected directly to an end face of the respective tube
Implementation Method 3
centrifugal separator (a cyclone filter)
Implementation Method 4
condenser
Implementation Method 5
burner mounted on the face tangential to the side face of the combustor
Implementation Method 6
evaporator and a burner. The burner is mounted on the face tangential to the side face of the combustor
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The device for processing rubber waste comprises a reactor with a screw conveyor and a thermal decomposition unit, a burner, a condenser, a cyclone filter, solids discharge devices, and a steam-gas mixture arranged in a heating chamber. The reactor consists of two parallel sections. The thermal decomposition unit is formed by screws in each reactor section with heating tubes along their axis. Further features include the arrangement of the heating tubes, the removal of the gas mixture, filtration by means of the cyclone filter, and the condenser connections. The invention improves product quality and reduces energy consumption.