Auger-Fed Rotary Reactor to Prevent Pyrolysis Feed Bridging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing rotary kiln reactors face challenges such as lumping of materials, limited residence time manipulation, high energy requirements due to thickness, and inability to handle multiple feedstocks efficiently, leading to inefficiencies and structural issues.
Innovation Solution
A continuous-feed rotary reactor system with an auger-based hopper, internal spiral ribbons, and a carbon removal mechanism with airlock valves, allowing for uniform heat distribution, manipulation of residence time, and efficient handling of various waste types, including MSW derived RDF, plastics, tires, and biomass, while minimizing energy consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional rotary kiln reactors are used, then pyrolysis and torrefaction can be performed, but materials lump together and residence time cannot be manipulated
Solution Approach 1:
The reactor is segmented into multiple zones with different functional characteristics. The feeding screw divides material into controlled portions, spiral ribbons create segmented flow paths, and airlock valves create discrete residence time zones. This segmentation enables independent control of residence time while maintaining pyrolysis efficiency.
Solution Approach 2:
The system incorporates dynamic control elements including variable speed drives for the feeding screw and reactor rotation, adjustable airlock valve timing, and controllable spiral ribbon rotation. These dynamic elements allow real-time manipulation of residence time while maintaining optimal pyrolysis conditions.
2Adaptability or versatility
If reactor thickness is increased to handle multiple feedstocks, then processing capacity improves, but energy requirements increase
Solution Approach 1:
The reactor is designed with universal processing capability through adjustable parameters including variable feeding rates, controllable residence time, and adjustable temperature zones. The spiral ribbons and airlock valves enable the same reactor to handle multiple feedstocks (plastics, tires, biomass, MSW) without increasing thickness or energy consumption.
Solution Approach 2:
The system achieves versatility by changing operational parameters rather than physical dimensions. Variable speed drives adjust feeding rates and residence times, airlock valves control material flow timing, and temperature zones are adjusted for different feedstocks. This parameter-based adaptability eliminates the need for increased reactor thickness.
3Productivity
If conventional feeding systems are used, then waste can be fed into the reactor, but bridging occurs and feeding is inefficient
Solution Approach 1:
The conventional gravity-based feeding system is replaced with a mechanically controlled feeding screw system. The feeding screw provides positive displacement feeding, eliminating bridging by applying mechanical force to individual particles. This mechanical substitution enables continuous, efficient feeding at higher rates without bridging problems.
Solution Approach 2:
The feeding screw performs preliminary action by pre-positioning and pre-moving material into the reactor before the main pyrolysis process begins. This preliminary mechanical handling ensures material is fed continuously and uniformly, preventing bridging and improving feeding efficiency.
4Productivity
If carbon char is not removed, then residence time is extended, but pyrolysis efficiency decreases
Solution Approach 1:
The carbon char removal system extracts and removes carbon char from the pyrolysis process continuously. The auger screw mechanism removes carbon char at controlled intervals, preventing it from accumulating and extending residence time. This extraction maintains optimal pyrolysis efficiency by removing unwanted byproducts.
Solution Approach 2:
The airlock valves act as intermediaries between the reactor and carbon removal system. They control the timing and flow of carbon char removal, mediating between the need for extended residence time and the need to maintain pyrolysis efficiency by removing carbon char.
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
The system achieves efficient pyrolysis and torrefaction of diverse waste materials, optimizing residence time, reducing reactor size and energy needs, and enhancing safety and yield, while allowing operation with multiple feedstocks.
Implementation Method 1
internal circumferentially placed spiral ribbons such that one or more spiral ribbon elements line an inner circumference of the reactor
Implementation Method 2
uniform heat distribution
Implementation Method 3
an auger screw mechanism, and an airtight collection mechanism, which comprises the second combinatorial airlock valve system
Implementation Method 4
a first combinatorial airlock valve system forming an airlock feeding system, in order to bridge transfer of feed
Implementation Method 5
Pyrolysis is a thermochemical decomposition of organic material at elevated temperatures in the absence of oxygen (or any halogen)
Implementation Method 6
configured to receive feed from said feeding screw in order mix said feed with a catalyst in order to output at least hydrocarbon gas and at least carbon char
Data Source
AI summary
A continuous-feed rotary reactor system, for pyrolysis and torrefaction, said reactor comprising: an auger-based hopper system, to resolve bridging of waste during feeding, said hopper system comprising an input hopper (H1, H2), being a two-step hopper (H1, H2), for receiving input feed; a first combinatorial airlock valve system (AV1, AV2) forming an airlock feeding system, to bridge transfer of feed, a reactor (R), containing a carbon removal mechanism (CRM) with a second combinatorial airlock valve system (AV3, AV4), said carbon removal mechanism comprising at least a carbon removal screw configured to receive said carbon char, to process said carbon char, and to output biochar, alternative charcoal, feedstock for bitumen modifier, said carbon removal mechanism (CRM) comprising an auger screw mechanism, and an airtight collection mechanism, which comprises the second combinatorial airlock valve system (AV3, AV4), to manipulate residence of time of said carbon char in said reactor.