Indirect Thermal Dryer Using Grease Waste Heat for Bio-Waste
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Solution Overview
Problem
Conventional thermal drying methods often introduce excessive pollutants into the environment due to the use of fuels like coal and oil, and the drying process can contaminate products, leading to a need for environmentally cleaner alternatives.
Innovation Solution
The use of heat generated by burning grease-related waste to thermally dry bio-waste, converting it into natural fertilizer, while processing byproducts like exhaust and ash before release, utilizing an indirect dryer with an adjustable feed rate and heat circulation system to achieve high solid content in the dried bio-waste.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If conventional fuels like coal and oil are used for thermal drying, then sufficient heat energy is provided, but excessive pollutants are introduced into the environment
Solution Approach 1:
The patent converts harmful waste materials (grease-related waste and bio-waste) into beneficial heat energy and fertilizer products. The grease-related waste is burned in a furnace to generate heat, while bio-waste is thermally dried to produce natural fertilizer, thereby eliminating pollutants and creating valuable resources from what would otherwise be harmful substances
Solution Approach 2:
The patent changes the parameters of the drying process by using indirect heating through a heat exchanger, controlling temperature ranges (200-500°C in furnace, 80-150°C in dryer), and adjusting feed rates to achieve high solid content (90-100%) in the dried product, thereby improving both energy efficiency and environmental performance
2Productivity
If hot air is passed over work product for drying, then drying efficiency is improved, but contaminants are picked up from the work product and introduced into the environment
Solution Approach 1:
The patent introduces a heat exchanger as an intermediary between the furnace and the dryer. The heat exchanger transfers thermal energy from the furnace to the drying chamber without direct contact between the hot combustion gases and the bio-waste, thereby maintaining drying efficiency while preventing contamination of the environment with contaminants from the work product
Solution Approach 2:
The drying system is segmented into separate functional zones: a combustion chamber for burning grease waste, a heat exchanger for heat transfer, and a drying chamber for processing bio-waste. This segmentation allows independent optimization of each zone, enabling efficient drying while isolating contaminants to the combustion chamber where they can be managed
3Productivity
If feed rate is increased to improve productivity, then more bio-waste can be processed, but drying quality and solid content may be compromised
Solution Approach 1:
The patent implements a feedback control system where the feed rate of bio-waste is adjusted based on monitoring of the dried product's solid content. The controller receives data on moisture content and adjusts the feed rate accordingly to maintain the target solid content range of 90-100%, thereby simultaneously achieving high productivity and consistent product quality
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 approach reduces environmental impact by utilizing waste heat for drying bio-waste into high-solid-content fertilizer, minimizing pollutant release and utilizing waste products, creating an environmentally friendly thermal drying system.
Implementation Method 1
burning the grease-related waste in a furnace to generate heat energy
Implementation Method 2
heating a first portion of an oil-circulating conduit using the heated air to heat oil contained within the oil-circulating conduit, where the first portion is outside the indirect dryer and a second portion of the oil-circulating conduit is located within the indirect dryer
Implementation Method 3
indirectly cooling the dried bio-waste exiting the indirect dryer using a cool-water conduit loop coupled to the cooling conveyor
Data Source
AI summary
The present disclosure relates to environmentally-clean thermal drying systems and methods. In accordance with one aspect, a method for thermal drying includes receiving a grease-related waste, burning the grease-related waste in a furnace to generate heat energy, receiving a bio-waste in an indirect dryer at an adjustable feed rate, drying the bio-waste in the indirect dryer using at least some of the heat energy, and metering the bio-waste into the indirect dryer at the adjustable feed rate. The adjustable feed rate is adjusted based on a percentage of solids of the bio-waste before entering the indirect dryer and a temperature within the indirect dryer, where the indirect dryer and the adjustable feed rate are coordinated to achieve a predetermined percentage of solids in a dried bio-waste exiting the indirect dryer.