Ash Flowability Additive for Incinerator Flue Gas
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Solution Overview
Problem
Ash collected from incinerators tends to form bridges, reducing its flowability and making it difficult to transport, leading to inefficiencies in ash removal and increased time for loading trucks due to the limited ability of ash to pass through valves and augers, and higher emissions of uncollected ash into the atmosphere.
Innovation Solution
Introducing a powdery additive material comprising clay and calcium carbonate, characterized by complete decomposition at 875°C, into the flue gas upstream of the ash separation device, which improves the flowability of the ash and reduces atmospheric emissions by enhancing the capture of ash particles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a device for capturing ash from flue gas is used, then ash emissions into the atmosphere are reduced, but the collected ash forms bridges and its flowability deteriorates
Solution Approach 1:
A powdery additive material comprising clay and calcium carbonate is introduced as an intermediary substance into the flue gas stream upstream of the ash separation device. This additive material acts as a mediator that modifies the properties of the ash particles, preventing bridge formation and improving flowability while maintaining effective ash capture by the separation device.
Solution Approach 2:
The chemical composition and physical properties of the ash particles are changed by introducing the powdery additive material. The additive material alters the surface characteristics and rheological properties of the ash, transforming it from a bridge-forming material to one with improved flowability, without compromising the ash capture efficiency.
2Object-affected harmful factors
If ash is collected from the incinerator, then emissions are reduced, but the ash adheres to inner surfaces and flowability is reduced
Solution Approach 1:
The powdery additive material serves as an intermediary that prevents ash particles from adhering to the inner surfaces of the incinerator and improves their flow characteristics. This reduces the time required for ash removal and loading operations while maintaining effective ash capture.
Solution Approach 2:
The additive material is introduced upstream of the ash separation device, performing preliminary action on the ash particles before they are collected. This preliminary modification of ash properties prevents subsequent handling problems such as adhesion to surfaces and bridge formation, thereby reducing loading time.
3Productivity
If a valve or auger is used to remove ash, then ash can be transported, but the ash may not pass the valve or enter the auger easily due to bridge formation
Solution Approach 1:
The physical and chemical parameters of the ash are changed by the additive material, specifically modifying its flowability and anti-bridge formation properties. This enables the ash to pass smoothly through valves and enter augers without obstruction, improving both transportability and removal efficiency.
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 additive significantly improves the flowability of collected ash, reducing the time required for loading trucks and minimizing ash emissions into the atmosphere by ensuring better capture and transportability of the ash, while maintaining the balance of the incineration process.
Implementation Method 1
calcium carbonate in a form that when characterized by means of Thermogravimetric_analysis under a nitrogen atmosphere with a rate of increase in temperature of 10°C per minute has decomposed completely when a temperature of 875°C has been reached
Implementation Method 2
introducing a powdery additive material comprising i) clay and ii) calcium carbonate using an injection port transverse to the flow of flue gas comprising ash into the flue gas comprising ash
Data Source
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AI summary
A method of operating an incinerator (100) for solid fuel, said incinerator (100) comprising a device (160) for separating ash from flue gas, which method comprises the step of collecting ash deposits originating from the flue gas comprising ash from the incinerator (100) resulting in collected ash; To improve the flowability of the ash collected, the method comprises the step of introducing a powdery additive material comprising i) clay and ii) calcium carbonate into the flue gas comprising ash wherein the flue gas comprising ash has at the location where the additive material is introduced a temperature of at least 700˚C, wherein the additive is introduced with a rate R of at least 0.1 times the mass of ash in the stream of flue gas comprising ash.