Modular Flue Gas Heat Exchanger for Rapid Quenching and Dust Control
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Solution Overview
Problem
Current technologies for cooling flue gas in ironwork plants are inefficient in reducing dioxin and furan synthesis, lead to increased maintenance costs, and are not effective in maintaining regulatory emission standards due to abrasive dusts and varying temperatures, which complicates heat recovery and chemical treatment processes.
Innovation Solution
A modular heat exchanger with a support structure featuring inlet and outlet manifolds, superimposed panels forming flow channels, and a cooling fluid circuit that allows for rapid cooling of flue gas from 800-900°C to 200°C with an average quenching speed of 300-400°C/sec, using diathermic oil to recover heat for energy production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the flow speed of the flue gas is reduced to limit dust abrasion on heat exchanger surfaces, then the abrasive effect is reduced, but the separation and depositing of dusts increase which reduces heat exchange capacity
Solution Approach 1:
The heat exchanger is divided into multiple independent channels formed by panels, allowing the system to handle high flow speeds while distributing dust exposure across segmented surfaces. The modular panel structure enables maintenance of high velocities without excessive abrasion on any single component.
Solution Approach 2:
The invention transitions from traditional horizontal tube arrangements to vertical panel structures with channels extending in the vertical dimension. This dimensional change allows gravity to assist in dust separation while maintaining high horizontal flow velocities, resolving the contradiction between speed and dust deposition.
2Temperature
If conventional heat exchangers are used for cooling flue gas, then heat recovery is achieved, but the temperature reduction is not rapid enough leading to dioxin and furan formation in cold sections
Solution Approach 1:
The heat exchanger is positioned and designed to perform preliminary rapid cooling of flue gas before it reaches temperatures where doxin and furan formation occurs. By establishing a steep temperature gradient at the inlet, the system prevents harmful substance formation in advance.
Solution Approach 2:
The invention dramatically changes the cooling rate parameter, achieving temperature reduction from 800-900°C to 200°C in a very short distance. This extreme parameter change in cooling speed prevents the flue gas from lingering in the dangerous temperature range where dioxins and furans form.
3Productivity
If complex heat exchanger structures are used to maximize heat recovery, then heat exchange capacity increases, but maintenance complexity increases requiring plant shutdowns
Solution Approach 1:
The heat exchanger is constructed from modular panels that can be independently accessed and maintained. This segmentation allows maintenance personnel to service individual channels or panels without shutting down the entire plant, combining high heat exchange capacity with ease of repair.
Solution Approach 2:
The panel structure serves multiple functions: heat exchange, structural support, and modular maintenance units. This multi-functionality reduces overall system complexity while maintaining high productivity, as the same components perform multiple roles.
4Speed
If high flow speeds are maintained in the heat exchanger, then rapid cooling is achieved preventing doxin formation, but dust abrasion on surfaces increases
Solution Approach 1:
By orienting channels vertically and using panel structures, the system allows high horizontal flow velocities while using the vertical dimension for dust separation. This dimensional separation enables high speed operation without proportional increase in abrasion damage.
Solution Approach 2:
The segmented panel design distributes abrasion across many small surfaces rather than few large ones, and the modular nature allows replacement of heavily abraded sections without affecting the entire system.
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 heat exchanger effectively reduces flue gas temperature, controls dioxin and furan synthesis, facilitates easy maintenance, and recovers heat for energy production, ensuring compliance with emission standards while maintaining high flow speeds and reducing operational costs.
Implementation Method 1
a heat exchanger for the rapid cooling of flue gas... comprising... circulation ducts of a cooling fluid associated with said panels
Implementation Method 2
recovering the heat subtracted to the flue gas crossing it... recovery of the heat subtracted to said flue gas to produce energy or a warm service fluid, such as steam or hot water
Data Source
AI summary
The present invention refers to a heat exchanger (1) for the rapid cooling of flue gas of ironwork plants, comprising a support structure (2) of at least one module (100) which in turn comprises an inlet manifold (3) of the flue gas and an outlet manifold (4) of the flue gas which are mutually opposed and aligned, a plurality of panels (5) that extend between the inlet manifold (3) and the outlet manifold (4) and which are mutually superimposed at a defined distance, wherein pairs of adjacent panels (5) define flow channels (6) of the flue gas which are closed laterally by shoulders (7) and which have at opposite ends respectively an inlet aperture (8) in communication with the inlet manifold (3) and an outlet aperture (9) in communication with the outlet manifold (4), and circulation ducts (10) of a cooling fluid associated with the panels (5), first selective closing means (14) of the inlet apertures (8) of one or more of said channels (6) and second selective closing means (15) of the outlet apertures (9) of one or more said channels (6), wherein each of said channels (6) is laterally closed by a respective pair of shoulders (7) of which at least one is of the removable type.