Expansion Joint Sealing Ring for Vertical Channel Wear
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Solution Overview
Problem
Existing high-temperature expansion joints in circulating fluidized bed reactors face issues with thermal insulation degradation, particulate material packing, and abrasive wear due to differential thermal expansions and particle flow, which lead to joint failure and maintenance challenges.
Innovation Solution
A high-temperature expansion joint design featuring a sealing ring with ceramic blocks on an outer circumference, positioned above the lower edge of the upper channel portion, allowing relative axial and lateral movements, and a flexible element connection on the outer side, with a pressurized insulating space to prevent particle ingress and wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If fabric bellows are used to connect upstream and downstream channel portions, then flexibility and sealing capability are improved, but temperature resistance deteriorates because fabric bellows cannot withstand high temperatures
Solution Approach 1:
The expansion joint is divided into multiple functional segments: a telescopic structure for movement, a ceramic seal ring for high-temperature sealing, and thermal insulation layers for heat protection. This segmentation allows each component to perform its specific function optimally - the fabric bellows provides flexibility while the ceramic and insulation components handle the high temperature environment
Solution Approach 2:
Thermal insulation material is introduced as an intermediary between the fabric bellows and the high-temperature particle flow. This intermediary protects the temperature-sensitive fabric bellows from direct exposure to high temperatures, enabling the flexible sealing solution to function in high-temperature environments
2Temperature
If thermal insulation is placed between channel portions, then heat flow to fabric belt is reduced, but insulation gets irreversibly tightened in repeated compressions allowing particles to pack and damage the joint
Solution Approach 1:
The sealing function is extracted from the thermal insulation system and assigned to a separate ceramic seal ring. This allows the thermal insulation to focus solely on heat protection without the added stress of maintaining sealing under compression, while the ceramic seal ring provides reliable particle-tight sealing that is not affected by compression
3Ease of operation
If intermediate elements slide on inner circumference of downstream channel portion, then axial movement is enabled, but sliding surface becomes accessible to abrasive particles causing wear
Solution Approach 1:
The design accepts that particles will flow in the channel but positions the sliding surface of intermediate elements in a location where they are protected from direct particle contact. The channel portions and seal ring act as protective barriers, converting the harmful particle flow into a controlled environment that allows movement without excessive wear
4Object-affected harmful factors
If sealing ring is positioned on upper plane above lower edge, then sealing blocks are protected from abrasive forces, but maintenance complexity increases
Solution Approach 1:
The sealing ring is positioned in a higher vertical dimension (on the upper plane) rather than at the lower edge where particles directly impact. This dimensional change protects the sealing blocks from abrasive forces while the telescopic structure maintains accessibility for maintenance through the available space
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 solution effectively protects the sealing ring from abrasive forces, minimizes particulate material entry, and allows for easy maintenance by keeping the sealing components outside the channel, reducing wear and the need for frequent replacements.
Implementation Method 1
The sealing ring is arranged to seal a space between the upper channel portion and the lower channel portion
Implementation Method 2
differential thermal expansions between components of a reactor have to be taken into account in order to avoid damages which may occur when the temperature of the reactor is changed
Implementation Method 3
with a pressurized insulating space to prevent particle ingress and wear
Data Source
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AI summary
An expansion joint and a method of forming an expansion joint in a vertical channel suitable for conducting hot particles, the expansion joint comprising an upper channel portion and a lower channel portion sealingly connected by a flexible element connected on the outer side of the vertical channel, wherein the upper channel portion comprises a lower end portion with a lower edge and the lower channel portion comprises an upper end portion with a horizontally extending upper plane,wherein in a predetermined vertical level range the upper end portion telescopically overlaps the lower end portion in a spaced relationship to permit relative axial and lateral movements of the upper and lower channel portions, whereby the upper plane is at a higher level than the lower edge, and on the upper plane is arranged a sealing ring comprising mutually connected sealing blocks positioned on an outer circumference of the lower end portion.