Industrial Chimney Lining with Inclined Joints
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Solution Overview
Problem
Industrial chimneys with wet stack operations face issues of liquid re-entrainment due to gas velocity, particularly at surface discontinuities like weld seams and joints in internal lining systems, leading to significant liquid discharge and acid-mist fallout.
Innovation Solution
The internal lining system in the industrial chimney features construction elements arranged in a pattern with joints inclined at an angle of at least 5 degrees from horizontal, eliminating horizontal adhesive joints at the flue gas contact surface, which enhances downward liquid flow and increases the critical re-entrainment velocity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If gas velocity is increased to enhance chimney capacity, then productivity is improved, but liquid re-entrainment increases due to gas-shear forces exceeding gravitational and surface tension forces
Solution Approach 1:
The invention changes the geometric parameter of the joints (inclining them at angle α ≥ 5° from horizontal) to modify the flow dynamics. This parameter change allows the chimney to operate at higher gas velocities without liquid re-entrainment, as the inclined joints prevent liquid accumulation and reduce the effectiveness of gas-shear forces in detaching liquid droplets.
2Ease of manufacture
If horizontal joints are used in internal lining system, then ease of manufacture is improved, but liquid discharge increases due to droplet formation at surface discontinuities
Solution Approach 1:
The invention applies asymmetry by inclining the joints at an angle α ≥ 5° from the horizontal position. This asymmetric configuration disrupts the symmetric flow pattern that occurs with horizontal joints, preventing liquid from pooling at joint locations and eliminating the primary sites for droplet formation and subsequent liquid discharge.
3Productivity
If gas velocity is increased above 27.4 m/s, then productivity is improved, but liquid film flow reverses direction and flows toward stack outlet
Solution Approach 1:
The invention modifies the geometric parameter of the joint configuration (inclining joints at angle α ≥ 5°) to change the flow dynamics. This parameter change raises the flow-reversal velocity threshold, allowing the system to operate at higher gas velocities without the liquid film reversing direction and flowing toward the stack outlet.
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 configuration increases the critical re-entrainment velocity, reducing liquid re-entrainment and allowing higher gas velocities without discharge, thereby enhancing safety margins and chimney capacity without risking liquid discharge.
Implementation Method 1
The liquid on the lining surface is produced by deposition and condensation. Its flow in the form of droplets, film or rivulets is governed by gravitational, surface-tension, and gas-shear forces. As the droplets accumulate, they are pulled downward by gravity
Implementation Method 2
The liquid on the lining surface is produced by deposition and condensation. Its flow in the form of droplets, film or rivulets is governed by gravitational, surface-tension, and gas-shear forces. The gas drags the liquid in the same direction as the flow direction of the gas
Implementation Method 3
The liquid on the lining surface is produced by deposition and condensation. Its flow in the form of droplets, film or rivulets is governed by gravitational, surface-tension, and gas-shear forces
Implementation Method 4
The liquid on the lining surface is produced by deposition and condensation
Implementation Method 5
The liquid on the lining surface is produced by deposition and condensation
Data Source
AI summary
An industrial chimney for wet stack operation is provided with an internal lining system attached to the inner surface of the chimney. The internal lining system comprises construction elements, that are arranged in a pattern, such that the joints between the construction elements in the pattern at the flue gas side of the internal lining system are inclined at an angle α of at least 5 degrees from horizontal.