Sealless Axial Pump Cover Plate Support Under High Pressure
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Solution Overview
Problem
The cover plates of hermetically sealed rotor and stator housings in axial direct drive integrated motor pumps and turbines are prone to deformation and potential breach under high-pressure process fluids, particularly when exposed to cryogenic liquids, due to varying air gaps and unequal thermal expansion.
Innovation Solution
The housing is filled with barrier material through ports in the rear surface after applying the cover plate, ensuring direct contact without gaps, using anti-bonding layers and matched thermal expansion coefficients to prevent deformation, and sealed with threaded or laser-welded plugs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the housing is filled with barrier material leaving an air gap between the barrier material and cover plate, then the barrier material and housing can expand and contract unequally with temperature without generating undue stress, but the cover plate may be deformed and deflected inward under high-pressure process fluid
Solution Approach 1:
The patent changes the physical state parameter of the barrier material from liquid (resin) to solid (foam) through expansion. This transformation allows the material to fill the housing completely and eliminate air gaps, converting the cover plate from a deformed state under pressure to a supported state where the expanded foam provides uniform backing resistance.
Solution Approach 2:
The patent applies local quality by creating uniform distribution of the expanded foam barrier material throughout the housing interior. The foam expands to fill all void spaces and provides localized support at every point behind the cover plate, preventing localized deformation while maintaining overall structural integrity.
2Adaptability or versatility
If the housing is filled with barrier material leaving an air gap, then thermal expansion is accommodated, but the hermetic seal may be breached due to cover plate deformation
Solution Approach 1:
The patent changes the physical state parameter of the barrier material from liquid (resin) to solid (foam) through expansion. This transformation allows the material to fill the housing completely and eliminate air gaps, converting the cover plate from a deformed state under pressure to a supported state where the expanded foam provides uniform backing resistance.
Solution Approach 2:
The patent applies beforehand cushioning by pre-filling the housing with barrier material that is then expanded to fill all void spaces before the cover plate is subjected to high-pressure conditions. The expanded foam acts as a pre-positioned cushion that supports the cover plate in advance, preventing deformation and maintaining hermetic seal integrity under subsequent pressure loads.
3Adaptability or versatility
If cryogenic process liquid is used, then the application is suitable for low-temperature processes, but the cover plate material becomes more brittle and prone to cracking
Solution Approach 1:
The patent applies beforehand cushioning by pre-filling the housing with barrier material that is then expanded to fill all void spaces before the cover plate is subjected to high-pressure conditions. The expanded foam acts as a pre-positioned cushion that supports the cover plate in advance, preventing deformation and maintaining hermetic seal integrity under subsequent pressure loads.
Solution Approach 2:
The patent applies composite materials by combining the metallic cover plate with the polymeric foam barrier material. The foam material provides thermal insulation and mechanical support to the cover plate, creating a composite structure that mitigates the brittleness of the metal at cryogenic temperatures while maintaining the functional requirements of the housing.
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
Prevents cover plate deformation and maintains a hermetic seal under high-pressure conditions, enhancing the integrity of the module against fluid ingress and thermal stress.
Implementation Method 1
The housing is filled with barrier material through ports in the rear surface after applying the cover plate, ensuring direct contact without gaps
Implementation Method 2
unequal thermal expansion
Implementation Method 3
sealed with threaded or laser-welded plugs
Data Source
AI summary
An axial direct drive integral motor pump (IMP) or integral motor turbine (IMT) includes a stator or impeller housing hermetically sealed in front by a cover plate. At least one port in a housing rear face enables a barrier material, such as a resin, to be injected into the housing after attachment of the cover plate, so that the barrier material abuts the cover plate with substantially no gap therebetween. The barrier plate is thereby protected from undue deformation and damage by a pressurized process fluid. The barrier material can be injected through one or more fill ports by vacuum impregnation, and/or displaced air can escape through one or more drain ports. The ports can be sealed by plugs. The ports and plugs can be threaded and/or tapered. The coefficient of thermal expansion (CTE) of the barrier material can be substantially equal to a CTE of the first housing.