Integrated Barrier Fluid Pumping in Mechanical Shaft Seals
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Solution Overview
Problem
Existing pump arrangements for mechanical shaft seals are complex and space-consuming in design, particularly when it comes to efficiently circulating barrier fluid for lubrication and cooling, as seen in double mechanical seals used in demanding operating conditions.
Innovation Solution
A pump arrangement with a housing that includes a force transmission projection and an impeller wheel, configured for direct power transmission with the rotatable shaft, allowing for efficient circulation of barrier fluid within a sealed space, reducing complexity and space requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an external second pump driven by a continuous flexible drive element is used to circulate barrier fluid, then the barrier fluid circulation is ensured, but the device complexity and space requirements increase
Solution Approach 1:
The patent merges the barrier fluid pump with the mechanical seal assembly, integrating the pumping function into the seal housing rather than using a separate external pump. This consolidation reduces device complexity while maintaining reliable barrier fluid circulation for lubrication and cooling of the seal surfaces.
Solution Approach 2:
The patent extracts the pump from its traditional external position and relocates it within the mechanical seal housing. This repositioning eliminates the need for complex external drive mechanisms and flexible drive elements, simplifying the overall system while preserving the essential barrier fluid circulation function.
2Reliability
If a second pump and motor are incorporated into the seal assembly, then barrier fluid circulation is improved, but the space requirements around the pump increase
Solution Approach 1:
The patent implements a nested arrangement where the barrier fluid pump is housed within the mechanical seal housing. The pump components are nested within the existing seal structure, utilizing the available internal space rather than requiring additional external space around the pump.
Solution Approach 2:
By combining the pump housing with the mechanical seal housing, the patent eliminates the need for separate space for the pump assembly. The merged structure allows the pump to operate within the confined space of the seal assembly, reducing overall space requirements while maintaining effective barrier fluid circulation.
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 design enables straightforward and space-saving barrier fluid flow, enhancing the reliability and efficiency of mechanical shaft seals by integrating a compact pumping mechanism that operates within the sealed space, effectively lubricating and cooling seal surfaces.
Implementation Method 1
an impeller wheel (104), which is configured to be in force transmission connection with the rotatable shaft (8), (12) providing power to operate the impeller wheel when in use
Implementation Method 2
the barrier fluid is not only introduced in the cavity between the primary and the secondary seals, but an outlet arrangement has been provided for the barrier fluid, too. Such a liquid circulation is especially needed when the seal surfaces need to be cooled whereby the barrier fluid act as a heat transfer medium.
Implementation Method 3
The use of such liquid is vital for the operation of a double mechanical seal, as it, on the one hand, lubricates and cools the slide surfaces
Data Source
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AI summary
Invention relates to a pump arrangement (100) for pumping barrier liquid in a sealed space (102) of a mechanical shaft seal, comprising a housing (110, 24) assemblable in connection with a rotatable shaft (8) of a device to be sealed by the mechanical shaft seal. The housing (100,24) is provided with a pumping means (104), which is configured to be in force transmission connection with the rotatable shaft (8) for providing power to operate the pumping means (104) when in use.