Low-Friction Suction Liner for Centrifugal Pump Nose Gap Sealing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Centrifugal pumps processing slurries face issues with fluid recirculation through the nose gap, leading to reduced performance and increased wear of components, particularly when handling abrasive slurries, and manual adjustment of liners is laborious and time-consuming.
Innovation Solution
A suction liner with a flange portion made of low friction polymer that abuts against the impeller to seal the axial gap, preventing recirculation and wear, featuring fastening seats for easy adjustment and potentially a metal substrate with a low friction polymer coating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the axial distance between the liner and the impeller is minimized to prevent recirculation, then pump performance is improved, but the risk of liner and impeller contact increases causing wear and damage
Solution Approach 1:
The flange portion is constructed as a composite structure with a metal substrate providing mechanical strength and a low friction polymer coating (such as PTFE, UHMWPE, or polyamide) providing wear-resistant, low-friction contact surfaces. This composite design enables the flange to contact the impeller continuously without damage, as the polymer layer absorbs wear and reduces friction while the metal substrate maintains structural integrity.
Solution Approach 2:
The invention changes the friction parameter at the contact interface by applying a low friction polymer coating to the flange portion. This material has a significantly lower coefficient of friction compared to traditional metal-on-metal or metal-on-rubber contacts, allowing the flange to slide against the impeller with minimal resistance and heat generation, thereby preventing wear and damage during continuous contact operation.
2Productivity
If manual adjustment of the liner is performed to minimize the nose gap, then recirculation is reduced, but labor time and operator skill requirements increase
Solution Approach 1:
The flange portion with its low friction polymer coating enables the liner to self-adjust and maintain optimal positioning through continuous contact with the impeller. The low friction characteristic allows the liner to slide into its correct position and remain stable during operation without requiring precise manual adjustment, thereby reducing installation time and eliminating the need for experienced operators to listen for specific sounds to determine proper positioning.
3Reliability
If traditional liner materials (high chrome alloy or natural rubber) are used, then wear protection is provided, but heat cracking or tearing occurs due to friction and contact with the impeller
Solution Approach 1:
The flange portion is constructed as a composite structure with a metal substrate providing mechanical strength and a low friction polymer coating (such as PTFE, UHMWPE, or polyamide) providing wear-resistant, low-friction contact surfaces. This composite design enables the flange to contact the impeller continuously without damage, as the polymer layer absorbs wear and reduces friction while the metal substrate maintains structural integrity.
Solution Approach 2:
The invention changes the friction parameter at the contact interface by applying a low friction polymer coating to the flange portion. This material has a significantly lower coefficient of friction compared to traditional metal-on-metal or metal-on-rubber contacts, allowing the flange to slide against the impeller with minimal resistance and heat generation, thereby preventing wear and damage during continuous contact operation.
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 suction liner effectively seals the nose gap, reducing recirculation and wear, enhancing durability and ease of installation, especially for abrasive slurries, with low friction polymer materials providing mechanical strength and heat resistance.
Implementation Method 1
at least the front end surface of the flange portion is made of a low friction polymer
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
The disclosure relates to a suction liner (8) for a centrifugal pump (1) for processing slurries, the centrifugal pump comprising an impeller (3) housed in a casing (2), the suction liner (8) comprising a cylindrical portion (10) arrangeable in the casing (2) of the centrifugal pump (1), and a flange portion (11) which protrudes outwards in a radial direction from the cylindrical portion (10). The flange portion (11) is arrangeable such that, when mounted in a centrifugal pump (1), at least a portion of a front end surface (12) of the flange portion (11) of the suction liner (8) abuts against at least a portion of a front end (14) of the impeller (3), such to seal an axial gap between the suction liner (8) and the impeller (3), and at least the front end surface (12) of the flange portion (11) is made of a low friction polymer. The disclosure further relates to a centrifugal pump (1) for processing slurries, the centrifugal pump comprising such a suction liner (8). The suction liner (8) and the centrifugal pump (1) allow preventing recirculation of pumping liquid in a centrifugal pump and, thereby, reducing wear.