Wet Rotor Pump Pre-Chamber Heat Dissipation and Particle Control

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Solution Overview

Problem

Glandless pumps face challenges in efficiently dissipating heat from the rotor space to the pumped medium while minimizing liquid exchange, which can lead to particle accumulation and limescale precipitation, causing wear and reduced cooling efficiency.

Innovation Solution

A glandless pump design featuring a large antechamber between the rotor space and the pump chamber, separated by a separating element that acts as a heat exchanger and filter, allowing controlled liquid exchange and preventing particle ingress, with the separating element being made of heat-conductive materials or flexible membranes to enhance heat dissipation and prevent particle accumulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If the rotor chamber is sealed off from the pump chamber to prevent particle accumulation, then particle contamination is reduced, but heat dissipation from the rotor chamber is insufficient

Engineering Contradiction:
Improveparticle accumulationVSAvoidheat dissipation
Core Design Contradiction:
Object-affected harmful factorsVSTemperature

Solution Approach 1:

A pre-chamber is introduced as an intermediary space between the rotor chamber and pump chamber. This pre-chamber receives particles from the rotor chamber through first channels and allows them to settle before any potential entry into the pump chamber. Simultaneously, the pre-chamber enables controlled fluid exchange that facilitates heat dissipation from the rotor chamber without direct particle contamination of the pump chamber.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The internal volume is segmented into three distinct chambers: rotor chamber, pre-chamber, and pump chamber, connected by controlled channels. This segmentation allows independent functioning of each chamber - the rotor chamber generates heat and particles, the pre-chamber filters particles and aids heat transfer, and the pump chamber remains protected from particle accumulation while still enabling thermal management.

Inventive Principle:
Principle #1Segmentation

2Temperature

If fluid exchange between rotor chamber and pump chamber is increased to improve cooling, then heat dissipation is enhanced, but particle accumulation and limescale precipitation increase

Engineering Contradiction:
Improvecooling efficiencyVSAvoidparticle accumulation
Core Design Contradiction:
TemperatureVSObject-affected harmful factors

Solution Approach 1:

The pre-chamber serves as a mediator that enables thermal coupling between rotor and pump chambers while filtering particles. Fluid can circulate between chambers through the pre-chamber, allowing heat transfer, but particles are trapped and settled in the pre-chamber before reaching the pump chamber.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The harmful function of particle transport is extracted from the fluid exchange process. By routing fluid through the pre-chamber with settling functionality, particles are separated from the circulating fluid, allowing continued thermal exchange without particle contamination.

Inventive Principle:
Principle #2Taking out (Extraction)

3Ease of manufacture

If plastic components are used in the rotor chamber, then manufacturing is simplified, but heat dissipation is insufficient due to insulating properties

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidheat dissipation
Core Design Contradiction:
Ease of manufactureVSTemperature

Solution Approach 1:

The pre-chamber acts as a thermal mediator that compensates for the insulating properties of plastic components in the rotor chamber. By establishing a controlled fluid circulation path through the pre-chamber, heat is actively transferred from the rotor chamber to the pumped medium, overcoming the thermal insulation effect of plastic materials.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 effectively dissipates heat from the rotor space to the pumped medium, minimizes particle accumulation, and prevents limescale precipitation, ensuring efficient operation and extended pump lifespan by isolating the rotor space from turbulence and particle contamination.

Implementation Method 1

fluid exchange between the fluid in the rotor chamber and the pumped medium, thereby simultaneously achieving heat exchange and thus cooling of the rotor

Methodology Applied
Scientific EffectFluid exchange: Convection

Implementation Method 2

a pre-chamber is located between the impeller and the flange, which is delimited towards the impeller by a separating element and towards the stator by the flange, wherein the pre-chamber is communicatively connected to the rotor chamber via channels

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 3

The fluid in the rotor chamber also lubricates the bearings, which are designed as plain bearings

Methodology Applied
Scientific EffectPlain bearing lubrication: Lubrication

Data Source

PatentEP2604860B1Wet rotor pump with pre-chamber
Publication Date: 2020.02.05 WILO SE
  • EP2604860B1 patent drawingFigure 1
  • EP2604860B1 patent drawingFigure 2
  • EP2604860B1 patent drawingFigure 3

AI summary

The pump (1) has a rotor shaft (5) i.e. hollow shaft, carrying an impeller (7) at an axial end. The impeller is arranged in a pump chamber (15). A gap pipe (2) includes a radially outwardly extending flange (8) at an impeller side end. A bearing support (9) with a sliding bearing (10) for bearing the shaft is arranged between the flange and the shaft. An annular prechamber (11) lies between the impeller and the flange, limited into the impeller by a dimensionally-stable separator (12), and communicatingly connected with a rotor chamber (4) by inner and outer channels (13, 14).