Centrifugal Separator Ejector Nozzle for Gas Cleaning

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Solution Overview

Problem

Centrifugal separators face challenges in separating small and low-density solid or liquid particles from gases, as these particles tend to adhere to and coat the rotating member and separation discs, leading to inefficient separation and transport issues, especially when dealing with water-based cutting liquids that can evaporate and become viscous, complicating the separation process.

Innovation Solution

The use of an ejector nozzle connected to a pressurized gas conduit to create an aerosol, which is then injected into the gas stream, increasing the size and weight of particles through humidification, preventing them from adhering to surfaces and facilitating their separation by reducing the risk of burning or sticking, and allowing for the use of any local liquid source without requiring pressurized water.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If pressurized water is used to humidify particles, then separation efficiency is improved, but availability is reduced due to lack of pressurized water supply

Engineering Contradiction:
Improveseparation efficiencyVSAvoidavailability of liquid source
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent uses an ejector nozzle that operates on pneumatic principles to generate a water mist. Pressurized gas (air) is supplied to the ejector nozzle, which creates a vacuum that draws water from a reservoir and atomizes it into fine mist particles. This eliminates the need for pressurized water supply systems while achieving the required humidification effect for particle separation.

Inventive Principle:
Principle #29Pneumatics and hydraulics

2Productivity

If cutting liquids are used to improve cutting process, then cutting performance is improved, but separation difficulty increases due to evaporation and viscosity increase

Engineering Contradiction:
Improvecutting performanceVSAvoidseparation difficulty
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The ejector nozzle continuously generates water mist that is introduced into the gas stream before the particles reach the separation discs. This preliminary humidification action prevents the cutting liquid from evaporating and becoming viscous during the separation process, maintaining its fluidity and ease of separation throughout the operation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes the physical state of the cutting liquid by introducing water mist that maintains the liquid's humidity and prevents evaporation. This parameter change (maintaining liquid viscosity through continuous humidification) keeps the cutting liquid in a state that is easy to separate and discharge from the centrifugal separator.

Inventive Principle:
Principle #35Parameter changes

3Quantity of substance

If small particles are present in gas, then contamination level is high, but separation efficiency is reduced due to particle adherence to surfaces

Engineering Contradiction:
Improveparticle concentrationVSAvoidseparation efficiency
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The water mist generated by the ejector nozzle acts as an intermediary substance between the small particles and the separation discs. The mist particles adhere to the small particles in the gas stream, increasing their size and weight, and preventing them from adhering to the separation surfaces. This intermediary action facilitates the separation of fine particles without causing surface contamination.

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 solution effectively prevents particle adherence to surfaces, enhances separation efficiency, and reduces the risk of particles being caught in the centrifugal separator, allowing for easier transport of impurities and maintaining the viscosity of water-based emulsions, thus improving the overall cleaning process.

Implementation Method 1

the supply member is configured to permit supply of a liquid to form of an aerosol to be supplied to the gas to be cleaned

Methodology Applied
Scientific EffectAerosol: Aerosol

Implementation Method 2

the supply member comprises an ejector nozzle connectable to a pressurised gas conduit and comprising a nozzle outlet, and that the nozzle outlet is provided at the outlet end of the supply conduit and arranged to permit ejection of the liquid in the form of said aerosol from the outlet end of the supply conduit by means of pressurised gas supplied to the ejector nozzle

Methodology Applied
Scientific EffectEjector nozzle: Injector

Implementation Method 3

a centrifugal separator for cleaning of gases, such as air, especially contaminated or heavily contaminated air

Methodology Applied
Scientific EffectCentrifugal separation: Centrifugal Separation

Data Source

PatentEP2574389B1A device comprising a centrifugal separator and a method for cleaning of a gas
Publication Date: 2022.09.28 ALFA LAVAL CORP AB
  • EP2574389B1 patent drawingFigure 1
  • EP2574389B1 patent drawingFigure 2

AI summary

A device comprises a centrifugal separator for cleaning of a gas, especially a gas containing impurities in the form of solid and/or liquid particles, comprises a stationary casing enclosing a separation space, an inlet channel, a rotating member in the separation space for separating at least a main part of the impurities from the gas, a gas outlet channel, and an outlet for discharging a separated phase of the gas. A supply member (50) is provided for supplying a liquid, to form of an aerosol, to the gas to be cleaned and which comprises a supply conduit (51) with an outlet end (52), and an ejector nozzle (56) connectable to a pressurised gas conduit (57) and comprising a nozzle outlet (58). The nozzle outlet at the outlet end permits ejection of the aerosol from the outlet end by means of the pressurised gas supplied to the ejector nozzle and the nozzle outlet.