Heat Exchanger Cleaning Nozzle Using Liquid-Driven Pivoting

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Solution Overview

Problem

Existing laundry treatment apparatuses, such as dryers with heat exchangers, face inefficiencies in removing accumulated fluff, which reduces heat exchanger performance and requires costly motor-driven mechanisms for cleaning.

Innovation Solution

A cost-efficient laundry treatment apparatus with a nozzle element that uses liquid pressure and flow to pivot and sweep over the heat exchanger, eliminating the need for a driving motor, utilizing a flexible coupling element and lever mechanisms actuated by liquid pressure and flow to direct a spray that washes off fluff, and optionally using condensate for cleaning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a motor-driven mechanism is used to pivot the nozzle element for cleaning the heat exchanger, then the cleaning effectiveness is improved, but the device complexity and cost increase

Engineering Contradiction:
Improvecleaning effectivenessVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The nozzle element pivots automatically using the kinetic energy of the liquid spray itself. The liquid flow through the nozzle creates a reaction force that causes the nozzle to rotate about its pivot axis, eliminating the need for external motors or actuators. The system uses its own operating fluid to perform the cleaning motion.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The invention utilizes hydraulic principles where the liquid pressure and flow rate through the nozzle element generate the torque needed for pivoting. The flexible coupling element transmits the liquid pressure to create a torque that acts on the nozzle element, causing it to sweep across the heat exchanger surface.

Inventive Principle:
Principle #29Pneumatics and hydraulics

2Area of stationary object

If a motor-driven mechanism is used to move the nozzle element along the heat exchanger, then the cleaning coverage is improved, but the cost and energy consumption increase

Engineering Contradiction:
Improvecleaning coverageVSAvoidenergy consumption
Core Design Contradiction:
Area of stationary objectVSUse of energy by stationary object

Solution Approach 1:

The nozzle element self-propels along the heat exchanger surface using the momentum of the liquid spray. As liquid flows through the nozzle, the reaction force and pressure differential cause the nozzle to move automatically, covering the required area without external power sources.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The nozzle element performs periodic sweeping motions across the heat exchanger surface. The liquid flow rate is modulated to create oscillating motion patterns that ensure comprehensive coverage of the heat exchanger area through repeated scanning movements.

Inventive Principle:
Principle #19Periodic action

3Manufacturing precision

If the nozzle element is made rigid and fixed, then the manufacturing precision is improved, but the adaptability to different cleaning angles is reduced

Engineering Contradiction:
Improvenozzle alignmentVSAvoidspray direction adjustment
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The nozzle element is designed with a pivot joint that allows it to rotate dynamically during operation. While the nozzle body itself maintains precise manufacturing tolerances for the spray outlets, the entire assembly can adapt its orientation in response to liquid pressure changes, enabling variable cleaning angles.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the operational parameters of the nozzle by varying the liquid flow rate and pressure. These parameter changes cause the nozzle element to pivot to different angles, providing adaptability without compromising the precise manufacturing of the nozzle geometry itself.

Inventive Principle:
Principle #35Parameter changes

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

Effectively removes fluff from heat exchanger surfaces without the need for a motor-driven nozzle, reducing costs and improving heat exchanger efficiency by using liquid pressure and flow to pivot and sweep the nozzle element, ensuring thorough cleaning with adjustable spray direction and angle.

Implementation Method 1

the flexible element is adapted to expand or to contract in dependency of the liquid pressure inside the flexible element and actuates thereby the lever element

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

the liquid is deflected in the nozzle element and the deflection of the liquid flow causes a momentum to an inner wall of the nozzle element. This momentum in connection with a nozzle element arrangement where the momentum acts at a position and direction that provides a lever torque momentum on the nozzle element with respect to the pivot axis results in a torque or swing movement

Methodology Applied
Scientific EffectMomentum: Conservation of Momentum

Implementation Method 3

A nozzle element is provided which is adapted to spray liquid to the heat exchanger in at least one liquid spray for cleaning the heat exchanger

Methodology Applied
Scientific EffectFluid spray: Fluid Spray

Data Source

PatentEP2628846B1Laundry treatment apparatus with heat exchanger cleaning
Publication Date: 2018.11.14 ELECTROLUX HOME PROD CORP NV
  • EP2628846B1 patent drawingFigure 1
  • EP2628846B1 patent drawingFigure 2
  • EP2628846B1 patent drawingFigure 3~4

AI summary

The invention relates to a laundry treatment apparatus (2), in particular dryer or washing machine having a dryer function, comprising a control unit, a laundry treatment chamber for treating laundry using process air, a process air loop for circulating the process air, a heat exchanger (10) arranged in the process air loop for cooling the process air, a nozzle element (42) comprising at least one outlet (44) each for providing a liquid spray in operation, wherein the nozzle element (42) is connected to a liquid supply source and is adapted to spray liquid to the heat exchanger (10) in at least one liquid spray for cleaning the heat exchanger (10), a flexible coupling element (52) arranged between the nozzle element (42) and the liquid supply source, and a pivot element (56) having a pivot axis (D) for pivotally supporting the nozzle element (42) such that at least one liquid spray can sweep over the heat exchanger (10). The arrangement of the pivot axis (10) and the flexible coupling element (56) with respect to the nozzle element (42) is configured such that the angular orientation of the nozzle element (42) is varied in dependency of the liquid pressure or the liquid flow, or the arrangement of the pivot axis (D) and the outflow or liquid spray direction of the at least one outlet opening (44) with respect to the nozzle element (42) is configured such that the angular orientation of the nozzle element (42) is varied in dependency of the liquid pressure or liquid flow out of the outlet (44).