Condenser Dryer Heat Exchanger Flushing With Pressurized Condensate

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Solution Overview

Problem

Condensation dryers with heat exchangers in the process air duct face challenges in effective cleaning due to the accumulation of fluff, which impairs heat exchange efficiency and increases the risk of malfunction, especially in heat pumps where components are permanently connected and difficult to clean.

Innovation Solution

A condensation dryer design incorporating a pressure flushing tank with a compressible medium and a liquid pump to build and maintain pressure, allowing for high-pressure bursts of condensed water to be discharged onto the heat exchanger for cleaning, along with a valve system for controlled pressure release and a movable piston or elastic membrane for compression, enhancing cleaning efficacy with minimal equipment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the heat exchanger is permanently connected (as in heat pumps), then the device structure is compact and reliable, but the heat exchanger becomes difficult to clean and maintain

Engineering Contradiction:
Improveheat exchanger connection stabilityVSAvoidheat exchanger cleaning accessibility
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The heat exchanger is divided into multiple cleaning zones with different fluff accumulation characteristics. The cleaning device includes multiple nozzle groups that can independently target different sections, allowing selective cleaning of heavily contaminated areas while maintaining the permanent connection structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A movable cleaning device with water nozzles is introduced as an intermediary between the permanent heat exchanger structure and the cleaning process. This cleaning device can be moved along the heat exchanger and activated to喷射 cleaning fluid, enabling effective cleaning without disconnecting the permanently connected heat exchanger.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If conventional cleaning methods are used, then the device structure remains simple, but the cleaning effectiveness is insufficient due to fluff accumulation

Engineering Contradiction:
Improvecleaning system structureVSAvoidheat exchange efficiency
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The cleaning device utilizes hydraulic principles by喷射 high-pressure cleaning fluid through nozzles onto the heat exchanger surfaces. This hydraulic action effectively removes accumulated fluff and debris, maintaining heat exchange efficiency without requiring complex mechanical disassembly or manual cleaning procedures.

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

The cleaning system changes the physical parameters of the cleaning fluid by heating it and applying it under pressure. This parameter change enhances the cleaning effectiveness against fluff accumulation, allowing the system to maintain reliability while keeping the overall device structure relatively simple.

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If the heat exchanger is removed for cleaning, then cleaning accessibility is improved, but the device complexity increases and permanent connections (heat pumps) cannot be cleaned

Engineering Contradiction:
Improveheat exchanger cleaning accessibilityVSAvoidcleaning process complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

A movable cleaning device with water nozzles is introduced as an intermediary between the permanent heat exchanger structure and the cleaning process. This cleaning device can be moved along the heat exchanger and activated to喷射 cleaning fluid, enabling effective cleaning without disconnecting the permanently connected heat exchanger.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The cleaning device is designed to be self-contained and movable, allowing it to service different sections of the heat exchanger autonomously. The device can be positioned, activated for cleaning, and moved to the next section without requiring external assistance or system disassembly, simplifying the overall cleaning process.

Inventive Principle:
Principle #25Self-service

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 configuration enables improved cleaning of the heat exchanger with increased pressure, reducing maintenance effort and preventing malfunctions by effectively removing fluff and debris, thus maintaining dryer performance.

Implementation Method 1

a liquid pump and a non-return valve are arranged in the first line in the direction from the condensed water tank to the pressure flushing tank

Methodology Applied
Scientific EffectPump: Pump

Implementation Method 2

the pressure flushing container is partially filled with condensed water and partially with a compressible medium, the compressible medium can be pressurized, and the pressure for compressing the compressible medium is built up by means of the liquid pump

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 3

a valve is arranged in the second line, the pressure flushing container is partially filled with condensed water and partially with a compressible medium

Methodology Applied
Scientific EffectPressure gradient: Pressure Gradient

Implementation Method 4

In this heat exchanger (e.g. air-to-air heat exchanger or heat sink of a heat pump), the moist process air is cooled so that the water contained in the moist process air condenses

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 5

air (so-called process air) is directed by a blower via a heat source into a drum containing moist laundry items

Methodology Applied
Scientific EffectHeating: Heating

Data Source

PatentEP3245326B1Condenser dryer and method for the operation thereof
Publication Date: 2018.10.17 BSH HAUSGERATE GMBH
  • EP3245326B1 patent drawingFigure 1
  • EP3245326B1 patent drawingFigure 2
  • EP3245326B1 patent drawingFigure 3~4

AI summary

The present invention relates to a condenser dryer (1) comprising a drying chamber (2) for objects to be dried, a process air channel (3), in which there are a heat source (4) for heating the process air, a heat exchanger (5) for cooling the process air after passing through the drying chamber (2) and a fan (6) for conveying process air, a pressure rinse container (7), a condensation water container (8), a rinsing device (9) for the heat exchanger (5) and a control device (10), wherein the pressure rinse container (7) is connected to the condensation water container (8) via a first line (11) and to the rinsing device (9) for the heat exchanger (5) via a second line (12), wherein a fluid pump (13) and a check valve (14) are arranged in the first line (11) in the direction from the condensation water container (8) to the pressure rinse container (7), and wherein a valve (15) is arranged in the second line (12), wherein the pressure rinse container (7) is filled partially with condensed water (16) and partially with a compressible medium (17), wherein the compressible medium (17) is present in a space above the condensed water (16) and pressure is applied thereto, and wherein the pressure for compressing the compressible medium (17) is built up by means of the fluid pump (13). The present invention also relates to a method for operating such a condenser dryer.