Dryer Recirculation Duct Filtration for Lint and Condensate Control
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Solution Overview
Problem
Vented dryers face inefficiencies due to fluff accumulation, which can lead to increased risk of fire, clogged airways, and excessive condensate formation, especially when using recirculation systems for energy efficiency.
Innovation Solution
A dryer design with a split process air duct that includes a circulating air duct for heating and an exhaust air duct, featuring an internally and externally cleanable fluff filter, a rinsing device using condensate or process air to clean the filter, and a scraping mechanism for efficient lint removal, along with a heat exchanger for energy recovery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If recirculation system is used to improve energy efficiency, then energy efficiency is improved, but fluff accumulation and fire risk increase
Solution Approach 1:
The patent extracts the fluff removal function from the recirculation system by introducing a separate cleaning device that actively removes fluff from the recirculation duct. This allows the recirculation system to maintain energy efficiency while the cleaning device independently manages fire risk by preventing fluff accumulation.
Solution Approach 2:
The cleaning device acts as an intermediary between the recirculation system and the fluff accumulation problem. It mediates by continuously removing fluff from the recirculation duct, thereby maintaining the benefits of recirculation (energy efficiency) without the harmful effects (fire risk).
2Use of energy by moving object
If recirculation system is used to improve energy efficiency, then energy efficiency is improved, but condensate formation increases
Solution Approach 1:
The patent extracts condensate from the recirculation system by introducing a separate drainage mechanism. This allows the recirculation system to maintain energy efficiency while condensate is actively removed, preventing excessive accumulation that would otherwise require larger ducts or more frequent maintenance.
3Reliability
If fluff filter is added to remove fluff, then fire risk is reduced, but device complexity increases
Solution Approach 1:
The patent merges the fluff removal function with the existing recirculation system by integrating a cleaning device that uses the recirculation airflow itself to remove fluff. This combines multiple functions (recirculation and fluff removal) into a single system, reducing overall device complexity while maintaining fire safety.
Solution Approach 2:
The recirculation system serves itself by using its own airflow to remove fluff through the cleaning device. This self-service approach eliminates the need for separate powered cleaning systems, reducing device complexity while maintaining effective fluff removal.
4Productivity
If exhaust air duct is extended to improve ventilation, then ventilation is improved, but condensate deposition increases
Solution Approach 1:
The patent extracts condensate from the exhaust air duct by introducing a separate drainage mechanism. This allows the exhaust air duct to be extended for improved ventilation while condensate is actively removed, preventing excessive deposition that would otherwise require shorter ducts or larger diameters.
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
Enhances energy efficiency, reduces fluff-related risks, minimizes condensate formation, and simplifies filter cleaning, thereby improving operational reliability and reducing fluff deposition in air ducts.
Implementation Method 1
a heater (11) for heating the process air
Implementation Method 2
the heated process air is guided by a fan (12) over the objects to be dried
Implementation Method 3
a heat exchanger for energy recovery
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
The invention relates to a dryer 1 with a drying chamber 3 for the items to be dried, a supply air duct 15, a process air duct 2 in which a heater 11 is located for heating the process air, and the heated process air is directed over the items to be dried by means of a blower 12 and can be directed via an exhaust air duct 13 to the exhaust air outlet 16, wherein the process air duct 2 splits at a branch 19 into a recirculation air duct 14 to the heater 11 and the exhaust air duct 13, which leads to the exhaust air outlet 16, and wherein an internally and/or externally cleanable lint filter 20 is arranged in the recirculation air duct 14, and the recirculation air duct 14 joins the supply air duct 15 upstream of the heater 11. The invention also relates to a preferred method for operating this dryer.