Multi-Surface Air Filter Unit Design to Reduce Size and Pressure Loss

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Solution Overview

Problem

Conventional inside air control systems for container refrigeration apparatuses require frequent filter replacements due to their short lifespan, leading to increased filter unit size when attempting to enhance dust holding capacity, which poses installation challenges.

Innovation Solution

The filter unit design includes a filter box with an air filter spaced apart from its walls, featuring a primary and secondary air flow system, and a unique intake port configuration that allows air to flow in and out through various surfaces, preventing water accumulation and reducing pressure loss, thus maintaining a compact size.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the size of the filter is increased to give the filter with a larger dust holding capacity, then the dust holding capacity is improved, but the size of the filter unit increases, making it difficult to install in the casing of the container refrigeration apparatus

Engineering Contradiction:
Improvedust holding capacityVSAvoidfilter unit size
Core Design Contradiction:
Quantity of substanceVSVolume of stationary object

Solution Approach 1:

The patent utilizes three-dimensional space efficiently by creating primary and secondary spaces around the air filter. The primary space between the air intake surface and the air filter, and the secondary spaces between other surfaces of the air filter and the filter box walls, allow air to flow through multiple pathways. This spatial arrangement maximizes the dust holding capacity within a compact filter unit volume by optimizing the utilization of available space rather than simply increasing filter size in one dimension.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Loss of energy

If the filter is spaced apart from the wall surfaces of the filter box to create flow spaces, then the pressure loss is reduced and water accumulation is prevented, but the device complexity increases

Engineering Contradiction:
Improvepressure lossVSAvoidfilter unit structure
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The space between the air filter and the filter box is segmented into a primary space and multiple secondary spaces. The primary space is formed between the air intake surface and the air filter, while secondary spaces are formed between other surfaces of the air filter and the filter box walls. This segmentation creates multiple air flow pathways that reduce pressure loss and prevent water accumulation, while the modular structure remains relatively simple to manufacture and assemble.

Inventive Principle:
Principle #1Segmentation

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 enables a larger dust holding capacity without increasing the filter unit's size, reduces water accumulation, and minimizes pressure loss, protecting the air pump and contents from water damage while maintaining a thinner filter box.

Implementation Method 1

an air filter (76) housed in the filter box (90)

Methodology Applied
Scientific EffectFiltration: Filter (physical)

Data Source

PatentEP3646932B1In-vehicle air conditioner and cooling device for container
Publication Date: 2023.06.14 DAIKIN INDUSTRIES LTD
  • EP3646932B1 patent drawingFigure 1
  • EP3646932B1 patent drawingFigure 2
  • EP3646932B1 patent drawingFigure 3

AI summary

A space which is present between an air intake surface (90a) provided with an air intake port and an air filter (76) is regarded as a primary space (P) through which air flows into the air filter (76), and a plurality of spaces, each of which is present between one of other surfaces of the air filter (76) and a filter box (90), are regarded as secondary spaces (Q) into each of which the air flows out from the air filter (76), so that the air is taken out from side surfaces and an upper surface of a filter unit (75). This configuration reduces the increase in size of the filter unit (75) of a gas supply device (30) even if a dust holding capacity of the filter is made larger than before.