Spray Assembly Filter Membrane Area Ratio for Clog Prevention
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Solution Overview
Problem
Existing spray arrangements for dispensing pharmaceutical or cosmetic liquids tend to clog during long-lasting discharges, disrupting the consistent spray pattern due to the use of depth filters with limited filtering capacity.
Innovation Solution
A spray arrangement featuring a silicon nozzle plate with numerous small nozzle openings and a filter membrane with a larger effective filter area than the nozzle opening area, where the filter membrane's separation limit is smaller than the nozzle openings, preventing clogging and maintaining a consistent spray pattern during extended use.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a depth filter with limited filter area is used in the spray arrangement, then the device structure is compact and easy to handle, but the filter becomes clogged during prolonged discharges disrupting the spray pattern
Solution Approach 1:
The invention transitions from a depth filter design where filtration occurs primarily in the vertical dimension (through the depth of the filter medium) to a membrane filter design where filtration occurs in the planar dimension (across the membrane surface). This dimensional shift allows the filter area to be significantly increased without increasing the depth dimension, thereby providing greater filtration capacity while maintaining a compact overall structure.
Solution Approach 2:
The invention employs a porous membrane filter material with specific pore size characteristics (separation limit smaller than nozzle opening diameter) that provides effective particle retention while maintaining adequate flow characteristics. The porous structure of the membrane filter enables high filtration efficiency across a large surface area, preventing clogging during prolonged operation while maintaining spray pattern consistency.
2Duration of action of moving object
If a filter membrane with large effective filter area is used, then clogging is prevented during prolonged spraying, but the device structure becomes more complex
Solution Approach 1:
The invention applies local quality by positioning the large-area membrane filter at a specific location in the liquid flow path where it can effectively filter particles before they reach the nozzle openings. The filter membrane is strategically placed upstream of the nozzle plate, creating a localized filtration zone that protects the critical spray generation area without requiring the entire device structure to be expanded.
Solution Approach 2:
The invention resolves the complexity issue by increasing the filter area in the planar dimension rather than increasing the overall device volume. The membrane filter is designed as a thin, flat component with large surface area but minimal thickness, allowing it to provide extensive filtration capacity while occupying minimal space in the vertical dimension, thus maintaining device compactness.
3Manufacturing precision
If the filter membrane separation limit is smaller than nozzle opening diameter, then fine particles are filtered effectively, but the risk of membrane clogging increases
Solution Approach 1:
The invention applies partial action by providing a membrane filter area that is at least 20 times larger than the total nozzle opening area. This excessive filter area relative to the nozzle area creates a large capacity margin, allowing the filter to handle the same particle load over a much larger surface area, thereby reducing the stress on any single point of the membrane and extending its operational life before clogging occurs.
Solution Approach 2:
The invention changes the critical parameter of filter area size, increasing it to be at least 20 times larger than the nozzle opening area. This parameter change fundamentally alters the filtration dynamics, distributing the particle capture load across a much larger surface area, which reduces the filtration rate per unit area and thereby extends the membrane's operational durability while maintaining fine particle filtration effectiveness.
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
The solution enables long-lasting, consistent spray processes with improved filtration efficiency, reducing the likelihood of clogging and maintaining a fine nebulization quality, particularly beneficial for applications like inhalers and cosmetic dispensers.
Implementation Method 1
a filter membrane in a flow path between the feed channel and the nozzle plate, the separation limit of which is smaller than the diameter of the nozzle openings
Implementation Method 2
a nozzle plate through which liquid can be discharged from the feed channel into the surrounding atmosphere... allowing for very fine atomization of the liquid
Data Source
Figure 1~2
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Figure 6~9
AI summary
A spray arrangement, particularly for dispensing pharmaceutical or cosmetic liquids, is known from the prior art. This spray arrangement comprises a feed channel (42A) for supplying liquid for the purpose of spraying, and a nozzle plate (54) through which liquid can be discharged from the feed channel (42A) into the surrounding atmosphere. The nozzle plate (54) has a plurality of nozzle openings (54B) with a maximum diameter of 15 µm, which together define a nozzle opening area (54A) of the nozzle plate (54). It is proposed to design the spray arrangement such that it includes a filter membrane (64) in a flow path (4) between the feed channel (42A) and the nozzle plate (54), the separation limit of which is smaller than the diameter of the nozzle openings (54b) and the effective filter area (64a) located in the flow path (4) is at least 20 times larger than the nozzle opening area (54a).