Throttle Insert for Uniform Droplet Dispensing

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Solution Overview

Problem

Existing tubes with deformable jackets face challenges in dispensing liquids of uniform droplet size due to pressure variations, leading to inconsistent volume flow and potential backflow of liquid into the reservoir, which affects dosing accuracy.

Innovation Solution

A tube design incorporating a throttle insert shaped like a dome, which is securely mounted within the dispensing channel to restrict the flow, ensuring uniform droplet formation by limiting the maximum volume flow and preventing excessive liquid discharge, even under compressive forces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a deformable tube jacket is used to enable liquid dispensing, then the tube can be compressed to force liquid through the dispensing channel, but the pressure variations cause inconsistent droplet size and volume flow

Engineering Contradiction:
Improveliquid dispensing capabilityVSAvoiddroplet size uniformity
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The patent applies parameter changes by introducing a throttle insert with specific geometric parameters (throttle opening size, shape, and position) into the dispensing channel. This throttle opening acts as a flow resistance element that limits the maximum volume flow of liquid. By carefully selecting the throttle opening parameters, the invention achieves consistent droplet formation and volume flow independence from pressure variations, thereby resolving the contradiction between ease of operation and droplet size uniformity.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If external pressure is applied to the deformable tube, then liquid flows through the dispensing channel, but excessive pressure causes liquid to discharge too quickly and prevents uniform droplet formation

Engineering Contradiction:
Improveliquid flow rateVSAvoiddroplet formation uniformity
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies preliminary anti-action by pre-installing a throttle insert in the dispensing channel that creates flow resistance before the liquid reaches the dispensing opening. This throttle element anticipates and counteracts the effect of excessive pressure by limiting the maximum volume flow rate. The flow resistance created by the throttle opening prevents liquid from discharging too quickly even when external pressure is applied, thereby maintaining uniform droplet formation while still allowing adequate liquid flow rate.

Inventive Principle:
Principle #9Preliminary anti-action

3Quantity of substance

If the tube is compressed to increase liquid flow, then more liquid can be dispensed, but the pressure difference causes liquid to suck back into the reservoir

Engineering Contradiction:
Improveliquid volume dispensedVSAvoiddosing accuracy
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent applies parameter changes by introducing a throttle insert with specific geometric parameters (throttle opening size, shape, and position) into the dispensing channel. This throttle opening acts as a flow resistance element that limits the maximum volume flow of liquid. By carefully selecting the throttle opening parameters, the invention achieves consistent droplet formation and volume flow independence from pressure variations, thereby resolving the contradiction between ease of operation and droplet size uniformity.

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

The throttle insert ensures consistent droplet formation and prevents excessive liquid discharge, maintaining dosing accuracy and uniformity regardless of external pressure variations, allowing for precise control over liquid output.

Implementation Method 1

This creates a throttling passage that acts as a flow resistance, limiting the volume flow of the dispensed liquid even when the tube is squeezed.

Methodology Applied
Scientific EffectFlow resistance: Drag

Implementation Method 2

In tubes with an elastically deformable outer layer, which may be made of plastic or a composite material containing plastic, the elastic recoil of the material, when external forces acting on the outer layer in addition to ambient pressure are removed, causes the pressure in the reservoir to be lower than the ambient pressure.

Methodology Applied
Scientific EffectElastic recoil: Elasticity

Implementation Method 3

Various factors influence the size or volume of the droplets that form at the dispensing opening before they detach from the nozzle. Such factors include, for example, surface tension.the surface tensions of the liquid to be dispensed and the nozzle

Methodology Applied
Scientific EffectSurface tension: Surface Tension

Data Source

PatentEP3241781B1Tube with throttle insert
Publication Date: 2019.02.06 HOFFMANN NEOPAC
  • EP3241781B1 patent drawingFigure 1~5
  • EP3241781B1 patent drawingFigure 6~8

AI summary

The tube (1) comprises a nozzle (9) with a dispensing channel (13) that connects a dispensing opening (11) to a reservoir (3). For metered dispensing of a liquid from the reservoir (3) through the dispensing opening (11), a throttle insert (31) is inserted into a distal section (9b) of the nozzle (9) and positively connected to the nozzle (9). The connection of the throttle insert (31) to the nozzle (9) is preferably achieved by radial compression. The throttle insert (31) is preferably dome-shaped and defines at least one primary throttle channel (47) that forms a constriction in the dispensing channel, limiting the volume flow of the liquid from the reservoir (3) to the dispensing opening (11).