Pump-Fed Test Leak for Low-Vapor-Pressure Liquid Detection

Solution Overview

Problem

Conventional leak detection methods are ineffective for test specimens filled with liquids having low vapor pressure, as they cannot efficiently introduce the test liquid into the detection system, and sniffer probe methods fail due to lack of gas escape in specimens with internal pressure lower than atmospheric pressure.

Innovation Solution

A test leak device with a reservoir filled with a test liquid of low vapor pressure, utilizing a pump to deliver the liquid in liquid or spray mist form into a leak detection device, allowing for sufficient quantity delivery and detection without a carrier gas, using a micro-metering pump and piezo liquid metering for precise flow control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If a capillary or membrane is used to deliver test liquid, then the device structure is simple, but liquids with low vapor pressure cannot be delivered in sufficient quantity

Engineering Contradiction:

Improvequantity of test liquidVSAvoiddevice complexity

Core Design Contradiction:

Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent replaces passive capillary or membrane-based delivery with an active pump system (peristaltic pump, syringe pump, or piston pump) to mechanically force the test liquid through the outlet. This mechanical substitution enables sufficient delivery quantity for low vapor pressure liquids by overcoming the pressure differential barrier that passive systems cannot overcome.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent utilizes hydraulic principles by employing a pump system that generates sufficient pressure to push the test liquid through the outlet in liquid form. The pump creates a pressure differential that forces the liquid through the system, enabling controlled delivery of liquids with vapor pressure below 500 mbar that cannot be delivered by passive pressure differential alone.

Inventive Principle:

Principle #29Pneumatics and hydraulics

2Reliability

If a sniffer probe method is used, then gas leaks can be detected, but it fails for specimens with internal pressure lower than atmospheric pressure

Engineering Contradiction:

Improvedetection reliabilityVSAvoidadaptability to different pressure conditions

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

Instead of trying to suck leakage gas out with a sniffer probe (which fails when internal pressure is lower than atmospheric), the patent inverts the approach by actively injecting test liquid into the test specimen through a pump system. This inversion transforms the detection method from passive gas extraction to active liquid injection, enabling reliable detection regardless of pressure differential direction.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent changes the fundamental parameter being tested from gas phase to liquid phase. By injecting liquid test substance and detecting its presence after evaporation in the vacuum chamber, the system becomes adaptable to specimens with internal pressures lower than atmospheric pressure, as liquid injection is not dependent on pressure differential in the same way gas flow is.

Inventive Principle:

Principle #35Parameter changes

3Quantity of substance

If test liquid is delivered without a pump, then the device is simpler, but sufficient quantity cannot be achieved for low vapor pressure liquids

Engineering Contradiction:

Improvequantity of test liquidVSAvoiddevice complexity

Core Design Contradiction:

Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent replaces passive delivery mechanisms with an active pump system (peristaltic pump, syringe pump, or piston pump) to mechanically force the test liquid through the outlet. This mechanical substitution enables sufficient delivery quantity for low vapor pressure liquids by overcoming the pressure differential barrier that passive systems cannot overcome.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent utilizes hydraulic principles by employing a pump system that generates sufficient pressure to push the test liquid through the outlet in liquid form. The pump creates a pressure differential that forces the liquid through the system, enabling controlled delivery of liquids with vapor pressure below 500 mbar that cannot be delivered by passive pressure differential alone.

Inventive Principle:

Principle #29Pneumatics and hydraulics

4Measurement precision

If conventional test leaks are used, then calibration can be performed, but they cannot deliver sufficient test liquid quantity for low vapor pressure substances

Engineering Contradiction:

Improvecalibration accuracyVSAvoidquantity of test liquid

Core Design Contradiction:

Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent replaces passive capillary or membrane-based delivery with an active pump system (peristaltic pump, syringe pump, or piston pump) to mechanically force the test liquid through the outlet. This mechanical substitution enables sufficient delivery quantity for low vapor pressure liquids by overcoming the pressure differential barrier that passive systems cannot overcome.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent utilizes hydraulic principles by employing a pump system that generates sufficient pressure to push the test liquid through the outlet in liquid form. The pump creates a pressure differential that forces the liquid through the system, enabling controlled delivery of liquids with vapor pressure below 500 mbar that cannot be delivered by passive pressure differential alone.

Inventive Principle:

Principle #29Pneumatics and hydraulics

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

Enables effective functional testing and calibration of leak detection devices for test specimens with low vapor pressure liquids, ensuring accurate detection of leaks without relying on gas escape or external carrier gases, improving detection sensitivity and specificity.

Implementation Method 1

a pump, which is configured to convey the test liquid from the reservoir, cooperates with the reservoir in such a way that the test liquid escapes from the pump through the outlet in liquid form from the reservoir

Methodology Applied

Scientific EffectPump: Pump

Implementation Method 2

The test liquid can be supplied to the detector in the form of molecular particles in evaporated form. Evaporation typically occurs after the test liquid escaped from the outlet of the test leak device

Methodology Applied

Scientific EffectEvaporation: Evaporation

Implementation Method 3

Parts of the liquid that escape from the test specimen are continuously conveyed out of the vacuum chamber by means of a vacuum system of a vacuum pump

Methodology Applied

Scientific EffectVacuum: Vacuum

Data Source

PatentUS20240159616A1Functionally testing a leak detection device for checking the sealing tightness of an inspection object filled with a liquid

Publication Date: 2024.05.16 INFICON GMBH

AI summary

A test leak device for functional testing of a leak detection device for the leak test of a test specimen (14) filled with a liquid (12) having an internal pressure that is lower than atmospheric pressure, comprisinga reservoir (102) filled with a test liquid (104), wherein the test liquid (104) has a vapor pressure of less than 500 mbar at room temperature, and the reservoir (102) comprises an outlet (106), anda pump (100) cooperating with the reservoir (102) and configured to convey the test liquid (104) from the reservoir (102) in such a way that the test liquid (104) escapes from the pump (100) through the outlet (106) in liquid form from the reservoir (102).