WO2025122107A1

WO2025122107A1 - A gas measurment device

Info

Publication number: WO2025122107A1
Application number: PCT/TR2024/051358
Authority: WO
Inventors: Alper BAYRAKDAR; Baris CALLI
Original assignee: Izmir Yuksek Teknoloji Enstitusu Rektorlugu
Current assignee: Izmir Yuksek Teknoloji Enstitusu Rektorlugu
Priority date: 2023-12-05
Filing date: 2024-11-19
Publication date: 2025-06-12
Anticipated expiration: 2026-06-05
Also published as: TR2023016518A1

Abstract

The invention relates to a measurement device for the volumetric measurement of ultra-low flow rate and low-quantity gases.

Description

A GAS MEASURMENT DEVICE

Technical Field of the Invention

The invention relates to a measurement device for volumetric measurement of ultra-low flow rate gases and gases produced in small quantities.

State of the Art Related to the Invention

Various gas measurement devices are used for the volumetric measurement of ultra-low flow rate and low-quantity gases. Such devices are typically used in biogas technology or for detecting leakage rates.

The most well-known device of this type is the RITTER MilliGascounter [1], For gas measurement, the incoming gas passes through the inlet nozzle and travels along a microcapillary tube at the base, directing it into a liquid casing filled with a packing liquid. In the packing liquid, the gas rises as small bubbles and reaches the measurement cell. The measurement cell consists of two measuring chambers, which are sequentially filled by the rising gas bubbles.When one of the chambers fills, the buoyancy of the filled chamber forces the measurement cell to tilt abruptly, positioning it so that the second chamber fills while the first chamber empties. The gas volume measurement is performed in discrete steps by counting the tilting actions of the measurement cell. The tilting procedure of the measurement cell generates a pulse, recorded by the counting unit via a magnet located on top of the cell and one of the two magnetic sensors, specifically the reed switches.

Although this device is a popular choice, it has several drawbacks. The resolution of the MilliGascounter is fixed, meaning the gas volume per cycle is constant and cannot be adjusted by the end user. Another issue is that the MilliGascounter can only measure accurately up to a flow rate of 1 L/hour. At flow rates above this limit, the meter fails to provide accurate results and requires a high operating pressure of around 5 mBar.

In addition, the following documents have also been encountered in the prior art.

US8871498B2 describes a device designed for measuring extremely low gas flow rates. US20190153380A1 describes a gas measurement method applicable to batch fermentation and in-vitro analysis platforms. The application details the methodology, equipment, and applications for gas measurement in these contexts.

The study by Liu et al. [2] describes a volumetric meter designed to monitor low gas flow rates from laboratory-scale biogas reactors.

The study by Moletta et al. [3] describes a gas meter designed to measure low gas flow rates in the context of methane fermentation.

The study by Dissing et al. [4] focuses on monitoring methanogenic processes, describing the use of a gas flow meter in conjunction with an immobilized mixed culture.

The study by Glauser et al. [5] introduces an affordable and automated gas meter designed for laboratory-scale methane digesters and other gas-producing systems.

The study by Angelidaki et al. [6] focuses on a compact, automated displacement gas measurement system developed to measure low gas flows from laboratory fermenters.

In conclusion, all the issues mentioned above have necessitated an innovation in this field.

Bulu§un Ama^lan vc Kisa A klamasi

The primary objective of the invention is to establish the structure of a gas measurement device for the volumetric measurement of ultra-low flow rate and low-quantity gases.

The objective of the invention is to establish the structure of a gas measurement device with adjustable resolution.

The objective of the invention is to establish the structure of a gas measurement device capable of operating over a wider flow range compared to alternatives.

Descriptions of Figures Illustrating the Invention

The figures and corresponding descriptions used to better explain the device developed with this invention are provided below.

Figure 1. Sequential schematic representations showing the measurement steps of the gas measurement device. Descriptions of Components/Parts/Elements Constituting the Invention

The parts and components featured in the figures to better explain the device developed with this invention are numbered, with each number corresponding to the descriptions provided below.

1. Gas measurment device

10. U-Tube

11. First arm

12. Second arm

13. Exhaust opening

14. Lid

15. Fitting

20. Magnetic float

30. Magnetic sensor

40. Valve

41. First inlet

42. Second inlet

43. Third inlet

50. Control unit

Av. Liquid displacement volume

S. Liquid

Detailed Description of the Invention

Referring to Figure 1, the current gas measurement device (1) utilizes a "U"-shaped tube (10). This tube (10) preferably includes a first arm (11) and a second arm (12), which are parallel to each other. Both ends of these arms are sealed with a lid (15). The interior of the tube (10) is filled with a liquid (S), and under normal conditions, the liquid (S) levels in the first arm (11) and the second arm (12) are equal. An outlet opening (13) is provided at the end of the second arm (12). A magnetic float (20) is placed within the liquid (S) to remain in the area of the second arm (12). This magnetic float (20) is designed to float within the liquid (S), meaning its density is lower than that of the liquid (S).

Additionally, a magnetic sensor (30) is preferably placed on the outer surface of the second arm (12). This magnetic sensor (30) is configured to detect the magnetic float (20) when they are aligned. Preferably, the magnetic sensor (30) is manufactured using a reed relay.

Here, the choice of a magnetic float (20) and magnetic sensor (30) enables a device structure that is less affected by external noise and environmental conditions compared to alternatives.

The first arm (11) is connected to a valve (40). This valve (40) has three inlets: a first inlet (41), a second inlet (42), and a third inlet (43). The first inlet (41) can direct gas to at least the second inlet (42) and the third inlet (43). Preferably, a three-way solenoid valve is used here. The primary arm (11) is connected to the second inlet (42), preferably through a connector tip (16). The first inlet (41) is connected to a gas source, while the third inlet (43) is either connected to a separate location for venting the gas from the gas source or remains open.

Preferably, the three-way solenoid valve (40) operates with a power source, specifically a 12 V power source. The device includes a transistor-based switch circuit and a reset button to trigger the solenoid valve (40).

The gas measurement device (1) also includes a control unit (50), preferably a microprocessor. This control unit (50) can communicate with both the magnetic sensor (30) and the valve (40). The control unit (50) receives data from the magnetic sensor (30) indicating whether the magnetic float (20) has reached the sensor level, and it sends commands to the valve (40) to direct the flow from the first inlet (41) to the appropriate outlet.

Accordingly, in its most basic form, the current gas measurement device (1) consists of: a U-shaped tube (10) comprising a first arm (11) and a second arm (12), a magnetic float (20) configured to float within the liquid (S) inside the tube (10), an outlet opening (13) and a magnetic sensor (30) provided on the second arm (12), a three-way valve (40) with a first inlet (41) for connection to a gas source, a second inlet (42) connected to the first arm (11), and a third inlet (43) for venting gas from the device, a control unit (50) that receives data from the magnetic sensor (30) and, based on this data, determines whether to direct the gas from the first inlet (41) to either the second inlet (42) or the third inlet (43).

In the described gas measurement device (1), a gas source is connected to the first inlet (41) of the valve (40). The gas supplied from this source flows from the first inlet (41) to the second inlet (42) and then into the first arm (11). The gas entering the first arm (11) pushes the liquid (S) within the tube (10), causing the liquid level in the first arm (11) to drop by a liquid displacement volume (Av), while the liquid level in the second arm (12) rises by the same amount.

The rise of the liquid in the second arm (12) elevates the magnetic float (20) by the liquid displacement volume (Av), eventually positioning the magnetic float (20) within detection range of the magnetic sensor (30). The magnetic sensor (30) then sends data to the control unit (50), indicating that it has detected the magnetic float (20). Upon receiving this data, the control unit (50) redirects the incoming gas from the first inlet (41) to the third inlet (43) instead of the second inlet (42), thus venting the gas from the system.

In this state, with no gas flow from the second inlet (42) to the first arm (11), the air pressure pushes the liquid (S) back to its original position through the outlet opening in the second arm (12), equalizing the liquid levels between the first arm (11) and the second arm (12). If the process is to continue, the magnetic float (20) will no longer be detected by the magnetic sensor (30), prompting the control unit (50) to redirect the incoming gas from the first inlet (41) back to the second inlet (42), thereby repeating all the steps in the cycle.

In this way, it has been observed that measurements can be performed at flow rates of up to 6 liters per hour.

The gas measurement device (1) also includes a counter (not shown in the figures), which can be integrated into the control unit (50). This counter records the time elapsed from the moment (tO) the control unit (50) directs gas from the gas source through the first inlet (41) to the second inlet (42) until the moment (tl) the magnetic sensor (30) detects the magnetic float (20). The amount of gas required to move the magnetic float (20) to the sensor's detection point within the tube (10) is known in advance. Based on this data, a time-cumulative gas graph can be generated in formats such as .csv. This graph is generated from the data provided by the gas measurement device (1) on an external processing unit, such as a computer. Alternatively, the graph can be created by a processing unit integrated within the gas measurement device (1).

Additionally, either the first arm (11), the second arm (12), or preferably both, include removable caps (15), allowing access to the inner volume of the tube (10). This enables the liquid (S) inside the tube (10) to be increased or decreased, allowing for the adjustment of the gas measurement device (1). As the amount of liquid (S) changes, the volume and time required for the magnetic sensor (30) to detect the magnetic float (20) can be adjusted accordingly.

1. REFERENCES

2. https://www.ritter.de/en/products/milligascounters/

3. Jing Liu , Gustaf Olsson , Bo Mattiasson, A volumetric meter for monitoring of low gas flow rate from laboratory-scale biogas reactor. Sensors and Actuators B 97 (2004) 369-372. 4. R. Moletta, G. Albagnac, A gas meter for low rates of gas flow: application to methane fermentation,

Biotechnol. Lett. 4 (1982) 319-322

5. U. Dissing, T.G.I. Ling, B. Mattiasson, Monitoring of methanogenic processes with an immobilized mixed culture in combination with a gas-flow meter. Anal. Chim. Acta 163 (1984) 127-133.

6. M. Glauser, B. Jenni, M. Aragno, An inexpensive, automatic gas meter for laboratory-scale methane digesters and other gas-evolving systems, J. Microbiol. Meth. 2 (1984) 159-164.

7. Angelidaki, L. Ellegaard, B.K. Ahring, Compact automated dis placement gas metering system for measurement of low gas rates from laboratory fermentors, Biotechnol. Bioeng. 39 (1992) 351-353.

Claims

1. A gas measurement device (1), characterized by:

A tube (10) comprising a first arm (11) and a second arm (12) that are physically connected, A magnetic float (20) designed to float within the liquid (S) inside the tube (10),

An outlet opening (13) and a magnetic sensor (30) provided on the second arm (12), A three-way valve (40) with a first inlet (41) for connection to a gas source, a second inlet (42) connected to the first arm (11), and a third inlet (43) for venting gas from the device, A control unit (50) that receives data from the magnetic sensor (30) and determines, based on this data, whether to direct the gas from the first inlet (41) to either the second inlet (42) or the third inlet (43).

2. A gas measurement device (1) according to Claim 1, characterized by the control unit (50) being configured to direct the incoming gas from the first inlet (41) to the third inlet (43) upon receiving data from the magnetic sensor (30) indicating detection of the magnetic float (20), and to direct the incoming gas from the first inlet (41) to the second inlet (42) otherwise.

3. A gas measurement device (1) according to Claim 1, characterized by including a counter that measures the time elapsed between the direction of gas from the first inlet (41) to the second inlet (42) and the detection of the magnetic float (20) by the magnetic sensor (30).

4. A gas measurement device ( 1 ) according to any of Claims 1 to 3 , characterized by including an external processing unit configured to create a time-cumulative gas graph by recording time data each time the magnetic sensor (30) detects the magnetic float (20).

5. A gas measurement device (1) according to Claim 1, characterized by the control unit (50) being a microcontroller.

6. A gas measurement device (1) according to Claim 1, characterized by the valve (40) being a solenoid valve.

7. A gas measurement device ( 1 ) according to Claim 1 , characterized by including a connector tip (16) that connects the first arm (11) to the second inlet (42).

8. A gas measurement device (1) according to Claim 1 or Claim 7, characterized by the first arm (11) and/or the second arm (12) including a removable cap (15).

9. A gas measurement device (1) according to Claim 1, characterized by the tube (10) being "U"-shaped.