Humidifying device for chilled mirror dew-point instrument

Abstract

The utility model relates to the technical field of dew-point instruments, in particular to a humidifying device for a chilled mirror type dew-point instrument, which comprises a gas circuit module and a gas supply power module, the gas circuit module is provided with a gas inlet, a gas outlet and a humidifying port which are communicated with one another, the gas inlet is connected with a sampling pipe, and the gas supply power module is connected with the humidifying port. The air outlet is connected with an inlet of a test chamber of the chilled mirror dew-point instrument, the humidifying port is connected with an air supply power module, and an electromagnetic valve module for controlling the on-off of an air path is arranged on the air path where the humidifying port is located; according to the utility model, the air supply power module and the electromagnetic valve module are used for directly collecting the environment air into the test chamber of the dew point sensor for humidification, so that the humidity of the collected air flow is not reduced along with the increase of the humidification times, and the device is suitable for high-frequency repeated verification test of low-dew-point air.

Description

Technical Field

[0001] This utility model relates to the field of dew point meter technology, and in particular to a humidification device for a cold mirror type dew point meter. Background Technology

[0002] A cold mirror dew point meter uses a cooling element to cool the mirror of the dew point sensor, causing water vapor in the gas passing through the mirror to condense into dew or frost on the mirror surface (dew above 0℃, frost below 0℃). The photoelectric system automatically controls the balance to keep the dew or frost layer on the mirror surface constant. At this time, the temperature of the mirror surface measured by the temperature sensor below the mirror is the dew (frost) point temperature of the gas.

[0003] When measuring gases with low dew points (typically below -40°C) using a cold mirror dew point meter, the water vapor content in these gases is very low, and it often takes several hours for dew or frost to form on the mirror surface and stabilize at the equilibrium temperature. To accelerate the formation of dew or frost, patent CN2205229082U discloses an auxiliary humidification device for cold mirror dew point meters, including a gas path module and a humidifying gas path pipe. The gas path module has two three-way channels connected in series, and the bypasses of each three-way channel are connected through the humidifying gas path pipe. A solenoid valve for switching on and off is installed on the bypass. Since the humidifying gas path pipe can absorb water vapor from the air outside the pipe, during the humidification process, the solenoid valve opens, the gas being measured flows through the humidifying gas path pipe, and a portion of the water vapor in the pipe is carried to the mirror surface, thereby shortening the time for dew or frost to form on the mirror surface.

[0004] However, although the humidifying gas pipe in the aforementioned patent can permeate water vapor, the permeation speed is slow. The water vapor in the humidifying gas pipe gradually decreases with the increase of humidification times. In particular, when performing repetitive testing of the gas, the humidifying gas pipe needs to be connected frequently. After multiple tests, the humidifying gas pipe can no longer perform the humidification function. Utility Model Content

[0005] To address the shortcomings of the existing technology, this invention provides a humidification device for a cold mirror dew point meter, which can adapt to high-frequency detection of low dew point gases.

[0006] The technical solution of this utility model is as follows: a humidification device for a cold mirror dew point meter, comprising a gas path module and a gas supply power module. The gas path module has an inlet, an outlet, and a humidification port that are interconnected. The inlet is connected to a sampling tube, the outlet is connected to the inlet of the test chamber of the cold mirror dew point meter, and the humidification port is connected to the gas supply power module. A solenoid valve module for controlling the on / off state of the gas path is provided on the gas path where the humidification port is located. By adding a gas supply power module and a solenoid valve module to the gas path module, the gas supply power module, through the solenoid valve module, supplies ambient gas with a certain humidity into the gas path module. This gas, along with the low dew point gas to be tested supplied by the sampling tube, flows into the test chamber of the cold mirror dew point meter, thereby achieving the purpose of rapidly forming dew or frost on the mirror surface. Compared with the prior art, since the ambient gas is directly sampled by the gas supply power module, the humidity of the incoming airflow will not decrease with the increase of humidification times, thus making it suitable for high-frequency repeatability testing of low dew point gases.

[0007] The air supply power module is a miniature air pump. The air inlet of the miniature air pump is connected to the ambient air, and the air outlet of the miniature air pump is connected to the humidification port via a pipeline.

[0008] The solenoid valve module is electrically connected to the control unit of the cold mirror dew point meter via a first switching circuit, and the air supply power module is electrically connected to the control unit of the cold mirror dew point meter via a second switching circuit to receive pulse signals from the control unit. The control employs a small, multiple pulse humidification method to ensure both humidification efficiency and appropriate humidification level.

[0009] The solenoid valve module is integrated with the air circuit module, forming a two-position, three-way solenoid valve. The valve core of the solenoid valve controls the opening and closing of the humidification port and the internal passage of the air circuit module. The integrated design of the solenoid valve module and the air circuit module ensures the integration and simplicity of the device.

[0010] The solenoid valve module is a two-position two-way solenoid valve, and its two ends are respectively connected to the humidification port and the air supply power module.

[0011] The solenoid valve module is a two-position two-way solenoid valve, one end of which is connected to the air inlet of the micro air pump.

[0012] The micro air pump has a filter element installed at its air inlet.

[0013] The beneficial effects of this invention are as follows: This device adds a gas supply power module and a solenoid valve module to the gas path module. The gas supply power module delivers ambient gas with a certain humidity to the gas path module through the solenoid valve module. This gas, along with the low dew point gas to be tested delivered by the sampling tube, is then fed into the test chamber of the cold mirror dew point meter, thereby achieving the purpose of quickly forming a dew or frost layer on the mirror surface. Compared with the prior art, since the ambient gas is directly obtained by the gas supply power module, the humidity of the incoming airflow will not decrease due to the increase in the number of humidification cycles. Therefore, it is suitable for high-frequency repeatability verification tests of low dew point gases. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of this utility model installed inside a cold mirror dew point meter;

[0015] Figure 2 This is a schematic diagram of the solenoid valve in Example 1;

[0016] Figure 3 These are schematic diagrams illustrating the principles of other embodiments. Figure 3 (a) is a schematic diagram of a two-position two-way solenoid valve located between the pneumatic module and the micro air pump. Figure 3 (b) is a schematic diagram of a two-position two-way solenoid valve located at the air inlet end of a miniature air pump;

[0017] Figure 4 This is the control principle diagram of this utility model;

[0018] Figure 5 This is a schematic diagram of the connection between the two switching circuits in this utility model;

[0019] Figure 6 This is a comparison chart of the effects after multiple measurements using existing technologies;

[0020] Figure 7 This is a comparison chart of the effects of this utility model after multiple measurements.

[0021] Reference numerals: 1. Dew point sensor; 2. Air circuit module; 201. Air inlet; 202. Air outlet; 203. Humidification port; 3. Miniature air pump; 301. Filter element; 4. Solenoid valve module; 401. Valve core; 5. Control unit. Detailed Implementation

[0022] To enable those skilled in the art to better understand the technical solutions of this utility model, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings. Other embodiments obtained by those skilled in the art without creative effort should all fall within the protection scope of this utility model.

[0023] like Figures 1-3As shown, this utility model provides a humidification device for a cold mirror dew point meter, including a gas path module 2 and a gas supply power module, both installed inside the cold mirror dew point meter. The internal structure of the cold mirror dew point meter is the same as that of the prior art, including a dew point sensor 1 for measuring the dew point of the gas and a control unit 5 for controlling the cooling of the internal cooler of the dew point sensor 1 and receiving the measurement signal of the dew point sensor 1 and the mirror temperature signal. The dew point sensor 1 has a test chamber. Specifically, the gas path module 2 has an inlet 201, an outlet 202 and a humidification port 203 that are interconnected. The inlet 201 is connected to the sampling tube, the outlet 202 is connected to the inlet of the test chamber, and the humidification port 203... 203 is connected to the gas supply power module, and the gas path where the humidification port 203 is located is equipped with a solenoid valve module 4 to control the opening and closing of the gas path; by adding a gas supply power module and a solenoid valve module 4 to the gas path module 2, the gas supply power module delivers ambient gas with a certain humidity to the gas path module 2 through the solenoid valve module 4, and merges it together with the low dew point gas to be tested delivered by the sampling tube into the test chamber, thereby achieving the purpose of quickly forming dew or frost on the mirror surface. Compared with the prior art, since the ambient gas is directly obtained by the gas supply power module, the humidity of the merged airflow will not decrease due to the increase of humidification times, thus making it suitable for high-frequency repeatability verification tests of low dew point gases.

[0024] In Example 1, the solenoid valve module 4 and the pneumatic circuit module 2 are integrated to form a solenoid valve with a two-position three-way structure, thereby ensuring the integration and simplicity of the device. Figure 2 As shown, the air inlet 201, air outlet 202 and humidification port 203 are opened on the valve seat of the solenoid valve. The air inlet 201 and air outlet 202 are the two ends of the passage arranged axially inside the valve seat. The valve core 401 of the solenoid valve controls the opening and closing of the humidification port 203 and the passage inside the valve seat.

[0025] The air supply power module is a miniature air pump 3. The air inlet of the miniature air pump 3 is connected to the ambient air, and the air outlet of the miniature air pump 3 is connected to the humidification port 203 via a pipeline. In this embodiment, the miniature air pump 3 is a DC pump with a flow rate range of 1-5 L / min. Corresponding air connectors are configured at the air inlet, air outlet, and each interface of the solenoid valve of the miniature air pump 3, and the corresponding air connectors are connected by pipelines. To ensure the humidification efficiency and humidification effect of the humidification device, such as... Figure 5 As shown, the solenoid valve is electrically connected to the control unit 5 of the cold mirror dew point meter via the first switching circuit, and the miniature air pump 3 is electrically connected to the control unit 5 of the cold mirror dew point meter via the second switching circuit to receive pulse signals from the control unit 5. Specifically, the control principle of the control unit 5 is as follows: Figure 4As shown, the pulse signal emitted by the control unit 5 has a low-level duration of 3-5 seconds and a high-level duration of 0-1 seconds. The output level of the IO pin of the control unit 5 is amplified by the operational amplifier and drives the switching transistor to turn on or off. When the solenoid valve and the micro air pump 3 are powered on at the same time, ambient air (humidity) is injected into the air circuit module 2 and flows into the test chamber of the dew point sensor 1 together with the test sample gas. When the measurement signal of the dew point sensor 1 received by the control unit 5 tends to be in a balanced state, it means that humidification is completed. At this time, the control unit 5 stops outputting pulse signals, the solenoid valve and the micro air pump 3 are closed, and only the test sample gas enters the dew point sensor 1 for dew point detection. By using the above-mentioned small amount and multiple pulse humidification method, both the humidification efficiency and the humidification moderation are ensured. At the same time, the high-level duration can be adjusted according to the flow rate of the micro air pump 3. When the rated air flow rate of the micro air pump 3 is small, the high-level duration can be increased, and vice versa.

[0026] like Figure 3 As shown, the solenoid valve module 4 can also be configured as a two-position two-way solenoid valve, as in embodiment 2, such as... Figure 3 As shown in (a), the two-position two-way solenoid valve is located between the air circuit module 2 and the micro air pump 3. Specifically, the air circuit module 2 is a three-way connector. The two straight ends of the three-way connector are the air inlet 201 and the air outlet 202, respectively. The bypass end of the three-way connector is the humidification port 203. The two ends of the two-position two-way solenoid valve are connected to the humidification port 203 and the air outlet of the micro air pump 3, respectively.

[0027] In Example 2, as Figure 3 As shown in (b), a two-position two-way solenoid valve is installed at the air inlet of the micro air pump 3. The air circuit module 2 is a three-way connector. The two straight ends of the three-way connector are the air inlet 201 and the air outlet 202, respectively. The bypass end of the three-way connector is the humidification port 203. The humidification port 203 is connected to the air outlet of the micro air pump 3 through a pipeline.

[0028] In the above embodiments, in order to ensure the cleanliness of the gas delivered to the test chamber by the micro air pump 3, a filter element 301 is installed at the air inlet end of the micro air pump 3.

[0029] Taking Example 1 as an example, the humidification device was installed inside a cold mirror dew point meter. Using a cold mirror dew point meter equipped with a humidification device from the prior art as a comparative example, a repeatability test of low dew point gases was conducted. Figure 6 As shown, in the prior art, with the increase of the number of tests, the amount of moisture in the humidifying gas path pipe decreases, and the time required for dew or frost to form on the corresponding mirror surface increases, until the moisture content in the humidifying gas path pipe is almost the same as the moisture content of the gas being tested, at which point the humidifying gas path pipe loses its humidifying function. Figure 7As shown, each time the control unit 5 controls the solenoid valve and the micro air pump 3 to open, the micro air pump 3 directly draws in the ambient gas as a humidifying gas source. The humidity of the airflow formed after mixing with the gas to be tested remains constant. During high-frequency testing, it is always ensured that a dew or frost layer in a balanced state is formed on the mirror surface within 10-15 minutes.

Claims

1. A humidification device for a cold mirror dew point meter, characterized in that, It includes a gas path module and a gas supply power module. The gas path module has an air inlet, an air outlet and a humidification port that are interconnected. The air inlet is connected to a sampling tube, the air outlet is connected to the test chamber inlet of a cold mirror dew point meter, and the humidification port is connected to the gas supply power module. A solenoid valve module for controlling the on / off of the gas path is provided on the gas path where the humidification port is located.

2. The humidification device for a cold mirror dew point meter according to claim 1, characterized in that, The air supply power module is a miniature air pump. The air inlet of the miniature air pump is connected to the ambient air, and the air outlet of the miniature air pump is connected to the humidification port via a pipeline.

3. The humidification device for a cold mirror dew point meter according to claim 2, characterized in that, The solenoid valve module is electrically connected to the control unit of the cold mirror dew point meter via a first switching circuit, and the air supply power module is electrically connected to the control unit of the cold mirror dew point meter via a second switching circuit.

4. A humidification device for a cold mirror dew point meter according to any one of claims 1-3, characterized in that, The solenoid valve module is integrated with the air circuit module to form a solenoid valve with a two-position three-way structure. The valve core of the solenoid valve controls the opening and closing of the humidification port and the internal passage of the air circuit module.

5. A humidification device for a cold mirror dew point meter according to any one of claims 1-3, characterized in that, The solenoid valve module is a two-position two-way solenoid valve, and its two ends are respectively connected to the humidification port and the air supply power module.

6. A humidification device for a cold mirror dew point meter according to claim 2 or 3, characterized in that, The solenoid valve module is a two-position two-way solenoid valve, one end of which is connected to the air inlet of the micro air pump.

7. A humidification device for a cold mirror dew point meter according to claim 2, characterized in that, The micro air pump has a filter element installed at its air inlet.

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