Permeable mercury vapor source temperature control device

Abstract

The utility model provides a temperature control device for a permeable mercury vapor source, which can realize accurate temperature control and ensure stable output of the permeable mercury vapor source, and is good in anti-interference performance. Comprising a mercury vapor source evaporation chamber, the mercury vapor source evaporation chamber is covered with a heat preservation shell, a heating piece is arranged in the heat preservation shell, a temperature sensor and a capillary tube are arranged in the mercury vapor source evaporation chamber, and the capillary tube is led out from an air outlet of the mercury vapor source evaporation chamber. The heating piece and the temperature sensor are connected with a PID temperature controller arranged outside the heat preservation shell.

Description

Technical Field

[0001] The utility model relates to the technical field of mercury vapor source temperature control, in particular to a permeation type mercury vapor source temperature control device. Background Art

[0002] In order to understand the changing trend of mercury emissions, it is necessary to measure the mercury content in water, soil, air and other environmental substances in the domestic natural environment.

[0003] Mercury is currently measured using a mercury analyzer. When measuring mercury, the mercury analyzer needs to be calibrated with equipment such as standard liquid or a mercury generator to ensure the authenticity of the test results. Therefore, calibration equipment is crucial for mercury measurement. There are two main types of calibration sources available: one uses a prepared mercury standard solution to react with relevant reagents to generate mercury vapor for calibration; the other is a mercury vapor source, which places liquid mercury in an evaporation vessel to generate saturated mercury vapor at a specific temperature. The calibration method using a mercury standard solution to react with reagents to generate mercury vapor requires extensive manual work, the preparation of reagents that cannot be stored for long periods of time, and the time required to complete the calibration, so it is generally only used in laboratories. In the other calibration method, mercury vapor sources are divided into two types: injection extraction and permeation. The injection extraction type has a larger chamber, and during use, the saturated mercury vapor in the chamber must be extracted with a syringe. It is mainly used for manual operation in the laboratory. The injection extraction type mercury vapor source relies on manual operation and cannot be integrated into mercury analyzers. The permeation type replaces the chamber with a capillary tube and uses an extremely low-flow carrier gas to automatically drive the generated saturated mercury vapor out of the capillary tube. The direction of the outflowing gas is controlled by a switching valve, thereby automatically turning the mercury vapor generator on and off. Therefore, it is commonly used in automatic analytical instruments. Therefore, the vast majority of mercury analyzer calibrations are completed using a permeation type mercury vapor source.

[0004] At present, high-precision temperature control is usually used to ensure the stable output of the permeable mercury vapor source. A permeable mercury vapor source temperature control structure is currently used, which is to assemble a heating wire in the mercury vapor source evaporation chamber, and then control the temperature by controlling the start and stop of the heating wire. However, the heating wire has only two states: on and off, so its temperature trend graph is sawtooth-shaped, which makes it difficult to accurately maintain a specific temperature, especially when faced with situations with high temperature requirements, it is often difficult to meet the requirements. For this reason, another permeable mercury vapor source temperature control structure is currently proposed, which is to assemble a heating wire, a temperature measuring probe, and a voltage regulator in the mercury vapor source evaporation chamber, measure the temperature in the mercury vapor source evaporation chamber by the temperature measuring probe, and feed it back to the voltage regulator, and then the voltage regulator adjusts the temperature according to the measured temperature. The difference between the measured value of the temperature probe and the temperature set value is used to adjust the voltage driving the heating wire, and then the heating power of the heating wire is controlled to achieve temperature control; however, in this temperature control method, the heating power of the heating wire is related to the temperature in the mercury vapor source evaporation chamber, the temperature set value, etc., that is, the greater the difference between the temperature of the mercury vapor source evaporation chamber and the temperature set value, the greater the voltage driving the heating wire. Conversely, the smaller the difference between the temperature of the mercury vapor source evaporation chamber and the temperature set value, the smaller the voltage driving the heating wire. Therefore, after a certain stabilization time, although it can accurately maintain a certain specific temperature, the closer to the set temperature, the lower the heating power. Therefore, the mercury vapor source with this temperature control design often requires a longer stabilization time, and the temperature control is easily affected by external temperature and is more susceptible to interference. Utility Model Content

[0005] In response to the above problems, the present invention provides a temperature control device for a permeable mercury vapor source, which can achieve precise temperature control, ensure stable output of the permeable mercury vapor source, and has good anti-interference performance.

[0006] The utility model adopts the following technical solution: a permeable mercury vapor source temperature control device comprises a mercury vapor source evaporation chamber, the mercury vapor source evaporation chamber is covered with a heat-insulating shell, a heating plate is installed in the heat-insulating shell, a temperature sensor and a capillary are installed in the mercury vapor source evaporation chamber, the capillary is led out from the air outlet of the mercury vapor source evaporation chamber, and the heating plate and the temperature sensor are both connected to a PID temperature controller externally arranged on the heat-insulating shell.

[0007] Furthermore, the heating plates are provided in two groups, and mounting grooves are provided in the insulation shell, and the heating plates are installed in the mounting grooves;

[0008] Furthermore, the heat-insulating shell is made of aluminum metal;

[0009] Furthermore, the mounting groove and the mercury vapor source evaporation chamber are both filled with thermally conductive silicone grease;

[0010] Furthermore, the mercury vapor source evaporation chamber is provided with a carrier gas inlet for introducing a carrier gas;

[0011] Furthermore, a mercury vapor source is placed in the mercury vapor source evaporation chamber, and the temperature sensor is installed on one side of the mercury vapor source evaporation chamber close to the mercury vapor source.

[0012] The beneficial effect of the utility model is that it is covered with an insulation shell outside the evaporation chamber of the mercury vapor source, which can effectively isolate the interference of the external environment on the temperature control, and the PID temperature controller adopted can control the heating plate to quickly reach the target temperature and stabilize, thereby realizing precise temperature control, thereby ensuring the stable output of the permeable mercury vapor source, and having good economic use value. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a structural diagram of the present utility model. DETAILED DESCRIPTION

[0014] like Figure 1 As shown, the permeation type mercury vapor source temperature control device of the present invention includes a mercury vapor source evaporation chamber 3, which is covered with an insulation shell 9, and a heating plate 4 is installed in the insulation shell 9. The mercury vapor source evaporation chamber 3 is equipped with a temperature sensor 2 and a capillary 7. The capillary 7 is led out from the air outlet 8 of the mercury vapor source evaporation chamber 3. The heating plate 4 and the temperature sensor 2 are both connected to a PID temperature controller 1 externally arranged on the insulation shell 9. The PID temperature controller 1 adopts existing devices to realize automatic temperature control.

[0015] There are two groups of heating plates 4, and an installation groove (not shown in the figure) is provided in the insulation shell 9, and the heating plates 4 are installed in the installation groove; the insulation shell 9 is made of metal aluminum; the installation groove and the mercury vapor source evaporation chamber 3 are filled with thermal grease (not shown in the figure).

[0016] The mercury vapor source evaporation chamber 3 is provided with a carrier gas inlet 5 for introducing a carrier gas. The mercury vapor source evaporation chamber 3 has a built-in mercury vapor source 6 , and the temperature sensor 2 is installed on one side of the mercury vapor source evaporation chamber 3 near the mercury vapor source 6 .

[0017] The utility model uses a heat-insulating shell 9 made of metal aluminum to wrap the entire mercury vapor source evaporation chamber 3, which can improve the resistance of the entire temperature control device to external interference, and installs two heating plates 4 in the heat-insulating shell 9, thereby achieving constant temperature heating of the entire mercury penetration source. At the same time, the PID temperature controller 1 is used. By setting the corresponding PID parameters of the PID temperature controller 1 in advance, the set temperature can be quickly reached.

[0018] The specific working principle is that two heating plates 4 are installed in the installation grooves reserved in the insulation shell 9 made of metal aluminum. Due to the excellent thermal conductivity of metal aluminum, when the heating plates 4 are heated, the heat can be evenly transferred to the entire insulation shell 9, so that the mercury vapor source 6 is heated in all directions, eliminating local temperature differences; the PID temperature controller 1 is installed outside the insulation shell, which can avoid the temperature fluctuation of the mercury vapor source 6 caused by the self-heating of the PID temperature controller 1 during operation; the temperature sensor 2 is installed on one side of the mercury vapor source evaporation chamber 3 close to the mercury vapor source 6. By setting the PID temperature controller 1 in advance, due to the performance of the existing PID temperature controller 1 itself, the PID temperature controller 1 can optimize itself according to the situation, thereby realizing temperature control, and is not affected by changes in the external ambient temperature. Then, after a period of stabilization, a trace amount of carrier gas is introduced at the carrier gas inlet 5 to take away the saturated mercury vapor generated by the evaporation of the mercury vapor source 6 to the capillary 7 to be fully mixed with the carrier gas, and finally output from the gas outlet 8.

[0019] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the present invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be encompassed within the present invention. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

[0020] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A permeation type mercury vapor source temperature control device, comprising a mercury vapor source evaporation chamber, characterized in that: The mercury vapor source evaporation chamber is covered with an insulation shell, a heating plate is installed in the insulation shell, a temperature sensor and a capillary are installed in the mercury vapor source evaporation chamber, the capillary is led out from the air outlet of the mercury vapor source evaporation chamber, and the heating plate and temperature sensor are both connected to a PID temperature controller externally arranged on the insulation shell.

2. The permeation type mercury vapor source temperature control device according to claim 1, characterized in that: The heating plates are provided in two groups, and mounting grooves are provided in the heat-insulating shell, and the heating plates are installed in the mounting grooves.

3. The permeation type mercury vapor source temperature control device according to claim 1, characterized in that: The heat-insulating shell is made of metal aluminum.

4. The permeation type mercury vapor source temperature control device according to claim 2, characterized in that: The mounting groove and the mercury vapor source evaporation chamber are both filled with thermally conductive silicone grease.

5. The permeation type mercury vapor source temperature control device according to claim 1, characterized in that: The mercury vapor source evaporation chamber is provided with a carrier gas inlet for introducing carrier gas.

6. The permeation type mercury vapor source temperature control device according to claim 1, characterized in that: A mercury vapor source is housed in the mercury vapor source evaporation chamber, and the temperature sensor is installed on one side of the mercury vapor source evaporation chamber close to the mercury vapor source.

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