Measuring the dew point temperature

 

(57) Abstract:

The invention relates to the field of measurement technology, in particular to a device for measuring the humidity of gases by the method of dew point. To reduce inertia and to improve the accuracy of measurement measuring the dew point is supplied by the element set the upper level of the laminar zone of the sample tube, the input of which is installed in a pre-calculated without taking into account item setup diffusion zone, and the output part is connected with a plot of exhaust gas from the diffusion zone of the sample tube. 7 C.p. f-crystals, 1 Il.

The invention relates to the field of measurement technology, in particular to a device for measuring the humidity of gases by the method of dew point and can be used in the condensation hygrometers and indicators of corrosive condensate.

Known for measuring the dew point temperature, containing a cooled section of optically transparent body, enclosed in the housing and connected through the optical fibers with the emitter and transducer of the light flux that is connected to the recorder, a cooler and a temperature sensor.with. USSR N 1744618, CL G 01 N 25/66, from 06.06.89 year).

A disadvantage of the known isopropranolol body, resulting in reduced accuracy and loss of efficiency.

The technical nature closest to the proposed technical solution is measuring the dew point temperature, containing a cooled section of optically transparent body, enclosed in the housing and connected through the optical fibers with the emitter and transducer of the light flux that is connected to the logger, cooler, temperature sensor and a sampling tube having in the operating mode turbulent, laminar and diffusion zone, one end of the sampling tube mounted on the housing of the cooled area of the optically transparent body, the other end is installed in the direction of the action of gravitational forces (see RF patent N 2085925, CL G 01 N 25/66, from 25.06.95 year).

In the known device provided with the necessary reliability by reducing possible contamination of the optically transparent body.

However, due to the considerable thickness of structural elements of the fastening on the gas pipeline 14 (flange 15 and the welding seam 16), a shut-off valve (Fig. absent), which usually precedes optically transparent body 1, the length L of the sample tube increases, and the requirements for its value to cause the bulkiness of the design, and the use of small diameter leads to an increase in the length of the diffusion zone 13 and thus to increase the inertia of the device.

The technical result is to reduce the inertia of the device by reducing the length of the diffusion zone.

For this meter dew point temperature, containing a cooled section of optically transparent body, enclosed in the housing and connected through the optical fibers with the emitter and transducer of the light flux that is connected to the logger, cooler, temperature sensor and a sampling tube having in the operating mode turbulent, laminar and diffusion zone, one end of the sampling tube mounted on the housing of the cooled area of the optically transparent body, the other end is installed in the direction of the action of gravitational forces, according to the invention, the meter is equipped with an element set the upper level of the laminar zone of the sample tube having a penetration hole, the input part of which is installed in a pre-calculated without taking into account item setup diffusion zone, and the output part is connected with a plot of exhaust gas from the diffusion zone of the sample tube, the element installation vernagemery sampling tube dCRand above a small tube attached inside the sample tube, the upper end of the small tube is the input part of the installation of the upper level of the laminar zone of the sample tube, the lower end of an output part of the element and is located abroad cutoff line of the sample tube, in addition, the lower end of the small tube has a bend in the direction of gas flow, and dm< 0.5 dCRin addition, according to the invention can be additionally introduced a regulating valve in the casing or on the upper end of the sampling tube, the needle valve is located near the refrigerated section of optically transparent body, and the output is associated with a region of atmospheric pressure, it also set an upper level of the laminar zone of the sample tube can be made in the form of a needle valve mounted on the case or on the upper end of the sampling tube, the inlet needle valve is the input part and the output of the output part of the installation of the upper level of the laminar zone of the sample tube, and the part of the exhaust gas is an area of atmospheric pressure, in addition, test inside is made of stainless steel or PTFE.

The essence of the invention lies in the fact that the introduction of an element of the Assembly of the upper level of the laminar zone allows to reduce the length of the diffusion zone, providing a reduction of inertia and therefore increasing performance.

The comparison of the proposed device with the prototype allows to speak about the criterion of "novelty", and the lack of distinctive features in the equivalent of the criterion of "inventive step".

Preliminary tests allow to judge about the wide industrial use of the claimed device.

The drawing shows the design of the proposed device.

The meter contains a cooled section 1 optically transparent body, enclosed in the casing 2 and connected through the optical fibers 3 and 4 respectively with the emitter 5 and inverter 6 of the light flux, the output of which is connected to the recorder 7. In the housing 2 is installed the temperature sensor 8 and the cooler 9. The device is equipped with a sampling tube 10, one end of which is fixed on the housing 2 around the cooled section 1 optically transparent body and the other end is made with a bevel and installed in the direction of the action of gravitational forces. Problem three zones 11 - 13 transfer of molecules of the test gas to the cooled section 1: respectively, turbulent, laminar and diffusion.

The meter is installed in the hole of the pipe 14 having a flange 15, is bonded with the pipe 14 by a locking connection 16.

In addition, the meter is equipped with an element set the upper level of the laminar zone 12 of the sampling tube 10, having a penetration hole of the input part of which is installed in a pre-calculated without taking account of the above item setup diffusion area 13, and the output part is connected with the site (place) of the exhaust gas from the diffusion zone 13 of the sample tube 10.

One of the versions of the installed top-level laminar zone 12 is the fulfillment of it in the form of a small tube 17, the diameter dmwhich is less than the diameter dCRthe sample tube 10.

The best option execute when dm< 0.5 dCR.

Shallow tube 17 is fixed inside of the sample tube 10, the upper end of it is the input part of the installation of the upper level of the laminar zone 12, and the lower end of an output part of the element and is located abroad cutoff line of robotberget set an upper level of the laminar zone 12 is the fulfillment of it in the form of a needle valve 18, mounted on the housing 2 or on the upper end of the sampling tube 10.

At the entrance of the adjusting valve 18 is input part and the output of the output part of the installation of the upper level of the laminar zone 12, and a portion of the exhaust gas is an area of atmospheric pressure.

In addition, the meter can be equipped with skirt 19 that is installed inside of the sample tube 10 around the cooled section 1 optically transparent body.

Skirt 19 may be made of stainless steel or PTFE.

In addition, according to the invention possible embodiment of the measuring device, which contains a regulating valve 18, the inlet of which is installed near the refrigerated section 1 optically transparent body, the output is associated with a region of atmospheric pressure, and a small tube 17 that is installed as described above.

The ratio of the area S of the internal cross section of the sampling tube 10 and the area S of the surface of the cooled section 1 optically transparent body should be less than 5, a L2/S > 25, where L is the length of the sample tube 10.

When such ratios inside the sample tube 10 during operation are formed three zones 11, 12, 13: Turbonegro body can be used in optical fibre, and as the emitter 5 led type AL-B.

The meter operates as follows.

When a device is placed in the environment of the test gas or mixture of gases the last act on the condensation surface of the cooled section 1 optically transparent body, in the absence of moisture condensation on the surface of the condensate is not allocated, and the flow of light from the emitter 5 to the optical fiber 3 passes through the cooling section 1 and the light guide 4, goes to the input of the Converter 6, but output it to the Registrar 7 nothing is supplied, indicating the absence of the condensate, and it does not register the temperature of the dew point.

In the sampling tube 10 are formed three zones 11, 12, 13, and the upper level of the laminar zone 12, coinciding with the lower level of the diffusion zone 13, is determined by the location of the input part of the installation of the upper level of the laminar zone 12. For the case of execution in the form of a small tube 17 this level will be determined by the cross section of the upper end of the small tube 17, through which through injection will be suction gas in the area of exhaust gas from the diffusion zone, located outside the boundary of the cutoff line attached to the needle valve 18 in the upper level of the laminar zone 12 will be determined by the level of the axis of the hole, which has a regulating valve and through which there will be a suction gas into the atmosphere of the diffusion zone in the region of least pressure, reducing the length of the diffusion zone and reducing the inertia of the meter.

The use of a needle valve 18 in the presence of a small tube 17 is needed for other functions. In particular, through the valve 18 may be taken the sample gas or can be used other necessary actions.

The presence of the skirt 19 is necessary to protect the refrigerated section 1 from damage. In addition, the lower level of the skirt 19 affects the boundary diffusion and laminar zones 12 and 13, which may be taken into account when setting.

In the presence of moisture in the analyzed gas cooled section 1 optically transparent body at a certain temperature it forms a layer of condensate from the fine droplets of spherical shape having a diameter commensurate with the diameter of the core of the applicable light guide 3. Due to the dispersion of the luminous flux surfaces of fine droplets of condensate intensity sharply decreases until complete dispersion in the refrigerated section 1 optically transparent body Converter 6 vegetatio 8 temperature, which role can play a thermocouple connected to the galvanometer. The measured dew point temperature can be used to determine the hygrometric parameters of the analyzed gas mixture or process automation, which yields this gas mixture.

The leakage test gas in the sample tube 10 is on the opposite side of the bevel, thus protected from direct splashes, droplets and particles in the sensor area.

In the sampling tube 10 there are three zones 11 - 13 transmission of the test gas molecules to plot 1. Direct air cooling of the sample tube 10 by the gas flow causes turbulence inside her in the zone 11, which carry the molecules of the test gas, possible impurities, aerosols and solid particles in zone 12. The energy of the vortices is lost and in zone 12, the movement of the gases is laminar in nature, and bringing the gas into the zone 13 diffusive exchange of molecules, the presence of which leads to filtration of aerosols and trace contaminants present in the analyzed gas and aerosols and solids reach only zone 12 laminar flows, not penetrating into the diffusion zone 13 due to the impact on H12, it is turbulent, then the laminar flow will bring aerosols and trace amounts of condensation on the surface of the sensor and cause contamination. The lengths of the zones 11 and 12 depends on the size of the sampling tube 10 and the speed notcause gas on the bevel of the sample tube 10. If the sample tube 10 is cylindrical, then the sum of the lengths of the zones 11 and 12 does not exceed five diameters, i.e., if the length of the tube 10 to be shorter than five diameters, particles and aerosols from contaminating the mirror and cause a malfunction.

If the sample tube has a cross section the shape of a circle, then there is a limit of L2/S > 25, where L is the length of the sampling tube 10, S - the area of its inner section.

Thus, the existence of an Assembly of the upper level of the laminar zone of the sample tube can reduce the length of the diffusion zone, to reduce inertia, providing due to this high performance meter and thereby improving the measurement accuracy.

1. Measuring the dew point temperature, containing a cooled section of optically transparent body, enclosed in the housing and connected through the optical fibers with the emitter and transducer luminous flux connected to registrou and diffusion zone, one end of the sampling tube mounted on the housing of the cooled area of the optically transparent body, the other end is installed in the direction of the action of gravitational forces, characterized in that the meter is supplied by the element set the upper level of the laminar zone of the sample tube having a penetration hole, the input of which is installed in a pre-calculated without taking into account item setup diffusion zone, and the output part is connected with a plot of exhaust gas from the diffusion zone of the sample tube.

2. Measure p. 1, characterized in that the element set the upper level of the laminar zone of the sample tube made in the form of a small tube, the diameter dmless than the diameter of the sampling tube dCRand above a small tube attached inside the sample tube, the upper end of the small tube is the input part of the installation of the upper level of the laminar zone of the sample tube, and the lower end of an output part of the element and is located abroad cutoff line of the sample tube.

3. Measure p. 2, characterized in that the lower end of the small tube has a bend in the direction of gas flow.

4. Receiving, that added a regulating valve in the casing or on the upper end of the sampling tube, the needle valve is located near the refrigerated section of optically transparent body, and the output is associated with a region of atmospheric pressure.

6. Measure p. 1, characterized in that the element set the upper level of the laminar zone of the sample tube made in the form of a needle valve mounted on the case or on the upper end of the sampling tube, the inlet needle valve is the input part and the output of the output part of the installation of the upper level of the laminar zone of the sample tube, and the part of the exhaust gas is an area of atmospheric pressure.

7. Measure p. 1, characterized in that the inside of the sampling tube around the cooled area of the optically transparent body installed skirt.

8. Measure p. 7, characterized in that the skirt is made of stainless steel or PTFE.

 

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