CN206818487U - A multi-functional flue gas mercury automatic sampling system - Google Patents

Abstract

The utility model relates to a multifunctional flue gas mercury automatic sampling system. The system includes: a sampling gun, which is composed of the connection between the top of the sampling gun and the base of the sampling gun. A sampling hole and a flue gas mixing chamber are arranged on the top of the sampling gun, and a thermocouple can also be set at the sampling hole; A filter screen is provided, and an adsorption tube and a flue gas analysis sampling tube are provided at the gas outlet end of the sampling gun base, and a back-blowing gas inlet is further provided at the sampling gun base for blowing and cleaning; the flow metering device, which is connected with the adsorption Pipe connection, used to measure the flue gas flow; suction pump; flue gas analyzer, which is connected with the flue gas analysis sampling pipe for flue gas analysis. It further includes computer for real-time data display, recording, processing and remote control. The flue gas sampling of the utility model is more representative, and can simultaneously collect and analyze mercury and detect other components, ensure simultaneous sampling from the same point, improve measurement efficiency and accuracy; and simultaneously measure temperature distribution in the flue.

Description

A multi-functional flue gas mercury automatic sampling system

technical field

The utility model belongs to the technical field of flue gas analysis, in particular to a multifunctional flue gas mercury automatic sampling system.

Background technique

In recent years, due to the concealment, high volatility, easy migration, high bioaccumulation and potential persistent harm of trace elements, especially mercury, in environmental pollution, it has attracted widespread attention from the international community. Coal-fired power plants are the largest source of man-made mercury pollution. Mercury in coal enters the open environment through combustion for migration, transformation and redistribution, and the environmental pollution is becoming increasingly serious.

The detection and treatment of tail gas emitted after coal combustion can better reduce the emission of mercury from coal combustion, which requires sampling and measurement of flue gas. The existing flue gas mercury sampling gun has a single sampling point, is not flexible, and the sampling is not representative, and the cleaning of the sampling gun is inconvenient. When measuring the flue gas temperature, it is necessary to bind the thermocouple to the sampling gun with iron wire, which greatly increases the workload of the test.

In order to study the oxidation removal efficiency of mercury and the reduction efficiency of NO by SCR catalyst, the sampling and detection of mercury and NO are very important issues. However, in the existing technology, there is only a separate sampling and detection method for NO or mercury in the flue gas, and there is no method for sampling and detecting both at the same time, which easily leads to unrepresentative flue gas sampling.

In the field of thermal power generation and coal chemical industry, after pulverized coal is burned or gasified, real-time monitoring of the flue gas is required, focusing on pollutants such as nitrogen oxides and sulfur dioxide, combustibles such as carbon monoxide and hydrogen, and residual oxygen. Provide accurate information for boiler combustion adjustment or gasifier parameter adjustment. In order to accurately measure the flue gas composition, it is necessary to take the flue gas out of the boiler or gasifier and perform purification treatment to obtain qualified flue gas that can be used for instrument detection. At present, for the measurement of flue gas components of power plant boilers, a single thin iron pipe is mostly used, only two ends are open, one end is inserted into the flue, and the other end is connected to the flue gas analyzer. During the measurement, the sampling pipe is gradually pulled out according to a certain length. , a set of data is measured at each point to achieve the target test of the entire section grid method. After the measurement of the flue gas composition is completed, when measuring the boiler flue temperature, the iron pipe for testing the flue gas composition should be replaced with a pipe for flue gas temperature measurement. A thermocouple is installed inside the tube, and the end of the tube is connected with a hand-held temperature measuring instrument, so as to realize the measurement of the flue gas temperature. In this method, the smoke composition test and the smoke temperature measurement cannot be carried out simultaneously, and the measurement time is long, the workload is large, the manual error is large, and the measurement accuracy is low.

Therefore, it is of great practical significance to produce a device that can simultaneously sample mercury, analyze and detect flue gas components, and measure flue gas temperature to solve existing problems.

Utility model content

Aiming at the deficiencies of the prior art, the utility model provides a multi-functional flue gas mercury automatic sampling system.

A multifunctional flue gas mercury automatic sampling system, the system includes,

Sampling gun, which is formed by connecting the top of the sampling gun with the base of the sampling gun; the top of the sampling gun is a cavity structure, the far end is sealed, and the side wall of the top of the sampling gun is provided with 1 to a plurality of sampling holes; the sampling gun The base is a cavity structure, and a filter screen is arranged in the base of the sampling gun, and an adsorption tube and a sampling tube for flue gas analysis are arranged at the outlet end of the base of the sampling gun;

A flow metering device, which is connected to the adsorption pipe, is used to measure the flue gas flow; a valve is provided on the connecting pipe between the flow metering device and the adsorption pipe;

Air extraction pump, which is connected to the pipeline for collecting flue gas mercury and flue gas flow measurement;

The flue gas analyzer is connected with the flue gas analysis sampling pipe for flue gas analysis; a valve is arranged on the connecting pipe between the flue gas analyzer and the flue gas analysis sampling pipe.

In one embodiment, the top of the sampling gun is formed by detachable connection of one or more sections of sampling tubes; sampling holes are provided on the sampling tubes.

In one embodiment, the inner wall of the sampling gun is covered with a heating layer.

In one embodiment, a thermocouple is provided on each sampling hole.

In one embodiment, two adsorption tubes are arranged on the base of the sampling gun, and each adsorption tube corresponds to a flow metering device.

In one embodiment, the adsorption tube is connected to the acid removal device through a heat tracing pipeline, and the acid removal device, dehumidification device, flow metering device, and air suction pump are connected in sequence.

In one embodiment, on the base of the sampling gun, temperature and pressure measuring devices are respectively provided on the front and rear sides of the filter screen.

In one embodiment, the filter screen is a cylindrical structure in which porous mesh sheets are wound.

In one embodiment, the base of the sampling gun is provided with a backflush gas inlet connected to a compressed air pipeline, and the opening and closing of the backflush gas inlet is controlled by a valve.

In one embodiment, the system further includes a computer, which is used for real-time data display, recording, processing, and process monitoring, as well as controlling the start and stop of the air pump and the opening and closing of the valve, so as to perform remote control of the sampling process.

The beneficial effects of the utility model are:

1. The utility model can perform multi-point sampling of flue gas, and the sampling flue gas is fully mixed in the cavity at the top of the sampling gun, so that the flue gas taken is representative. The length of the sampling gun can adjust the number of sampling pipes according to the width of the flue, and the sampling hole can be blocked as required. The utility model can improve the representativeness, flexibility and convenience of flue gas sampling of the power station boiler, and can effectively reduce the working time of measurement.

2. The utility model can measure the temperature of each sampling point and indirectly measure the temperature field in the flue, which simplifies the work and does not need to measure the temperature in the flue separately for temperature measurement.

3. The flue gas of the two adsorption pipelines is always processed independently, and the two groups of gases do not intersect, ensuring that each gas path has an independent flue gas mercury collection device and an independent flow metering device, ensuring the balance between the two Comparability enables parallel sampling and results can be calibrated to each other.

4. There is a filtering device in the sampling gun of the utility model, which can be used for sampling and measurement in a high-ash environment, prevents the adsorption tube from being blocked, and expands the scope of use.

5. The utility model has an automatic back-blowing function, which can conveniently clean the sampling gun, not only prevent the smoke from clogging the pipeline, reduce the risk of the experiment terminal, improve the efficiency and accuracy of sampling, but also the operator can work away from the noise and dust area , Reduce personal injury, simple and convenient operation.

6. The utility model can analyze sulfur dioxide, oxygen, NO and other components of the flue gas while collecting mercury in the flue gas, ensuring simultaneous sampling from the same point, reducing measurement errors, and improving measurement efficiency and accuracy.

Description of drawings

Fig. 1 is a structural schematic diagram of a multifunctional flue gas mercury automatic sampling system in an embodiment.

Fig. 2 is a cross-sectional view of a sampling gun in an embodiment.

Explanation of symbols: 1-sampling gun, 2-heating pipeline, 3-first valve, 4-second valve, 5-1-first acid removal device, 5-2-second acid removal device, 6-1- The first dehumidification device, 6-2-the second dehumidification device, 7-1-the first flow metering device, 7-2-the second flow metering device, 8-1-the first suction pump, 8-2-the second pumping Air pump, 9-computer, 10-flue gas analyzer, 11-third valve, 12-fourth valve, 13-backflush gas inlet, 1-1-top of sampling gun, 1-2-sampling hole, 1-3 -thermocouple, 1-4-nut, 1-5-sampling gun base, 1-6-temperature and pressure measuring device, 1-7-filter, 1-8-first adsorption tube, 1-9-second Adsorption tube, 1-10-flue gas analysis sampling tube.

detailed description

The utility model will be further described below in conjunction with the accompanying drawings and specific embodiments. It should be emphasized that the following descriptions are only illustrative, not intended to limit the scope of the present utility model and its application.

As shown in Fig. 1, it is a kind of multifunctional smoke mercury automatic sampling system that the utility model provides, and this system comprises sampling gun 1, flow measuring device, flue gas analyzer, suction pump, and the computer 9 that carries out remote control, by The computer 9 performs real-time display, recording, analysis and monitoring of the sampling process of data.

The sampling gun 1 is composed of a sampling gun top 1-1 connected to a sampling gun base 1-5, as shown in FIG. 2 . A heating layer is also covered on the inner walls of the sampling gun top 1-1 and the sampling gun base 1-5 to keep the internal temperature above 120°C.

The top 1-1 of the sampling gun is formed by connecting multiple sections of sampling tubes through threads, and a sampling hole 1-2 is arranged on the sampling tube, and the end of the sampling tube at the farthest end is sealed. The inner cavity of the top 1-1 of the sampling gun is a flue gas mixing cavity. The number of sampling pipes can be adjusted according to the width of the flue, and each sampling hole 1-2 is equipped with matching bolts, which can be used to block the sampling holes as required, so that the collected flue gas is more representative. Each sampling hole 1-2 is respectively provided with a thermocouple 1-3, which can measure the temperature of the corresponding position in the flue, and obtain the temperature distribution in the flue. The nut 1-4 can be welded on the outer wall of the sampling gun 1, and the thermocouple 1-3 is fixed on the outside of the sampling gun 1 by welding on the nut 1-4, so as to prevent the temperature in the sampling gun 1 from affecting the measurement of smoke by the thermocouple 1-3. temperature in the tunnel.

The sampling gun base 1-5 is a cavity structure, and a filter screen 1-7 is arranged in the sampling gun base 1-5, and the filter screen 1-7 adopts a cylindrical structure wound by a porous mesh, which can prevent smoke Filter the air to prevent smoke and dust from entering subsequent pipelines and devices, and protect the equipment from damage.

The first adsorption tube 1-8, the second adsorption tube 1-9 and the flue gas analysis sampling tube 1-10 are arranged side by side at the gas outlet end of the sampling gun base 1-5, the first adsorption tube 1-8, the second adsorption tube Pipes 1-9 and flue gas analysis sampling pipes 1-10 can be disassembled and replaced. The first adsorption tube 1-8, the second adsorption tube 1-9 and the flue gas analysis sampling tube 1-10 are all high temperature resistant and unbreakable quartz tubes. 9 is loaded with an adsorbent for adsorbing mercury.

The first adsorption pipe 1-8 is connected to the first acid removal device 5-1 through the heat tracing pipeline 2, the first acid removal device 5-1, the first dehumidification device 6-1, the first flow metering device 7-1 and the first acid removal device 5-1. A suction pump 8-1 is connected in turn. A first valve 3 is provided on the heating line 2 of this road.

The second adsorption pipe 1-9 is connected with the second deacidification device 5-2 through the heat tracing pipeline 2, the second deacidification device 5-2, the second dehumidification device 6-2, the second flow metering device 7-2 and the second deacidification device 5-2. Two suction pumps 8-2 are connected in turn. A second valve 4 is provided on the heating line 2 of this road.

In the above-mentioned two-way flow metering mechanism, an identification number can be set for each adsorption tube for subsequent analysis. The flue gas of the two pipelines is always processed independently, and the two groups of gases do not cross, ensuring that each gas path has an independent flue gas mercury collection device and an independent flow metering device, ensuring the comparability of the two , parallel sampling is achieved, and the results can be calibrated to each other. The pipelines between acid removal device, dehumidification device, flow metering device and air pump are all made of acid-resistant polytetrafluoroethylene material. The flue gas first passes through the acid removal device, and then enters the dehumidification device and flow metering device, which ensures that the corrosive gas in the flue gas will not corrode the pipeline and subsequent devices.

The flue gas analysis sampling pipe 1-10 is connected to the flue gas analyzer 10 through the heating line 2, and the third valve 11 is arranged on the heating line 2. The flue gas analyzer 10 can be used to analyze components such as sulfur dioxide, oxygen, and NO in the flue gas. The detection of other components in the flue gas is realized while the mercury sampling is completed on the flue gas, ensuring that the obtained mercury, NO, sulfur dioxide, and oxygen contents are at the same sampling point, which improves the sampling efficiency and reduces the detection cost.

The back blowing gas inlet 13 is connected with the compressed air pipeline on the sampling gun base 1-5, and a fourth valve 12 is arranged on the connecting pipeline to control the opening and closing of the back blowing gas inlet 13. During normal pumping, the fourth valve 12 is closed, and the first valve 3, the second valve 4, and the third valve 11 are opened. When the sampling gun 1 needs to be back-flushed and cleaned, the first valve 3, the second valve 4, and the third valve 11 are closed, the fourth valve 12 is opened, and compressed air enters the sampling gun 1 to purge the sampling gun 1.

On the sampling gun base 1-5, the front and rear sides of the filter screen 1-7 are respectively provided with temperature and pressure measuring devices 1-6.

The thermocouple 1-3, the first flow metering device 7-1, the second flow metering device 7-2, the flue gas analyzer 10, and the temperature and pressure measuring device 1-6 are respectively connected to the computer 9, and the flue temperature is measured by the computer 9. , flue gas flow, flue gas composition, temperature and pressure before and after the filter 1-7 are displayed, recorded and processed in real time. The first air pump 8-1 and the second air pump 8-2 are respectively connected to the computer 9, and the computer 9 controls the automatic start and stop of the air pump. The first valve 3, the second valve 4, the third valve 11, and the fourth valve 12 are respectively connected to the computer 9, and the computer 9 controls the automatic opening and closing of the valves. Thus, the remote control of the sampling process is realized.

The heating pipeline 2 mentioned above includes an acid-resistant polytetrafluoroethylene tube and a resistance wire capable of adjusting the heating temperature from 0 to 180° C., and the resistance wire is wound outside the polytetrafluoroethylene tube.

Work process of the present invention:

During normal operation, the sampling gun 1 is extended into the flue, and the fourth valve 12 is closed by the remote control of the computer 9, the first valve 3, the second valve 4, and the third valve 11 are opened, and the first air pump 8-1, the second valve Two suction pumps 8-2 are opened. The flue gas passes through the sampling hole 1-2 and is fully mixed in the cavity at the top of the sampling gun 1-1. Since the sampling holes are distributed at different depths in the same section, the flue gas mixing can make the extracted flue gas more representative. At the same time, the thermocouples 1-3 measure the temperature of the corresponding position in the flue, and transmit the temperature data of the flue to the computer 9 .

The mixed flue gas passes through the filter screen 1-7 to filter out dust and other particles, and the two temperature and pressure measuring devices 1-6 measure the temperature and pressure before and after the filter screen 1-7, and transmit the temperature and pressure data to the computer 9, so that Calculate the amount of flue gas drawn in.

The flue gas is divided into 3 strands after passing through the filter screen 1-7, two of which pass through the first adsorption tube 1-8 and the second adsorption tube 1-9 containing the adsorbent respectively, the mercury in the flue gas is absorbed by the adsorbent, and the After the end, the first adsorption tube 1-8 and the second adsorption tube 1-9 can be taken to analyze the mercury content in them. The flue gas after passing through the adsorption tube enters the acid removal device through the heating pipeline 2, and the flue gas passes through the acid removal device. Absorb corrosive gas, remove moisture through dehumidification device, and finally enter flow metering device to measure flow, and transmit the flow data of the two channels to computer 9 . The third flue gas enters the flue gas analyzer 10 through the heating pipeline 2 to analyze other components in the flue gas and transmit the flue gas component data to the computer 9 . The heat tracing pipeline 2 can ensure that the flue gas will not be condensed and produce too much moisture during the transmission process.

The computer 9 calculates whether the pressure difference between the front and rear sides of the filter screen 1-7 is greater than the set value. When the pressure difference exceeds the set value, the filter screen 1-7 is blocked by smoke and dust. At this time, the computer 9 controls the first valve 3 and the second valve. The second valve 4 and the third valve 11 are closed, the work of the flow metering device and the flue gas analyzer 10 is suspended, the fourth valve 12 is opened, and the compressed air enters the sampling gun 1 from the back blowing gas inlet 13 through the fourth valve 12 to realize For the cleaning of the sampling gun 1, the cleaning time is fixed for 5 minutes, and the cleaning time can also be adjusted according to actual needs, then the fourth valve 12 is closed, the first valve 3, the second valve 4, and the third valve 11 are opened, and the flow metering device and the smoke The work of the gas analyzer 10.

Claims (10)

1. A multifunctional flue gas mercury automatic sampling system is characterized in that the system comprises, Sampling gun, which is formed by connecting the top of the sampling gun with the base of the sampling gun; the top of the sampling gun is a cavity structure, the far end is sealed, and the side wall of the top of the sampling gun is provided with 1 to a plurality of sampling holes; the sampling gun The base is a cavity structure, and a filter screen is arranged in the base of the sampling gun, and an adsorption tube and a sampling tube for flue gas analysis are arranged at the outlet end of the base of the sampling gun; A flow metering device, which is connected to the adsorption pipe, is used to measure the flue gas flow; a valve is provided on the connecting pipe between the flow metering device and the adsorption pipe; Air extraction pump, which is connected to the pipeline for collecting flue gas mercury and flue gas flow measurement; The flue gas analyzer is connected with the flue gas analysis sampling pipe for flue gas analysis; a valve is arranged on the connecting pipe between the flue gas analyzer and the flue gas analysis sampling pipe. 2. The system according to claim 1, wherein the top of the sampling gun is formed by detachable connection of one or more sections of sampling tubes; sampling holes are provided on the sampling tubes. 3. The system according to claim 1 or 2, characterized in that the inner wall of the sampling gun is covered with a heating layer. 4. The system according to claim 1 or 2, characterized in that a thermocouple is respectively provided on each sampling hole. 5. The system according to claim 1, characterized in that two adsorption tubes are arranged on the base of the sampling gun, and each adsorption tube corresponds to a flow metering device. 6. The system according to claim 1 or 5, characterized in that, the adsorption pipe is connected to the acid removal device through a heating line, and the acid removal device, dehumidification device, flow metering device, and air pump are connected in sequence. 7. The system according to claim 1, characterized in that, on the base of the sampling gun, temperature and pressure measuring devices are respectively provided on the front and rear sides of the filter screen. 8. The system according to claim 1, wherein the filter screen is a cylindrical structure wound with a porous mesh. 9. The system according to claim 1, characterized in that, the base of the sampling gun is provided with a back blowing gas inlet connected to a compressed air pipeline, and the opening and closing of the back blowing gas inlet is controlled by a valve. 10. The system according to claim 1, further comprising a computer, which is used for real-time data display, recording, processing and process monitoring, as well as controlling the start and stop of the suction pump and the opening and closing of the valve.