Dynamic sampling system and method for flue gas in high-temperature easy-to-bond high-dust environment

Abstract

The invention discloses a dynamic sampling system and method for flue gas in a high-temperature easily-bonded high-dust environment, and relates to the field of online flue gas analysis, the dynamic sampling system comprises a measuring instrument, a flow limiting pore plate, a high-temperature metal filter cartridge, a sampling tube, an analysis tube, a vacuum power system and a back flushing system, a detection probe of the measuring instrument extends into the analysis tube, the analysis tube is connected with the sampling tube, and the back flushing system is connected with the high-temperature metal filter cartridge. The other end of the sampling pipe is mounted in a high-temperature flue gas side equipment lining measuring hole; the high-temperature metal filter cartridge is positioned in the sampling tube; an opening of the high-temperature metal filter cartridge is sealed with the inner wall of one end, close to the analysis tube, of the sampling tube; the restriction orifice plate is mounted in the analysis tube; the analysis tube is connected with a vacuum tube, the vacuum power system is connected to the vacuum tube, and the vacuum power system is used for enabling the analysis tube to be in negative pressure; and the back flushing system is used for blowing instrument gas into the opening of the high-temperature metal filter cartridge. Online ash removal and blockage removal are realized, so that flue gas process parameters can be accurately monitored in real time.

Description

Technical Field

[0001] The present invention relates to the field of online analysis of flue gas under adverse working conditions, and in particular to a power sampling system and method for flue gas in a high-temperature, easy-to-adhere, high-dust environment. Background Art

[0002] Many hazardous wastes or solid wastes have a large ash content and extremely fine particle size, and the ash often contains alkali metals such as K and Na. When they are disposed of by high-temperature incineration, the flue gas often carries a large amount of dust. The dust has extremely fine particle size, low ash melting point, and is adhesive.

[0003] Many measuring instruments, such as thermocouples and oxygen analyzers, are often required to operate under extremely harsh conditions and frequently fail during actual use.

[0004] For example, in the incinerator furnace thermocouple under high temperature environment, fly ash seriously erodes the thermocouple jacket, and some low melting point substances are easy to adhere to the thermocouple, resulting in inaccurate thermocouple measurement, which in turn leads to high furnace temperature. This not only affects the process control of the incinerator, but also further deteriorates the operating conditions and accelerates the failure of the thermocouple. The replacement cycle is generally 1-3 months.

[0005] For example, oxygen analyzers are often installed on high-temperature flues to monitor the oxygen concentration of flue gas after incineration online, so as to provide real-time feedback on the excess oxygen coefficient during the incineration of hazardous waste. The monitored oxygen concentration directly participates in the control of the incineration process of hazardous waste, and its accuracy directly determines the quality of the combustion process, and plays a vital role in the combustion control of pollutants such as NOx, SO2, and HCl.

[0006] However, the dust content in the flue gas from the incineration of hazardous waste or solid waste is high and has strong adhesion. During the actual operation, the measuring instruments are covered with dust, resulting in a short operation cycle and the need for frequent shutdowns for offline maintenance. This not only affects production, but also the dust itself is hazardous waste, which poses a safety hazard during maintenance. Especially in some areas, the dust particle size is extremely fine, the ash melting point is low, the thermocouple is severely worn, and the dust adheres to the zirconium cell of the oxygen analyzer, resulting in a high frequency of instrument damage, requiring maintenance after 3-15 days of operation.

[0007] Patent CN201920959106.2 "Oxygen analysis and measurement device for dusty environments" extracts flue gas by vacuum extraction, avoiding direct contact between dust and the oxygen analyzer as much as possible. It only solves the problem of vacuum system failure, but does not solve the problem of dust contact with the oxygen analysis zirconium cell.

[0008] Patent CN201921802122.7 "An anti-blocking device for an online high-dust flue gas oxygen analyzer" uses water washing to wash the dust in the flue gas for detection. This method ignores the evaporation of water after high-temperature dust washing and the reaction between dust and water, and indirectly measures the oxygen concentration in the flue gas. However, for materials such as CaO and MgO contained in the dust after the incineration of calcium carbide purification ash, they will react with water, causing water evaporation, which will lead to low oxygen content in the detection, and the oxygen concentration display is seriously delayed, and cannot be displayed online. In addition, a large amount of wastewater is generated, which incurs additional costs for treating the wastewater. Summary of the invention

[0009] The technical problem solved by the present application is: to overcome the deficiencies of the prior art and provide a dynamic sampling system and method for flue gas in a high-temperature, easily sticky and high-dust environment, so as to achieve online dust and blockage removal, thereby ensuring real-time and accurate monitoring of flue gas process parameters and guiding combustion parameter control.

[0010] The technical solutions provided by this application are as follows:

[0011] In the first aspect, a dynamic sampling system for flue gas in a high-temperature, easy-to-bond, high-dust environment is disclosed, which is used to sample the flue gas inside the lining of the high-temperature flue gas side equipment, including a measuring instrument, a flow limiting orifice plate, a high-temperature metal filter cartridge, a sampling tube, an analysis tube, a vacuum power system and a back-blowing system. The measuring instrument is connected to one end of the analysis tube so that the detection probe of the measuring instrument extends into the analysis tube, and the other end of the analysis tube is connected to the sampling tube, and the other end of the sampling tube is installed in the measuring hole of the lining of the high-temperature flue gas side equipment; the high-temperature metal filter cartridge is located in the sampling tube, and the opening of the high-temperature metal filter cartridge is connected to one end of the sampling tube close to the analysis tube, and the opening of the high-temperature metal filter cartridge is sealed with the inner wall of the sampling tube; the flow limiting orifice plate is installed in the analysis tube; the analysis tube is connected to a vacuum tube, and the connection position of the vacuum tube and the analysis tube is located on the side of the flow limiting orifice plate facing the sampling tube, the vacuum power system is connected to the vacuum tube, and the vacuum power system is used to make the analysis tube negatively pressurized; the back-blowing system is used to blow instrument gas into the opening of the high-temperature metal filter cartridge.

[0012] The back-blowing system includes a back-blowing solenoid valve and a second branch pipe, one end of the second branch pipe is connected to the instrument gas source, and the other end passes through the analysis tube and extends into the opening of the high-temperature metal filter cartridge. The back-blowing solenoid valve is installed on the second branch pipe, and the back-blowing solenoid valve is used to control the connection and closing of the second branch pipe.

[0013] The backflush system also includes a first branch pipe, an acoustic wave solenoid valve and an acoustic wave generator. One end of the first branch pipe is connected to the acoustic wave generator and the other end is connected to an instrument gas source. The acoustic wave generator is arranged on the side wall of the analysis tube. The acoustic wave solenoid valve is installed on the first branch pipe. The acoustic wave solenoid valve is used to control the connection and closing of the first branch pipe.

[0014] The vacuum power system is a vacuum pump or an ejector; when the vacuum power system is a vacuum pump, the vacuum pump is connected to one end of the vacuum tube, and a finned heat exchange tube and a sampling solenoid valve are provided on the vacuum tube. The sampling solenoid valve is used to control the connection and closing of the vacuum tube, and the finned heat exchange tube is used to dissipate the heat of the flue gas entering the vacuum tube from the analysis tube; when the vacuum power system is an ejector, the ejector is connected to one end of the vacuum tube, and the ejector is also connected to an ejection pipeline, and the other end of the ejection pipeline is connected to the instrument gas source, and a sampling solenoid valve is provided on the ejection pipeline, and the sampling solenoid valve is used to control the connection and closing of the ejection pipeline, and the instrument gas enters the ejector through the ejection pipeline, and the flue gas in the vacuum tube is ejected in the ejector and ejected from the ejector.

[0015] When the lining of the high-temperature flue gas side equipment is in a horizontal state or the angle between the lining of the high-temperature flue gas side equipment and the horizontal direction is not greater than 30°, the end of the sampling tube away from the analysis tube is semi-cylindrical, and the end of the semi-cylindrical shape away from the analysis tube extends out of the inner side of the lining of the high-temperature flue gas side equipment, and the inner side of the semi-cylindrical shape is the windward side.

[0016] The distance that the end of the semi-cylindrical shape away from the analysis tube protrudes from the inner side surface of the lining of the high-temperature flue gas side equipment is 1-1.5 times the diameter of the sampling tube 5.

[0017] When the lining of the high-temperature flue gas side equipment is in a vertical state or the angle between the lining of the high-temperature flue gas side equipment and the vertical direction is not greater than 60°, the end of the sampling tube extending into the inner side of the lining of the high-temperature flue gas side equipment is flush with the inner wall of the lining of the high-temperature flue gas side equipment, and the sampling tube is arranged at an angle of 55-75° to the horizontal direction. A baffle is provided at the end of the sampling tube extending into the inner side of the lining of the high-temperature flue gas side equipment, and the baffle covers the top of the end of the sampling tube to the axis position.

[0018] The distance between the flow limiting orifice plate 1 and the detection probe of the measuring instrument is 1 / 5-1 / 2 of the diameter of the analysis tube 6 .

[0019] When the measuring instrument is a gas detection instrument, the analysis tube is also connected to a standard gas pipeline. The connection position between the standard gas pipeline and the analysis tube is located on the side of the limiting orifice plate away from the sampling tube. A calibration valve is provided on the standard gas pipeline. The standard gas pipeline is used to introduce standard gas, and the calibration valve is used to control the connection and closing of the standard gas pipeline.

[0020] In the second aspect, a sampling method of a dynamic sampling system for flue gas in a high-temperature, easy-to-bond, high-dust environment is disclosed, comprising:

[0021] Continuous sampling is performed according to small cycles, each small cycle includes an intermittent sampling process and a backwash process, the backwash process is a first backwash process or a second backwash process, and a second backwash process is performed every interval of at least one first backwash process in different small cycles;

[0022] The sampling process includes: the backflush system is turned off, the vacuum power system is started, the sampling tube and the analysis tube are under negative pressure, and the flue gas inside the lining of the high-temperature flue gas side equipment is sampled;

[0023] The first backblowing process includes: the vacuum power system is shut down, the backblowing solenoid valve of the backblowing system is opened, and the sonic solenoid valve is closed; the second backblowing process includes: the vacuum power system is shut down, the backblowing solenoid valve of the backblowing system is closed, and the sonic solenoid valve is opened, and then the sonic solenoid valve is closed and the backblowing solenoid valve is opened.

[0024] In summary, this application at least includes the following beneficial technical effects:

[0025] 1) It can be used in high temperature, high dust and adhesive dust environment. The dust does not come into direct contact with the measuring instrument, which prolongs the service life of the measuring instrument from the original 3-15 days to more than 1 year.

[0026] 2) Online dust cleaning can be achieved, and the dust returns to the original flue gas sample. There is no need for users to frequently disassemble the analyzer components and handle the filter ash, which effectively reduces the labor intensity of personnel.

[0027] 3) Reduce the harm to human body caused by dangerous dust produced after the incineration of hazardous waste, and no waste such as sewage is generated.

[0028] 4) Reduce the cost of frequent replacement of measuring instruments.

[0029] 5) The whole system can be operated remotely and locally, and is easy to operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A structural diagram of a power sampling system for flue gas in a high-temperature, easy-to-adhesive, high-dust environment provided by Example 1 of the present invention;

[0031] Figure 2 A schematic diagram of the distance between the current limiting orifice plate and the detection probe of the measuring instrument;

[0032] Figure 3 It is a schematic diagram of the distance between the semi-cylindrical shape and the inner side of the high-temperature flue gas side equipment liner 12 when the high-temperature flue gas side equipment liner is in a horizontal state;

[0033] Figure 4 A structural diagram of a power sampling system for flue gas in a high-temperature, easy-to-adhesive, high-dust environment provided by Example 2 of the present invention;

[0034] Figure 5 This is a structural diagram of the end of the sampling tube when the lining 12 of the high-temperature flue gas side equipment is in a vertical state.

[0035] Explanation of the accompanying figures: 1. Measuring instrument; 2. Flow limiting orifice; 3. High-temperature metal filter cartridge; 4. Backblowing solenoid valve; 5. Sampling tube; 6. Analysis tube; 7. Sound wave generator; 8. Sound wave solenoid valve; 9. Fin heat exchange tube; 10. Sampling solenoid valve; 11. Vacuum power system; 12. High-temperature flue gas side equipment lining; 13. Instrument gas buffer tank; 14. Calibration valve. DETAILED DESCRIPTION

[0036] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments disclosed in the present invention will be further described in detail below with reference to the accompanying drawings.

[0037] This embodiment discloses a flue gas online oxygen analyzer for an environment prone to dust adhesion, comprising a measuring instrument 1, a flow limiting orifice plate 2, a high-temperature metal filter cartridge 3, a backflush solenoid valve 4, a sampling tube 5, an analysis tube 6, a sonic generator 7, a vacuum power system 11, a high-temperature flue gas side equipment lining 12, an instrument gas buffer tank 13, a calibration valve 14, and connecting pipes, etc. The vacuum power system 11 can be a vacuum pump or an ejector.

[0038] The measuring instrument 1 is connected to one end of the analysis tube 6 through a flange so that the detection probe of the measuring instrument 1 extends into the analysis tube 6. The other end of the analysis tube 6 is connected to the sampling tube 5 through a flange. The other end of the sampling tube 5 is arranged in the measuring hole of the lining 12 of the high-temperature flue gas side equipment. The high-temperature metal filter cartridge 3 is arranged in the sampling tube 5. The outer diameter of the high-temperature metal filter cartridge 3 is smaller than the inner diameter of the sampling tube 5. The opening of the high-temperature metal filter cartridge 3 is connected to one end of the sampling tube 5 close to the analysis tube 6 through an end face flange. The opening of the high-temperature metal filter cartridge 3 is sealed with the sampling tube 5. The flow limiting orifice is installed in the analysis tube 6. The analysis tube 6 is connected with a vacuum tube. The connection position of the vacuum tube and the analysis tube 6 is located on the side of the flow limiting orifice 2 facing the sampling tube. The vacuum tube is connected with a vacuum power system 11. The vacuum power system 11 is used to make the analysis tube 6 negatively pressurized so that the sampling tube 5 can suck the flue gas inside the lining 12 of the high-temperature flue gas side equipment. The acoustic wave generator 7 is arranged on the side wall of the analysis tube 6, and the acoustic wave generator 7 is connected to the instrument gas buffer tank 13 through the first branch pipe. The first branch pipe is provided with an acoustic wave solenoid valve 8. The instrument gas buffer tank 13 is also connected to a second branch pipe. The end of the second branch pipe passes through the analysis tube 6 and extends into the opening of the high-temperature metal filter cartridge 3. The second branch pipe is provided with a back-blowing solenoid valve 4.

[0039] When the high-temperature flue gas side equipment lining 12 is in a horizontal state or nearly horizontal state, the sampling tube 5 can be sampled in a vertical state. At this time, the end of the sampling tube 5 away from the analysis tube 6 is semi-cylindrical, and the end of the semi-cylindrical shape away from the analysis tube 6 extends out of the inner side of the high-temperature flue gas side equipment lining 12. The distance that the end of the semi-cylindrical shape away from the analysis tube 6 extends out of the inner side of the high-temperature flue gas side equipment lining 12 is 1-1.5 times the diameter of the sampling tube 5. The end of the semi-cylindrical shape close to the analysis tube 6 is located between the inner side and the outer side of the high-temperature flue gas side equipment lining 12, and the flow direction of the flue gas is opposite to the inner side of the semi-cylindrical shape (that is, the inner side of the semi-cylindrical shape is the windward side). Through this arrangement, during the sampling process, the sampling tube 5 draws in smoke, and some of the dust in the smoke will hit the semi-cylindrical surface and then fall along the semi-cylindrical surface, reducing the dust sucked into the sampling tube 5. At the same time, under the same vacuum degree, the semi-cylindrical arrangement makes the suction force generated by the suction greater, and the backblown dust falls more smoothly.

[0040] When the high-temperature flue gas side equipment lining 12 is in a vertical or nearly vertical state, one end of the sampling tube 5 extending into the inner side of the high-temperature flue gas side equipment lining 12 is flush with the inner wall of the high-temperature flue gas side equipment lining 12, and the sampling tube 5 is arranged at an angle of 60° to the horizontal direction, and a baffle is provided at the end of the sampling tube 5 extending into the inner side of the high-temperature flue gas side equipment lining 12, and the baffle covers the top of the end of the sampling tube 5 to the axial position; so that during the backblowing process, the backblown dust falls more smoothly along the inclined sampling tube 5, and for the vertical or nearly vertical state, the flue gas flow direction inside the high-temperature flue gas side equipment lining 12 is upward, and after the dust falls from the end of the sampling tube 5, it will be blown upward by the flue gas and easily blown back into the sampling tube 5, and the setting of the baffle greatly reduces the situation where the dust is blown back into the sampling tube 5 by the flue gas.

[0041] When the measuring instrument 1 is a gas detection instrument, such as an oxygen analyzer, the analysis tube 6 is also connected to a standard gas pipeline. The connection position between the standard gas pipeline and the analysis tube 6 is located on the side of the limiting orifice 2 away from the sampling tube. A calibration valve 14 is provided on the standard gas pipeline, and the standard gas pipeline is used to pass standard gas.

[0042] During the sampling process, the vacuum power system 11 operates to establish negative pressure in the entire system. Under the action of negative pressure, the high-temperature flue gas (maximum 1200°C) inside the lining of the sample device passes through the sampling tube 5 and is filtered by the high-temperature metal filter cartridge 3. The filter cartridge adopts a sintered filter cartridge made of high-temperature resistant metal material, which can withstand flue gas temperatures of 500-1200°C. The filter aperture is selected to be 2.5-10μm according to the particle size of the dust. The clean flue gas enters the analysis tube 6, and the flue gas flow is controlled by the flow limiting orifice 2, so that a small amount of flue gas contacts the measuring instrument 1, and the detection results of the flue gas are fed back in real time. The remaining high-temperature flue gas is emptied through the vacuum tube or returned to the flue gas of the sampling sample equipment.

[0043] During the back-blowing process, by opening the back-blowing solenoid valve 4, the instrument air enters the high-temperature metal filter cartridge 3 from the second branch pipe, and blows the dust on the outer surface of the high-temperature metal filter cartridge 3 outward through the filter holes thereon. This part of the back-blowing is a pulsed spray, which can make the fine ash on the surface of the high-temperature metal filter cartridge 3 fall off. By opening the sonic solenoid valve 8, the instrument air enters the sonic generator 7, and the sonic generator 7 converts air energy into sonic waves or infrasonic waves, thereby blowing away the adhesive dust between the outer surface of the high-temperature metal filter cartridge 3 and the sampling tube 5. Conventional compressed air back-blowing has insufficient energy and is prone to cooling dust with a low ash melting point, thereby aggravating the adhesion of dust here. However, the blowing of sonic waves or infrasonic waves has large energy and can effectively convert gas energy into vibration waves to make the adhesive ash fall off. The fallen dust can flow back into the equipment, thereby achieving online dust cleaning.

[0044] When some instruments need to be calibrated, for example, when the measuring instrument 1 is an oxygen analyzer, the calibration of the oxygen analyzer can be achieved by opening the calibration valve 14 and introducing the standard gas.

[0045] The flow rate of the flow-limiting orifice plate 2 is 0.1-2 L / min, and the distance between the flow-limiting orifice plate 2 and the head of the oxygen analyzer is 5-30 mm.

[0046] like Figure 1 As shown, when sampling from the top, the sampling component has a hole on the windward side to facilitate direct contact with the smoke. The distance from the windward side hole to the sample device lining 12 in the length direction is 50-100mm, and the diameter direction is a semicircle. Figure 5 As shown, when sampling the side wall, a semicircular baffle is set at the head of the sampling component.

[0047] The suction flow rate of the vacuum power system 11 is 3-20 L / min, and the pressure is -20 to -70 kPag.

[0048] The back-blowing solenoid valve 4, the sonic wave solenoid valve 8, and the sampling solenoid valve 10 need to be connected to the control system, and the on-off of the three solenoid valves is controlled by the control system. Among them, the back-blowing solenoid valve 4 and the sampling solenoid valve 10 have opposite switching states, and the working time interval is adjustable. The single working time of the sampling solenoid valve 10 is counted as a minute, generally 3-20 minutes, and the single working time of the back-blowing solenoid valve 4 is 3-20 seconds. The sampling system works according to the repetition cycle b, and the repetition cycle b includes multiple small cycles: each small cycle includes the following steps: the sampling solenoid valve 10 works according to the single working time, and the back-blowing solenoid valve 4 works according to the single working time. At least one small cycle is separated, and there will be a small cycle in which the sonic wave solenoid valve 8 is inserted between the sampling solenoid valve 10 and the back-blowing solenoid valve 4 to work, that is, after the sampling solenoid valve 10 works, the sonic wave solenoid valve 8 works, and then the back-blowing solenoid valve 4 works again.

[0049] The characteristics of the flue gas environment are: high temperature environment, specifically 500-1200℃ flue gas environment. High dust environment, specifically dust content in flue gas is greater than 3000mg / Nm 3 working conditions, where the dust particle size D 50 ≤100μm. The easily bonded dust condition refers specifically to the dust condition where the maximum operating temperature is higher than the ash melting point of solid waste containing K and Na alkali metals during incineration. It generally refers to the dust condition where the ash melting point is lower than 900℃ or the dust condition where the particle size is extremely fine, the electrostatic force is large, and the water content is high.

[0050] The sampling process and back-blowing process work intermittently. Compressed air is used to back-blown conventional fine ash through the back-blowing solenoid valve 4, and the sonic wave generator 7 and the sonic wave solenoid valve 8 are used to back-blown the adhesive fly ash. The compressed air is buffered in the compressed air buffer tank, with a pressure of 0.3-0.8MPaG and a flow rate of 0.5-5Nm 3 / h.

[0051] Example 1

[0052] The embodiment of the present application discloses a dynamic sampling system for flue gas in a high-temperature, easy-to-bond, high-dust environment. It is used to monitor the oxygen concentration of flue gas at the outlet of an incinerator, with an operating temperature of 800-950°C, wherein the fly ash particle size D50≤50μm. These particles are extremely fine in size and have a large specific surface area. They are easily affected by van der Waals forces, electrostatic forces, etc., resulting in strong adhesion. At the same time, the ash contains K and Na alkali metals. The presence of these elements leads to the easy generation of substances with low ash melting points, which are bonded layer by layer after softening. Conventional zirconia analyzers often have serious blockage in the sampling tube after running for 2-3 days, and cannot be measured normally.

[0053] In this embodiment, the measuring instrument 1 is a zirconia analyzer, the vacuum power system 11 is a vacuum pump, and the vacuum tube is provided with a finned heat exchange tube 9 and a sampling solenoid valve 10 .

[0054] like Figure 1 As shown, when sampling, a negative pressure is established by the vacuum pump 11, the suction force is -50kPag, and the flow rate is 4L / min. Open the sampling solenoid valve 10 to make the analysis tube 6 a negative pressure. The flue gas temperature at the outlet of the incinerator is 800-950°C, the sintering aperture of the high-temperature metal filter cartridge 3 is selected to be 5μm, and the material is selected to be 310S. Under the action of negative pressure, the flue gas passes through the high-temperature metal filter cartridge 3 to filter the dust and then enters the analysis tube 6, and then contacts the zirconium oxide analyzer 1 through the flow limiting orifice 2, so as to measure the oxygen concentration in the flue gas in real time. The flow rate of the flow limiting orifice is 1L / min, and the distance between the flow limiting orifice 1 and the head of the oxygen analyzer is 20mm. Figure 2 The remaining high-temperature flue gas is cooled to below 100° C. by heat dissipation in the finned heat exchange tube 9 and then enters the vacuum pump 11 to be emptied or returned to the flue gas.

[0055] The sampling system is installed at the top of the flue. The sampling component 5 has a hole on the windward side, which can be in direct contact with the flue gas. The distance from the windward side hole to the inner side of the high-temperature flue gas side equipment lining 12 in the length direction is 50mm, and the diameter direction is semicircular. Figure 3 shown.

[0056] During the backflush process, the backflush solenoid valve 4 is opened periodically to utilize 0.5MPaG, 4Nm 3 / h instrument air pulse sprays the dust on the outer surface of the high-temperature metal filter cartridge 3 to remove the fine dust on the filter cartridge surface. Periodically open the sonic solenoid valve 8, 0.5MPaG, 2Nm 3 / h instrument air enters the sound wave generator 7 to convert air energy into sound waves, which blow away the adhesive dust between the outer surface of the high-temperature metal filter cartridge 3 and the sampling tube 5. The fallen dust is blown back into the sample device by the compressed air, thus achieving online dust cleaning.

[0057] The back-blowing solenoid valve 4, the sonic solenoid valve 8, and the sampling solenoid valve 10 need to be connected to the PLC control system, and the on-off of the three solenoid valves is controlled by the control system. a is 15 minutes (the time for the sampling solenoid valve 10 to be opened alone), b is 46.5 minutes (a cycle of the whole process), and the whole process b includes: 15 minutes (sampling solenoid valve) + 20 seconds (back-blowing solenoid valve) + 15 minutes (sampling solenoid valve) + 20 seconds (back-blowing solenoid valve) + 15 minutes (sampling solenoid valve) + 30 seconds (sonic solenoid valve) + 20 seconds (back-blowing solenoid valve).

[0058] During the calibration process of the zirconium oxide analyzer, the calibration of zirconium oxide can be achieved by opening the calibration valve 14 and introducing the standard gas.

[0059] Example 2

[0060] The present invention proposes a flue gas dynamic sampling system for high-temperature, easy-to-bond, high-dust environments, which is used for incinerator temperature monitoring, with an operating temperature of 850-1050°C. The flue gas carries fly ash with severe erosion, and the fly ash particle size is fine, D50≤30μm, and the van der Waals force between the dust particles is obvious, with strong adhesion. At the same time, due to the incineration, the flue gas contains a large amount of corrosive gases such as HCl and SO2, which causes conventional thermocouples to be subjected to multiple effects such as wear, corrosion and adhesion, and the service life is extremely short.

[0061] In this embodiment, the measuring instrument 1 is a thermocouple, and the vacuum power system 11 is an ejector. The ejector is arranged at one end of the vacuum tube. An ejector pipeline is also connected between the ejector and the instrument gas buffer tank 13. The instrument gas in the instrument gas buffer tank 13 enters the ejector through the ejector pipeline, and the fluid in the vacuum tube is ejected in the ejector and ejected from the ejector. A sampling solenoid valve 10 is arranged on the ejector pipeline. Sampling through the ejector does not require heat dissipation, does not require additional power supply (the vacuum pump needs power supply), and is more stable.

[0062] like Figure 4 As shown, when the system is sampling, the sampling solenoid valve 10 is opened, and the instrument gas enters the ejector. The instrument gas is ejected to generate negative pressure in the vacuum tube, and the negative pressure is established. The suction force is -30kPag, and the flow rate is 3L / min. The negative pressure in the vacuum tube causes the analysis tube 6 to become negative pressure. The ejector material is selected as 310S. The flue gas temperature in the dense phase zone of the fluidized bed is 850-1000℃, and the sintering aperture of the high-temperature metal filter cartridge 3 is selected to be 10μm, and the material is selected to be 310S. Under the action of negative pressure, the flue gas passes through the high-temperature metal filter cartridge 3 to filter the dust and then enters the analysis tube 6, and then contacts the thermocouple 1 through the flow limiting orifice 2, so that the temperature of the flue gas is measured in real time. The flow rate of the flow limiting orifice is 2L / min, and the distance between the flow limiting orifice and the thermocouple is 20mm. Figure 2 The high-temperature flue gas is mixed with the compressed air through the ejector and then returns to the flue gas in the lining 12 of the high-temperature flue gas side equipment.

[0063] like Figure 5 As shown, the sampler is installed on the vertical side wall of the incinerator, and the sampling tube 5 is arranged at an angle of 60° to the horizontal direction. A baffle is set on the upper front end of the sampling tube 5 to further reduce scouring and ensure that the fallen dust falls back into the sampling lining. Figure 5 shown.

[0064] During the backflush process, similarly, the backflush solenoid valve 4 is opened periodically to use 0.7 MPaG, 3 Nm 3 / h instrument air pulse spraying high temperature metal filter cartridge 3 outer surface of the dust. For sticky ash, periodically open the sonic solenoid valve 8, 0.7MPaG, 1Nm 3 / h instrument air is used to generate sound waves through the sound wave generator 7 to sweep the adhesive dust between the outer surface of the high-temperature metal filter cartridge 3 and the sampling tube 5. The dust that falls off is returned to the sample device.

[0065] The back-blowing solenoid valve 4, the sonic wave solenoid valve 8 and the sampling solenoid valve 10 need to be connected to the PLC control system. The running time a is 10min, and b is 42min. The whole process b includes: 10min (sampling solenoid valve) + 20s (back-blowing solenoid valve) + 10min (sampling solenoid valve) + 20s (back-blowing solenoid valve) + 10min (sampling solenoid valve) + 20s (back-blowing solenoid valve) + 10min (sampling solenoid valve) + 40s (sonic wave solenoid valve) + 20s (back-blowing solenoid valve).

[0066] The contents not described in detail in this application specification belong to the common knowledge of those skilled in the art.

[0067] The present application is described in detail above in conjunction with specific implementation methods and exemplary examples, but these descriptions cannot be understood as limiting the present application. Those skilled in the art understand that, without departing from the spirit and scope of the present application, a variety of equivalent replacements, modifications or improvements can be made to the technical solution of the present application and its implementation methods, all of which fall within the scope of the present application. The scope of protection of the present application shall be subject to the attached claims.

Claims

1. A dynamic sampling system for flue gas in a high-temperature, easy-to-adhesive, high-dust environment, used for sampling flue gas inside a lining (12) of a high-temperature flue gas side device, characterized by: The invention comprises a measuring instrument (1), a flow limiting orifice plate (2), a high-temperature metal filter cartridge (3), a sampling tube (5), an analysis tube (6), a vacuum power system (11) and a back-blowing system. The measuring instrument (1) is connected to one end of the analysis tube (6) so that the detection probe of the measuring instrument (1) extends into the analysis tube (6). The other end of the analysis tube (6) is connected to the sampling tube (5). The other end of the sampling tube (5) is installed in the measuring hole of the lining (12) of the high-temperature flue gas side equipment. The high-temperature metal filter cartridge (3) is located in the sampling tube (5). The opening of the high-temperature metal filter cartridge (3) is connected to one end of the sampling tube (5) close to the analysis tube (6), and the opening of the high-temperature metal filter cartridge (3) is sealed with the inner wall of the sampling tube (5); the flow limiting orifice plate is installed in the analysis tube (6); the analysis tube (6) is connected to a vacuum tube, and the connection position of the vacuum tube and the analysis tube (6) is located on the side of the flow limiting orifice plate (2) facing the sampling tube, and the vacuum power system (11) is connected to the vacuum tube, and the vacuum power system (11) is used to make the analysis tube (6) present a negative pressure; the back-blowing system is used to blow instrument gas into the opening of the high-temperature metal filter cartridge (3).

2. The dynamic sampling system for flue gas in a high-temperature, easy-to-adhesive, high-dust environment according to claim 1 or 2, characterized in that: The back-blowing system comprises a back-blowing solenoid valve (4) and a second branch pipe, one end of the second branch pipe is connected to an instrument gas source, and the other end passes through an analysis tube (6) and extends into an opening of a high-temperature metal filter cartridge (3). The back-blowing solenoid valve (4) is installed on the second branch pipe, and the back-blowing solenoid valve (4) is used to control the connection and closing of the second branch pipe.

3. The dynamic sampling system for flue gas in a high-temperature, easy-to-adhesive, high-dust environment according to claim 1 is characterized in that: The backflush system further comprises a first branch pipe, a sonic solenoid valve (8) and a sonic generator (7); one end of the first branch pipe is connected to the sonic generator (7) and the other end is connected to an instrument gas source; the sonic generator (7) is arranged on a side wall of the analysis tube (6); the sonic solenoid valve (8) is installed on the first branch pipe; and the sonic solenoid valve (8) is used to control the connection and closing of the first branch pipe.

4. The dynamic sampling system for flue gas in a high-temperature, easy-to-adhesive, high-dust environment according to claim 1 is characterized in that: The vacuum power system (11) is a vacuum pump or an ejector; When the vacuum power system (11) is a vacuum pump, the vacuum pump is connected to one end of a vacuum tube, and a finned heat exchange tube (9) and a sampling electromagnetic valve (10) are provided on the vacuum tube. The sampling electromagnetic valve (10) is used to control the connection and closing of the vacuum tube, and the finned heat exchange tube (9) is used to dissipate heat from flue gas entering the vacuum tube from the analysis tube (6); When the vacuum power system (11) is an ejector, the ejector is connected to one end of the vacuum tube, and the ejector is also connected to an ejection pipeline. The other end of the ejection pipeline is connected to an instrument gas source. A sampling solenoid valve (10) is arranged on the ejection pipeline. The sampling solenoid valve (10) is used to control the connection and closing of the ejection pipeline. The instrument gas enters the ejector through the ejection pipeline, ejects the smoke in the vacuum tube in the ejector, and ejects it from the ejector.

5. The dynamic sampling system for flue gas in a high-temperature, easy-to-adhesive, high-dust environment according to claim 1 is characterized in that: When the high-temperature flue gas side equipment lining (12) is in a horizontal state or the angle between the high-temperature flue gas side equipment lining (12) and the horizontal direction is not greater than 30 degrees, the end of the sampling tube (5) away from the analysis tube (6) is semi-cylindrical, the end of the semi-cylindrical shape away from the analysis tube (6) extends out of the inner side of the high-temperature flue gas side equipment lining (12), and the inner side of the semi-cylindrical shape is the windward side.

6. The dynamic sampling system for flue gas in a high-temperature, easy-to-adhesive, high-dust environment according to claim 5 is characterized in that: The distance that the end of the semi-cylindrical part away from the analysis tube (6) protrudes from the inner side of the lining (12) of the high-temperature flue gas side equipment is 1-1.5 times the diameter of the sampling tube 5.

7. The dynamic sampling system for flue gas in a high-temperature, easy-to-adhesive, high-dust environment according to claim 1 is characterized by: When the high-temperature flue gas side equipment lining (12) is in a vertical state or the angle between the high-temperature flue gas side equipment lining (12) and the vertical direction is not greater than 60 degrees, the end of the sampling tube (5) extending into the inner side of the high-temperature flue gas side equipment lining (12) is flush with the inner wall of the high-temperature flue gas side equipment lining (12), and the sampling tube (5) is arranged at an angle of 55-75 degrees to the horizontal direction. A baffle is provided at the end of the sampling tube (5) extending into the inner side of the high-temperature flue gas side equipment lining (12), and the baffle covers the top of the end of the sampling tube (5) to the axis position.

8. The dynamic sampling system for flue gas in a high-temperature, easy-to-adhesive, high-dust environment according to claim 1 is characterized by: The distance between the flow limiting orifice plate 1 and the detection probe of the measuring instrument (1) is 1 / 5-1 / 2 of the diameter of the analysis tube 6.

9. The dynamic sampling system for flue gas in a high-temperature, easy-to-adhesive, high-dust environment according to claim 1 is characterized in that: When the measuring instrument (1) is a gas detection instrument, the analysis tube (6) is also connected to a standard gas pipeline. The connection position between the standard gas pipeline and the analysis tube (6) is located on the side of the flow limiting orifice plate (2) away from the sampling tube. A calibration valve (14) is provided on the standard gas pipeline. The standard gas pipeline is used to introduce standard gas. The calibration valve (14) is used to control the connection and closing of the standard gas pipeline.

10. The sampling method of the dynamic sampling system for flue gas in a high-temperature, easy-to-adhesive, high-dust environment according to any one of claims 3 to 9, characterized in that: include: Continuous sampling is performed according to small cycles, each small cycle includes an intermittent sampling process and a backwash process, the backwash process is a first backwash process or a second backwash process, and a second backwash process is performed every interval of at least one first backwash process in different small cycles; The sampling process includes: the backflush system is closed, the vacuum power system (11) is started, the sampling tube (5) and the analysis tube (6) are negatively pressurized, and the flue gas inside the lining (12) of the high-temperature flue gas side equipment is sampled; The first back-blowing process includes: the vacuum power system (11) is turned off, the back-blowing solenoid valve (4) of the back-blowing system is turned on, and the sonic solenoid valve (8) is turned off; the second back-blowing process includes: the vacuum power system (11) is turned off, the back-blowing solenoid valve (4) of the back-blowing system is turned off, and the sonic solenoid valve (8) is turned on, and then the sonic solenoid valve (8) is turned off and the back-blowing solenoid valve (4) is turned on.

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