Residual oxygen analysis system

Abstract

The present invention discloses a residual oxygen analysis system, including a sampling probe, the air inlet of the sampling probe is connected to the flue gas duct, the air outlet of the sampling probe is sequentially connected to a processing unit and an analysis unit through an air pipe, and internal and external heating units are respectively provided in the middle and outer wall of the filter element of the inner cavity of the sampling probe, the processing unit is used to remove solid and liquid impurities in the sample gas, and the analysis unit is used to analyze the oxygen content in the sample gas. The above scheme ensures that the temperature of the inner filter element is maintained at 300°C through internal and external dual heating of the sampling probe, so as to avoid the blockage of the filter element caused by the solidification of impurities in the sample gas, and effectively prolong the service life of the filter element and the sampling probe; the sample gas is then processed and filtered by the processing unit, which protects the analytical instrument, improves the accuracy of data analysis, and at the same time prolongs the maintenance cycle of the system and reduces maintenance costs.

Description

Technical Field

[0001] The invention relates to the technical field of gas detection, and in particular to a residual oxygen analysis system for an outlet of a flue gas waste heat boiler. Background Art

[0002] Flash smelting is mainly used for matte smelting of sulfide ores such as copper and nickel. Its sulfation technology requires the introduction of oxygen-enriched air or air at the inlet of the ascending flue and the inlet of the waste heat boiler to cause the molten metal oxides in the flue gas to undergo sulfate formation reaction, so that the adhesive formed on the flue gas flow path can be easily cleaned. However, the introduction of oxygen-enriched air or air will also increase the SO3 concentration in the flue gas. In terms of equipment corrosion protection and acid production systems, it is required to reduce the SO3 concentration in the flue gas. Therefore, there is a contradiction between increasing the sulfation reaction and reducing the SO3 concentration in flash smelting. Reasonable control of the O2 content and finding the best balance between the two have become issues that need to be solved urgently.

[0003] According to the production practice of foreign manufacturers, it is known that the detection points of O2 concentration in flue gas are set at the outlet of boiler and electric dust collector, and the O2 concentration in the flue gas at the outlet of waste heat boiler is confirmed to be 0.5% and 7% at the outlet of electric dust collector by O2 analyzer, otherwise the occurrence rate of SO3 in flue gas will be too high. That is, controlling the O2 content in flue gas can control the sulfation reaction.

[0004] In the prior art, some manufacturers use residual oxygen analyzers to analyze and monitor the O2 content in the waste heat boiler. However, due to the complex composition of the flue gas at the outlet of the waste heat boiler, the operating environment of the residual oxygen analyzer is very harsh, resulting in too much maintenance workload and maintenance cost. Basically, maintenance and repair are required 2-3 times a week, and it will cause huge spare parts and cooperation costs, so its application is not ideal. Summary of the invention

[0005] The object of the present invention is to provide a residual oxygen analysis system with a long maintenance period and low maintenance cost.

[0006] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a residual oxygen analysis system, characterized in that: it includes a sampling probe, the air inlet of the sampling probe is connected to the flue gas duct, and the air outlet of the sampling probe is connected to a processing unit and an analysis unit in sequence through an air pipe, and internal and external heating units are respectively provided in the middle and outer wall of the filter element in the inner cavity of the sampling probe, the processing unit is used to remove solid and liquid impurities in the sample gas, and the analysis unit is used to analyze the oxygen content in the sample gas.

[0007] In the above scheme, the sampling probe is provided with internal and external heating units, which ensure that the temperature of the filter element in the sampling probe is maintained at 300°C through internal and external dual heating, so that the impurities in the sample gas are always in a fluid state, avoiding the blockage of the filter element caused by the solidification of impurities in the sample gas, and extending the service life of the filter element and the sampling probe; the sample gas is then processed and filtered by the processing unit to completely remove solid and liquid impurities in the sample gas, effectively protecting the analytical instrument, improving the accuracy of data analysis, and at the same time extending the maintenance cycle of the system and reducing maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is a schematic diagram of this system;

[0009] Figure 2 It is a structural schematic diagram of the sampling probe of the present invention. DETAILED DESCRIPTION

[0010] In conjunction with the accompanying drawings, a residual oxygen analysis system includes a sampling probe 10, the air inlet of the sampling probe 10 is connected to the flue gas duct A, and the air outlet of the sampling probe 10 is connected to the processing unit 20 and the analysis unit 30 in sequence through the air pipe. The inner and outer heating units are respectively provided on the filter element in the middle and outer wall of the inner cavity of the sampling probe 10. The processing unit 20 is used to remove solid and liquid impurities in the sample gas, and the analysis unit 30 is used to analyze the oxygen content in the sample gas. The core of the present invention is to ensure that the temperature of the filter element in the sampling probe is maintained at 300°C by double heating the inside and outside of the sampling probe. Under high temperature conditions, the impurities in the sample gas are always in a fluid state, which can effectively avoid the blockage of the filter element caused by the solidification of impurities in the sample gas, and extend the service life of the filter element and the sampling probe; then the sample gas is processed and filtered by the processing unit to completely remove the solid and liquid impurities in the sample gas, effectively protecting the analytical instrument, improving the accuracy of data analysis, and at the same time extending the maintenance cycle of the system and reducing maintenance costs.

[0011] Preferably, the sampling probe 10 includes a tube body 11, the air inlet end of the tube body 11 is connected to the sampling tube 12 through a flange, the air outlet end of the tube body 11 is provided with an end cap 13, a through hole 131 is opened in the middle of the end cap 13, a tubular heater 40 is provided on the outer tube wall of the tube body 11, a barrel filter element 50 is provided in the tube cavity of the tube body 11, the open end of the barrel filter element 50 points to the direction of the end cap 13 and a filter element seat 51 with a hole in the middle is provided at its port, and the filter element seat 51 is fixedly connected to the end cap 13. The tube body 11 is heated by the tubular heater 40 to ensure the temperature of the tube cavity of the tube body 11. The barrel filter element 50 uses a high-efficiency silicon carbide filter element, which performs preliminary filtration of the sample gas in the tube cavity of the tube body 11, and can filter out more than 90% of dust impurities, which plays a certain protective role for the subsequent sample gas processing equipment.

[0012] When the sampling probe 10 is only heated externally, the temperature of the barrel filter element 50 in the tube cavity of the tube body 11 cannot be maintained at 300°C all the time, so that some impurities in the sample gas will form solids on the outer wall of the barrel filter element 50, thereby causing clogging of the filter element. Therefore, a fixing seat 14 is provided on the outer side of the end cover 13, and a hollow chamber 141 connected to the through hole 131 is provided in the fixing seat 14. One end of the heating rod 60 is fixed to the fixing seat 14 through the insulating seat 61, and the other end is freely suspended through the through hole 131 into the inner cavity of the barrel filter element 50. A sample gas outlet 142 connected to the hollow chamber 141 is provided on the fixing seat 14 as the gas outlet of the sampling probe 10. Through the dual heating cooperation of the heating rod 60 and the tubular heater 40, the overall temperature of the barrel filter element 50 can be maintained at 300°C, thereby extending the service life of the barrel filter element 50.

[0013] Preferably, an outer blowing port 111 is provided on the tube wall of the tube body 11 near the end cover 13, and an inner blowing port 143 communicating with the hollow chamber 141 is provided on the fixing seat 14, and the outer blowing port 111 and the inner blowing port 143 are respectively connected to the heating gas storage tank 70 through air pipes. Specifically, 300°C N2 is stored in the heating gas storage tank 70, and the inner cavity of the sampling probe 10 is back-blown through the outer blowing port 111 and the inner blowing port 143, and the sample gas impurities adsorbed on the barrel filter element 50 are back-blown back to the flue gas duct A, thereby cleaning the inner cavity of the sampling probe 10 and extending the service life of the sampling probe 10.

[0014] Furthermore, the sample gas outlet 142 is connected to the air inlet of the desulfurization gun 21 through an air pipe, and a back-blowing port 211 is provided at the air outlet of the desulfurization gun 21, and the back-blowing port 211 is connected to the heated gas storage tank 70 through an air pipe. In specific implementation, the desulfurization gun 21 is filled with granular desulfurization glass crystals to remove liquid sulfide in the sample gas and filter the sample gas; the back-blowing port 211 uses high-temperature nitrogen to purge the liquid sulfide impurities attached to the crystals, thereby cleaning the desulfurization gun 21 and extending the service life of the desulfurization gun 21.

[0015] Furthermore, the gas outlet of the desulfurization cannon 21 is connected to the mist filter 22, the dehumidifier 23, the vacuum pump 24, the filter 25 and the analysis unit 30 in sequence through the air pipe. Specifically, after the sample gas passes through the desulfurization cannon 21, the mist filter 22 first performs secondary filtration on the finer dust particles and residual mist droplets in the sample gas, and then the dehumidifier 23 removes the water vapor in the sample gas, and the imported high-performance diaphragm vacuum pump 24 is used for sampling, and finally the sample gas is finely filtered by the filter 25 to completely remove the solid and liquid impurities in the sample gas, effectively preventing the impurities in the sample gas from affecting the analysis unit 30.

[0016] Preferably, the gas pipe is a high-temperature heating pipe, which can ensure that the temperature of the sample gas is constant during the transmission process, and avoid the impurities in the sample gas condensing on the pipe wall due to the temperature drop during the transmission process.

Claims

1. A residual oxygen analysis system, characterized in that: The sampling probe (10) comprises an air inlet of the sampling probe (10) connected to a flue gas duct (A), and an air outlet of the sampling probe (10) connected in sequence to a processing unit (20) and an analysis unit (30) via an air pipe, wherein inner and outer heating units are respectively provided in the middle and on the outer wall of a filter element in the inner cavity of the sampling probe (10), the processing unit (20) is used to remove solid and liquid impurities in the sample gas, and the analysis unit (30) is used to analyze the oxygen content in the sample gas; The sampling probe (10) is further provided with a blowing port and is connected to the heating gas storage tank (70) through an air pipe, and the temperature of the gas stored in the heating gas storage tank (70) is consistent with the target temperature of the filter element; The processing unit (20) comprises a desulfurization gun (21), the gas outlet of the sampling probe (10) is connected to the gas inlet of the desulfurization gun (21) through an air pipe, a backflush port (211) is provided at the gas outlet end of the desulfurization gun (21), and the backflush port (211) is connected to the heating gas storage tank (70) through an air pipe.

2. The residual oxygen analysis system according to claim 1, characterized in that: The sampling probe (10) comprises a tube body (11), the air inlet end of the tube body (11) is connected to the sampling tube (12) via a flange, the air outlet end of the tube body (11) is provided with an end cover (13), the middle portion of the end cover (13) is provided with a through hole (131), the outer tube wall of the tube body (11) is provided with a tubular heater (40), the tube cavity of the tube body (11) is provided with a barrel-shaped filter element (50), the open end of the barrel-shaped filter element (50) points in the direction of the end cover (13) and a filter element seat (51) with a hole in the middle portion is provided at the end portion thereof, and the filter element seat (51) is fixedly connected to the end cover (13).

3. The residual oxygen analysis system according to claim 2, characterized in that: A fixing seat (14) is provided on the outer side of the end cover (13), and a hollow chamber (141) is provided in the fixing seat (14) and is communicated with the through hole (131). One end of the heating rod (60) is fixed to the fixing seat (14) via an insulating seat (61), and the other end is freely extended through the through hole (131) to the inner cavity of the barrel-shaped filter element (50). A sample gas outlet (142) communicated with the hollow chamber (141) is provided on the fixing seat (14) as a gas outlet of the sampling probe (10).

4. The residual oxygen analysis system according to claim 3, characterized in that: An outer blowing port (111) is provided on the tube wall of the tube body (11) adjacent to the end cover (13), and an inner blowing port (143) communicating with the hollow chamber (141) is provided on the fixing seat (14). The outer blowing port (111) and the inner blowing port (143) are respectively connected to the heating gas storage tank (70) via air pipes.

5. The residual oxygen analysis system according to claim 1, characterized in that: The gas outlet of the desulfurization cannon (21) is connected in sequence to a mist filter (22), a dehumidifier (23), an air pump (24), a filter (25), and an analysis unit (30) through an air pipe.

6. The residual oxygen analysis system according to claim 5, characterized in that: The gas pipe is a high-temperature heating pipe.

Images