Online ratio analyzer sampling probe back flushing method

Abstract

The invention discloses an online ratio analyzer sampling probe back flushing method, and belongs to the field of sulfur recovery pipeline sampling probe blockage treatment.The online ratio analyzer sampling probe back flushing method comprises the following steps that when back flushing needs to be started, the blockage degree of a sampling probe is obtained; and the reverse blowing controller starts a reverse blowing electromagnetic valve and controls pulse reverse blowing according to the blockage degree to perform reverse blowing according to different reverse blowing periods and reverse blowing flows, so that impurities on the sampling probe are blown back into the sulfur recovery pipeline. When the sampling probe needs to be subjected to back flushing, the back flushing controller sets the corresponding back flushing flow and back flushing period according to different blocking degrees, so that compared with the existing mode of not distinguishing the blocking degrees, the back flushing time is saved, the efficiency of eliminating the blocking obstacles is improved, and the conventional analysis and measurement of the gas sample by the analyzer are ensured.

Description

Technical Field

[0001] The invention belongs to the field of sulphur recovery pipeline sampling probe blockage treatment, and in particular relates to a backflushing method for an online ratio analyzer sampling probe. Background Art

[0002] An online ratio analyzer is installed at the outlet of the natural gas Claus sulfur recovery unit to measure the concentration of H2S and SO2. The high-temperature sample gas enters the sampling probe from the sampling tube, is filtered through the probe filter, and finally enters the back-end analyzer measurement room for measurement and analysis. The probe filter removes the adsorbed sulfur and impurities by regularly back-flushing with high-temperature nitrogen to keep the probe sampling unobstructed.

[0003] The existing probe backflush method has only one fixed purge mode. The sampling probe uses high-temperature nitrogen to backflush the sulfur blocked on the probe filter at a fixed mode, i.e., fixed flow and fixed duration. If the blockage is low, backflush at a fixed flow and fixed duration may cause a waste of time. If the blockage is serious, the fixed flow cannot purge the probe impurities clean, affecting the sampling of the sampling probe. In other words, the existing method is not adaptable to different working conditions. The effect of removing sulfur and impurities is poor under some working conditions, which may cause sulfur or impurities to block the gas path, making it impossible for the probe to sample smoothly, resulting in a decrease in the sample gas flow entering the analyzer and an inability to measure normally.

[0004] The existing technology adopts a fixed flow backflushing form, which is not adaptable to different working conditions and has problems such as backflushing waste, poor effect and low efficiency. Summary of the invention

[0005] The purpose of the present invention is to provide a backflushing method for an online ratio analyzer sampling probe to solve the technical problems in the prior art that backflushing adopts a fixed flow backflushing form, has poor adaptability to different working conditions, and has backflushing waste, poor effect and low efficiency.

[0006] To achieve the above object, the technical solution of a backflushing method for a sampling probe of an online ratio analyzer provided by the present invention is:

[0007] A backflushing method for a sampling probe of an online ratio analyzer comprises the following steps: when backflushing needs to be started, obtaining the blockage degree of the sampling probe, adjusting the backflushing flow rate, the backflushing cycle and the total backflushing time according to the blockage degree, and blowing the impurities on the sampling probe back into a sulfur recovery pipeline. The backflushing cycle comprises the cycle length and the proportion of the backflushing time in one cycle.

[0008] The beneficial effects are: when the sampling probe needs to be backblown, the backblowing controller sets the corresponding backblowing flow, backblowing cycle and total backblowing time according to different degrees of blockage; when the blockage degree is low, the backblowing time is saved compared with the existing method that does not distinguish between the degrees of blockage; when the blockage degree is serious, through intermittent backblowing, the discontinuous peaks generated by the shock wave produce a jump-like change in pressure on the impurities blocking the gas path, which improves the efficiency of eliminating blockage obstacles compared with the existing technical solutions and ensures the analyzer's routine analysis and measurement of gas samples.

[0009] As a further improvement, the judgment steps for starting backblowing are: obtaining the spectral signal of the gas sample in the analyzer measurement chamber and / or obtaining the gas sample flow rate of the gas sample passing through the analyzer measurement chamber; when the spectral signal is less than the corresponding spectral signal threshold and / or the gas sample flow rate is less than the flow threshold, starting backblowing.

[0010] The beneficial effect is that when the sampling probe is blocked, the flow rate and spectral signal of the gas sample obtained by the analyzer will become smaller accordingly, so using the flow rate and spectral signal of the gas sample as a basis for judging whether to start backflushing can enable better judgment.

[0011] As a further improvement, the condition for judging the degree of blockage is: the smaller the spectral signal or the gas sample flow rate is, the more serious the corresponding degree of blockage is.

[0012] The beneficial effect is that the blockage degree judgment condition is established according to the relationship between the spectral signal and the smaller the flow rate, the more serious the blockage of the corresponding sampling probe, so that the severity of the blockage can be judged more accurately.

[0013] As a further improvement, the spectrum signal includes a first wavelength spectrum signal and a second wavelength spectrum signal, and when at least one of the first wavelength spectrum signal and the second wavelength spectrum signal is smaller than a corresponding spectrum threshold, backflush is started.

[0014] The beneficial effect is that in order to improve the accuracy of spectral signal judgment, two relatively sensitive wavelengths are selected as the basis for starting backflush judgment, thereby improving the accuracy of starting backflush judgment based on spectral signals.

[0015] As a further improvement, the first wavelength is 190 nm and the second wavelength is 250 nm.

[0016] The beneficial effect is: the first wavelength and the second wavelength are the absorption wavelengths of H2S and SO2 gases respectively. In the ultraviolet band, the instrument measures the concentrations of the two gases based on these two bands. The spectral signals of these two bands change, which can most intuitively measure the blockage of the front pipeline and improve the accuracy of data analysis.

[0017] As a further improvement, as the blockage becomes more serious, the backwash flow rate, cycle length, backwash ratio and / or total backwash time are correspondingly increased.

[0018] The beneficial effect is: within a certain intensity, the longer the cycle length, the higher the backwash proportion, the longer the total backwash time and the larger the backwash flow rate, the better the corresponding backwash effect; the backwash effect is improved by multiple combinations of these four conditions.

[0019] As a further improvement, the degree of blockage is divided into mild blockage, moderate blockage and moderate blockage according to the size of the spectral signal or the gas sample flow rate; different backwash flow rates, cycle lengths, backwash proportions and / or total backwash time are set corresponding to mild blockage, moderate blockage and severe blockage respectively.

[0020] The beneficial effect is that the blockage degree is divided into three levels and three backflush parameters are set accordingly, so that the blockage problems at each level can be eliminated; and the phenomenon of waste of controller overhead caused by too many levels is avoided. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of an online ratio analyzer in a sampling probe backflushing method of an online ratio analyzer of the present invention;

[0022] Figure 2 It is a flow chart of the backflushing method of the sampling probe of the online ratio analyzer of the present invention;

[0023] 1. Sulfur recovery pipeline; 2. Sampling tube; 3. Filter; 4. Sampling probe; 5. Backflush solenoid valve;

[0024] 6. Backflush controller; 7. Sampling solenoid valve; 8. Analyzer measurement room; 9. Analyzer; 10. Exhaust gas emission pipeline;

[0025] 11. High-pressure nitrogen pipeline. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention, that is, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0027] Online ratio analyzer sampling probe backflushing method embodiment:

[0028] like Figure 1 As shown, the online ratio analyzer includes: a sampling probe 4, a backflush controller 6 and an analyzer 9;

[0029] The sampling probe 4 is connected to the analyzer 9 through a gas pipeline, and a sampling solenoid valve 7 is provided on the gas pipeline. The sampling probe 4 is connected to the backflush controller 6 through a backflush pipeline, and the backflush controller 6 is also connected to a high-pressure nitrogen pipeline 11, and a backflush solenoid valve 5 is provided on the backflush pipeline; the sampling probe 4 is used to collect gas from the sulfur recovery pipeline 1 as a gas sample for the analyzer 9.

[0030] Among them, the sampling probe 4 includes a filter 3 and a sampling tube 2; the sampling tube 2 is used to collect gas from the sulfur recovery pipeline 1, and the filter 3 is used to filter impurities in the above gas; the analyzer 9 includes an analyzer measurement chamber 8, and the analyzer measurement chamber 8 is used to analyze the spectral signal of the gas sample and the gas sample flow.

[0031] The backflush controller 6 is used to open the backflush solenoid valve 5 and obtain the blockage degree of the sampling probe 4 when backflush is needed, adjust the backflush flow rate, backflush cycle and total backflush time according to the blockage degree, and blow the impurities on the sampling probe 4 back into the sulfur recovery pipeline 1. The backflush cycle includes the cycle length and the proportion of backflush time in one cycle.

[0032] like Figure 2 As shown, the steps of the sampling probe backflushing method of the online ratio analyzer are as follows:

[0033] 1) Data collection: The sampling probe 4 collects the gas from the sulfur recovery pipeline 1 as a gas sample, and the gas sample passes through the filter 3 and enters the analyzer measurement chamber 8. The analyzer 9 obtains the spectrum signal of the gas sample in the analyzer measurement chamber 8 when the ultraviolet light passes through the analyzer measurement chamber 8, detects the spectrum signal of the first wavelength and the spectrum signal of the second wavelength, and obtains the gas sample flow rate of the gas sample passing through the analyzer measurement chamber 8; wherein the first wavelength is 190nm and the second wavelength is 250nm.

[0034] 2) The judgment steps for starting backblowing are: obtaining the first and second wavelength spectral signals of the gas sample in the analyzer measuring chamber 8 and / or obtaining the gas sample flow rate of the gas sample passing through the analyzer measuring chamber 8; when the first and second wavelength spectral signals are less than the corresponding spectral signal thresholds and / or the gas sample flow rate is less than the flow threshold, starting backblowing.

[0035] 3) The blockage degree judgment condition is: the smaller the spectral signal or gas sample flow rate, the more serious the corresponding blockage degree; the blockage degree is divided into mild blockage, moderate blockage and moderate blockage according to the size of the spectral signal or gas sample flow rate.

[0036] Mild blockage judgment: When the spectral intensity of the first wavelength is less than 20,000, the spectral intensity of the second wavelength is less than 25,000, or the flow rate is within the range of 1-2 L / min, the blockage intensity of filter 3 is mild blockage;

[0037] Moderate blockage judgment: When the spectral intensity of the first wavelength is less than 15000, the spectral intensity of the second wavelength is less than 20000, or the flow rate is within the range of 0.2-1L / min, the blockage intensity of filter 3 is moderate blockage;

[0038] Severe clogging judgment: When the spectrum intensity of the first wavelength is less than 10,000, the spectrum intensity of the second wavelength is less than 15,000, or the flow rate is less than or equal to 0.2 L / min, the clogging intensity of the filter 3 is severe clogging.

[0039] This embodiment takes three congestion levels as an example. According to actual needs, two levels, four levels or other multiple levels may be used to divide the congestion degree.

[0040] 4) As the blockage becomes more serious, the backwash flow rate, cycle length, backwash ratio and / or total backwash time are increased accordingly. Different backwash flow rates, cycle lengths, backwash ratios and / or total backwash time are set for mild blockage, moderate blockage and severe blockage, respectively.

[0041] The backflush controller 6 controls the backflush solenoid valve 5 to open, the sampling solenoid valve 7 to close, and the gas collection of the sulfur recovery pipeline 1 is stopped; the set cycle corresponding to the mild blockage is: backflush for 20 seconds, pause for 10 seconds, the total backflush time is 15 minutes, the backflush flow rate is 50L / min, and the impurities on the filter 3 are blown back into the sulfur recovery pipeline 1.

[0042] The set cycle corresponding to moderate blockage is: backflush for 10 seconds, pause for 10 seconds, and repeat these two actions 6 times; backflush for 30 seconds, pause for 10 seconds, and repeat these two actions 3 times. The total backflush time is 20 minutes, and the backflush flow rate is 50L / min, and the impurities on the filter 3 are blown back to the sulfur recovery pipeline 1.

[0043] The set cycle corresponding to severe blockage is: backflush for 20 seconds, pause for 10 seconds, these two actions are repeated for 1 cycle, the corresponding backflush flow rate is 100L / min, and then the set cycle is: backflush for 20 seconds, pause for 10 seconds, these two actions are repeated for 5 cycles, the corresponding backflush flow rate is 50L / min, and the total backflush time is 15 minutes. The impurities on the filter 3 are blown back to the sulfur recovery pipeline 1.

[0044] Pulse backwash uses high-pressure nitrogen. According to actual needs, the corresponding backwash flow, cycle length, backwash ratio and total backwash time are adjusted to adapt to different degrees of blockage. Improving the backwash effect by simply increasing the time or flow of a certain backwash parameter is limited. The backwash effect can also be improved by combining multiple types of backwash cycles or backwash flows.

[0045] 5) The collected gas samples are finally discharged through the exhaust gas emission pipe 10 to ensure the stability of the gas pressure inside the online ratiometer.

[0046] By obtaining the spectral signal of the gas sample or the gas flow rate, it is judged whether the filter 3 for filtering gas impurities is blocked. For example, a decrease in gas flow or a weakening of the spectral signal reflects that the gas sample entering the analyzer measurement chamber 8 has decreased, indicating that the filter 3 is blocked. According to different degrees of blockage, the corresponding backwash flow rate and cycle are set. Compared with the existing method that does not distinguish the degree of blockage, the backwash time is saved, the efficiency of eliminating blockage obstacles is improved, and the analyzer 9 is guaranteed to perform routine analysis and measurement of gas samples. The pulse backwash method is based on the discontinuous peak generated by the flow shock wave of the purge gas, which produces a jump-like change in pressure on the impurities blocking the gas path. Compared with the existing fixed flow purge method, the backwash effect is improved.

[0047] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention is described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions recorded in the aforementioned embodiments without creative work, or replace some of the technical features therein with equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A backflushing method for a sampling probe of an online ratio analyzer, characterized in that: The method comprises the following steps: when backflushing needs to be started, obtaining the blockage degree of the sampling probe, adjusting the backflushing flow, backflushing cycle and total backflushing time according to the blockage degree, and blowing the impurities on the sampling probe back into the sulfur recovery pipeline, wherein the backflushing cycle comprises the cycle length and the proportion of the backflushing time in one cycle.

2. The backflushing method for the sampling probe of the online ratio analyzer according to claim 1, characterized in that: The judgment steps for starting backblowing are: obtaining the spectral signal of the gas sample in the analyzer measurement chamber and / or obtaining the gas sample flow rate of the gas sample passing through the analyzer measurement chamber; when the spectral signal is less than the corresponding spectral signal threshold and / or the gas sample flow rate is less than the flow threshold, starting backblowing.

3. The backflushing method for the sampling probe of the online ratio analyzer according to claim 2, characterized in that: The condition for judging the degree of blockage is that the smaller the spectrum signal or the gas sample flow rate is, the more serious the corresponding degree of blockage is.

4. The sampling probe backflushing method of the online ratio analyzer according to claim 2 is characterized in that: The spectrum signal includes a first wavelength spectrum signal and a second wavelength spectrum signal. When at least one of the first wavelength spectrum signal and the second wavelength spectrum signal is smaller than a corresponding spectrum threshold, backflush is started.

5. The backflushing method for the sampling probe of the online ratio analyzer according to claim 4, characterized in that: The first wavelength is 190 nm, and the second wavelength is 250 nm.

6. The backflushing method for the sampling probe of the online ratio analyzer according to any one of claims 1 to 5, characterized in that: As the blockage becomes more severe, the backflush flow rate, cycle length, backflush ratio and / or total backflush time are increased accordingly.

7. The backflushing method for the sampling probe of the online ratio analyzer according to any one of claims 1 to 5, characterized in that: The degree of blockage is divided into slight blockage, moderate blockage and medium blockage according to the size of the spectral signal or the gas sample flow rate; Different backwash flow rates, cycle lengths, backwash proportions and / or total backwash time are set correspondingly to light blockage, medium blockage and heavy blockage.

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