A method for sampling a filter bag of a baghouse dust collector

Abstract

This invention provides a sampling method for filter bags in a baghouse dust collector, belonging to the field of filter bag sampling technology. The method includes the following steps: Based on the different installation positions of the filter bags in the dust collector, nine sampling areas are divided according to their positions: front left of the furnace, front center of the furnace, front right of the furnace, left center of the furnace, center of the furnace, right center of the furnace, rear left of the furnace, rear center of the furnace, and rear right of the furnace. Samples are selected from each sampling area, and the total number of samples taken is greater than or equal to nine. The sampling method for filter bags in a baghouse dust collector provided by this invention divides the filter bags into nine sampling areas based on their different installation positions in the dust collector, according to their positions: front left of the furnace, front center of the furnace, front right of the furnace, left center of the furnace, center of the furnace, right center of the furnace, rear left of the furnace, rear center of the furnace, and rear right of the furnace. Samples are selected from each sampling area, and the total number of samples taken is greater than or equal to nine. The samples are representative and complete, enabling the formation of a unified and effective conclusion, and avoiding the influence of sampling deviations on the overall judgment of the baghouse dust collector.

Description

Technical Field

[0001] This invention relates to the field of filter bag sampling technology, and specifically to a sampling method for filter bags in a baghouse dust collector. Background Technology

[0002] Currently, there are numerous devices available for treating dust in flue gas, including electrostatic precipitators, wet electrostatic precipitators, bag filters, and electrostatic-bag filters. Among these, bag filters are a highly efficient flue gas treatment device, widely used due to their high filtration efficiency and stable performance. The core component of a bag filter is the filter bag; each bag filter contains hundreds to thousands of filter bags. The performance and lifespan of the filter bags directly determine the effectiveness of the bag filter. Due to the complex and variable operating conditions, the degree of clogging, damage, and utilization rate of filter bags vary at different locations within a bag filter. To ensure that the performance of the filter bags meets the requirements of flue gas filtration, filter bag performance testing technology has been widely adopted. However, how to sample effectively to maximize the authenticity and reliability of the samples remains a challenge. Summary of the Invention

[0003] Therefore, the present invention provides a sampling method for filter bags of baghouse dust collectors.

[0004] To solve the above-mentioned technical problems, the present invention provides a sampling method for filter bags of baghouse dust collectors, comprising the following steps:

[0005] Based on the different installation positions of the filter bags in the dust collector, the sampling areas are divided into 9 regions according to their positions: front left of the furnace, front middle of the furnace, front right of the furnace, left middle of the furnace, center of the furnace, right middle of the furnace, rear left of the furnace, rear middle of the furnace, and rear right of the furnace.

[0006] Samples must be selected for each sampling area, with a total of 9 or more samples taken.

[0007] Optionally, the formula for judging abnormal filter bags is:

[0008] Y=T∪P∪(S∩K)∪(H∪K)∪(C∩D)∪(C∩J)∪(L∩D)∪(K∩E);

[0009] Among them, S is an event of abnormal sulfur content in the coal fed into the furnace, T is an event of abnormal operating temperature in the baghouse area, P is an event of abnormal resistance in the dust removal system, H is an event of water leakage in upstream equipment, C is an event of excessive dust discharge, L is an event of deformation, J is an event of ash accumulation on the tube sheet, K is an event of bag clogging, D is an event of hole breaking, and E is an event of abnormal soot blowing pressure and frequency.

[0010] The following formula is used to determine whether the bag-sealing event K has occurred. K occurs when the result is true, that is, when the following formula is satisfied:

[0011]

[0012] p0 refers to the initial filter bag resistance (Pa);

[0013] p t The filter bag resistance (Pa) refers to the operating time t.

[0014] p max The maximum resistance (Pa) during the filter bag's lifespan is taken as 6.5p0;

[0015] t refers to the time (s) the filter bag has been running;

[0016] T refers to the filter bag life cycle (s);

[0017] G0 refers to the initial weight of the filter bag (g / m³). 2 );

[0018] G t The filter bag weight (g / m³) refers to the weight of the filter bag during operation time t. 2 );

[0019] G max The maximum weight per cubic meter of filter bag over its lifespan (g / m³) 2 ), take 1.38G0.

[0020] Optionally, when sampling filter bags in abnormal operation, if event T or event P occurs, the sampling method for normal operation filter bags shall be followed; if event K occurs, another filter bag in the area where the glued filter bag is located shall be selected as a sampling sample; if event C∩D occurs, another filter bag in the area where the punctured filter bag is located shall be selected as a sampling sample; if event C∩J occurs, another filter bag in the dust accumulation area of ​​the tube sheet shall be selected as a sampling sample; if event L∩D occurs, another filter bag in the area where the punctured filter bag is located shall be selected as a sampling sample.

[0021] Optionally, when more than one sample is selected in the same sampling area, the sample location is selected in a continuous manner.

[0022] Optionally, before sampling, all filter bags in the dust collector are numbered, and the sample at each numbered position is sampled only once within one life cycle.

[0023] Optionally, the filter bags used for sampling are from the same batch and have the same initial properties.

[0024] Optionally, the unit's historical operating status includes data on the sulfur content of the coal fed into the furnace, records of water and steam leakage faults in upstream equipment, historical data on the operating temperature of the baghouse area, historical data on the resistance of the dust removal system, data on soot blowing pressure or frequency, and records of excessive dust emissions.

[0025] The technical solution of this invention has the following advantages:

[0026] 1. The sampling method for filter bags of baghouse dust collectors provided by the present invention divides the filter bags into 9 sampling areas according to their different installation positions in the dust collector: front left of the furnace, front middle of the furnace, front right of the furnace, left middle of the furnace, center of the furnace, right middle of the furnace, rear left of the furnace, rear middle of the furnace, and rear right of the furnace. Samples are selected from each sampling area, and the total number of samples taken is greater than or equal to 9. The samples are representative and complete, and can form a unified and effective conclusion, avoiding the influence of sampling deviation on the overall judgment of the baghouse dust collector.

[0027] 2. The sampling method for filter bags of a baghouse dust collector provided by the present invention forms an overall judgment of the baghouse dust collector by judging various events, so as to judge the filtration effect of the baghouse dust collector.

[0028] 3. The sampling method for filter bags of baghouse dust collectors provided by the present invention involves numbering all filter bags in the dust collector before sampling. The sample at each numbered position is only sampled once within one life cycle, ensuring that the test results are not affected by the sampling of newly installed filter bags at the same position. Attached Figure Description

[0029] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0030] Figure 1 This is a distribution diagram of the dust collector sampling area provided in an embodiment of the present invention.

[0031] Explanation of reference numerals in the attached figures:

[0032] 1. Front left of the furnace; 2. Front center of the furnace; 3. Front right of the furnace; 4. Left center of the furnace; 5. Center of the furnace; 6. Right center of the furnace; 7. Rear left of the furnace; 8. Rear center of the furnace; 9. Rear right of the furnace. Detailed Implementation

[0033] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0035] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0036] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0037] Example

[0038] This embodiment provides a specific implementation method for sampling filter bags in a baghouse dust collector, including the following steps: Based on the different installation positions of the filter bags in the dust collector, the system is divided into nine sampling areas: Furnace Left Front 1, Furnace Center Front 2, Furnace Right Front 3, Furnace Center Left 4, Furnace Center 5, Furnace Center Right 6, Furnace Left Rear 7, Furnace Center Rear 8, and Furnace Right Rear 9. Samples must be selected from each sampling area, and the total number of samples taken must be greater than or equal to nine, ensuring that at least one filter bag is selected from each area. The samples are representative and complete, enabling the formation of a unified and valid conclusion, and avoiding the influence of sampling bias on the overall judgment of the baghouse dust collector.

[0039] Sampling and testing were conducted in each sampling area, with at least one filter bag selected from each area for testing. First, samples from the same location at different time points were sampled and tracked for testing, representatively reflecting the usage and performance trends of the filter bags. Second, samples from different locations were compared and tested to identify the causes of differences. Finally, comprehensive analysis provided a reference for the management of the filter bags throughout their entire lifecycle.

[0040] In this embodiment, the formula for judging abnormal filter bags is:

[0041] Y=T∪P∪(S∩K)∪(H∪K)∪(C∩D)∪(C∩J)∪(L∩D)∪(K∩E);

[0042] Among them, S is an event of abnormal sulfur content in the coal fed into the furnace, T is an event of abnormal operating temperature in the baghouse area, P is an event of abnormal resistance in the dust removal system, H is an event of water leakage in upstream equipment, C is an event of excessive dust emission, L is an event of deformation, J is an event of ash accumulation on the tube sheet, K is an event of bag clogging, D is an event of hole breaking, and E is an event of abnormal soot blowing pressure and frequency.

[0043] Specifically, the occurrence of the bag-sealing event K is determined by the following formula. The bag-sealing event K occurs when the result is true, that is, when the following formula is satisfied:

[0044]

[0045] p0 refers to the initial filter bag resistance (Pa);

[0046] p t The filter bag resistance (Pa) refers to the operating time t.

[0047] p max The maximum resistance (Pa) during the filter bag's lifespan is taken as 6.5p0;

[0048] t refers to the time (s) the filter bag has been running;

[0049] T refers to the filter bag life cycle (s);

[0050] G0 refers to the initial weight of the filter bag (g / m³). 2 );

[0051] G t The filter bag weight (g / m³) refers to the weight of the filter bag during operation time t. 2 );

[0052] G max The maximum weight per cubic meter of filter bag over its lifespan (g / m³) 2 ), take 1.38G0.

[0053] According to the above formula, a bag clogging event can be determined. A bag clogging event occurs when dust adheres to the filter bag due to the adhesion of dust to the air or moisture in the dust collector. Since the dust is relatively fine, it may be difficult for operators to identify whether bag clogging occurs by visual inspection alone. Therefore, the above formula can be used to determine whether bag clogging has occurred, eliminating the need for high-end equipment for observation.

[0054]

[0055] Table 1. Relationship between sulfur content in coal and normal range of flue gas temperature for filter bags of different materials

[0056] As shown in Table 1, the normal range of coal sulfur content and flue gas temperature (i.e., baghouse operating temperature) will vary depending on the filter material. When judging events of abnormal coal sulfur content and abnormal baghouse operating temperature, it is necessary to determine whether the coal sulfur content and flue gas temperature are within the corresponding normal range based on the type of filter material. If they are outside the normal range, the event should be judged as abnormal.

[0057]

[0058] Table 2. Relationship between bag zone velocity and normal resistance of different types of dust collectors

[0059] As shown in Table 2, the outlet smoke concentration can be used to determine whether dust emissions exceed the limit. Depending on the required range of outlet smoke concentration, the range of dust collector resistance also varies. It can be determined whether there is an abnormal resistance in the dust collection system based on whether the dust collector resistance meets the range. In other words, the abnormal resistance event of the dust collection system is determined by whether the dust collector resistance meets the normal range.

[0060] Specifically, when sampling filter bags that are not operating normally, if event T or event P occurs, the sampling method for normal operating filter bags should be followed; if event K occurs, another filter bag in the area where the clogged filter bag is located should be selected as a sample; if event C∩D occurs, another filter bag in the area where the punctured filter bag is located should be selected as a sample; if event C∩J occurs, another filter bag in the dust accumulation area of ​​the tube sheet should be selected as a sample; if event L∩D occurs, another filter bag in the area where the punctured filter bag is located should be selected as a sample.

[0061] In this embodiment, when more than one sample is selected within the same sampling area, the sample positions are selected in a continuous manner.

[0062] In this embodiment, before sampling, all filter bags in the dust collector are numbered. The sample at each number position is sampled only once within one life cycle. At the same time, the filter bags used as samples are from the same batch and have the same initial performance, and are put into use at the same time.

[0063] The unit's historical operating status includes data on the sulfur content of the coal fed into the furnace, records of water and steam leakage faults in upstream equipment, historical data on the operating temperature of the baghouse area, historical data on the resistance of the dust removal system, data on soot blowing pressure or frequency, and records of excessive dust emissions.

[0064] When making a sample, you can make a sample sequentially from the nine sampling regions, or you can randomly select a sampling region.

[0065] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A sampling method for filter bags in a baghouse dust collector, characterized in that, Includes the following steps: Based on the different installation positions of the filter bags in the dust collector, the sampling areas are divided into 9 regions according to their positions: front left of the furnace, front middle of the furnace, front right of the furnace, left middle of the furnace, center of the furnace, right middle of the furnace, rear left of the furnace, rear middle of the furnace, and rear right of the furnace. Samples must be selected in each sampling area, and the total number of samples taken must be greater than or equal to 9. The formula for judging abnormal filter bags is as follows: Y=T∪P∪(S∩K)∪(H∪K)∪(C∩D)∪(C∩J)∪(L∩D)∪(K∩E); Among them, S is an event of abnormal sulfur content in the coal fed into the furnace, T is an event of abnormal operating temperature in the baghouse area, P is an event of abnormal resistance in the dust removal system, H is an event of water leakage in upstream equipment, C is an event of excessive dust discharge, L is an event of deformation, J is an event of ash accumulation on the tube sheet, K is an event of bag clogging, D is an event of hole breaking, and E is an event of abnormal soot blowing pressure and frequency. The following formula is used to determine whether the bag-sealing event K has occurred. K occurs when the result is true, that is, when the following formula is satisfied: p0 refers to the initial filter bag resistance (Pa); p t The filter bag resistance (Pa) refers to the operating time t. p max The maximum resistance (Pa) during the filter bag's lifespan is taken as 6.5p0; t refers to the time (s) the filter bag has been running; T refers to the filter bag life cycle (s); G0 refers to the initial weight of the filter bag (g / m³). 2 ); G t The filter bag weight (g / m³) refers to the weight of the filter bag during operation time t. 2 ); G max The maximum weight per cubic meter of filter bag over its lifespan (g / m³) 2 ), take 1.38G0.

2. The sampling method for filter bags of a baghouse dust collector according to claim 1, characterized in that, When sampling filter bags that are not operating normally, if event T or event P occurs, the sampling method for filter bags in normal operation shall be followed; if event K occurs, another filter bag in the area where the clogged filter bag is located shall be selected as a sample; if event C∩D occurs, another filter bag in the area where the punctured filter bag is located shall be selected as a sample; if event C∩J occurs, another filter bag in the dust accumulation area of ​​the tube sheet shall be selected as a sample; if event L∩D occurs, another filter bag in the area where the punctured filter bag is located shall be selected as a sample.

3. The sampling method for filter bags of a baghouse dust collector according to claim 1, characterized in that, When more than one sample is selected from the same sampling area, the sample locations are selected in a continuous manner.

4. The sampling method for filter bags of a baghouse dust collector according to claim 1, characterized in that, Before sampling, all filter bags in the dust collector are numbered, and the sample at each numbered position is only sampled once within one life cycle.

5. The sampling method for filter bags of a baghouse dust collector according to claim 1, characterized in that, The filter bags used for sampling were from the same batch and had the same initial properties.

6. The sampling method for filter bags of a baghouse dust collector according to claim 1, characterized in that, The unit's historical operating status includes data on the sulfur content of the coal fed into the furnace, records of water and steam leakage faults in upstream equipment, historical data on the operating temperature of the baghouse area, historical data on the resistance of the dust removal system, data on soot blowing pressure or frequency, and records of excessive dust emissions.

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