Initial treatment method for online replacement of filter bag

Abstract

The invention relates to an initial treatment method for online replacement of a filter bag, which is characterized in that an observation device and an ash spraying device are arranged at an ash hopper of a bag chamber, and the method specifically comprises the following steps: S1, before replacement of a new filter bag, retaining a certain amount of ash in the ash hopper of the bag chamber where the damaged filter bag is located; s2, enabling the bag chamber to be offline, closing back-blowing dust removal of the bag chamber at the same time, and then replacing a new filter bag; s3, compressed air is introduced into an air inlet pipe of the ash spraying device to stir the ash in the ash hopper, so that the ash is raised and attached to the surface of the filter bag, and meanwhile, the ash attaching condition of the surface of the filter bag is observed through an observation device; s4, when dust is completely attached to the surface of the filter bag, dust spraying is stopped, and the bag chamber is put into operation; according to the invention, ash is quickly attached to the surface of a new replaced filter bag, so that the new replaced filter bag can quickly reach a normal use state, the mode of replacing the filter bag on line can be smoothly implemented, and the continuity and stability of the production process are ensured.

Description

Technical Field

[0001] This invention relates to the field of copper smelting production technology, specifically a preliminary treatment method for online filter bag replacement. Background Technology

[0002] The particulate matter concentration in the flue gas generated during the smelting of scrap copper in a vertical shaft furnace exceeds emission standards. Currently, baghouse dust collectors are generally used to purify the flue gas. However, in actual production, the filter bags of these dust collectors frequently become damaged. After damage, the particulate matter concentration at the flue gas outlet increases and may even exceed the standard. If the baghouse dust collector is shut down and the filter bags are replaced offline, the vertical shaft furnace must also be shut down, resulting in significant economic losses. Therefore, baghouse dust collectors adopt a multi-baghouse design, such as... Figure 4 , Figure 5 As shown, to achieve online filter bag replacement, the specific online filter bag replacement method is as follows: After a filter bag is found to be damaged, both the vertical shaft furnace and the bag filter continue to operate. The lifting valve of the bag chamber containing the damaged filter bag is closed to shut off its flue gas outlet, while other bag chambers continue to operate normally. The cover plate of the upper box of the bag chamber containing the damaged filter bag is manually opened, the damaged old filter bag is removed from the upper box, a new filter bag is replaced, and then the bag chamber is put back into operation.

[0003] While the aforementioned online filter bag replacement method avoids furnace shutdowns and ensures normal production, the following problems exist in practical application: After replacing the filter bags, the hourly average concentration of particulate matter at the flue gas outlet increases significantly compared to the normal operation period before the filter bags were damaged. Furthermore, the more filter bags replaced and the higher the replacement ratio, the greater the increase in the average particulate matter concentration at the flue gas outlet. Frequent and widespread exceedances of minute particulate matter values ​​sometimes even force an emergency shutdown of the vertical furnace to avoid environmental penalties for exceeding hourly particulate matter standards. This adversely affects the furnace's safety and production safety, causing significant economic losses and contradicting the original intention of online filter bag replacement to achieve uninterrupted furnace operation. Summary of the Invention

[0004] To address the technical problem of low dust removal efficiency in the initial stage of use of newly replaced filter bags in online applications, this invention provides an initial treatment method for online filter bag replacement.

[0005] The specific solution of the present invention is as follows: An initial treatment method for online filter bag replacement, comprising: setting at least one observation port at the ash hopper of the bag chamber; each observation port being equipped with an observation device on its outer side for observing the filter bags inside the bag chamber; and an ash spraying device on the outer side of the ash hopper, the ash spraying device comprising a ring-shaped pipe, an air inlet pipe connected to one side of the ring-shaped pipe, and several spray pipes extending into the ash hopper on the ring-shaped pipe, each spray pipe being arranged towards the soot inside the ash hopper; the treatment method comprising the following steps:

[0006] S1, before replacing the new filter bag, a certain amount of soot is reserved in the ash hopper of the bag chamber where the damaged filter bag is located;

[0007] S2, make the bag chamber offline, at the same time, close the back-blowing ash cleaning of the bag chamber, and then replace the new filter bag;

[0008] S3, pass compressed gas into the air inlet pipe of the ash injection device to stir the soot in the ash hopper, make the soot rise and adhere to the surface of the filter bag, and observe the soot adhesion on the surface of the filter bag through the observation device;

[0009] S4, stop injecting ash when the lower surface of the new filter bag cannot be observed to be the original color of the filter bag, then lift the new filter bag upward from the top of the bag chamber, check the soot adhesion on the upper surface of the filter bag, if the original color of the filter bag can be observed on the upper surface, reset the new filter bag and repeat steps S3 and S4, until the original color of the filter bag cannot be observed on the upper surface of the new filter bag, then install the new filter bag;

[0010] S5, put the bag chamber into operation.

[0011] Further, in step S5, before the bag chamber is put into operation, start the back-blowing ash cleaning of the bag chamber where the new filter bag is located in the manual mode, and back-blow for several times.

[0012] Further, in step S5, after the bag chamber is put into operation, observe the running resistance of the bag-type dust collector, if it is greater than the normal level before the filter bag is damaged, start the back-blowing ash cleaning of the bag chamber where the new filter bag is located, so that the running resistance falls to the level during normal operation, and then start the automatic mode to make the bag chamber where the new filter bag is located enter normal operation.

[0013] Further, the observation device comprises an observation cylinder, an eyepiece is installed at the outer end of the observation cylinder, the inner end of the observation cylinder is connected with the ash hopper shell, a cleaning pipe is arranged in the middle part of the observation cylinder, one end of the cleaning pipe is communicated with the observation cylinder, and the other end is connected to a compressed air source.

[0014] Further, the observation cylinder comprises a base pipe and an eyepiece mounting pipe, the base pipe and the eyepiece mounting pipe are connected through a flange, the cleaning pipe is mounted on the eyepiece mounting pipe, and a protection valve is mounted on the eyepiece mounting pipe between the flange and the cleaning pipe.

[0015] Further, the diameter of the eyepiece mounting pipe is smaller than that of the base pipe, and a tapered connecting pipe is arranged at the end of the eyepiece mounting pipe facing the base pipe.

[0016] Further, a gate is arranged at the end of the base pipe facing the ash hopper, and a plug is arranged at the gate, which is used to close or open the observation port of the ash hopper.

[0017] Further, the spray pipe is inclined downward by 30-60° and points to the center line of the ash hopper, the number of spray pipes is 2-8, and they are uniformly arranged.

[0018] Compared with existing technologies, this invention has the following beneficial effects: 1. In the initial stage of new filter bag use, the average particulate matter concentration at the flue gas outlet is at a normal level, and the minute particulate matter value does not exceed the standard, eliminating the risk of environmental incidents and avoiding the risks to furnace safety and production safety caused by emergency shutdown of the vertical furnace, thus avoiding economic losses. This allows for the smooth implementation of online filter bag replacement, ensuring the continuity and stability of the production process. After the new filter bags are put into use, the operating resistance of the bag filter does not exceed the normal operating level, and will not increase the power consumption of the exhaust fan. 2. This invention is easy to operate; it simultaneously applies ash to all new filter bags in the same bag chamber, resulting in high operating efficiency. The operation process does not generate pollution and does not increase the amount of flue gas ash produced by the bag filter. The online filter bag replacement initial treatment process device of this invention is not only low in cost but also low in operating cost. 3. The observation device set in this invention can not only be used when dust accumulates after replacing new filter bags online, but also for monitoring the inside of the bag filter during daily operation. If dust accumulation is found, the dust discharge force can be increased; if clumping is found, the vibration intensity can be increased in time; if individual filter bags are found to be damaged, they can be replaced online immediately to prevent the damage from spreading to other filter bags, thus avoiding the risk of excessive particulate matter at the flue gas outlet and saving filter bag replacement costs. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the observation device and the ash spraying device of the present invention;

[0020] Figure 2 yes Figure 1 AA section view;

[0021] Figure 3 yes Figure 1 Enlarged view of point V;

[0022] Figure 4 This is a structural schematic diagram of an existing bag filter dust collector;

[0023] Figure 5 yes Figure 4 Side view;

[0024] In the diagram: 1. Bag chamber; 2. Filter bag; 3. Upper housing; 4. Lifting valve; 5. Ash hopper; 6. Observation device; 61. Base tube; 62. Insert plate; 63. Flange; 64. Protective valve; 65. Eyepiece mounting tube; 66. Eyepiece; 67. Cleaning tube; 68. Manual valve; 7. Ash spraying device; 71. Air inlet pipe; 72. Circular pipe; 73. Spray pipe. Detailed Implementation

[0025] See Figures 1-3This embodiment describes an initial treatment method for online filter bag replacement. Four observation ports are provided at the ash hopper 5 of the bag chamber 1. Each observation port is equipped with an observation device 6 on its outer side. The observation device 6 is used to observe the filter bags 2 inside the bag chamber 1. The observation device 6 includes an observation cylinder with an eyepiece 66 mounted on its outer end. The inner end of the observation cylinder is connected to the shell of the ash hopper 5. A cleaning pipe 67 is provided in the middle of the observation cylinder, with one end connected to the observation cylinder and the other end connected to a compressed air source. The observation cylinder includes a base tube 61 and an eyepiece mounting tube 6. 5. The base tube 61 and the eyepiece mounting tube 65 are connected by a flange 63. The cleaning tube 67 is installed on the eyepiece mounting tube 65, and a protective valve 64 is installed on the eyepiece mounting tube 65 between the flange 63 and the cleaning tube 67. The diameter of the eyepiece mounting tube 65 is smaller than that of the base tube 61, and a tapered connecting tube is provided at the end of the eyepiece mounting tube 65 facing the base tube 61. A gate is provided at the end of the base tube 61 facing the ash hopper 5, and a slide plate 62 is installed at the gate. The slide plate 62 is used to close or open the observation port of the ash hopper 5. In this embodiment, the protective valve 64 is a manual butterfly valve. When the butterfly valve is fully open, the valve plate plane is parallel to the axis of the eyepiece mounting tube 65, and at this time the line of sight of the eyepiece 66 is basically not obstructed by the valve. The outer side of the ash hopper 5 is also provided with an ash spraying device 7. The ash spraying device 7 includes a ring pipe 72. An air inlet pipe 71 is connected to one side of the ring pipe 72. Eight spray pipes 73 are evenly arranged on the ring pipe 72 and extend into the ash hopper 5. Each spray pipe 73 is arranged towards the soot in the ash hopper 5. The spray pipes 73 are inclined downward at 30°-60° and point towards the center line of the ash hopper 5.The replacement of filter bag 2 is carried out by the above-mentioned observation device 6 and ash spraying device 7. The specific method includes the following steps: S1, before replacing the new filter bag 2, a certain amount of soot is retained in the ash hopper 5 of the bag chamber 1 where the damaged filter bag 2 is located; S2, the bag chamber 1 is disconnected, and the back-blowing cleaning of the bag chamber 1 is closed at the same time, and then a new filter bag 2 is replaced; S3, compressed gas is introduced into the air inlet pipe 71 of the ash spraying device 7 to stir the soot in the ash hopper 5, so that the soot rises and adheres to the surface of the filter bag 2, and the ash adhesion on the surface of the filter bag 2 is observed through the observation device 6; during the observation process, the protective valve 64 is opened, and the insert plate 62 is pulled out. The ash accumulation at the observation port is checked through the eyepiece 66 to confirm that the eyepiece 66 does not obstruct the line of sight to the bag chamber 1; otherwise, the eyepiece 66 is unscrewed, the manual valve 68 of the cleaning pipe 67 is opened, and compressed gas is introduced into the eyepiece mounting pipe 65 to blow away the ash. If necessary, the flange 63 is disassembled and the soot at the port of the base pipe 61 is cleaned with a steel rod. Clumping is prevented to ensure that the filter bag 2 inside the bag chamber 1 can be observed through eyepiece 66; S4, when the original color of the filter bag 2 can no longer be observed on the lower surface of the new filter bag 2, the dust spraying is stopped, and then the cover plate is opened from the top of the upper box 3 of the bag chamber 1. Then, the new filter bag 2 is lifted up one end distance to check the dust accumulation on the upper surface of the filter bag 2. If the original color of the filter bag 2 can be seen on the upper part, the new filter bag 2 is reset and steps S3 and S4 are repeated until the original color of the filter bag 2 can no longer be seen on the upper surface of the new filter bag 2. S5. Install filter bag 2 and close the cover of upper housing 3; S6. In manual mode, start the back-flushing cleaning of bag chamber 1 where the new filter bag 2 is located, back-flushing several times, and then open the lifting valve 4 to put bag chamber 1 into operation; S7. Observe the operating resistance of the bag filter and compare it with the level before the filter bag 2 was damaged: If the operating resistance is greater than the normal level before the filter bag 2 was damaged, start the back-flushing cleaning of bag chamber 1 where the new filter bag 2 is located, and use the automatic mode to make the operating resistance of the bag filter return to the level of normal operation. If the operating resistance is less than the normal level before the filter bag 2 was damaged, continue to stop the back-flushing cleaning until the operating resistance value increases to the normal level before the filter bag 2 was damaged, then start the back-flushing cleaning again, and use the automatic mode to make the operating resistance of the bag filter return to the level of normal operation. In this embodiment, after replacing 36 filter bags 2 in the same bag chamber 1 online, all new filter bags 2 were simultaneously dusted, and the dusting was completed in 25 minutes. Then bag chamber 1 was put back into operation. After the new filter bag 2 was put into use, the hourly average particulate matter concentration at the flue gas outlet was 1.7 mg / Nm3 to 4.3 mg / Nm3, and the minute value ranged from 0.5 mg / Nm3 to 6.5 mg / Nm3, which is better than the normal operating level and fully meets the environmental protection requirements.

Claims

1. A preliminary treatment method for online filter bag replacement, characterized in that: At least one observation port is provided at the ash hopper of the baghouse, and an observation device is installed on the outside of each observation port for observing the filter bags inside the baghouse. A dust spraying device is also provided on the outside of the ash hopper. The dust spraying device includes a ring-shaped pipe, with an air inlet pipe connected to one side of the ring-shaped pipe. Several spray pipes extending into the ash hopper are provided on the ring-shaped pipe, with each spray pipe facing the soot inside the ash hopper. The treatment method includes the following steps: S1. Before replacing the filter bag, retain a certain amount of soot in the ash hopper of the bag chamber where the damaged filter bag is located; S2. Take the bag chamber offline and turn off the back-flushing cleaning of the bag chamber at the same time, then replace the filter bag with a new one; S3. Compressed gas is introduced into the air inlet pipe of the ash spraying device to agitate the soot in the ash hopper, causing the soot to rise and adhere to the surface of the filter bag. At the same time, the ash adhesion on the surface of the filter bag is observed through the observation device. S4. Stop spraying ash when the original color of the filter bag can no longer be observed on the lower surface of the new filter bag. Then lift the new filter bag upward from the top of the bag chamber and check the ash on the upper surface of the filter bag. If the original color of the filter bag can be seen on the upper part, reset the new filter bag and repeat steps S3 and S4 until the original color of the filter bag can no longer be seen on the upper surface of the new filter bag. Then install the new filter bag. S5. Put the bag chamber into operation.

2. The initial treatment method for online filter bag replacement according to claim 1, characterized in that: In step S5, before the bag chamber is put into operation, the back-blowing cleaning of the bag chamber where the new filter bag is located is started in manual mode, and back-blowing is performed several times.

3. The initial treatment method for online filter bag replacement according to claim 2, characterized in that: In step S5, after the bag chamber is put into operation, observe the operating resistance of the bag filter. If it is greater than the normal level before the filter bag is damaged, start the back-flushing cleaning of the bag chamber where the new filter bag is located to reduce the operating resistance back to the level of normal operation; then start the automatic mode to bring the bag chamber where the new filter bag is located into normal operation.

4. The initial treatment method for online filter bag replacement according to claim 1, characterized in that: The observation device includes an observation tube with an eyepiece at the outer end and the inner end of the observation tube connected to the ash hopper shell. A cleaning pipe is provided in the middle of the observation tube, with one end of the cleaning pipe connected to the observation tube and the other end connected to a compressed air source.

5. The initial treatment method for online filter bag replacement according to claim 4, characterized in that: The observation tube includes a base tube and an eyepiece mounting tube, which are connected by a flange. The cleaning tube is installed on the eyepiece mounting tube, and a protective valve is installed on the eyepiece mounting tube between the flange and the cleaning tube.

6. The initial treatment method for online filter bag replacement according to claim 5, characterized in that: The diameter of the eyepiece mounting tube is smaller than that of the base tube, and a tapered connecting tube is provided at the end of the eyepiece mounting tube facing the base tube.

7. The initial treatment method for online filter bag replacement according to claim 5 or 6, characterized in that: The base tube has a gate at one end facing the ash hopper, and an insert plate is installed at the gate. The insert plate is used to close or open the observation port of the ash hopper.

8. The initial treatment method for online filter bag replacement according to claim 1, characterized in that: The nozzles are tilted downwards at 30°-60° and point towards the center line of the ash hopper. There are 2-8 nozzles in total, and they are evenly arranged.

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