JP5848175B2 - Cleaning method for eliminator - Google Patents

Description

  The present invention relates to a method for cleaning an eliminator placed in a flue.

  The eliminator is used for the purpose of removing mist contained in the gas in the gas cleaning tower, the humidification tower, and the cooling tower. Eliminators are classified into several types according to their structure, and are used according to their needs. One of these is the vane type eliminator. FIG. 1 is a cross-sectional view of a vane type eliminator 10. As shown in FIG. 1, the vane type eliminator 10 has a structure in which a plurality of zigzag plates (vanes) 11 each having a plurality of folds are overlapped and arranged. When the gas containing mist passes between the vanes 11, the gas collides with the vanes 11 and the mist is separated.

  Such a vane type eliminator is provided in an exit flue of a cleaning tower, a humidifying tower, or a cooling tower for combustion gas discharged from a combustion engine such as a furnace or an engine. Dust such as smoke ash and dust contained in the gas enters the vane type eliminator provided in the flue and adheres to the vane. For this reason, as the operating time of the combustion engine increases, dust adheres to the vanes of the eliminator, and the pressure loss of the eliminator increases. As the pressure loss in the eliminator increases, the amount of energy consumed by the fans and pumps responsible for gas circulation increases. In order to avoid this, the vanes of the eliminator are washed.

  FIG. 2 is a diagram illustrating a conventional eliminator cleaning method. As shown in FIG. 2, the conventional cleaning device 100 for an eliminator 101 cleans the eliminator 101 by spraying a cleaning liquid toward the eliminator 101 from the upstream side and the downstream side where the gas flows. Replace the eliminator when the amount of dust attached increases and the increase in pressure loss cannot be suppressed even after cleaning the eliminator.

Patent Documents 1 to 4 are disclosed as technical documents related to the present invention. Patent Document 1 discloses a technique for cleaning a demister. In Patent Document 1, clogging of the demister is eliminated by spraying and cleaning the demister from the same direction as the flow direction of the gas rising from the bottom of the tower to the top of the tower, or the direction opposite to the gas flow direction. Patent Document 2 discloses an apparatus that removes a soluble gas by suction by gas-liquid contact. The device of Patent Document 2 is provided with a gas-liquid contact material to which water is supplied on the upstream side, and an eliminator is provided on the downstream side, thereby reducing the size of the device and reducing pressure loss. Patent Document 3 discloses a technique for changing the flow rate of the cleaning liquid for cleaning the eliminator according to the liquid level in the tower. Patent Document 4 discloses a technique for changing the cleaning interval of the eliminator according to the amount of SO ₂ .

JP 2011-16045 A JP 2006-341194 A JP-A-5-301019 JP 2003-62426 A

  As described above, in the vane type eliminator, since the zigzag vanes overlap several times, the cleaning liquid hardly enters the eliminator. For this reason, it is not easy to wash away dust adhering to the gap between the inner vane, the flow path resistance between the vanes cannot be reduced, and the increase in pressure loss cannot be suppressed. As a result, it was necessary to frequently replace the eliminator.

  In view of the above problems, an object of the present invention is to propose a method for cleaning an eliminator that suppresses an increase in pressure loss.

An eliminator cleaning method of the present invention that solves such a problem is a vane that is disposed in a flue through which a gas discharged in a copper smelting process flows , removes mist contained in the gas, and is a folded plate. A plurality of eliminator cleaning methods comprising: removing a ceiling lid for closing an opening for exchanging the eliminator provided in the flue and removing the plurality of eliminators from the outside of the flue through the opening vanes into the gap, sprayed cleaning liquid from the side to the flow direction of the gas flowing through the flue, longer than the length in the direction of the eliminator perpendicular to a flow direction of the gas flowing through the flue At the tip of the handle, a dust removing jig in which a scraping portion formed in accordance with the shape of the gap of the vane that is folded is fixed from the outside of the flue to the opening hole through the scraping portion. Inserting the cleaning unit into the gap of the vane from the side to the flow direction of the gas flowing through the flue, characterized in that. According to this eliminator cleaning method, since the cleaning liquid enters between the vanes in the eliminator, dust in the gaps of the vanes can be washed away. Thereby, the rise of the pressure loss of an eliminator can be suppressed. As a result, the frequency of eliminator replacement can be reduced.

  In the above eliminator cleaning method, the eliminator may be arranged in a flue through which the gas flows in the horizontal direction, and the cleaning liquid may be sprayed from the vertically upward direction.

  In the above-described eliminator cleaning method, the gas may include a mist adsorbing fluorine generated from an upstream facility or dust generated from an upstream facility, and the eliminator may separate the mist and dust from the gas.

  The eliminator cleaning method described above may spray the cleaning liquid intermittently. Further, the above-described eliminator cleaning method may spray the cleaning liquid at all times.

In the above eliminator cleaning method, the gas flow from the outside of the flue is removed through the opening by removing a lid that closes the opening provided in a part of the flue upstream from the position of the eliminator. You may add spraying a washing | cleaning liquid to the said eliminator from the upstream of a direction.

  According to the eliminator cleaning method of the present invention, an increase in pressure loss of the eliminator can be suppressed.

It is sectional drawing of a vane type eliminator. It is a figure explaining the washing | cleaning method of the conventional eliminator. It is the figure which showed the outline of the gas processing plant which processes the gas discharged | emitted in the copper smelting process. It is sectional drawing of the large diameter part of the flue provided with the eliminator. It is AA sectional drawing in FIG. It is a top view of an eliminator. It is a bottom view of an eliminator. It is a figure which wash | cleans an eliminator from the upper opening part of an eliminator. It is a figure which wash | cleans an eliminator from the opening part of a flue. It is the figure which showed a mode that dust was removed with a dust removal jig | tool. It is an enlarged view of the scraping part of a dust removal jig. It is the figure which compared the pressure loss of the cleaning method of the conventional cleaning method and this embodiment. It is the figure which showed the washing | cleaning apparatus of the eliminator of the other example of embodiment. It is the figure which showed the washing | cleaning apparatus of the eliminator of the other example of embodiment.

  The eliminator explaining embodiment of this invention is provided in the gas processing plant discharged | emitted in the copper smelting process. DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. FIG. 3 is a diagram showing an outline of the gas processing plant 1 for processing the gas discharged in the copper smelting process. As shown in FIG. 3, the gas processing plant 1 includes a furnace 2, a waste heat boiler 3, a first dust collector 4, a blower 5, a humidification tower 6, a cooling tower 7, and a second dust collector 8. The furnace 2 is a flash smelting furnace that melts copper concentrate and separates it into a mat and a slag. The furnace 2 may be a converter that increases the purity of the copper mat. The waste heat boiler 3 cools the gas by heat exchange between the gas discharged from the furnace 2 and the cooling water. The first dust collector 4 is located downstream of the waste heat boiler 3 and collects dust such as smoke ash and dust contained in the gas. The 1st dust collector 4 is an apparatus which collects dust electrically or mechanically, such as a bag filter, a cyclone, and a cot rel, for example. The blower 5 is a device that blows the gas that has passed through the first dust collector 4 to the downstream side.

The humidification tower 6 is a hollow tower formed so that gas rises. In the humidification tower 6, dilute sulfuric acid is sprayed from a spray provided so as to face the gas flow to the gas rising from the bottom of the tower toward the top of the tower, and the gas is humidified and cooled along the adiabatic cooling line. The cooling tower 7 further cools the gas that has passed through the humidification tower 6. The cooling tower 7 is a packed tower formed so that gas rises. In the cooling tower 7, low-temperature dilute sulfuric acid is sprayed from a spray provided so as to face the gas to the gas rising from the bottom of the tower toward the top of the tower. The cooling tower 7 is provided with a packing so that the gas and dilute sulfuric acid come into efficient contact with each other. The gas in contact with the low-temperature dilute sulfuric acid is humidified and cooled. The second dust collector 8 is a wet dust collector provided downstream of the cooling tower 7. The second dust collector 8 can be an apparatus that collects dust electrically or mechanically, such as a bag filter, a cyclone, or a cotrel. The gas that has passed through the second dust collector 8 is sent to a sulfuric acid production plant that uses SO ₂ contained in the gas as a raw material.

  By the way, the humidification tower 6 and the cooling tower 7 are connected by a flue 9. The flue 9 changes the gas flow entering vertically upward from the top (exit part) of the humidification tower 6 in the horizontal direction, and further changes the direction downward in the vertical direction and sends it to the cooling tower 7. An eliminator 10 is disposed in the flue 9. More specifically, the eliminator 10 is provided in the horizontal traveling section 91 of the flue 9. A large diameter portion 92 having a large diameter is formed in the horizontal travel section 91 of the flue 9 in order to provide the eliminator 10.

  Next, the structure of the eliminator 10 will be described in detail. FIG. 4 is a cross-sectional view of the large diameter portion 92 of the flue 9 provided with the eliminator 10. FIG. 5 is a cross-sectional view taken along the line AA in FIG. FIG. 6 is a top view of the eliminator 10. FIG. 7 is a bottom view of the eliminator 10. The eliminator 10 is a vane-type eliminator in which a plurality of zigzag vanes 11 each having a plurality of folds are overlapped and arranged as described with reference to FIG. The plurality of vanes 11 of the eliminator 10 are arranged so that gas passes in the horizontal direction. The vanes 11 are arranged in an upright state. These vanes 11 are made of polypropylene. The vane 11 may be a metal plate having an appropriate strength.

  A manhole 93 is opened in the ceiling of the large diameter portion 92. The manhole 93 is an opening for exchanging the eliminator 10. In the exchange operation, the eliminator 10 is exchanged by pulling it sideways with respect to the gas flow direction. In this embodiment, the eliminator 10 is provided with a hook (not shown), and when the eliminator 10 is replaced, the eliminator 10 is pulled up by the crane device. During normal operation, the manhole 93 is closed with a ceiling lid 94 and fixed with bolts. An opening 95 is formed in a part of the large diameter portion 92 of the flue 9 upstream of the position of the eliminator 10. The opening 95 is a hole for spraying the cleaning liquid from the jet cleaner toward the surface 10a located on the upstream side of the gas flow of the eliminator 10. The opening 95 may be formed at any position (for example, the upper portion or the side surface) of the large-diameter portion 92 as long as it can spray the cleaning liquid onto the surface 10a. As an example, the opening 95 may be formed so that the cleaning liquid from the jet cleaner is sprayed at 45 ° to the upstream surface 10 a of the eliminator 10. During normal operation, the opening 95 is closed with a lid.

  As shown in FIG. 6, an upper opening 121 is provided on the ceiling surface 12 of the eliminator 10. As shown in FIG. 7, a bottom opening 131 is provided on the bottom surface 13 of the eliminator 10.

  By the way, the combustion gas generated in the copper smelting process contains fluorine. This fluorine corrodes the bricks constituting the inner wall of the cooling tower 7 and the packing provided inside. Fluorine is collected in the dilute sulfuric acid (mist) formed by the humidification cooling in the humidification tower 6. The eliminator 10 provided between the humidifying tower 6 and the cooling tower 7 removes fluorine from the gas by collecting the fluorine collected in the mist in the humidifying tower 6 together with the mist. Since dust is still mixed in the gas passing through the humidification tower 6, the mist also collects dust remaining in the gas. The dust collected in this way is also collected by the eliminator 10 together with the mist. Since the dust collected in the eliminator 10 is not naturally removed, the dust accumulates in the eliminator 10 as the operation time of the gas processing plant 1 increases, and the pressure loss of the eliminator 10 increases. When the pressure loss of the eliminator 10 increases, the power consumption of the blower 5 responsible for gas circulation increases, and thus the eliminator 10 is cleaned to suppress this.

  Next, cleaning of the eliminator 10 will be described. FIGS. 8 and 9 are views showing the state of the eliminator 10 during cleaning. FIG. 8 shows how the eliminator 10 is cleaned from the upper opening 121 of the eliminator 10, and FIG. 9 shows how the eliminator 10 is cleaned from the opening 95 of the flue 9. First, the case where the eliminator 10 is cleaned from the upper opening 121 shown in FIG. 8 will be described. At the time of cleaning, the worker opens the manhole 93 of the flue 9 and sprays the cleaning liquid from the jet cleaning machine 20 toward the upper opening 121 of the internal eliminator 10. Here, with reference to the drawing of the eliminator 10 in FIG. 1, in the cleaning from the upper opening 121, the cleaning liquid is sprayed from the front side to the back side in FIG. 1. Since the upper opening 121 is located on the side with respect to the gas flow direction and further faces the gap between the vanes 11, the cleaning liquid sprayed from the upper opening 121 enters the interior between the vanes 11. To do. This cleaning liquid further descends between the vanes 11 according to gravity to wash away dust adhering to the inside. The cleaning liquid is discharged from the lower opening 131 together with the dust.

  Moreover, it is good also as removing the dust adhering to the vane 11 using the dust removal jig | tool 30 as needed. FIG. 10 is a view showing how dust is removed by the dust removing jig 30. The dust removing jig 30 is fixed to the handle 31 longer than the length L of the eliminator in the direction (arrow a in FIG. 10) orthogonal to the flow direction of the gas flowing through the flue and the tip of the handle 31. Scraping section 32. FIG. 11 is an enlarged view of the scraping unit 32. The scraping portion 32 is formed with a fold portion in accordance with the shape of the gap of the vane 11. The length of the scraping portion 32 in the direction perpendicular to the handle is about 5 cm, which is considerably shorter than the length L (several tens of cm) of the eliminator. Both the handle 31 and the scraping portion 32 are made of metal, but the material is not particularly limited. The dust removal operation using the dust removal jig 30 is performed by an operator. The worker inserts the dust removing jig 30 into the gap between the upper opening 121 and the vane 11 and scrapes off the dust adhering to the vane 11. The worker inserts the dust removing jig 30 several times in one gap to remove dust. The dust thus peeled off from the vane 11 is discharged from the lower opening 131.

  In the conventional cleaning method, since the cleaning liquid is sprayed from the direction along the gas flow direction, the cleaning liquid only cleans the surface of the eliminator and cannot clean the inside of the eliminator. On the other hand, in the cleaning method according to the present embodiment, the cleaning liquid is sprayed from the side toward the gap of the vane 11 with respect to the gas flow direction, or the dust removing jig 30 is inserted into the gap of the vane 11. The dust inside can be cleaned and removed. As described above, in the cleaning method according to the present embodiment, dust that has conventionally been removed in the gaps between the vanes of the eliminator 10 can be cleaned. can do.

  Next, a case where the eliminator 10 is cleaned from the opening 95 of the flue 9 shown in FIG. 9 (cleaning of the upstream surface (upstream surface) of the eliminator 10) will be described. At the time of cleaning, the worker removes the lid of the opening 95 of the flue 9 and sprays the cleaning liquid from the jet cleaning machine 20 toward the upstream surface 10 a of the eliminator 10. Since the upstream surface 10a of the eliminator 10 is the surface on which the gas collides first, dust easily adheres to it, which causes a gas flow path resistance and is a major factor in an increase in pressure loss. In the present embodiment, by performing jet injection to the upstream surface 10a of the eliminator 10, dust that could not be removed by conventional spray injection can be cleaned. Thus, by cleaning the upstream surface 10 a of the eliminator 10, the flow resistance of the eliminator 10 can be reduced, so that the pressure loss of the eliminator 10 can be reduced.

In the cleaning from the upper opening 121 and the cleaning from the opening 95, the jet of the cleaning liquid is preferably about 4 kPa / m ³ or more. The cleaning of the eliminator 10 may be performed by either cleaning from the upper opening 121 or cleaning from the opening 95 according to the pressure loss of the eliminator 10. However, in consideration of minimizing the pressure loss, it is preferable to perform both cleaning operations in the same manner.

  Next, the change in the pressure loss of the eliminator due to the cleaning will be described by comparing the eliminator cleaning method of this embodiment with the conventional eliminator cleaning method. FIG. 12 is a diagram comparing pressure loss between the conventional cleaning method and the cleaning method of the present embodiment. The vertical axis in FIG. 12 indicates the pressure loss of the eliminator, and the horizontal axis indicates the passage of time. In the first month (first month) in FIG. 12, cleaning is performed by a conventional cleaning method, and in the next month (second month), a cleaning method by jet injection from the opening 95 is performed. In the subsequent three months (3rd to 5th month), cleaning is performed by jet injection from the upper opening 121. In any case, the cleaning is not always performed, and the time point of the mountain in the figure is the time when the cleaning is performed. The conventional cleaning method is a method of spraying the cleaning liquid from the upstream side and the downstream side in the gas flow path to the eliminator as described in FIG. The eliminator is replaced after cleaning from the opening 95 (upstream surface cleaning) and before changing to cleaning from the upper opening 121, that is, after the second month has passed.

In the second month when cleaning from the opening 95 (upstream surface cleaning) was performed, the pressure loss was greatly reduced when the cleaning was performed (at times P _{1 to} P _{4 in} FIG. 12). Recognize. Further, when the increase in pressure loss in the first month, the second month, and the third to fifth months (approximate slope indicated by a broken line in FIG. 12) is compared, the cleaning from the upper opening 121 is performed 3 to 5 Since the month is rising more slowly than in the previous February, it can be seen that the rise in pressure loss of the eliminator 10 is suppressed. Thereby, since the period until it reaches | attains the pressure loss which needs replacement | exchange becomes long, the replacement frequency of the eliminator 10 can be reduced. In fact, when the conventional cleaning method was adopted, the eliminator was changed seven times a year, approximately once every February. On the other hand, when the cleaning from the upper opening 121 described in the present embodiment is employed, the replacement frequency of the eliminator is reduced because the replacement is performed once in June.

  Next, other embodiments of the present invention will be described. FIG. 13 is a diagram showing an embodiment described here. The cleaning method of the embodiment described here includes conventional cleaning in addition to cleaning by jet injection from the upper opening 121 and cleaning by dust removal jig 30 and cleaning by jet injection from the opening 95 described above. Cleaning is performed by spraying the spray 15 from the upstream side and the downstream side of the eliminator 10 in the method. In addition, it is preferable to perform injection from the spray 15 at all times. By performing the injection from the spray 15, the upstream side of the eliminator 10 where much dust is attached is washed, and an increase in pressure loss of the eliminator 10 is suppressed.

  Furthermore, another embodiment of the present invention will be described. FIG. 14 is a diagram showing an embodiment described here. In the embodiment described here, as shown in FIG. 14, a first cleaning machine 21 is provided that sprays a cleaning liquid into the gap of the vane 11 of the eliminator 10 from the side in the gas flow direction by jet injection. Moreover, the 2nd washing machine 22 which sprays a washing | cleaning liquid by jet injection from the opening part 95 provided in a part of the flue 9 in the upstream of the flow of gas to the surface 10a of the upstream of the eliminator 10 is provided. In this way, by configuring the mechanism for cleaning the eliminator 10, the work burden on the worker can be reduced. In addition, the jet of cleaning liquid by the first cleaning machine 21 and the second cleaning machine 22 can be jetted constantly or intermittently. In addition, it is preferable to always inject. In addition, a control device that controls injection of the first cleaning machine 21 and the second cleaning machine 22 may be provided, and cleaning liquid jet injection may be performed according to a preset program. When dust adheres and accumulates on the eliminator 10 and a long time has passed, it is difficult to remove it by cleaning. However, since dust immediately after adhering is easy to remove, always spraying (continuous cleaning) pressure loss loss Greatly suppresses the rise of

  In the cleaning method for the eliminator 10 according to the above-described embodiment, the eliminator 10 is disposed in the flue 9 through which gas flows in the horizontal direction, and the cleaning liquid is sprayed from the vertical direction. As a result, the cleaning liquid descends due to gravity and enters the interior of the eliminator 10 to wash away dust adhering to the vane 11, thereby reducing the pressure loss of the eliminator 10. Moreover, since the dust in the gap of the vane 11 can be directly removed by the dust removing jig 30, the pressure loss of the eliminator 10 is reduced. Moreover, in the cleaning method of the eliminator 10 of the above embodiment, the cleaning liquid is sprayed to the eliminator 10 from the upstream side in the gas flow direction. Thereby, the upstream surface 10a of the eliminator 10 to which dust easily adheres was cleaned, and the pressure loss of the eliminator 10 was reduced.

  By the way, the replacement of the eliminator 10 causes cleaning and maintenance costs, replacement work costs, and operation loss due to plant stoppage due to replacement work. Since the exchange frequency of the eliminator 10 is reduced, the cost for the exchange is reduced. In addition, although it takes about 1 hour to replace the eliminator 10, the time required to perform the cleaning operation of the eliminator 10 of the above-described embodiment is about 30 minutes, and the inspection time is performed after the operation of the furnace is stopped. Since the cleaning operation is completed, the furnace shutdown time just for the operation is not required, and the operation loss is reduced.

  The replaced eliminator 10 is sent to a process for removing dust adhering to the vane 11. Conventionally, dust adhering to the vane 11 has been removed from the upstream surface or downstream surface of the gas flow direction using a tool such as a screwdriver or a hammer, so the dust adhering to the vane 11 is removed. In the treatment, the vane 11 may break. In the present embodiment, the dust attached to the vane 11 by attaching the upper opening 121 in FIG. 6 to the eliminator 10 can be removed with the cleaning water of the jet cleaner without using tools. It was. As a result, the frequency of breakage of the vane 11 due to the dust removal process is reduced, the life of the eliminator 10 is extended, and the time required for the dust removal process can be shortened. Further, the reduction in the replacement frequency also reduces the number of dust removal processes and the vane 11 breakage frequency, thereby extending the life of the eliminator 10.

  The above-described embodiments are merely examples for carrying out the present invention, and the present invention is not limited thereto. Various modifications of these embodiments are within the scope of the present invention. It is apparent from the above description that various other embodiments are possible within the scope.

DESCRIPTION OF SYMBOLS 1 Gas processing plant 9 Flue 93 Manhole 95 Opening part 10 Eliminator 11 Vane 121 Upper opening part 21 1st washing machine 22 2nd washing machine 30 Dust removal jig 31 Handle 32 Scraping part

Claims (5)

A cleaning method for an eliminator that is disposed in a flue through which a gas discharged in a copper smelting process flows , removes mist contained in the gas, and includes a plurality of vanes that are folded plates ,
To the smoke by removing the ceiling lid for closing the opening hole for replacement of the eliminator provided on passage from the outside of the flue through the opening hole of said plurality of vanes gap, the gas flowing through the flue I sprayed the cleaning solution from the side with respect to the flow direction,
A scraping portion formed in accordance with the shape of the gap of the vane that is folded is fixed to the tip of the handle longer than the length of the eliminator in the direction orthogonal to the flow direction of the gas flowing through the flue. The dust removing jig is inserted into the opening hole from the outside of the flue from the scraping portion, and the scraping portion is inserted into the gap of the vane from the side with respect to the flow direction of the gas flowing through the flue. An eliminator cleaning method characterized by being inserted . The smoke placing the eliminator along the way, eliminator cleaning method of claim 1, wherein the sprayed from the vertically upward direction the cleaning liquid flowing through said gas in a horizontal direction. 3. The eliminator according to claim 1 , wherein the gas includes mist adsorbing fluorine generated from an upstream facility and dust generated from an upstream facility, and the eliminator separates the mist and dust from the gas in the eliminator. Cleaning method. The eliminator cleaning method according to any one of claims 1 to 3 , wherein the cleaning liquid is sprayed intermittently or constantly. A lid that closes an opening provided in a part of the flue upstream from the position of the eliminator is removed, and from the outside of the flue to the eliminator from the upstream in the gas flow direction through the opening . The method for cleaning an eliminator according to any one of claims 1 to 4 , further comprising spraying a cleaning liquid.

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