WO2007052448A1

WO2007052448A1 - Cleaning apparatus for electric furnace by-product gas recovery duct

Info

Publication number: WO2007052448A1
Application number: PCT/JP2006/320270
Authority: WO
Inventors: Tetsuo Yanagimori; Takayuki Nishi; Masato Nagasaki; Yasuo Sekizawa
Original assignee: Nippon Denko Co., Ltd.; Sekizawa, Chikako
Priority date: 2005-11-04
Filing date: 2006-10-11
Publication date: 2007-05-10
Also published as: JP4939036B2; JP2007127346A

Abstract

A cleaning apparatus for electric furnace by-product gas recovery duct that is capable of removing any dust deposited in a gas duct from precooling column to Venturi scrubber at the time of dust removal from by-product gas generated in reducing refining of alloy iron, etc. by means of a dust removing apparatus including the Venturi scrubber without the need to halt the operation of the electric furnace. Accordingly, at a gas-outlet-side end portion of traverse duct extending from precooling washing column to Venturi scrubber, there is provided a traverse duct deposit dust cleaning lance which is inserted through a gas seal portion in the traverse duct in a fashion permitting forward and back traveling and which at its proximal end is fitted with a pressurized water supply portion and at its distal end is fitted with a pressurized water jetting nozzle. Just above region of the traverse duct where the Venturi scrubber is fitted, there is provided a vertical duct deposit dust cleaning lance which is inserted through a gas seal portion in a vertical duct extending from the traverse duct to the Venturi scrubber in a fashion permitting forward and back traveling and which at its proximal end is fitted with a pressurized water supply portion and at its distal end is fitted with a pressurized water jetting nozzle.

Description

Specification

Cleaning device for electric furnace byproduct gas recovery duct

Technical field

TECHNICAL FIELD [0001] The present invention relates to a cleaning device for an electric furnace generated gas recovery duct that removes dust accumulated in a duct for recovering an electric furnace generated gas outside the duct. In the present invention, a by-product gas containing CO generated particularly when producing alloy iron such as ferromanganese and ferrochromium is cooled by a pre-cooling washing tower, and then dust is removed by a venturi scrubber, and the duct is provided in a duct that leads to a gas holder. The present invention relates to a cleaning device for an electric furnace byproduct gas recovery duct that can remove dust accumulated in the furnace when dust begins to accumulate.

Background art

[0002] Iron alloys such as ferromanganese and iron mouth chrome are mixed with these raw ores as a reducing agent such as cotas and charged in a closed electric furnace. Manufactured by heating the raw material together with a reducing agent by means of juule heat. In the production of this iron alloy, by-product gas containing CO is generated by the reaction of the raw ore and a reducing agent such as Cortas. As shown in FIG. 6, this by-product gas is generally led to the pre-cooling washing tower 4 through the ascending pipe 2 and the descending pipe 3 attached to the furnace lid of the electric furnace 1, and inside the inside thereof, the dust is removed together with the spray. After cooling to a temperature (approximately 50 to 150 ° C.), after passing through the transverse duct 5, the dust is removed by the venturi scrubber 6, the washing water and mist are separated by the gas-liquid separator 7, etc., and then stored in the gas holder 8.

[0003] A large amount of dust, for example, about 5 to 20 gZm ³ is present in the gas guided from the pre-cooling washing tower 4 of this type of by-product gas recovery device 4 to the bench uristulano 6 via the transverse duct 5. This deposits on the throat of the transverse duct 5 and the venturi scrubber 6. Since this accumulated dust becomes a resistance to gas flow, hatches 9 and 10 are provided in the transverse duct 5 and the hatches 9 and 10 are opened after the electric furnace is stopped to remove dust. Yes.

[0004] However, such a dust removal operation cannot be performed while the electric furnace is stopped. Furthermore, since the by-product gas contains a large amount of CO, before the removal operation, the gas in the gas duct in the transverse duct 5 and this force also reaches the venturi scrubber 6, for example, It is necessary to make the work environment harmless to the worker by performing an operation to completely replace it with the atmosphere. This preparatory operation requires a considerable amount of time, for example, about 1 to 3 hours, and it takes several hours to remove dust accumulated in the duct. There is a problem that the operating rate of the furnace decreases.

[0005] As a dust accumulation preventing device for a dust collection duct of an electric furnace, a device described in Patent Document 1 has been proposed, although it relates to an electric furnace for steelmaking. In this proposal, the dust accumulation prevention device for the electric furnace smoke collection duct is configured such that the substantially horizontal smoke collection duct that guides the exhaust gas of the electric furnace power to the combustion tower is separated from other dust collection duct partial forces. At the same time, it is configured to be provided with a turning device that is rotatably supported around the axis of the smoke collection duct and further rotated to the left and right around the axis of the smoke collection duct.

[0006] Patent Document 1: Japanese Patent Laid-Open No. 6-194069

Disclosure of the invention

Problems to be solved by the invention

[0007] However, the dust accumulation prevention device described in Patent Document 1 must rotate a smoke collection duct provided separately from the dust collection duct of the electric furnace around its axis, Therefore, a support mechanism and drive mechanism outside the smoke collector are required. This device burns the recovered gas in the combustion tower and uses the generated thermal energy mainly for preheating the scrap charged in the electric furnace. Therefore, it is sufficient that the dust accumulated in the smoke collection duct is sent from the smoke collection duct to the combustion tower side by the gas flow, and the route to the venturi scrubber 6 shown in FIG. It cannot be used to remove dust accumulated on the surface and collect the dust-removed gas.

[0008] The present invention is intended to improve the efficiency of dust removal work that accumulates in a gas duct that occurs when dust is removed from a by-product gas that contains a large amount of CO, particularly when reducing iron such as iron alloy. The gas duct from the precooling washing tower to the venturi scrubber without shutting down the operation of the electric furnace must be cleaned before the dust begins to accumulate in the duct. The purpose is to provide.

Means for solving the problem

[0009] An electric furnace by-product gas recovery duct cleaning apparatus according to the present invention is a by-product generated from an electric furnace. A transverse duct for guiding the gas to the venturi scrubber from the pre-cooling washing tower is mounted horizontally or obliquely upward in the direction in which the by-product gas flows, and the end of the transverse duct on the gas outlet side is connected to the end portion. Side force A gas duct can be inserted into and removed from the transverse duct, and a transverse duct cleaning lance equipped with a high-pressure water supply section at the base end and a high-pressure water injection nozzle at the distal end is provided. Directly on the upper side, the force on the upper side is the gas tight in and out of the vertical duct leading to the throat part of the venturi scrubber, and the high pressure water supply nozzle at the base end and the high pressure water injection nozzle at the front end. A vertical duct cleaning lance is provided.

[0010] In the above invention, it is preferable that the transverse duct is inclined by 2 to 7 degrees in the direction in which the by-product gas flows.

[0011] In addition, it is desirable that the transverse duct cleaning lance and the vertical duct cleaning lance be configured to be rotatable around the axis of the lance. At the tip of the lance, high-pressure water is directed toward the duct wall. It is desirable to provide a high-pressure water spray nozzle for spraying.

[0012] The electric furnace byproduct gas recovery duct cleaning apparatus described above is provided with a plurality of transverse ducts that guide the byproduct gas generated by the electric furnace power to the venturi scrubber from the precooling cleaning tower. It can be provided for each of the transverse ducts.

The invention's effect

[0013] According to the present invention, when recovering by-product gas containing a large amount of CO in an electric furnace used for reduction ironmaking such as alloy iron, the precooling washing tower without stopping the operation of the electric furnace is changed into a venturi scrubber. The incoming ducts can be cleaned before dust begins to accumulate in the ducts, thereby substantially eliminating the work of removing dust that has been trapped in the past for several hours.

BEST MODE FOR CARRYING OUT THE INVENTION

As shown in FIG. 1, even in the case of the present invention, the by-product gas generated in the production of the alloy iron is pre-cooled and cleaned through the ascending pipe 2 and the descending pipe 3 attached to the furnace lid of the electric furnace 1. Tower 4 is guided, dusted by spray inside it, cooled to a predetermined temperature (approximately 50 to 150 ° C), passed through the transverse duct 5, dusted by the Vetris rubber 6 and washed by the gas-liquid separator 7 etc. After the mist is separated, it is stored in the gas holder 8. [0015] In the above configuration, as shown in FIG. 2, the transverse duct 5 that leads from the pre-cooling washing tower 4 to the venturi scrubber 6 is mounted horizontally or obliquely upward by force in the direction in which by-product gas flows. The transverse duct cleaning lance 23 can be inserted into the transverse duct 5 through the end plate 21 on the gas outlet side. On the other hand, the vicinity of the end portion of the transverse duct 5 is an attachment site for the venturi scrubber 6, and a vertical duct 35 reaching the throat portion of the force bench yuri scrubber 6 is connected thereto. Furthermore, a short branch pipe 36 is branched from the transverse duct 5 in the vertical direction directly above the vertical duct 35, and the vertical duct 35 is passed through an end plate 31 provided at the end of the branch pipe 36 into the vertical duct 35. Allow the cleaning lance 33 to be inserted.

[0016] High-pressure water supply hoses 24 and 34 are connected to the base end portions of the transverse duct cleaning lance 23 and the vertical duct cleaning lance 33, respectively. The washing water spouts out toward the inner wall of the vertical duct 35. The transverse duct cleaning lance 23 and the vertical duct cleaning lance 33 are both freely inserted into and removed from the transverse duct 5 and the vertical duct 35 while being kept airtight by a gas seal portion or the like attached to the end plates 21 and 31. Further, high-pressure water jet nozzles 22 and 32 are attached to the tips of the transverse duct cleaning lance 23 and the vertical dirt cleaning lance 33, respectively. The detailed structures of the gas seal part and the high-pressure water injection nozzle will be described later.

[0017] Therefore, when dust begins to accumulate in the transverse duct, the transverse duct cleaning lance 23 is advanced from the end plate 21 side on the gas outlet side toward the precooling washing tower 4 side, and high-pressure water is supplied. Nozzle 22 force By spraying toward the inner wall of the transverse duct 5, the dust that has started to accumulate in the transverse duct 5 can be washed and flowed and discharged into the water seal 11 at the bottom of the pre-cooling washing tower 4. It ’s like this.

[0018] On the other hand, when it is recognized that dust has started to accumulate in the vertical duct 35, the vertical duct cleaning lance 33 is moved through the end plate 31 provided at the end of the short branch pipe 36 provided in the transverse duct 5. The turret of the turret cruslan 6 is lowered to the throat, and high pressure water is jetted from the nozzle 32 toward the inner wall of the vertical duct 35, so that the dust that has started to accumulate on the inner wall of the vertical duct 35 and thus the venturi scrubber 6 is Can be peeled off and poured into the gas-liquid separator 7.

[0019] In the above structure, the transverse duct 5 is horizontal in the direction in which the by-product gas flows. It is important that it be installed diagonally upward. This is because when the dust accumulated in the transverse duct 5 is discharged by the jet water flow from the transverse duct cleaning lance 23, the water flow is prevented from being directed toward the end plate 21 on the gas outlet side, and more actively. This is to ensure that the seal part (which will be described later) installed on the end plate 21 on the gas outlet side is not damaged, so that it is directed toward the precooling washing tower 4 side. In order to achieve such a purpose, the inclination angle of the transverse duct 5 should be 2 to 7 ° from the horizontal plane.

[0020] The specific structure of the transverse duct cleaning lance 23 and its installation are as shown in Figs. As shown in FIG. 3, the transverse duct cleaning lance 23 includes a lance shaft 25 and a high-pressure water injection nozzle 22 attached to the tip of the lance shaft 25. In the standby state, the high-pressure water injection nozzle 22 is located inside the cleaning pipe 42. Then, the force lance shaft 25 extends in the right direction in the figure toward the gear box 45 through the seal portion 43. On the other hand, in the operating state, that is, in the cleaning state, the high pressure water jet nozzle 22 is located inside the transverse duct 5, and the lance shaft 25 is connected to the end plate 21 of the transverse duct. Then, it passes through the cleaning pipe 42 and further through the gas seal portion 43 and extends toward the gear box 45 to the right in the figure.

A pedestal 51 is provided below the transverse duct cleaning lance 23 (lance shaft 25) extending as described above over the lower force gear box 45 of the gas seal portion 43 at least. The pedestal 51 includes a support column 52 and a pedestal 53 provided on the column 52, and the gear box 45 is movably attached to the pedestal 53. A sprocket 54 is attached to one end of the cradle 53 and below the seal portion 43, and a sprocket 55 corresponding to the sprocket 54 is attached to the other end.

[0022] Between the sprockets 54 and 55, a chain 56 is stretched around an end portion thereof fixed in the vicinity of the front and rear ends of the gear box 45. The sprocket 54 on at least one of the sprockets (in this case, below the seal portion 43) is driven by a motor 57 mounted on a bracket attached to the support column 52. Therefore, when the motor 57 is started, the sprocket 54 rotates, and the gear box 45 is pulled through the chain 56 so as to move on the cradle 53. As a result, the transverse duct cleaning lance 23 can be freely taken into and out of the transverse duct 5. [0023] It should be noted that the ball valve 41 is closed during normal operation of the electric furnace, that is, in a standby state of the cleaning device of the present invention, and prevents leakage of by-product gas to the outside. However, when the transverse duct 5 is cleaned, the transverse duct cleaning lance 23 can enter the transverse duct 5 as an open position. In addition, an inlet 48 and an outlet 47 of shower water are connected to the cleaning pipe 42, and dust attached to the transverse duct cleaning lance 23 is cleaned here. Further, as shown in FIG. 3 (b), that is, the AA sectional view of FIG. 3 (a), the seal portion 43 is a short, tubular body having a seal material 49 disposed on the inner wall thereof. Maintain the transverse shaft 25 of the transverse duct cleaning lance 23 to be gastight. Therefore, when the ball valve 41 is in the open state, the transverse duct cleaning lance 23 can be passed through the seal portion 43 while being cooled and washed with the washing pipe 42, thereby maintaining the gas tight state while maintaining the transverse duct. The cleaning lance 23 can be taken in and out of the transverse duct 5.

FIG. 4 is a partially cutaway front view of the gear box 45 and shows its internal structure. In this gear box 45, the rear end portion 61 of the lance shaft 25 of the transverse duct cleaning lance 23 is inserted into the rotation itself, and the rear end thereof is connected to the water-cooled pipe 66 through a swivel joint 62, for example. . The water cooling pipe 66 is connected to the high pressure water supply hose 24 outside the gear box 45. Further, a gear 63 is fitted in the vicinity of the rear end 61 of the transverse duct cleaning lance 23, and this gear 63 is rotated by a motor 64 fixedly attached to the rear end of the gear box 45. Combined with gear 65. Therefore, when the motor 64 is started, the lance shaft 25 of the transverse duct cleaning lance 23 rotates, thereby rotating the high-pressure water injection nozzle 22 attached to the leading end thereof and injecting high-pressure water evenly into the transverse duct 5. It becomes possible to do. Appropriate means, for example, a gear and a rack, are provided between the lower part of the gear box 45 and the cradle 53 of the gantry 51 to enable movement of the gear box 45 on the cradle 53.

[0025] The force described above for the mounting structure of the transverse duct cleaning lance 23 with respect to the transverse duct 5 The mounting structure of the vertical duct cleaning lance 33 with respect to the vertical duct 35 also conforms to the mounting structure of the transverse duct cleaning lance 23 with respect to the transverse duct 5 Just do it. In other words, it is only necessary to set up a support column on the side of the vertical duct 35 and provide a moving mechanism and a rotating mechanism for the vertical duct cleaning lance 33! ,. The transverse duct cleaning lance 23 and the vertical duct cleaning lance 33 are configured by attaching high-pressure water injection nozzles 22 and 32 to the tips of the lance shafts 25 and 35, respectively. As shown in FIG. 5, the high-pressure water spray nozzles 22 and 32 are provided with a tip 72 at the tip of the nozzle body 71 and side tips 73 and 74 at the sides. As a result, in the transverse duct 5 or in the vertical duct, washing water can be sprayed forward and high-pressure water can be sprayed to the duct pipe wall on the side of the nozzle. Accumulated dust can be removed. The side tips 73 and 74 should be deflected slightly forward from the vertical direction with respect to the axis of the main body 71, specifically, so that the Θ force in FIG. As a result, the inner wall of the duct can be cleaned more efficiently.

[0027] As described above, the washing apparatus for the by-product gas recovery duct of the electric furnace according to the present invention is a direction in which the by-product gas flows through the transverse duct that guides the by-product gas generated from the electric furnace to the precooling washing tower force venturi scrubber. It is mounted horizontally or diagonally upward, and is inserted from the gas outlet side of the transverse duct into the transverse duct through the gas seal portion so as to be able to move forward and backward. In addition, a transverse duct cleaning lance equipped with a high-pressure water jet nozzle at the tip is provided, and in a vertical duct that extends from just above the venturi scrubber mounting part of the transverse duct to the throat part of the venturi scrubber through the gas seal part. It has a structure with a vertical duct cleaning lance inserted through the gas seal so that it can move forward and backward, with a high-pressure water supply at the base and a high-pressure water spray nozzle at the tip. Because it is adopted, the power of the precooling washing tower without stopping the operation of the electric furnace is recovered to recover the by-product gas containing a large amount of CO in the electric furnace used for reduction ironmaking such as alloy iron. Dust that starts to accumulate in the duct can be removed.

[0028] In the above description, one example of the transverse duct for guiding the by-product gas generated in the electric furnace power to the pre-cooling cleaning tower power Bench Julis club is shown. However, it is not necessary to limit the above-described conditions.For example, the transverse duct 5 is pulled out radially from the pre-cooling washing tower 4, and the above configuration is applied to the washing of each drawn transverse duct and the accompanying vertical duct. You can also. As a result, when one of a plurality of ducts is being cleaned, the other gas can be recovered using the other ducts. In other words, it becomes possible to sequentially clean the ducts for a plurality of transverse ducts, and to operate the electric furnace for cleaning the ducts. No need to stop.

In carrying out the present invention, for example, when cleaning the transverse duct 5, first, water injection into the cleaning pipe 42 is started, and then the ball valve 41 is opened and the transverse duct cleaning lance 23 3 is opened. The high pressure water injection nozzle 22 is advanced and guided into the transverse duct 5 from the cleaning pipe 42 which is the standby position. In advance of the transverse duct cleaning lance 23, the motor 64 is started to rotate the lance shaft 25, and the high-pressure water supply circuit is opened by, for example, an electromagnetic valve (not shown) to wash a sufficient amount and sufficient pressure. Water is sprayed from 22 high-pressure water spray nozzles.

[0030] After confirming that the high pressure injection nozzle 22 at the tip of the transverse duct cleaning lance 23 has reached the base of the transverse duct 5, the cleaning water supply is stopped and the motor 64 is stopped to rotate the lance 23. The high pressure water jet nozzle 22 of the transverse duct cleaning lance 23 is returned to the standby position. Furthermore, after closing the ball valve 41, the water injection to the cleaning pipe 42 is stopped, and finally the high pressure water supply circuit is closed to stop the water supply to the high pressure hose 24 force transverse duct cleaning lance 23. The vertical duct 35 may be cleaned by the same procedure as that for the above-described transverse duct. It is efficient to set up a program for automatic operation and perform it according to this cleaning process.

Brief Description of Drawings

[0031] FIG. 1 is an explanatory view showing a schematic configuration of an electric furnace by-product gas dust removal / recovery device to which the present invention is applied.

FIG. 2 is a conceptual diagram showing a basic configuration of a cleaning device for an electric furnace byproduct gas recovery duct according to the present invention.

FIG. 3 is a cross-sectional view showing the overall structure of a transverse duct cleaning lance used in the present invention.

FIG. 4 is a partially cutaway front view showing the internal structure of the gear box.

FIG. 5 is a front view showing an embodiment of a nozzle shape attached to the tip of a lance used in the present invention.

FIG. 6 is an explanatory view showing an outline of a conventional electric furnace byproduct gas recovery device.

Explanation of symbols

[0032] 1: Electric furnace, 4: Pre-cooling washing tower, 5: Transverse duct, 6: Venturi scrubber, 22: High pressure water injection nozzle 23: Cross duct cleaning lance, 24: High pressure water supply hose, 32: High pressure water injection nozzle, 3 3: Vertical duct cleaning lance, 34: High pressure water supply hose, 35: Vertical duct, 71: Nozzle body, 7 2: Tip, 73, 74: Side insert

Claims

The scope of the claims

[1] A transverse duct that leads by-product gas that also generates electric furnace power to the pre-cooling washing tower force to venturi scrubber is mounted horizontally or obliquely upward in the direction in which the by-product gas flows, and the end of the transverse duct on the gas outlet side On the part side, there is provided a transverse duct cleaning lance that can be freely inserted and removed from the end side into the transverse duct and that has a high-pressure water supply part at the base end part and a high-pressure water injection nozzle at the front end part.

Directly above the venturi scrubber mounting portion of the traverse duct, the gas duct can be put into and out of the vertical duct extending from the top side to the throat part of the venturi scrubber, and a high-pressure water supply section is provided at the base end. An electric furnace by-product gas recovery duct cleaning apparatus comprising a vertical dart cleaning lance provided with a high-pressure water injection nozzle at the tip.

[2] The apparatus for cleaning an electric furnace by-product gas recovery duct according to claim 1, wherein the transverse duct is inclined 2 to 7 ° upward in a direction in which the by-product gas flows.

[3] The apparatus for cleaning an electric furnace by-product gas recovery duct according to claim 1 or 2, wherein the transverse duct cleaning lance and the vertical duct cleaning lance are configured to be rotatable around the axis of the lance. .

[4] The electric furnace by-product gas recovery according to any one of claims 1 to 3, wherein a high-pressure water injection nozzle that injects high-pressure water toward the duct wall is provided at the tip of the lance. Duct cleaning device.

[5] Electric furnace power A plurality of transverse ducts for introducing the by-product gas generated into the venturi scrubber as well as precooling washing tower power are provided, and each of the plurality of transverse ducts is described in any one of claims 1 to 4. An electric furnace by-product gas recovery duct cleaning device provided with a horizontal duct accumulated dust cleaning lance and a vertical duct accumulated dust cleaning lance.