JP4116603B2 - Blocking prevention device in chlorination furnace - Google Patents

Description

The present invention mechanically prevents clogging in a chloride gas pipe from which the produced chloride gas is led out in a chlorination furnace used to produce chloride gas, particularly titanium tetrachloride, which is a raw material for producing titanium sponge. The present invention relates to an occlusion prevention device.

  Titanium tetrachloride, which is a raw material for producing sponge titanium, is produced by bringing titanium ore containing titanium, oxygen and iron into contact with chlorine gas in the presence of carbon. More specifically, in a state where granular titanium ore and granular coke are charged into a chlorination furnace, chlorine gas is blown from the bottom of the furnace to form a fluidized bed at a temperature range of 800 to 1200 ° C. continue.

  Examples of the reaction product gas include ferrous chloride, ferric chloride, other chlorides, carbon monoxide, carbon dioxide and the like in addition to titanium tetrachloride. These reaction product gases are sent from the top of the chlorination furnace through the gas pipe to the titanium tetrachloride recovery section, but ferrous chloride in the gas agglomerates and adheres to the inner surface of the gas pipe, particularly the inner surface of the inlet due to the melting point. This can cause pipe clogging. And when piping was obstruct | occluded, the operation | movement of the chlorination furnace was stopped, the piping part was disassembled, and it was necessary to remove obstruction | occlusion and to replace piping.

  However, the dismantling of the piping part takes time, and the reduction in productivity due to the shutdown of the furnace operation also becomes a problem. Therefore, the present inventors have considered the installation of a blocking prevention device as shown in FIG. By installing the blockage prevention apparatus as shown in FIG. 2, it becomes possible to remove the blockage without disassembling the pipe portion.

  The blockage prevention apparatus shown in FIG. 2 is attached to a reaction product gas lead-out gas pipe 2 connected to the top of the chlorination furnace 1. The gas pipe 2 includes an introduction part 2 a connected to the top of the chlorination furnace 1 and a pipe body 2 b extending from the introduction part 2 a to the side, and is configured to be bent at a right angle above the chlorination furnace 1. ing. The deposit 3 is concentrated in the vicinity of the inlet in the gas pipe 2.

  The blocking prevention device includes a cleaning rod 4 that is vertically attached to the introduction portion 2 a of the gas pipe 2. The cleaning rod 4 is driven in the axial direction while being driven to rotate around an axis like a drill by a drive unit (not shown). Then, by descending while rotating from the upper retracted position, the deposit 3 deposited near the inlet in the gas pipe 2 is mechanically scraped off by the head portion 4a at the tip, and returns to the upper retracted position. The shaft portion 4 b of the cleaning rod 4 is externally sealed by a seal mechanism 5.

  However, such a blockage prevention device in a chlorination furnace has the following problems related to its structure.

  First, while the cleaning rod 4 is retracted upward, the head portion 4a provided at the tip of the cleaning rod 4 is exposed in the gas pipe 2 and exposed to the flow of chloride gas. For this reason, the head portion 4a is severely corroded and has a very short service life.

  Secondly, when the rotary cutting is performed with the head portion 4a like a drill, the sealing mechanism 5 between the cleaning rod 4 and the gas pipe 2 is simple, but the deposit 3 deposited near the inlet in the gas pipe 2 is removed. It is difficult to remove sufficiently. This is because the deposit 3 is very firmly fixed. For this reason, it becomes impossible to remove deposits with the cleaning rod, and the chlorination furnace must be stopped each time, and there is a concern that reliability, work efficiency, and productivity will be reduced.

  An object of the present invention is to provide a clogging prevention device that can effectively prevent clogging in a chloride gas pipe and is excellent in corrosion resistance.

  In order to achieve the above object, the present inventor has intensively studied a countermeasure against the problem that the tip of the cleaning rod is exposed to chloride gas in the pipe and corrosion proceeds. As a result, it has been found that it is effective to provide the gas pipe with a storage part for accommodating the cleaning bar so that the head part is discharged from the gas pipe when the cleaning bar is retracted.

  The inventor has also intensively studied a method for efficiently removing the deposits that cause the blockage of the chloride gas pipe. As a result, it has been found that if a striking function by axial vibration such as a rock drill is added to the cleaning rod, the removal efficiency of the deposits can be dramatically improved. The reason why the impact is effective on the deposit is that the deposit is hard and brittle with respect to the impact. However, on the other hand, the deterioration of the outer surface sealing performance of the cleaning rod due to the addition of the striking function has become a problem.

  If the external sealing performance of the cleaning rod is reduced, when operating the chloride furnace in a pressurized state, chloride gas in the furnace leaks out of the furnace, and when operating in a depressurized state, the air outside the furnace enters the furnace. By mixing, water vapor in the air reacts with chlorine in the furnace to become hydrochloric acid, which causes the corrosion of the furnace and piping to be accelerated. This gas leakage may be a problem even in a blocking prevention device that performs rotation driving and forward / backward driving of the cleaning rod, but when a striking function is added, the load on the seal portion increases, and as a result It seems to be a problem. And it became clear that such a gas leak can be solved by providing a seal part in two stages and making the pressure between the two seal parts higher than both the furnace pressure and the atmospheric pressure.

The present invention has been completed on the basis of such knowledge, and the clogging prevention device is a chloride that derives the produced chloride gas from a chlorination furnace that produces titanium tetrachloride gas as a chloride gas by a fluidized bed. A clogging prevention device in a chlorination furnace that is provided in a gas pipe and mechanically prevents clogging in the gas pipe, wherein the head portion is inserted into a portion where the clogging in the gas pipe is conspicuous A cleaning rod that is movably supported by the motor, a drive unit that imparts an advance / retreat function in the axial direction to the cleaning rod, and the gas pipe that is airtightly isolated from the outside of the furnace. when the rod is retracted, the storage portion when the housing part to which the head part for accommodating the cleaning rod to be discharged from the gas pipe, the head portion of the cleaning rod is received in the receiving portion In the gas pipe Sequestered by and a shutoff valve for preventing gas exposure of the head portion, the head portion of the cleaning rod accommodated in the receiving portion, the receiving portion is isolated from the gas pipe and the chlorination furnace by opening and closing valve In this case, a configuration is adopted in which the pressure in the storage portion is maintained higher than the furnace pressure .

About the drive part which drives the said cleaning stick, it is preferable to provide the cleaning stick with the rotational cutting function which scrapes off an attached material by rotation around an axis | shaft. Moreover, it is preferable to provide the cleaning rod with an axial striking function. About the storage part, it is preferable that the outer surface of the cleaning rod is sealed by a plurality of seal parts provided in two or more stages in the axial direction so that the pressure between the two seal parts is higher than both the furnace pressure and the atmospheric pressure. .

The blockage preventing apparatus in the chlorination furnace of the present invention accommodates the cleaning rod inside so that the head portion is completely discharged from the gas pipe when the cleaning rod is retracted , and the inside is airtight from the outside of the furnace. The gas pipe is provided with an isolated storage part, and when the head part of the cleaning rod is housed in the storage part, the storage part is isolated from the gas pipe to prevent gas exposure of the head part. When the storage part is isolated from the gas pipe and the chlorination furnace by the on-off valve, the pressure in the storage part is maintained higher than the furnace pressure , thereby causing corrosion of the cleaning rod by chloride gas. This can be effectively prevented and the replacement frequency can be greatly reduced.

  Further, by adding an axial striking function to the cleaning rod, the deposit removing ability can be remarkably enhanced, and blockage in the chloride gas piping can be effectively prevented.

  In addition, the outer surface seal portion of the cleaning rod is provided in two or more stages, and the pressure between the two seal portions is made higher than both the furnace pressure and the atmospheric pressure, so that the outer surface sealability is improved and the impact function is added. It is possible to prevent the outer surface sealing performance of the cleaning rod from being deteriorated.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of an occlusion prevention device showing an embodiment of the present invention.

  The blocking prevention apparatus of this embodiment is equipped in a chlorination furnace 1 used for manufacturing titanium tetrachloride. The chlorination furnace 1 is formed by injecting chlorine gas from the bottom of the furnace with granular titanium ore and granular coke charged into the chlorination furnace to form a fluidized bed in a temperature range of 800 to 1200 ° C. Titanium is produced. Examples of the reaction product gas include ferrous chloride, ferric chloride, other chlorides, carbon monoxide, carbon dioxide and the like in addition to titanium tetrachloride. These reaction product gases are sent from the top of the chlorination furnace 1 to the titanium tetrachloride recovery section through the gas pipe 2.

  The gas pipe 2 is composed of an introduction part 2 a provided at the top of the chlorination furnace 1 and a pipe body 2 b extending from the introduction part 2 a to the side, and is bent right above the chlorination furnace 1. . The blockage prevention device includes a cleaning rod 4 that moves up and down directly above the inlet of the gas pipe 2 and a tubular storage portion 6 that is attached to the introduction portion 2 a of the gas pipe 2 to store the cleaning rod 4. . The cleaning rod 4 includes a head portion 4a and a shaft portion 4b that supports the head portion 4a. The tubular storage portion 6 is on the extension line of the inlet of the gas pipe 2 and extends vertically upward from the head portion 4a.

  A seal portion 7 that seals the outer surface of the shaft portion of the cleaning rod 4 is provided in two stages in the axial direction at the upper portion of the storage portion 6. By the two-stage seal portions 7 and 7, the inside of the storage portion 6 is airtightly isolated from the outside of the furnace. On the other hand, a ball valve 9 as an on-off valve is attached to the lower part of the storage unit 6. The inside of the storage unit 6 is opened and closed with respect to the inside of the furnace by the ball valve 9.

  A space sandwiched between the two-stage seal portions 7 and 7 is a preload chamber 8, and the pressure thereof is higher than the atmospheric pressure outside the furnace. Further, the pressure in the lower storage section 6 is set lower than the pressure in the preload chamber 8 and higher than the pressure in the chlorination furnace 1. In the storage unit 6, an inert gas or dry air is supplied to maintain the pressure in the storage unit 6 and the preload chamber 8. The pressure in the chlorination furnace 1 is higher than the atmospheric pressure outside the furnace in the case of a pressurized operation, and is lower than the atmospheric pressure outside the furnace in the case of a reduced pressure operation.

  The cleaning rod 4 is driven by a first drive unit 10 and a second drive unit 11 as drive units. The first drive unit 10 imparts vibration for an axial impact and rotation about the axis to the cleaning rod 4. The second drive unit 11 drives the cleaning rod 4 to advance and retreat in the axial direction together with the first drive unit 10 to lower the head unit 4a from the inside of the storage unit 6 to at least the inlet part of the gas pipe 2, and the inlet part thereof. To the storage unit 6.

  Next, the function of the blocking prevention apparatus of this embodiment will be described.

  In a normal operation, the cleaning rod 4 is raised and the head portion 4 a is accommodated in the accommodating portion 6. Further, the ball valve 9 is closed, and the inside of the storage unit 6 is isolated from the inside of the chlorination furnace 1 and the inside of the gas pipe 2. In addition, since the pressure in the storage unit 6 is maintained higher than the pressure in the furnace, there is no possibility that the manufactured chloride gas enters the storage unit 6 except during the operation of removing the deposit 3. A small amount of chloride gas enters the storage unit 6 during the removal operation, and since there is no gas flow, the head unit 4a is not significantly corroded. Further, the chloride gas may be pushed back into the furnace by the pressure in the storage unit 6 that is higher than the pressure in the furnace, so that this is not a big problem. Thus, since exposure of the head portion 4a to the chloride gas flow is limited only during the removal operation, rapid progress of corrosion can be prevented, and the life of the head portion 4a can be greatly extended. Further, since the pressure in the preload chamber 8 is higher than the pressure in the storage unit 6 and higher than the atmospheric pressure, both gas leakage from the storage unit 6 to the atmosphere and mixing of the atmosphere into the furnace can be prevented.

  As the operation progresses, if the deposit 3 accumulates at the inlet of the gas pipe 2, the ventilation resistance increases here, and the internal pressure of the chlorination furnace 1 increases. Using this increase in internal pressure as a guide, the deposit 3 is removed.

  In the operation of removing the deposit 3, the ball valve 9 is first opened. However, even if the ball valve 9 is opened, there is no possibility that the produced chloride gas will enter the preload chamber 8. When the ball valve 9 is opened, the cleaning rod 4 descends while performing vibration and rotation for applying an impact. As a result, the deposit 3 is easily destroyed and removed by the head portion 4a. After the destructive removal of the deposit 3 is completed, the cleaning rod 4 is raised until the head portion 4a enters the storage portion 6. Finally, the ball valve 9 is closed and the original standby state is restored.

  Since the cleaning rod 4 vibrates for applying an impact, the seal portions 7 and 7 are severely damaged. However, this is a double structure and the space between the seal portions 7 and 7 is a preload chamber 8 higher than the atmospheric pressure. Therefore, even if the sealing performance is deteriorated, there is no possibility that the outside air enters.

The clogging prevention device in the chlorination furnace of the present invention is provided in the upper part of the gas pipe introduction part 2a in the example of FIG. 1, but is not limited to this position, and is a chloride gas pipe for extracting chloride gas from the chlorination furnace. It may be installed anywhere as long as it is desired to prevent blockage, such as in the middle.

  Moreover, in FIG. 1, although the cleaning stick 4 is arrange | positioned at an up-down direction and it is the structure to raise / lower, you may install the cleaning stick 4 in a horizontal direction. For example, if a blockage prevention device is added to the side of the introduction part 2a so that the cleaning rod penetrates from the introduction part 2a to the pipe body 2b in FIG. An effect can be obtained.

It is a block diagram of the obstruction | occlusion prevention apparatus which shows one Embodiment of this invention. It is a block diagram of the obstruction | occlusion prevention apparatus used as the foundation of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Chlorination furnace 2 Chloride gas piping 3 Deposits 4 Cleaning rod 6 Storage part 7 Seal part 8 Preloading chamber 9 Ball valve 10 1st drive part 11 2nd drive part

Claims (5)

A chlorination furnace that is provided in a chloride gas pipe for deriving the produced chloride gas from a chlorination furnace that produces titanium tetrachloride gas as a chloride gas by a fluidized bed and mechanically prevents clogging in the gas pipe. And a cleaning rod supported so as to be movable in the axial direction so that the head portion is inserted into a portion where the clogging in the gas pipe is conspicuous, and the cleaning rod has an axial advance / retreat function. The driving unit to be applied and the gas pipe are provided in a state where the inside is airtightly isolated from the outside of the furnace, and when the cleaning rod is retracted, the head part is discharged from the gas pipe. a housing portion for accommodating the cleaning rod, an opening and closing valve head portion of the cleaning rod to prevent isolated to gas exposure of the head portion of the receiving portion when it is accommodated in the accommodating portion from the gas pipe equipped with, the cleaning rod Head portion is housed in the storage portion, the storage portion when it is isolated from the gas pipe and the chlorination furnace by opening and closing valves, the pressure in the housing portion, characterized in that it is maintained above the furnace pressure chloride Blockage prevention device in the furnace.   The blockage prevention device in the chlorination furnace according to claim 1 provided with the seal part which carries out the outside seal of said cleaning stick, and isolates the inside of said storage part from the outside of a furnace secretly.   2. The blockage preventing device for a chlorination furnace according to claim 1, wherein the driving unit gives the cleaning rod a rotary cutting function for scraping off deposits by rotation around an axis. 3.   2. The blockage prevention device for a chlorination furnace according to claim 1, wherein the drive unit imparts an axial striking function to the cleaning rod. 3. The chlorination according to claim 1 or 4 , wherein the cleaning rod is externally sealed by a plurality of seal portions provided in two or more stages in the axial direction, and the pressure between the two seal portions is higher than both the furnace pressure and the atmospheric pressure. Blockage prevention device in the furnace.

Images