JP2011140315A - Tower with resin lining - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a deformation of a lining provided to, for example, a tower, a tank and a drum, abrasion of the lining caused thereby, and damages to a lining sheet such as a worn hole and fracture. <P>SOLUTION: The tower with a resin lining includes a device which can introduce gas so that the internal pressure of the tower may exceed the external pressure of the tower so as to maintain a shape of the resin lining. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a tower provided with a resin lining.

  For towers, tanks, drums, etc. that handle highly corrosive hydrochloric acid, chlorine, etc. (hereinafter sometimes referred to as tower tanks), tower tanks can be used as a method for producing towers and tanks at low cost and with high corrosion resistance. There is known a method of constructing a lining made of resin on the inner wall.

  Examples of such a lining include baking lining in which the lining is bonded to the inner wall of the tower tanks, non-bonded so-called loose lining, and molding.

  For example, Patent Document 1 discloses a method for improving corrosion resistance by providing a minute gap between a resin coating layer and a resin film in a coating composed of a resin coating layer and a loose sheet lining of a resin film as loose lining. Is disclosed. Patent Document 2 discloses a lining tank in which a line includes an outer sheet and an inner sheet, and a spacer that holds a space communicating with the outside of the tank is provided between these sheets.

JP-A-2005-007841 JP 2003-063591 A

  During operation of towers and tanks that handle hydrochloric acid, chlorine, etc., the internal pressure of the tower or tank may be lower than the external pressure depending on the operating conditions. The linings such as 1 and 2 were damaged such as peeling from the inner wall of the tower tanks, piercing of the lining sheet, and breakage.

  The present invention has been made in view of the above-mentioned problems. Inert gas and gas that does not condense inside the tank are blown into the tower tanks so that the internal pressure of the tower tanks does not become lower than the external pressure. Thus, deformation of the lining is prevented and the lining is held in contact with the inner wall of the tower or tank.

  Specifically, the first aspect of the present invention relates to a tower provided with a resin lining, and includes a device capable of introducing a gas so that the internal pressure of the tower is equal to or higher than the external pressure of the tower in order to maintain the shape of the resin lining. It is characterized by that.

  It is preferable that the apparatus which can introduce | transduce the said gas contains an apparatus provided with gas piping, the pressure gauge in a tower, and the valve linked with this pressure gauge. Moreover, the aspect which has a seal pot is also contained in the apparatus which can introduce | transduce the said gas.

  The present invention also relates to a resin lining deformation prevention method in which the resin lining is held on the inner wall of the tower by introducing a gas so that the pressure in the tower becomes equal to or higher than the pressure.

  According to the present invention, the internal pressure of the towers and tanks can be adjusted so as not to be lower than these external pressures, so that the lining can be prevented from being peeled off or damaged. Moreover, the pressure drop during operation can be suppressed, and the plant can be operated stably.

It is typical sectional drawing of an example of the tower | column of this invention. It is a schematic diagram for demonstrating an example of the manufacturing process of chlorine containing the tower | column of this invention. It is a schematic diagram for demonstrating another example of the manufacturing process of chlorine containing the tower | column of this invention. (A) is typical sectional drawing of an example of a seal pot, (b) is a one part enlarged view of (a).

  Hereinafter, the present invention will be described in more detail. In the following description of the embodiments, the description is made with reference to the drawings. In the drawings of the present application, the same reference numerals denote the same or corresponding parts. In the present invention, the “tower” refers to tower tanks such as towers, tanks, drums and the like, and includes the same configuration as in the present invention.

  FIG. 1 shows a schematic cross-sectional view of an example of a tower provided with the resin lining of the present invention. As shown in FIG. 1, a tower 10 having a resin lining according to the present invention includes a tower main body 1, a coating 2 as a resin lining on the inner surface of the tower main body 1, and a loose lining sheet 3 disposed inside the tower. Is provided. FIG. 1 shows a part below the tower.

  In the tower 10 having the resin lining, the ends of the coating 2 and the loose lining sheet 3 are strongly pressed by, for example, a ring-shaped gasket 4 and a lid 5 attached to the end face of the tower body 1 to It is fixed to the end face. Even if the lid 5 has a planar shape, it may have a spherical shape and a peripheral edge that has a planar shape and overlaps with the end surface of the tower body 1, as in the shape of a distillation column in FIG.

  The loose lining sheet 3 is arranged via the coating 2 and a spacer (not shown). With such a structure, the space between the coating 2 and the loose lining sheet 3 communicates with the tower body 1 and the outside. Further, instead of providing a spacer, the space between the coating 2 and the loose lining sheet 3 is provided by mounting a spacer ring (not shown) between the end surface of the coating 2 and the end of the loose lining sheet 3. You can also.

  A pipe (not shown) to a suction device such as a suction pump or an aspirator is usually connected to the end of the space as described above, and the contents of the tower such as gas slightly permeate the loose lining sheet 3. Even if it oozes out, it is discharged to the outside by the suction device, so that gas or the like does not accumulate in the space between the loose lining sheet 3 and the coating 2.

  The tower body 1 has a cylindrical shape, and a cylindrical one is usually used. As the material of the tower body 1, a metal material such as carbon steel or stainless steel is used in terms of mechanical strength, as in a known sheet lining tank. The size of the tower body is appropriately selected depending on the internal volume, but is usually about 15 cm to 4 m in outer diameter and about 10 cm to 15 m in length.

  The coating 2 and the loose lining sheet 3 are inactive with respect to the contents. For example, a fluororesin such as polytetrafluoroethylene (PTFE) or tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA). The fluororesin sheet | seat which consists of is applied. In addition to fluororesin sheets, even towers that use resin sheets such as olefin resin sheets made of olefin resins such as polyethylene and polypropylene, and vinyl chloride resin sheets made of polyvinyl chloride are resistant to the contents. If there is, it can be used. The thickness of the lining sheet is selected depending on the size of the tower body 1, the type of contents, and the like, but is usually about 1 mm to 6 mm.

  The thickness of the spacer ring mounted between the coating 2 and the end of the loose lining sheet 3 is usually about 1 cm to 10 cm, although it depends on the size of the tower. The spacer ring is usually made of a fluororesin filled with a filler in terms of sealing properties and prevention of deformation called creep, and the filler is silica particles, glass fiber, carbon material. Etc. are exemplified.

  The spacer is not particularly limited in its shape and material as long as it can maintain the space between the coating 2 and the loose lining sheet 3 and the column contents have corrosion resistance. For example, the same material as the coating, that is, a material made of fluororesin can be used. Such a spacer is adhered between the coating 2 and the loose lining sheet 3 by welding or an adhesive. In this case, it is sufficient that the spacer is attached to at least the coating 2.

  The tower provided with the resin lining having the above configuration is used in a part of a production apparatus for chlorine and the like as shown in FIGS. In such a series of production apparatuses, the tower provided with the resin lining of the present invention as shown in FIG. 2 can be used as a distillation tower.

  In FIG. 2, a liquid containing hydrochloric acid is supplied to the first distillation column 6, hydrogen chloride gas and a part of water are distributed from the top of the column by a known stripping process, and discharged as a first distillate gas. On the other hand, the first hydrochloric acid water is discharged from the bottom of the column as a column output and supplied to the second distillation column 7. In the second distillation column 7, the first hydrochloric acid water is distilled, a second distillate gas is obtained from the top of the column, and a second hydrochloric acid water is obtained as a tower effluent. The first distillate gas is high-purity hydrogen chloride gas, which is a raw material for the hydrochloric acid oxidation process.

  Here, in such a series of manufacturing apparatuses, when an apparatus for pressure reduction (a vacuum pump in FIG. 2) or the like is connected before and after the tower provided with the resin lining, the pressure inside the tower is an external pressure. The pressure may be lower than that. In addition, for example, when the gas is rapidly condensed by a condenser connected to the top of the first distillation column 6 or when the first distillate gas is cooked at the top of the first distillation column 6 as shown in FIG. When only the above liquid is supplied to the top of the tower in a state where the raising is stopped, the gas inside the tower is condensed or absorbed by the liquid, so the pressure inside the tower is lower than the pressure outside the tower. May be.

  In this way, when the pressure inside the tower is lower than the pressure outside the tower, the loose lining sheet 3 shown in FIG. 1 is not pressed against the spacer or the like by the pressure, and the shape is deformed without being maintained. It peels off and extends inside the tower. In order to prevent such deformation of the loose lining sheet 3 and breakage due to perforation or breakage of the deformed loose lining sheet, the present invention is such that the internal pressure of the tower provided with the resin lining is equal to or higher than the external pressure of the tower. Including a device capable of introducing gas into

  As the gas introduced into the tower for the above purpose, an inert gas such as nitrogen gas, a gas that does not condense inside the tower, or a gas such as air that does not condense the contents of the tower can be used alone or in combination.

  The apparatus that can introduce the gas includes an apparatus that includes a gas pipe, a pressure gauge in the tower, and a valve that operates in conjunction with the pressure gauge. For example, a pressure gauge capable of detecting the pressure in the first distillation column 6 is disposed, and a gas pipe 11 connected to a gas tank 8 such as nitrogen gas is connected to the first distillation column 6. A valve 9 linked to the pressure gauge is connected to the gas pipe 11. The valve 9 is opened and a gas such as nitrogen gas is introduced into the tower so that the pressure inside the tower does not become lower than the pressure outside the tower (usually atmospheric pressure). 2 and 3, “PIC” indicates a pressure gauge and a controller for opening and closing a valve provided in the pressure gauge.

The valve 9 linked with the pressure gauge is programmed so that, for example, the valve 9 is opened when the difference (P _IN −P _OUT ) between the pressure P _OUT outside the tower and the pressure P _IN inside the tower becomes −0.5 kPa or less. Aside, the valve can be operated to open. The pressure gauge inside the tower is not particularly limited as long as it can measure the pressure of the gas part in the tower, but it is preferably installed at the top of the tower and the lower part of the gas part in the tower. It is desirable.

  Moreover, in the apparatus which can introduce | transduce the said gas, the aspect which has a seal pot is also contained in this invention.

A conventionally well-known seal pot can be applied, and has a structure as shown in FIGS. 4 (a) and 4 (b). FIG. 4A shows a cross-sectional view of a seal pot in an apparatus capable of introducing gas in the present invention. In the seal pot, the pressure difference between the outside and inside of the tower can be easily detected. As shown in FIG. 4A, a partition plate 13 is provided in the middle portion of the seal pot main body 12, and a pressure adjusting pipe 14 is provided through the partition plate 13. The seal pot body 12 includes a container 15 for holding the liquid 17, a pipe 21 communicating with the outside (atmosphere), a pipe 18 for supplying the liquid, a pipe 19 for introducing a gas into the liquid, and a process gas. Is provided with a gas introduction pipe 20. FIG. 4B is an enlarged view of a part of FIG. 4A due to the liquid 17 held in the container 15 provided inside the seal pot body 12 and the liquid held in the tube 21 communicating with the outside. ), The relationship between the external pressure P _OUT and the tower internal pressure P _IN can be detected from the liquid level.

When the pressure of the process gas is maintained between the pressure P _{OUT +} slightly higher than the atmospheric pressure and the pressure P _OUT− slightly lower than the atmospheric pressure in the seal pot, the seal pot main body starts from the lower end of the pressure adjusting pipe 14. The liquid 17 is put so that the height of the side wall 12 to the mounting position of the overflow pipe 22 becomes a liquid head corresponding to the pressure P _{OUT +} (P _{α in the} figure). The liquid 17 is poured so that the height to the mounting position of the pipe 21 communicating with the atmosphere provided on the upper side wall of the plate 13 becomes a liquid head corresponding to the pressure P _OUT− (P _{β in the} figure). A pipe 18 for supplying a liquid is provided above the upper end of the pressure adjustment pipe 14 of the partition plate 13, and a gas discharge pipe 23 is provided below the partition plate 13, and the pressure adjustment pipe 14 provided in the seal pot main body 12 is provided. When the difference between the liquid head of the liquid 24 and the liquid 16 of the container 25 increases, the gas is discharged to the outside from the gas discharge pipe 23, and conversely, when the liquid head becomes low, the atmosphere is sucked from the pipe 21 to The pressure of the process gas can be maintained between a slightly higher pressure P _{OUT +} and a pressure P _OUT− slightly lower than atmospheric pressure.

In the process of dissipating chlorine in the production of chlorine and the like, the use of the tower having the resin lining having the above-described configuration prevents the pressure inside the tower from being lower than the pressure outside the tower. The lining sheet 3 is always subjected to pressure from the inside of the tower to the outside, and the sheet is not deformed. Further, the valve 9 linked with the pressure gauge is programmed so that the valve 9 is opened when, for example, the difference P _IN -P _OUT between the pressure P _OUT outside the tower and the pressure P _IN inside the tower becomes −0.5 kPa. In addition, it is possible to reliably prevent deformation of the loose lining sheet by operating the valve so that the gas is supplied by opening the valve. As a result, damage such as piercing or breaking of the loose lining sheet does not occur, and the entire apparatus can always be operated safely.

  As described above, the embodiments of the present invention have been described, but it is also planned from the beginning to appropriately combine the configurations of the above-described embodiments.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The present invention is not limited to a tower provided with a lining made of resin, but is effective for preventing peeling of the lining in towers and tanks provided with a loose lining, and tower tanks such as a drum.

  1 Tower body, 2 coating, 3 loose lining sheet, 4 spacer, 5 lid, 10 tower with resin lining.

Claims (4)

  A tower equipped with a resin lining, including a device capable of introducing a gas so that the internal pressure of the tower becomes equal to or higher than the external pressure of the tower in order to maintain the shape of the resin lining.   The tower equipped with the resin lining according to claim 1, wherein the apparatus capable of introducing the gas includes a gas pipe, a pressure gauge in the tower, and a valve linked to the pressure gauge.   The tower equipped with the resin lining according to claim 1, wherein the apparatus capable of introducing the gas has a seal pot.   A method for preventing deformation of a resin lining, wherein the shape of the resin lining is maintained by introducing a gas so that the pressure inside the tower provided with the resin lining is equal to or higher than the pressure outside the tower.

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