JPH0942501A - Safety valve for treating vessel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a safety valve for a treating vessel for avoiding accidents caused by a rise of pressure in the vessel with a simple structure. SOLUTION: Constituted are packed beds 11, 12 packed with small pieces 9 in predetermined parts in a vessel 1, 2. A treating vessel executes predetermined treatment by passing a fluid to be treated through the packed beds 11, 12. Pressure relief pipelines 21, 22 penetrated through the packed beds 11, 12 at their upper and lower parts are formed in the packed beds 11, 12. Sump parts 23, 24 are formed in the pressure relief pipelines 21, 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to, for example, a distillation column or an evaporation column of a sulfuric acid recovery device for regenerating used sulfuric acid,
The present invention relates to a safety valve for a processing tank for preventing damage to the device due to an increase in pressure.

[0002]

2. Description of the Related Art FIG. 5 shows a sulfuric acid recovery apparatus for concentrating, refining and regenerating used sulfuric acid. The concentrating tower 1 evaporates and removes water, and the sulfuric acid vapor evaporates to remove impurities. It consists of an evaporation tower 2 for separation, condensers 3 and 4 for liquefying and recovering the evaporated gas, and other incidental equipment, and most of these devices are made of glass to ensure corrosion resistance. .

The lower sides of the concentrating tower 1 and the evaporating tower 2 are storage parts 5 and 6, and are maintained at predetermined temperatures (concentrating tower: 310 to 320 ° C., evaporating tower: about 330 ° C.) by heaters 7 and 8. There is. Filled layers 11 and 12 formed by filling a small piece of Raschig ring 9 are provided in the middle part, and coolers 13 and 14 through which cooling oil flows are provided in the upper part. Discharge pipes 15 and 16 for discharging steam are provided at the top, and condensers 3 and 4 are attached to the discharge pipes 15 and 16, respectively.
Is connected to a drain, and the condenser 4 is connected to a purified sulfuric acid recovery container.

A supply port 17 for waste sulfuric acid is provided above the packed bed 11 of the concentration tower 1, and a liquid feed pipe 18 for feeding the concentrated liquid to the evaporation tower 2 of the next step is provided in the storage part 5. There is.
As shown in FIG. 4 (a), the lahi ring 9 is a glass-made tubular piece having a diameter of 10 mm and a length of 10 mm, which is supported by a supporting structure and has a reticulated space 1
1 and 12 are configured. In addition, as this filling,
As shown in (b) and (c) of the figure, a lessing ring 9a having a partition therein, and a small piece 9 having a shape in which a plurality of rings are combined
b, a saddle-shaped small piece, or the like, which has large voids, allows the downflowing liquid to uniformly flow down, and has a large surface area and is light. The material is
A material suitable for the fluid to be treated is used from ceramics, metals, plastics, etc., but in the case of sulfuric acid, it is glass.

In the storage section 5 of the concentrating tower 1, sulfuric acid having a concentration of about 70% is evaporated by heating and rises in the packed bed 11.
On the other hand, the waste sulfuric acid solution is supplied from the supply port 17 and descends in the packed bed. In the packed bed 11, the gas phase and the liquid phase thus form a flow in which they face each other, and a temperature gradient that decreases as they go upward is formed. Then, heat exchange and material transfer are performed between the gas phase and the liquid phase that flow in opposition, as a result, the vapor with a low sulfuric acid concentration rises from the upper surface of the packed bed 11, and the liquid with a high sulfuric acid concentration propagates through the Raschig ring 9. And returns to the storage section 5. The rising vapor is cooled in the cooler 13, part of which is condensed and flows into the packed bed 11, and the rest is liquefied by flowing from the discharge pipe 15 to the condenser 3 and is discharged to the drain as about 5% diluted sulfuric acid. It In the evaporation tower 2, sulfuric acid having a concentration of about 96% is evaporated, reaches the condenser 4 through the packed bed 12 and the cooler 14, and is recovered as a product.

[0006]

In the above apparatus, when the amount of liquid flowing down is large or the amount of vaporized vapor is large, the reticulated spaces in the packed layers 11 and 12 are closed and vaporized. Gas may become difficult to escape, the pressure may rise, the Raschig ring 9 made of glass may be lifted, and may fall and be damaged. In order to prevent such an accident, a pressure relief means such as a check valve may be provided at a predetermined location, but since the device is made of glass and handles highly corrosive fluid, the structure and It has been difficult to construct a pressure relief means that is easy to maintain. An object of the present invention is to provide a safety valve for a processing tank that can avoid an accident due to a pressure increase in the tank with a simple structure.

[0007]

According to a first aspect of the present invention, a filling layer is formed by filling a predetermined portion of a container with small pieces, and a fluid to be treated is passed through the filling layer to perform a predetermined treatment. In the processing tank, a pressure relief pipe line is formed in the packed bed so as to pass through the packed bed vertically, and a liquid reservoir is formed in the pressure relief pipe path. . The invention according to claim 2 is the safety valve for a processing tank according to claim 1, characterized in that the depressurizing conduit is constituted by an S-shaped pipe.

The invention according to claim 3 is characterized in that an introduction structure for guiding the fluid to be treated to this opening is formed in the vicinity of the upper opening of the depressurizing conduit. This is a safety valve for the processing tank described. For this, for example, a method of forming the opening in a divergent manner, providing the opening in contact with the wall of the container, or forming a projection for dropping a fluid on the upper portion of the opening is adopted. The invention described in claim 4 is
The safety valve for a processing tank according to any one of claims 1 to 3, wherein the small piece and / or the depressurizing pipe line is made of glass.

According to a fifth aspect of the present invention, the processing tank comprises:
The safety valve for a processing tank according to any one of claims 1 to 4, which is a refining device for heating and fractionating a fluid. The invention according to claim 6 is the safety valve for a processing tank according to any one of claims 1 to 4, wherein the processing tank is an evaporator that heats and evaporates a fluid. The invention according to claim 7 is the safety valve for a processing tank according to claim 5 or 6, characterized in that the fluid is sulfuric acid.

[0010]

According to the present invention, when a pressure difference above and below the packed bed exceeds a predetermined level, the fluid flows against the pressure of the liquid accumulated in the liquid reservoir of the depressurizing pipe line, thereby causing a difference. Relieve pressure. In the invention described in claim 2, the liquid reservoir is easily configured by forming a part of the depressurizing tube in an S shape.

In the third aspect of the invention, the fluid to be treated is guided to the opening by the introduction structure, and the liquid is naturally accumulated in the liquid reservoir. In the invention according to claim 4, the small piece and / or the depressurizing pipe line is formed of glass, and the corrosion resistance to the fluid to be treated is improved. In the invention according to claim 5, the fluid is heated under the treatment tank, rises in the treatment tank, and is fractionated and purified in the process. In the sixth aspect of the invention, the fluid is heated under the treatment tank to rise in the treatment tank, and is separated from the non-volatile components to be purified. In the invention according to claim 7,
Sulfuric acid is fractionated and purified.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a safety valve of a processing tank according to an embodiment of the present invention. The same parts as in the prior art are designated by the same reference numerals and the description thereof will be omitted. In this embodiment, the packing layers 11, 12 are
And the pressure-removing pipes 21 and 2 inserted through the upstream and downstream of the packed bed.
2 is attached to the frame that holds the pieces. The depressurization tubes 21 and 22 are formed as glass S-shaped tubes,
As a result, liquid reservoirs 23 and 24 are formed. The depressurizing tube is formed with funnel portions 25 and 26 whose upper ends are widened upward.

The depressurizing tube 21 of the concentrating tower 1 is attached so that its edge contacts the inner wall 1a of the container. Height h of the overlapping portions of the S-shaped depressurization tubes 21 and 22 (see FIG. 2)
Is set according to the pressure at which this safety valve operates. Further, the thickness of the depressurizing pipes 21 and 22 is such that, in a normal operating state, the liquid flowing into the depressurizing pipes 21 and 22 is not pushed out by the differential pressure, and the vapor and the liquid are replaced with each other, and the predetermined pressure rise is achieved. If there is, set it so that the liquid can be pushed out and vapor can escape.

The operation of the safety valve of the processing tank thus constructed will be described with respect to the concentration tower 1. Cooling device 13 of the concentration tower 1
The cooled liquid is transmitted from the surrounding wall 1a and descends and flows into the depressurizing pipe 21, so that the liquid reservoir 23 of the depressurizing pipe 21 always naturally forms a liquid reservoir having a height h. During normal operation, vapor is blocked by the liquid reservoir 23, so the depressurizing pipe 2
It does not flow through 1 to the upper side. When the pressure in the storage part 5 rises, the equilibrium of the liquid storage part 23 is disrupted as shown in FIG. 2 (b), and the pressure becomes twice the height h of the liquid storage part 23 of the depressurization pipe 21. When the determined pressure is exceeded, the vapor in the reservoir 5 is ejected through the depressurization pipe 21 as shown in FIG. 2 (c). This suppresses an abnormal increase in pressure, and prevents an accident such as a small piece of the packed bed 11 moving up and down and being damaged. Since the liquid reservoir 23 is formed naturally, the work for forming the liquid reservoir is not required.

FIG. 3 shows the structure of the safety valve of the evaporation tower 2, in which the protrusion 27 protruding downward is formed on the cooler 14.
The depressurization tube 22 is opened below the protrusion 27. According to this embodiment, a part of the liquid condensed in the cooler 14 always flows into the depressurizing pipe 22, so that a constant amount of the liquid reservoir is maintained more stably.

The embodiment of the present invention is not limited to the above-described embodiment, and the type of the processing tank used may be, for example, a filtering device, the material of each member, and the small pieces to be filled. Any appropriate shape, size, shape of the liquid reservoir of the depressurization tube, and the like may be used. In addition, S that constitutes the liquid reservoir
As shown in FIGS. 2 (d) and 2 (e), the character tube may be a coupling tube 21a in which overlapping portions are coupled to each other to save space and improve strength.

[0017]

According to the first aspect of the present invention, the pressure difference between the upper and lower sides of the packed bed is automatically relieved, and the occurrence of an accident due to the pressure increase in the tank can be avoided with a simple structure. Due to its simple structure, it can be made of a corrosion resistant material such as glass, and is easily applied to the treatment of corrosive fluids. Maintenance is easy because the structure is simple and the fluid normally accumulates in the liquid reservoir. According to the invention as set forth in claim 2, the liquid reservoir can be manufactured only by bending a part of the depressurizing tube into an S shape, and the cost is low.

According to the third aspect of the invention, since the liquid is naturally accumulated in the liquid reservoir by the introduction structure, the maintenance is easy. In the invention of claim 4,
The above-mentioned small piece and / or the depressurizing pipe line are formed from glass, and can be applied to the treatment of a highly corrosive fluid to be treated. In the invention described in claim 5, the process of fractionating and refining the fluid to be treated is stably performed, resulting in an improvement in efficiency and a reduction in cost.
In the invention described in claim 6, the step of evaporating and purifying the fluid to be processed is stably performed, which improves the efficiency and reduces the cost. In the invention according to claim 7,
Sulfuric acid fractionation / purification process is performed stably, resulting in improved efficiency and cost reduction.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a sulfuric acid recovery apparatus according to an embodiment of the present invention.

FIG. 2 is a view showing the operation of the pressure relief pipe according to the embodiment of the present invention.

FIG. 3 is a view showing the operation of the pressure relief pipe of another embodiment of the present invention.

FIG. 4 is a diagram showing an example of a small piece of a filling tank used in the present invention.

FIG. 5 is a schematic view of a conventional sulfuric acid recovery device.

[Explanation of symbols]

 1 Concentration Tower (Container) 2 Evaporation Tower (Container) 9, 9a, 9b Raschig Ring (Small Piece) 11, 12 Packed Bed 21, 21a, 22 Depressurization Tube 23, 24 Liquid Reservoir 25, 26 Funnel 27 Protrusion

Claims (7)

[Claims] 1. A treatment tank in which a predetermined layer of a container is filled with small pieces to form a filling layer, and a predetermined treatment is carried out by passing a fluid to be treated through the filling layer, wherein the filling layer has the filling layer. A safety valve for a processing tank, characterized in that a pressure release pipe line is formed so as to pass through the upper and lower sides of the container and a liquid reservoir is formed in the pressure release pipe line. 2. The safety valve for a processing tank according to claim 1, wherein the depressurizing pipe line is composed of an S-shaped pipe. 3. The safety valve for a treatment tank according to claim 1, wherein an introduction structure for guiding the fluid to be treated to the opening is formed in the vicinity of the upper opening of the depressurizing pipe line. . 4. The small piece and / or the depressurizing pipe line are made of glass.
The safety valve for the processing tank according to any one of 1. 5. The safety valve for a processing tank according to claim 1, wherein the processing tank is a refining device for heating and fractionating a fluid. 6. The safety valve for a processing tank according to claim 1, wherein the processing tank is an evaporator that heats and evaporates a fluid. 7. The safety valve for a processing tank according to claim 5, wherein the fluid is sulfuric acid.