JP4835866B2 - Sealing method of pressure cooker - Google Patents

Description

  The present invention relates to a method for sealing a pressure kettle used for heat treating a product or causing a reaction under high pressure, and more particularly to a sealing method suitable for a retort kettle for thermally sterilizing retort food.

  Many foods in a sealed container can be maintained for a long period of time by heat sterilization in a retort kettle after filling and sealing. Since a high pressure is applied to the lid of a pressure cooker such as this retort kettle, a sealing mechanism for sealing is important. Usually, sealing is maintained by pressing the lid against the sealing material attached to the hook flange. In this case, it is necessary to firmly fasten the hook flange and the lid sandwiching the seal so as not to leak from the seal portion due to the internal pressure of the hook. As this fastening mechanism, a clutch type such as that found in a retort hook is often used. In such a pressure cooker, when the lid is opened and closed, a system is adopted in which the engaged member and the engaging member are engaged with each other by engagement of the clutch mechanism and the seal is pressed from one to the other. When the seal is pressed, a large power is required for the clutch mechanism. Further, since the sealing material is deteriorated due to aging, there is a problem that when the thickness of the sealing material is changed, the compression force is changed and the sealing performance is affected.

  On the other hand, in order to solve these problems, a method has been proposed in which the sealing material is pressed against the lid by high-pressure air through a sealing groove from the back side of the sealing material. The invention described in Patent Document 1 reduces the power with which the engaged member and the engaging member are engaged and disengaged, and even if the seal packing deteriorates due to aging, the seal packing in the packing groove The purpose is to provide a “pressure vessel sealing device” that adjusts the pressurization to completely seal the inside of the pressure vessel A. As shown in FIG. The member is passed through the engaged member provided in the container body, either the engaged member or the engaging member is moved, and both of them are loosely engaged, and then high-pressure air is introduced into the packing groove. The seal packing is extruded, the seal packing is pressed against the door surface, the container body and the door are clamped, and the pressure container is hermetically sealed. Then, the high pressure air in the packing groove is exhausted, the pressing pressure of the seal packing is released, the engagement between the engaged member and the engaging member is released, and the door is opened. In this method, when sealing the pressure vessel, the sealing material is pressed against the lid with high-pressure air to seal it, and when opening the lid after decompression, the high-pressure air that presses the sealing material is released. If so, there is a concern that the packing may pop out when the lid is opened and closed. Further, when the lid opening / closing mechanism is a slide type, there is a disadvantage that the packing becomes a resistance when the lid slides in a state where the packing protrudes.

Patent Document 2 discloses “annular packing and airtight mechanism of pressure vessel”. An object of the present invention is to provide an annular packing capable of preventing deterioration in sealing performance at a bent corner as much as possible. As shown in FIG. 6, the opening of an airtight chamber closed by a door is provided. On the peripheral surface of the part, it is slidably inserted into an annular groove formed in an annular shape so as to surround the opening, and between the bottom surface and the lower end surface of the annular groove is pressurized and decompressed, In the annular packing formed of an elastic material whose upper end surface is in contact with and away from the inner surface of the door, each of the side surfaces which are inclined surfaces inclined in the direction of the lower end surface wider than the upper end surface width W1 of the annular packing; When the annular packing is inserted into the annular groove, the protruding corner portion formed by the lower end surface and the protruding portion formed in the middle of each side surface are in sliding contact with the inner wall surface of the annular groove. And each of the projecting portions is an annular packing. Is characterized in that the formed on the ridge portion is extended in the longitudinal direction. In the operation of the annular packing, a fluid passage hole for supplying and discharging compressed air is provided on the bottom surface of the annular groove where the packing is inserted, and the bottom surface side of the groove is provided with the fluid passage hole. When compressed air pressurized by compression means such as a compressor is supplied, the annular packing that is slidably inserted into the annular groove is pushed in the direction of the door, and its upper end surface comes into contact with the inner surface of the door. The sterilization chamber can be sealed in an airtight state by sealing between the inner surface of the door and the periphery of the opening. After sterilization is completed, the object to be sterilized is returned to the normal pressure after being returned to normal pressure. When opening the door, the compressed air is discharged from the fluid passage hole, and then the pressure between the lower end surface of the annular packing and the bottom surface of the groove is reduced by vacuum generating means such as a vacuum pump. Pull into the groove. For this reason, a gap is formed between the front end surface of the annular packing and the inner surface of the door, and the door can be opened smoothly. With such a packing drive, when the lid is opened, the back surface of the sealing material is in a negative pressure state, so there is no inconvenience that the packing pops out when the lid is opened / closed. Since a pressure source is required, there is a problem that the apparatus becomes complicated and expensive.
JP 7-323416 A "Pressure Vessel Sealing Device" Published December 12, 1995 Japanese Patent Laid-Open No. 2001-200935 “Annular packing and airtight mechanism of pressure vessel” published on July 27, 2001

  An object of the present invention is to provide a sealing method for a pressure hook sealing mechanism comprising a combination of a hook flange and a lid, which has a safe and reliable sealing function and can simplify a mechanism for fastening and releasing the hook flange and the lid. It is another object of the present invention to provide a sealing device for a pressure cooker that realizes the method.

The pressure hook sealing method of the present invention is such that a sealing material is inserted into a sealing groove provided in the hook flange or lid, and the sealing material is pressed against the facing lid or hook flange surface with high-pressure steam from the back side of the sealing material. In the sealing method, when the pressure kettle is decompressed and the lid is opened, the high-pressure steam leading to the back side of the sealing material is released and decompressed, and cooling water or cooling gas is sprayed onto a part of the pipe supplying the high-pressure steam, By condensing the steam, a configuration was adopted in which the inside of the seal groove was in a negative pressure state and the seal material was pulled back.
The method for sealing a pressure cooker according to the present invention includes a step of applying high-pressure steam to the back side of the sealing material and pressing the sealing material against the opposite lid or hook flange surface to seal, and maintaining the sealed state by continuously applying high-pressure steam. A step of stopping the application of high-pressure steam, opening the back side region of the seal material in the seal groove to an atmospheric pressure state, and spraying cooling water or a cooling gas on a part of the piping leading to the back side of the seal material And a step of condensing steam in the pipe.
Further, the pressure kettle sealing method of the present invention is applied to the retort kettle sealing method in which the retort treatment is performed in the pressure kettle while the high pressure steam is continuously applied to maintain the sealed state.

In the pressure hook sealing device of the present invention, a sealing groove is provided in the flange or lid of the hook facing the lid or the hook flange surface, a sealing material is inserted therein, and a pipe is arranged in the groove on the back side of the sealing material. A high-pressure steam source is connected to be able to be intermittently connected to the pipe, and a valve member capable of communicating with the atmosphere, a heat exchange part, and a means for cooling the heat exchange part are arranged, and the sealing material is pressed against the face The function of sealing the hook and the function of pulling back the sealing material with the inside of the seal groove in a negative pressure state. And the form which sprays cooling water or a cooling gas was taken as the means to cool the said heat exchange part.
The pressure hook sealing device according to the present invention adopts a swing type or a type that slides through a rail, and has a function of being able to seal with a protrusion of a sealing material without pressing the lid against the hook flange. I prepared.

The pressure cooker of the present invention is constructed by inserting a sealant into a seal groove provided in the hook flange or lid, and sealing the sealant by pressing the sealant against the opposite lid or hook flange surface with high-pressure steam from the back side of the sealant. In the sealing method, when the pressure kettle is decompressed and the lid is opened, the high-pressure steam leading to the back side of the sealing material is released and decompressed, and cooling water or cooling gas is blown to a part of the pipe supplying the high-pressure steam, Since a configuration for condensing steam is adopted, the inside of the seal groove can be easily brought into a negative pressure state without preparing a negative pressure source, and a function of pulling back the seal material can be provided. Thereby, it is possible to prevent the sealing material from jumping out of the sealing groove when the lid is opened, and the sealing material is stably held in the sealing groove. Further, the pressing force of the sealing material can be easily adjusted by the supplied steam pressure.
In the pressure hook sealing method of the present invention, the mechanism for opening and closing the hook flange and the lid can be simplified by adopting the above-described new method for the pressure hook sealing mechanism. Further, the mechanism for fastening / releasing the hook flange and the lid can be simplified.
In the pressure hook sealing device of the present invention, a sealing groove is provided in the flange or lid of the hook facing the lid or the hook flange surface, a sealing material is inserted therein, and a pipe is arranged in the groove on the back side of the sealing material. Since the high-pressure steam source is connected to be able to be intermittently connected, the sealing material can be pressed against the opposite surface to tightly seal the hook, and the sealing material can be connected to the pipe with a valve member capable of communicating with the atmosphere, Further, since the means for cooling the heat exchanging portion is arranged, it is possible to prevent the accident that the seal material is pulled back when the inside of the seal groove is brought into a negative pressure state by cooling and the seal material is ejected when the lid is opened.
The pressure hook sealing device according to the present invention employs a type in which the lid slides through the rail, so that a mechanism such as a clutch generally used as a pressure mechanism for the lid can be made unnecessary. Without pressing the lid against the hook flange, it can be easily sealed only by the protrusion of the sealing material.
Further, the pressure hook sealing device of the present invention uses a clutch mechanism that is generally used as a pressure mechanism for the lid when a swing type or a slide type is used for the lid opening / closing mechanism with respect to the flange of the hook. However, since it is not necessary to apply pressure when fastening and releasing the lid and the hook flange, it is possible to reduce the power required for operating the device.

  The method for sealing a pressure cooker according to the present invention presents a new mechanism in which a sealing material is pressed against a lid using high-pressure steam to seal the pressure cooker, and a seal groove provided on the flange or lid of the kettle. This is a mechanism for inserting a sealing material into the cover and sealing it by pressing the sealing material against the corresponding lid or hook flange with high-pressure steam from the back side of the sealing material. When the pressure cooker is depressurized and the lid is opened, the high-pressure steam leading to the back side of the sealing material is released and decompressed, but the sealing material is in contact with the lid material as it is. Therefore, a structure is adopted in which cooling water or a cooling gas is blown to a part of a pipe for supplying high-pressure steam to condense the steam in the pipe, thereby reducing the pressure inside the seal groove and pulling back the seal material. Thereby, the sealing material can be protruded when sealed, and pulled back when the lid is released.

  An apparatus for carrying out the pressure kettle sealing method will be described with reference to FIG. 1 is a pressure cooker body, 1a is a hook flange, 2 is a lid, 3 is a sealing material, 4 is a high-pressure steam source, 5 is a heat exchange part, 6 is a cooling means, 7 is a supply source of cooling air or cooling water, 8 A pipe connecting the seal groove and the high-pressure steam source, 9 is a pipe for supplying cooling air or cooling water to the cooling means, 10 is an exhaust pipe connected to the seal groove, 11 is a seal groove, and 12 is provided in the pipe 8 13 is an on-off valve provided on the pipe 9, 14 is an on-off valve provided on the exhaust pipe 10, 15 is a pressure gauge for measuring the pressure applied to the back surface of the sealing material 3, and 16 is a heat exchanger. It is the drain discharge pipe of the cooling medium in. The heat exchange unit 5 is disposed in the middle of the exhaust pipe 10. In the example shown here, the sealing material 3 is arranged not in the lid 2 side but in the groove on the hook flange side, and the sealing material 3 is placed on the surface of the lid 2 facing the high pressure steam applied to the back surface thereof. Pressed and performs a sealing function. The structure of the seal portion will be described with reference to the partially enlarged view of FIG. 2. An annular seal groove 11 is formed in the hook flange 1a, and the annular seal member 3 is inserted therein. A pipe 8 connected to the high-pressure steam source 4 and an exhaust pipe 10 are connected to the bottom of the seal groove 11 in the same form.

  The pressure kettle sealing method performed using this apparatus will be described sequentially in time series. FIG. 3 shows an operating state in which the lid 2 and the hook flange 1a are sealed. The on-off valve 13 provided on the pipe 9 and the on-off valve 14 provided on the exhaust pipe 10 are set in a closed state. Thus, the on-off valve 12 provided in the pipe 8 is opened. Then, the high-pressure steam from the high-pressure steam source 4 is supplied to the seal groove 11 through the pipe 8 and applied to the back surface of the seal material 3. When the high-pressure steam acts on the back surface of the sealing material 3, the sealing material 3 is displaced and pressed toward the back surface of the facing lid 2. Since the sealing material 3 is arranged in an annular shape at the hook flange 1a, the inside and outside of the annular sealing material 3 are shielded in this pressed state, and the inside of the hook 1 is eventually sealed. This achieves sealing of the pressure cooker. The desired pressing force of the sealing material 3 is achieved by adjusting the pressure of the high-pressure steam source 4 while monitoring the pressure gauge 15. The state in which the sealing is ensured is continued while a desired process such as a retort process is performed in the pressure cooker 1 thereafter.

  Next, an operation for taking out the stored items after the desired processing in the pressure cooker 1 is completed. First, as shown in FIG. 4, the on-off valve 12 provided in the pipe 8 is closed. Subsequently, the on-off valve 14 provided in the exhaust pipe 10 is opened, and the high-pressure steam confined in the seal groove 11 space is released. In this state, since the high pressure applied to the back surface of the sealing material 3 is released, no pressure acts on the back surface of the sealing material 3 in this state, so that the space between the lid 2 and the hook flange 1a is not affected. The seal is released. Also at this time, the pressure gauge 15 is monitored to confirm that the pressure is the same as the outside air, generally atmospheric pressure, and the on-off valve 14 provided in the exhaust pipe 10 is closed.

  Subsequently, as shown in FIG. 5, the on-off valve 13 provided in the pipe 9 is opened, and cooling air or cooling water is supplied from the cooling medium source 7 to the cooling means 6 through the pipe 9. The supplied cooling air or cooling water is discharged from the cooling means 6 and cools the heat exchange unit 5. The space of the seal groove 11 is a closed space because the on-off valve 12 and the on-off valve 14 are closed, and since it is cooled by this heat exchanging part 5, the steam inside is condensed, and the space of the seal groove 11 is Negative pressure state. This state can be confirmed with the pressure gauge 15. In this state, a suction force acts on the back surface of the sealing material 3, and the sealing material 3 that has been in contact with the surface of the lid 2 is forcibly retracted toward the back of the sealing groove 11, Completely open to the open air. In this way, the lid 2 can be opened freely. In addition, the cooling water discharged | emitted in the heat exchange part 5, the dew condensation in the heat exchange part 5, etc. are discharged | emitted via the drain discharge pipe 16 of the cooling medium in a heat exchange part.

  The lid 2 in the illustrated embodiment is of a sliding type opening / closing lid type guided by a groove provided in the hook flange 1a, and the seal material 3 is projected without pressing the lid 2 against the hook flange 1a. Since sealing is possible, a mechanism such as a clutch generally used as a compression mechanism for the lid 2 can be eliminated, and a simple pressure cooker opening / closing lid is presented. Even if a swing mechanism or a slide mechanism is used as the lid opening / closing mechanism for the hook flange, and a clutch mechanism that is generally used as a lid compression mechanism is used, the lid and hook flange are fastened and released. Since it is not necessary to apply pressure when performing the operation, it is possible to reduce the power required for the operation of the apparatus, which is an energy saving type as compared with the conventional apparatus.

  The pressure kettle sealing method according to the present invention can be applied to a retort kettle, but as an application of this technique, it can also be used for a lid opening / closing mechanism of a sterilization kettle.

It is a figure which shows the structure of the apparatus which enforces the sealing method of the pressure cooker of this invention. It is the elements on larger scale which show the structure of the seal part in the apparatus of this invention. It is a figure explaining operation which implement | achieves sealing of the pressure cooker of this invention. It is a figure explaining the first operation which cancels | releases sealing of the pressure cooker of this invention. It is a figure explaining the next operation which cancels | releases sealing of the pressure cooker of this invention. It is a figure which shows the conventional "sealing apparatus of a pressure vessel" and its sealing form. It is a figure which shows the airtight mechanism of the conventional different pressure vessel.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pressure hook 1a Hook flange 2 Lid 3 Seal material 4 High pressure steam source 5 Heat exchange part 6 Cooling means 7 Cooling medium source 8 Piping 9 Supply pipe
10 Exhaust pipe 11 Seal groove
12, 13, 14 On-off valve 15 Pressure gauge
16 Drain discharge pipe

Claims (6)

  In a method in which a sealing material is inserted into the sealing groove provided in the hook flange or lid, and the sealing material is pressed against the opposite lid or hook flange surface with high-pressure steam from the back side of the sealing material, the pressure pot is depressurized. When opening the lid, the high pressure steam leading to the back side of the sealing material is released and decompressed, and cooling water or cooling gas is blown to a part of the pipe supplying the high pressure steam to condense the steam in the pipe, thereby sealing the groove. A pressure kettle sealing method characterized in that the inside is in a negative pressure state and has a function of pulling back the sealing material.   Applying high-pressure steam to the back side of the sealing material and pressing the sealing material against the opposite lid or hook flange surface to seal, step of continuing to apply high-pressure steam to maintain the sealed state, and stopping the application of high-pressure steam And opening the back side region of the seal material in the seal groove to an atmospheric pressure state, blowing the cooling water or the cooling gas to a part of the pipe leading to the back side of the seal material, and condensing the vapor in the pipe; The method for sealing a pressure cooker according to claim 1, wherein:   3. The pressure kettle sealing method according to claim 2, wherein retort treatment is performed in the pressure cooker while the high pressure steam is continuously applied to maintain the sealed state.   A seal groove is provided in the flange or lid of the hook facing the lid or hook flange surface, and a sealing material is inserted therein, and a pipe is arranged in the groove on the back side of the seal material so that the high-pressure steam source can be connected intermittently. The pipe has a valve member capable of communicating with the atmosphere, a heat exchanging portion, and a means for cooling the heat exchanging portion, thereby pressing the sealing material against the face and sealing the pot, and a seal groove Sealing device for pressure cooker that has the function of pulling back the sealing material under negative pressure.   5. The pressure kettle sealing device according to claim 4, wherein the means for cooling the heat exchanging section is configured to spray cooling water or cooling gas.   6. The lid according to claim 4 or 5, wherein the lid adopts a swing type or a type that slides through a rail, and has a function of being able to seal with the protrusion of the sealing material without pressing the lid against the hook flange. Pressure cooker sealing device.

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