JP2007268017A - Steam-heating apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent air retained in a reboiler and a steam supply pipe from being supplied to a processing tank when supplying steam to the processing tank. <P>SOLUTION: This steam-heating apparatus is provided with the processing tank 2 for storing a heated object 1, the reboiler 14 vaporizing soft water using the steam from a boiler 13 as a heat source, the steam supply pipe 22 supplying the steam from the reboiler 14 to the interior of the processing tank 2, a steam supply valve 24 provided in the steam supply pipe 22 and opening/closing the pipe line, and an exhaust valve 25 disposed adjacent to the steam supply valve 24 in the side of the boiler 14 of the steam supply valve 24. The exhaust valve 25 has an opening communicating between the inside/outside of the seam supply pipe 22 and closes the opening based on the temperature of the steam from the reboiler 14. A temperature regulation trap operated at a temperature lower than a saturated steam temperature by a prescribed temperature under the pressure of an installation place is used as the exhaust valve 25. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a steam heating apparatus for supplying steam into a treatment tank in which an object to be heated is accommodated to heat the object to be heated. In particular, the present invention relates to a steam heating device such as a saturated steam cooking device for cooking food to be cooked (food or food).

As disclosed in Patent Document 1 below, a steam heating apparatus is known in which steam is supplied into a treatment tank in which a food is stored, and the food is cooked. In this steam heating device, it is preferable to supply steam into the processing tank after exhausting the air in the processing tank in advance in order to increase the heat transfer efficiency. Further, as disclosed in Patent Document 2 below, it is preferable to vaporize soft water using a reboiler and supply the steam into the treatment tank in order to perform safe and hygienic cooking.
JP 2005-210959 A (paragraph numbers 0037-0038, FIG. 1) Japanese Patent Laying-Open No. 2005-65798 (paragraph numbers 0018-0019, FIG. 1)

  However, the air accumulated in the reboiler that generates steam into the treatment tank and in the steam supply pipe that supplies the steam from the reboiler into the treatment tank opens the steam supply valve provided in the steam supply pipe for treatment. When supplying steam into the tank, there was a problem of being supplied into the processing tank. For this reason, even if the air in the treatment tank is eliminated in advance, air may be introduced into the treatment tank at the initial stage of supplying steam to the treatment tank, and the effect of the air removal may be reduced or eliminated. It was.

  On the other hand, in the reboiler, if the air remains in the reboiler when the reboiler is activated, the steam temperature is lowered by the amount of the partial pressure of the air. There was a risk that this could not be done smoothly.

  The problem to be solved by the present invention is to prevent air that has accumulated on the upstream side of the steam supply valve from being supplied into the processing tank when the steam is supplied into the processing tank. Further, the reboiler is started as desired by removing the air accumulated in the reboiler.

  The present invention has been made to solve the above-mentioned problems, and the invention according to claim 1 supplies a steam from a steam generator into a processing tank in which an object to be heated is accommodated, and the processing tank. A steam supply pipe, a steam supply valve provided in the steam supply pipe for opening and closing the conduit, and provided in the steam supply pipe on the steam generator side from the steam supply valve, and at a temperature lower than a set temperature, the steam supply pipe The steam heating apparatus includes an exhaust valve that opens to communicate the inside and outside of the pipe, and closes the opening at a set temperature or higher.

  According to the first aspect of the present invention, the exhaust valve is open when air is accumulated in the steam generator or the steam supply pipe, such as when the steam generator is started. Therefore, the accumulated air is pushed out to the outside through the exhaust valve by the steam from the steam generator and discharged. However, since the steam from the steam generator is hotter than the air, the opening of the exhaust valve is closed after the air is discharged. Therefore, after that, only the steam can be supplied into the treatment tank by opening the steam supply valve provided in the steam supply pipe.

  According to a second aspect of the present invention, there is provided a decompression unit that sucks and discharges the air in the processing tank to the outside, a vapor pressure detection unit that detects a vapor pressure in the steam generator, and a detection signal of the vapor pressure detection unit The steam heating apparatus according to claim 1, further comprising: a control unit that controls opening and closing of the steam supply valve based on the above.

  According to invention of Claim 2, the air in the steam supply pipe | tube downstream from a steam supply valve and the air in a processing tank can be discharged | emitted outside by a pressure reduction means. On the other hand, as described above, the air in the steam supply pipe upstream of the steam supply valve and the air in the steam generator can be discharged from the exhaust valve to the outside. In this manner, it is possible to supply steam into the treatment tank without removing air in the treatment tank and introducing air into the treatment tank. Further, the steam pressure detection means can make the steam pressure in the steam generator desired, and then supply steam into the treatment tank by opening the steam supply valve.

  The invention according to claim 3 is a treatment tank in which an object to be heated is accommodated, a reboiler using steam from the boiler as heat source and soft water or pure water as steam, and supplying steam from the reboiler into the treatment tank. A steam supply pipe, a steam supply valve provided on the steam supply pipe for opening and closing the pipe, and disposed on the reboiler side from the steam supply valve, and in the vicinity of the steam supply valve, the steam supply pipe An exhaust valve that is provided in a pipe and has an opening that communicates the inside and outside of the steam supply pipe, closes the opening based on the temperature of the steam from the reboiler, and sucks and discharges the air in the processing tank to the outside. A decompression means for decompressing the inside of the treatment tank, a steam pressure detection means for detecting the steam pressure in the reboiler, a steam supply from the boiler to the reboiler based on a detection signal of the steam pressure detection means, Control means for controlling whether or not the steam supply valve can be opened and closed; A steam heating apparatus, characterized in that it comprises.

  According to the third aspect of the present invention, the exhaust valve is open in a state where air is accumulated in the reboiler or the steam supply pipe, such as when the reboiler is activated. Therefore, the accumulated air is pushed out by the steam from the reboiler and exhausted through the exhaust valve. However, since the steam from the reboiler is hotter than the air, the opening of the exhaust valve is closed after the air is discharged. Therefore, after that, only the steam can be supplied into the treatment tank by opening the steam supply valve provided in the steam supply pipe. Here, the air in the steam supply pipe on the downstream side of the steam supply valve and the air in the treatment tank can be discharged to the outside beforehand by the decompression means. In this manner, it is possible to supply steam into the treatment tank without removing air in the treatment tank and introducing air into the treatment tank. Further, the steam supply from the boiler to the reboiler is controlled based on the steam pressure detecting means, and the steam can be supplied into the treatment tank by opening the steam supply valve while maintaining the steam pressure in the reboiler as desired. Moreover, since the steam supplied into the treatment tank is obtained by vaporizing soft water or pure water, safe and sanitary heat treatment is possible.

  The invention according to claim 4 is characterized in that the exhaust valve is a temperature control trap that operates at a temperature lower than the saturated steam temperature under the pressure of the installation location by a predetermined temperature. 2. A steam heating apparatus according to item 1.

  According to invention of Claim 4, it can be comprised mechanically simply by using a temperature control trap.

  Furthermore, the invention according to claim 5 is such that the exhaust valve closes at a set temperature or higher based on a detection signal of a pipe temperature detecting means for detecting the temperature in the steam supply pipe upstream of the steam supply valve. It is set as the on-off valve controlled, It is a steam heating apparatus of any one of Claims 1-3 characterized by the above-mentioned.

  According to invention of Claim 5, it can comprise simply using an electrical control using an in-pipe temperature detection means and an on-off valve.

  According to the steam heating apparatus of the present invention, it is possible to prevent air that has accumulated on the upstream side of the steam supply valve from being supplied into the processing tank when supplying steam into the processing tank. Therefore, in the treatment tank, heating of the object to be heated with steam can be efficiently performed without being inhibited by air. Further, by removing the air accumulated in the reboiler, the reboiler can be started as desired.

Next, an embodiment of the present invention will be described.
The present invention is a steam heating apparatus that heats an object to be heated contained in a treatment tank with steam. Here, the type of the object to be heated is not particularly limited, but is typically an object to be cooked such as food or food. In this case, the steam heating device can be referred to as a steaming machine, a steamer, or a saturated steam cooking device that steams or boiles an object to be cooked with steam. In addition, after cooking by steam, when the air in the processing tank is sucked and discharged to the outside and the object to be cooked is vacuum-cooled, it can be called a steaming cooler. Alternatively, the object to be heated may be an object to be sterilized such as a surgical knife. In this case, the steam heating device can be referred to as a steam sterilization device. However, the present invention is not limited to the apparatus exemplified here, but can be applied to other apparatuses that supply steam into the treatment tank after the air is exhausted.

  The steam heating apparatus of this embodiment includes a processing tank in which an object to be heated is stored, a steam supply means for supplying steam into the processing tank, and a vacuum in the processing tank by sucking and discharging the gas in the processing tank to the outside. Pressure reducing means, a decompression means for introducing outside air into the decompressed processing tank to restore the pressure in the processing tank, and a discharging means for discharging the steam in the processing tank and its condensed water to the outside.

  The said processing tank is a metal can body formed in the hollow structure which can accommodate a to-be-heated material, and was typically formed in the substantially rectangular box shape. This processing tank is comprised from the processing tank main body which opens to one side and has a hollow part, and the door which opens and closes the opening part of this processing tank main body. In a state where the door is closed, the hollow portion is sealed. However, the configuration of the processing tank is not limited to this, and may be configured from a bottomed cylindrical processing tank main body that opens upward, and a door that closes the upper opening so as to be openable and closable.

  The processing tank is provided with a pressure sensor that detects the pressure in the processing tank. However, since the pressure in the processing tank has a predetermined relationship with the temperature, a temperature sensor that detects the temperature in the processing tank may be used instead of the pressure sensor. In addition, you may install the product temperature sensor which detects the temperature of the to-be-heated material accommodated in a processing tank in a processing tank.

  The steam supply means is means for supplying steam from the steam generator into the treatment tank. The steam generator is typically composed of a boiler. At this time, it is preferable to vaporize soft water or pure water in a reboiler (secondary boiler) using steam from the boiler (primary boiler) as a heat source, and supply clean steam from the reboiler into the treatment tank. Thereby, boiler water treatment chemicals such as rust in the pipe and rust preventive agent are not sanitized and are hygienic. In the following description, the steam generator is described as a reboiler, but the same applies to a simple boiler.

  Steam from a reboiler as a steam generator is supplied into the treatment tank through a steam supply pipe. In the middle of the steam supply pipe, a steam supply valve is provided to be openable and closable. By opening and closing this steam supply valve, the presence or absence of steam supply into the treatment tank is switched. The steam supply valve may be configured to be fully open or fully closed like an electromagnetic valve, or may be configured to be adjustable in opening degree such as a motor valve or a proportional control valve.

  Further, the steam supply pipe is provided with an exhaust valve. This exhaust valve opens so as to communicate the inside and outside of the steam supply pipe via the outer peripheral wall of the steam supply pipe, and is configured to close the opening based on the temperature of the steam from the reboiler. That is, the exhaust valve is configured to open so as to communicate with the inside and outside of the steam supply pipe when the temperature is lower than the set temperature, and closes the opening when the temperature is equal to or higher than the set temperature. Such an exhaust valve is disposed on the reboiler side of the steam supply valve, but is preferably provided at a position close to the steam supply valve. In addition, when steam is flowing in the steam supply pipe, it is preferable that the steam is installed so as to be detectable without lowering the temperature of the steam.

  A temperature control trap is typically used as the exhaust valve. This temperature control trap is configured to operate at a predetermined temperature lower than the saturated steam temperature under the pressure of the installation location and close the opening. In the case of the present invention, when the reboiler is started, it is under atmospheric pressure, and its saturated steam temperature is 100 ° C., so that the temperature is lower by a predetermined temperature selected from a range of several to tens of degrees C (for example, 95 ° C.). ), A temperature control trap that operates to close the opening is used. In this case, when the air remains in the steam supply pipe, the exhaust valve is open, and after the air is pushed out by the steam from the reboiler and discharged, the exhaust valve is closed based on the temperature of the steam. maintain. Such a temperature control trap is preferably installed so as to be detectable without lowering the temperature of the steam flowing in the steam supply pipe, for example, by directly attaching to the outer peripheral wall of the steam supply pipe. At this time, if it is installed on the upper peripheral surface of the horizontal pipe section of the steam supply pipe, drainage can be prevented and only air can be discharged.

  However, an open / close valve such as a solenoid valve may be used as an exhaust valve together with a temperature sensor as a pipe temperature detecting means instead of the temperature control trap. In this case, a short branch pipe is connected to the middle portion of the steam supply pipe at a position close to the steam supply valve, and an open / close valve is disposed in the branch pipe. The branch pipe has an open end, and the inside and outside of the steam supply pipe communicate with each other when the on-off valve is opened. The opening / closing valve is controlled to open / close based on a detection signal of a temperature sensor provided in the steam supply pipe upstream of the steam supply valve. That is, when the temperature is lower than the set temperature, the on-off valve is opened, and when the temperature is higher than the set temperature, the on-off valve is closed.

  The decompression means is means for decompressing the inside of the processing tank by sucking and discharging the gas (air and / or vapor) in the processing tank to the outside. The decompression means includes a vacuum pump, a steam ejector, a water ejector, or the like. Any of these may be used alone, or a plurality of them may be used in combination. By operating such a pressure reducing means, the gas in the processing tank is sucked and discharged to the outside through the exhaust pipe, and the pressure in the processing tank is reduced. The presence or absence of decompression in the treatment tank is made by switching the presence or absence of the operation of the decompression means. Alternatively, a vacuum valve may be provided in the middle of the exhaust pipe and its opening / closing may be operated.

  When a steam ejector is used as the decompression means, the exhaust pipe is usually provided with a heat exchanger as a condenser downstream of the steam ejector. When a vacuum pump is used as the decompression means, it is desirable that the exhaust pipe is provided with a heat exchanger as a condenser upstream of the vacuum pump. Here, the heat exchanger is a condenser that cools and condenses the steam in the exhaust pipe. In order to perform this cooling and condensation action, cooling water is supplied to the heat exchanger, and the exhaust pipe is cooled. When a vacuum pump is arranged on the downstream side of the heat exchanger, the steam in the exhaust pipe is condensed in advance with the heat exchanger, thereby reducing the load on the subsequent vacuum pump and increasing the decompression capacity. it can.

  The return pressure means is a means for introducing outside air into the treatment tank decompressed by the decompression means and restoring the pressure in the treatment tank. It is desirable to introduce outside air into the treatment tank through a filter in consideration of hygiene. The clean air that has passed through the filter is supplied into the treatment tank via the air supply pipe. By opening and closing an air supply valve provided in the middle of the air supply pipe, the presence or absence of outside air introduction into the processing tank can be switched.

  By the way, it is preferable that the vacuum valve and / or the air supply valve are configured to be adjustable in opening. In this case, the respective capacities can be adjusted for the decompression in the treatment tank by the decompression means and the return pressure in the treatment tank by the decompression means. Thereby, in the state which act | operated the pressure reduction means with fixed capability, the opening degree of a vacuum valve and / or an air supply valve is adjusted, and adjustment of the pressure in a processing tank, and temperature is easy. However, instead of this, or in addition to this, when the pressure in the processing tank is reduced, the pressure reducing means such as the ejector itself or the presence or absence of operation can be controlled to adjust the pressure in the processing tank and thus the temperature. it can.

  The discharging means is means for discharging the steam in the processing tank and its condensed water to the outside. This discharge means is comprised from the exhaust steam pipe which discharges | emits a steam from the inside of a processing tank, and the drainage pipe which discharges condensed water from the bottom part in a processing tank via a steam trap. Here, the exhaust pipe is connected to the bottom of the treatment tank, so that the condensed water can be discharged in addition to the steam. In the middle of the exhaust pipe from the treatment tank, an exhaust valve comprising an electromagnetic valve or the like is provided. In addition, a drain valve composed of an electromagnetic valve or the like is provided in the middle of the drain pipe from the treatment tank. By opening and closing the exhaust steam valve and / or drain valve, the presence or absence of the discharge of steam and / or condensed water from the processing tank can be switched. However, the exhaust valve may be configured so that the opening degree can be adjusted, and in that case, the steam discharge capacity to the outside of the processing tank by the discharge means can be adjusted.

  The above-described steam supply means, decompression means, return pressure means, discharge means, and the like are connected to and controlled by the control means. And according to the program set up beforehand, a predetermined operation process is performed one by one. At this time, the control is performed using the detected pressure from the pressure sensor for detecting the pressure in the processing tank and the elapsed time. Moreover, when providing the product temperature sensor which detects the temperature of the to-be-heated material in a processing tank, it controls using the detection temperature from the product temperature sensor.

  Although the operating method of a steam heating apparatus is not specifically limited, Typically, a heating process is made after an air exclusion process. Here, an air exclusion process is a process of discharging the air in a processing tank in the state which stored the to-be-heated object in the processing tank. Specifically, with the steam supply valve, the air supply valve, the steam exhaust valve, and the drain valve closed, the pressure reducing means is operated to suck and discharge the air in the processing tank to the outside. Thereby, not only the air in the treatment tank but also the air accumulated in the steam supply pipe on the downstream side of the steam supply valve is discharged.

  In the heating process performed thereafter, steam is supplied into the treatment tank by the steam supply means, and the object to be heated is heated. Here, even when air is accumulated in the reboiler or in the steam supply pipe that follows the reboiler, such as when the reboiler is started up, the air is controlled not to be supplied into the treatment tank. That is, in such a state, as described above, the exhaust valve provided immediately before the steam supply valve is opened. Therefore, the accumulated air is pushed out from the exhaust valve by the steam from the reboiler and discharged. However, since the steam from the reboiler is hotter than the air, the opening of the exhaust valve is closed after the air is discharged. And only a vapor | steam can be supplied in a processing tank by opening a steam supply valve after that.

  By the way, the steam pressure in the reboiler can be maintained as desired by controlling the steam supply from the boiler to the reboiler based on the detection signal of the steam pressure detecting means for detecting the steam pressure in the reboiler. Then, when supplying steam into the processing tank, the steam pressure in the reboiler becomes desired based on the detection signal of the steam pressure detecting means, and then the steam supply valve is opened to supply steam into the processing tank. it can. In order to increase the vapor pressure in the reboiler, it is necessary to close the exhaust valve. For this purpose, as described above, the air in the reboiler and the steam supply pipe needs to escape. Therefore, the vapor pressure is increased in the reboiler where air is excluded, and the reboiler can be started as desired.

  In the heating step, the object to be heated in the processing tank is heated by the steam supplied into the processing tank. At this time, the object to be heated may be heated by setting the inside of the processing tank to atmospheric pressure, the object to be heated may be heated while the inside of the processing tank is set to a pressure higher than atmospheric pressure, or the decompression unit is operated when desired. Thus, the object to be heated may be heated while the pressure is lower than the atmospheric pressure. Moreover, in a heating process, it controls to maintain the pressure or temperature in a processing tank, or the temperature of the to-be-heated material in a processing tank at a target value. At this time, the target value may be changed in a plurality of stages.

  And after a heating process, you may perform a vacuum cooling process if desired. In this vacuum cooling process, with the steam supply valve, the air supply valve, the steam exhaust valve and the drain valve closed, the pressure reducing means is operated to reduce the pressure in the treatment tank to the target pressure, thereby vacuum cooling the object to be heated. Is planned.

  Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic configuration diagram showing a first embodiment of the steam heating apparatus of the present invention, and shows an example applied to a saturated steam cooking apparatus. As shown in this figure, the saturated steam cooking apparatus of the present embodiment includes a processing tank 2 having a hollow structure in which an object to be cooked (food or food) 1 as an object to be heated is accommodated, and steam into the processing tank 2. A steam supply means 3 for supplying gas, a pressure reducing means 4 for sucking and discharging the gas (air and / or steam) in the processing tank 2 to the outside, and reducing the pressure in the processing tank 2, and an outside air into the decompressed processing tank 2 Pressure return means 5 for returning pressure, discharge means 6 for discharging steam and condensed water in the processing tank 2 to the outside, pressure sensor 7 for measuring the pressure in the processing tank 2, and the pressure sensor 7 Control means 8 for controlling the means 3, 4, 5 and 6 based on the output of the above.

  The processing tank 2 of the present embodiment is a metal can body that includes a processing tank main body 9 that opens to one side surface and has a hollow portion, and a door 10 that opens and closes the opening of the processing tank main body 9. Since it is such a structure, the hollow part of the processing tank main body 9 is sealed by closing the door 10. FIG. The to-be-cooked object 1 may be accommodated in the processing tank 2 via a wagon (not shown) that is taken in and out of the processing tank 2, or a shelf plate 11 is provided in the processing tank 2 as shown in the illustrated example. You may respond by doing. Moreover, the to-be-cooked object 1 may be accommodated in the processing tank 2 in an appropriate container 12.

  In order to detect the pressure in the processing tank 2, a pressure sensor 7 is provided in the processing tank 2. However, a temperature sensor (not shown) may be used instead of the pressure sensor 7. Any sensor can be used by converting pressure and temperature. Moreover, in order to detect the temperature of the to-be-cooked object 1 accommodated in the processing tank 2, you may further provide a product temperature sensor (not shown).

  In order to supply steam into the treatment tank 2, steam supply means 3 is connected to the treatment tank 2. The steam supply means 3 of the present embodiment includes a boiler (primary boiler) 13 and a reboiler (secondary boiler) 14, vaporizes soft water in the reboiler 14 using the steam from the boiler 13 as a heat source, and so on. The generated clean steam is supplied into the treatment tank 2. Normally, there is a risk that the steam generated by the boiler 13 is mixed with rust in the pipe or boiler water treatment chemicals such as a rust inhibitor. However, the steam supplied into the treatment tank 2 can directly come into contact with the object 1 to be cooked. Therefore, the reboiler 14 vaporizes the soft water and supplies the clean steam into the treatment tank 2.

  The reboiler 14 is a stainless steel heat exchanger, and the soft water supplied into the can 15 is heated with the steam from the boiler 13 to be vaporized. The steam from the boiler 13 is passed through the steam supply pipe 16 disposed in the can 15 to heat the soft water stored in the surroundings. Whether or not the steam is supplied into the steam supply pipe 16 is controlled by opening and closing a reboiler valve 17 constituted by an electromagnetic valve. Further, the condensed water of the steam supplied into the steam supply pipe 16 is discharged through the steam trap 18. By the way, soft water can be supplied into the can body 15 of the reboiler 14 via the water supply pump 19, and the water level in the can body 15 is automatically adjusted by controlling the water supply pump 19.

  Further, the reboiler 14 is provided with a control pressure switch 20 and a low pressure switch 21. The control pressure switch 20 detects the upper limit value and the lower limit value in order to maintain the vapor pressure in the can 15 as desired. The reboiler 14 is maintained at a desired vapor pressure by controlling the opening and closing of the reboiler valve 17 based on the detection signal of the control pressure switch 20. Further, the low pressure switch 21 detects an abnormality based on the pressure in the can 15 that falls below a predetermined value for some reason.

  Clean steam from the reboiler 14 is supplied into the processing tank 2 through the steam supply pipe 22. In this embodiment, the steam supply from the steam supply pipe 22 into the processing tank 2 is performed by jetting steam from a nozzle 23 provided at the end of the steam supply pipe 22, but this nozzle 23 can be omitted.

  A steam supply valve 24 is provided in the middle of the steam supply pipe 22 so as to be openable and closable. The steam supply valve 24 is preferably configured such that the opening can be adjusted, such as a motor valve or a proportional control valve. However, any configuration that can switch the presence / absence of supply of steam into the processing tank 2 is sufficient, and the opening degree cannot be adjusted, and an electromagnetic valve that takes either an open state or a closed state may be used. In any case, by opening and closing the steam supply valve 24, the pressure in the processing tank 2 and thus the temperature can be adjusted. Moreover, the pressure in the processing tank 2 can be adjusted by controlling not only the steam supply valve 24 but also the decompression means 4.

  Further, the steam supply pipe 22 is provided with an exhaust valve 25 on the upstream side (reboiler 14 side) of the steam supply valve 24 and in the vicinity of the steam supply valve 24. The exhaust valve 25 opens so as to communicate the inside and outside of the steam supply pipe 22 through the outer peripheral wall of the steam supply pipe 22. When steam is supplied from the reboiler 14, the temperature is detected and the opening is closed. It is.

  The exhaust valve 25 of this embodiment is composed of a temperature control trap. The temperature control trap 25 used is not particularly limited. In this embodiment, for example, a diaphragm type steam trap manufactured by Miyawaki Co., Ltd., D series “DC1-21H” or the like is used. The temperature control trap 25 is configured to operate at a temperature lower by a predetermined temperature (for example, 5 ° C.) than the saturated steam temperature under the pressure at the installation location and close the opening.

  Therefore, when the inside of the steam supply pipe 22 is filled with air, such as when the reboiler 14 is activated, the exhaust valve 25 opens and is under atmospheric pressure. Therefore, when warmed by the steam from the reboiler 14 from 100 ° C. of the saturated steam temperature to a temperature lower by the predetermined temperature (for example, 95 ° C.), the temperature control trap 25 is activated and the opening is closed.

  The exhaust valve 25 composed of a temperature control trap is directly attached to the upper peripheral surface of the horizontal piping portion of the steam supply pipe 22 or the like. As a result, when steam flows in the steam supply pipe 22, it can be detected without lowering the temperature of the steam, and drainage can be prevented and only air can be discharged.

  The processing tank 2 is connected to a decompression unit 4 that sucks and discharges air and vapor in the processing tank 2 to the outside and decompresses the processing tank 2. In this embodiment, a vacuum valve 27, a steam ejector 28, a heat exchanger 29, a check valve 30, and a water-sealed vacuum pump 31 are provided in the exhaust pipe 26 from the processing tank 2 in this order from the processing tank 2 side. Connected. The vacuum valve 27 may be an electromagnetic valve, but preferably has a configuration in which the opening degree can be adjusted, such as a proportional control valve or a motor valve.

  Water is supplied to the vacuum pump 31 via a sealed water supply valve 32, and the waste water from the vacuum pump 31 is discharged to a drain port (not shown). The sealed water supply valve 32 is opened in conjunction with the vacuum pump 31. Further, water is also supplied to the heat exchanger 29 via the heat exchange water supply valve 33 and drained to the drain outlet. By supplying the cooling water to the heat exchanger 29, the steam in the exhaust pipe 26 can be cooled and condensed.

  The treatment tank 2 is connected to a decompression means 5 for decompressing after the decompression by the decompression means 4. In the return pressure means 5 of the present embodiment, an air supply pipe 34 connected to the processing tank 2 is provided so as to be able to communicate with outside air via a check valve 35 and a sterilization filter 36. A supply valve 37 is provided in the middle of the supply pipe 34 so as to be openable and closable. By opening the supply valve 37, the inside of the processing tank 2 can be opened to atmospheric pressure.

  The treatment tank 2 is connected to a discharge means 6 for discharging the steam in the treatment tank 2 and its condensed water to the outside. The discharging means 6 is divided into a steaming means 38 for discharging steam and air in the processing tank 2 to the outside, and a draining means 39 for discharging condensed water generated in the processing tank 2 to the outside. .

  The steaming means 38 is a means for leading the air and steam in the processing tank 2 to the outside of the processing tank 2 through the steaming pipe 40. An exhaust steam valve 41 is provided in the middle of the exhaust pipe 40, and the exhaust valve 41 is preferably configured so that its opening degree can be adjusted. In the illustrated example, the exhaust pipe 40 is connected to the lower part of the processing tank 2, but a similar exhaust pipe (not shown) is provided at the upper part of the processing tank 2 instead of or in addition to this. Can do. The exhaust pipe 40 from the lower part of the processing tank 2 can also be used for discharging condensed water accumulated in the lower part of the processing tank 2 to the outside.

  On the other hand, the drainage means 39 includes a drain pipe 43 having a steam trap 42, and the condensed water accumulated at the bottom of the processing tank 2 can be drained out of the processing tank 2 through the drain pipe 43. And in the middle of this drain pipe 43, the drain valve 44 comprised from an electromagnetic valve is provided.

  The steam supply means 3, the decompression means 4, the return pressure means 5, the discharge means 6 and the like are controlled by a control means 8. This control means 8 is a controller 45 that controls each of the means 3, 4, 5, 6 based on the elapsed time grasped by it, detection signals from the pressure sensor 7 and the pressure switches 20, 21 and the like. is there. Specifically, the reboiler valve 17, the feed water pump 19, the steam feed valve 24, the vacuum valve 27, the vacuum pump 31, the sealed water feed water valve 32, the heat exchange water feed valve 33, the air feed valve 37, the steam feed valve 41, and the drain valve 44, the pressure sensor 7, the pressure switches 20 and 21, and the like are connected to the controller 45.

  And the controller 45 performs the heating cooking of the to-be-cooked object 1 in the processing tank 2 according to a predetermined procedure (program). When cooking by heating, first, the cooking object 1 is accommodated in the processing tank 2 and the door 10 of the processing tank 2 is closed. In this initial state, the steam supply valve 24, the vacuum valve 27, the sealed water supply valve 32, and the heat exchange water supply valve 33 are closed, and the operation of the steam ejector 28 and the vacuum pump 31 is stopped. The steam valve 41 and the drain valve 44 are open. And typically from this state, the air removal process which excludes the air in the processing tank 2, the heating process which supplies the vapor | steam to the processing tank 2, and heat-cookes the to-be-cooked object 1, and the processing tank 2 A return pressure process for returning the pressure to the atmospheric pressure is sequentially performed.

  In the air exclusion process, the controller 45 operates the pressure reducing means 4 with the steam supply valve 24, the air supply valve 37, the exhaust steam valve 41 and the drain valve 44 closed. That is, the sealed water supply valve 32 is opened to operate the vacuum pump 31, and the vacuum valve 27 is opened to suck and discharge the air in the processing tank 2 to the outside. Here, the steam ejector 28 may be operated after the inside of the treatment tank 2 is depressurized to a predetermined pressure. In addition, by opening the heat exchange water supply valve 33, the heat exchanger 29 can condense the steam and increase the decompression capacity.

  Such air exclusion from the processing tank 2 may be performed up to a set pressure by using the pressure sensor 7 or may be performed only for a set time. Then, the controller 45 stops the operation of the steam ejector 28 and the vacuum pump 31, closes the sealed water supply valve 32, the heat exchange water supply valve 33, and the vacuum valve 27, and ends the air exclusion process.

  In the next heating process, the controller 45 opens the steam supply valve 24 to supply steam into the processing tank 2. However, when air is accumulated in the reboiler 14 or the steam supply pipe 22 at the time of initial water supply to the reboiler 14 or at the time of initial steaming from the boiler 13 to the reboiler 14, first, the air is discharged from the exhaust valve 25 After being discharged to the outside, steam is supplied into the processing tank 2.

  That is, when the reboiler 14 is activated or the like, in a state where air is accumulated in the steam supply pipe 22, the temperature has not yet risen, so the exhaust valve 25 is open. Therefore, the air accumulated in the steam supply pipe 22 is pushed out from the exhaust valve 25 by the steam from the reboiler 14 and discharged. Since the temperature rises when air is released, the exhaust valve 25 is kept closed during the subsequent operation. The controller 45 prevents the inflow of air into the processing tank 2 by opening the steam supply valve 24 after removing air from the exhaust valve 25. Specifically, as described below, after confirming that the vapor pressure in the reboiler 14 has been increased to a desired level after the exhaust valve 25 is closed, the steam supply valve 24 is opened and steam enters the treatment tank 2. Supply.

  As described above, after the air in the reboiler 14 and the steam supply pipe 22 is discharged from the exhaust valve 25, the exhaust valve 25 is closed based on the temperature of the steam from the reboiler 14. In this state, the controller 45 controls the opening and closing of the reboiler valve 17 using the detection signal of the control pressure switch 20 as the vapor pressure detecting means, thereby increasing and maintaining the vapor pressure in the reboiler 14 as desired. To do. When the vapor pressure in the reboiler 14 is increased to a desired level, the controller 45 enables the steam supply valve 24 to be opened based on the detection signal from the control pressure switch 20 and heats the cooking object 1 in the treatment tank 2. Start cooking.

  In the heating process, the vacuum valve 27, the sealed water supply valve 32, the heat exchange water supply valve 33, the air supply valve 37, and the exhaust valve 41 are closed, and the steam ejector 28 and the vacuum pump 31 are stopped from operating. The valve 24 is opened to supply steam into the treatment tank 2. At this time, when the inside of the treatment tank 2 exceeds the atmospheric pressure, the drain valve 44 is opened to discharge condensed water from the bottom of the treatment tank 2 to the outside.

  In this way, steam is supplied into the processing tank 2 by the steam supply means 3 until the inside of the processing tank 2 reaches a desired set pressure. And the steam supply to the processing tank 2 by the steam supply means 3 is adjusted based on the detected pressure of the pressure sensor 7 so that the inside of the processing tank 2 is kept at the set pressure, and the cooked object 1 in the processing tank 2 Is cooked. During this heating process, the set pressure may be changed up and down stepwise.

  By the way, the cooking of the object 1 to be cooked by supplying steam into the treatment tank 2 is performed by pressureless cooking performed at atmospheric pressure, pressure cooking performed at a pressure exceeding atmospheric pressure, and the decompression means 4 operated when desired. And steaming under reduced pressure at a pressure lower than atmospheric pressure.

  In the case of non-pressure steaming, the vacuum valve 27, the sealed water supply valve 32, the heat exchange water supply valve 33, the air supply valve 37 are closed, and the steam ejector 28 and the vacuum pump 31 are stopped, and the steam supply valve 24, The steam exhaust valve 41 and the drain valve 44 are opened to supply and discharge steam into the treatment tank 2.

  In the case of pressurized steaming, the vacuum valve 27, the sealed water supply valve 32, the heat exchange water supply valve 33, the air supply valve 37, and the exhaust steam valve 41 are closed, and the operation of the steam ejector 28 and the vacuum pump 31 is stopped. The steam supply valve 24 and the drain valve 44 are opened to supply steam into the treatment tank 2. Therefore, in the case of pressurized steaming, the condensed water is automatically discharged from the drain pipe 43 to the outside.

  In the case of steaming under reduced pressure, the steam supply valve 24 is opened and the steam is supplied into the processing tank 2 with the air supply valve 37, the exhaust steam valve 41 and the drain valve 44 being closed. At this time, when the inside of the treatment tank 2 exceeds the set upper limit pressure, the decompression means 4 is operated to decompress the inside of the treatment tank 2 to the set lower limit pressure. That is, with the vacuum valve 27, the sealed water supply valve 32, and the heat exchange water supply valve 33 opened, the vacuum pump 31 (or the steam ejector 28 in some cases) is operated to reduce the inside of the treatment tank 2 to the set lower limit pressure. When the set lower limit pressure is reached, the valves 27, 32 and 33 are closed and the operation of the vacuum pump 31 and the like is stopped.

  In any case, basically, in order to keep a balance between the pressurizing factor in the processing tank 2 due to the supply of steam and the depressurizing factor in the processing tank 2 due to the condensation of the supplied steam, The cooking is performed by controlling the opening and closing to maintain the pressure in the treatment tank 2 at the target value. However, in the case of reduced-pressure steaming, if the set upper limit pressure is exceeded, the decompression means 4 may be operated as described above.

  In this way, in the heating process, the cooking object 1 accommodated in the processing tank 2 can be cooked by supplying steam into the processing tank 2. At this time, as described above, the steam supplied into the treatment tank 2 is clean steam generated from soft water in the reboiler 14. Therefore, safe and reliable cooking can be realized. Moreover, uniform heating cooking is made in a short time by spreading clean steam around the entire periphery of the object 1 to be cooked.

  In the heating step, the temperature in the processing tank 2 can be adjusted by adjusting the pressure in the processing tank 2 by supplying steam into the processing tank 2. In the present embodiment, cooking is possible by setting the temperature freely, for example, in the range of 60 ° C to 130 ° C. In this way, the saturated steam temperature is adjusted by adjusting the pressure of the treatment tank 2.

  And in the pressure-recovery process after completion | finish of a heating process, the steam supply valve 24 is closed. And if the inside of the processing tank 2 exceeds the atmospheric pressure, the exhaust steam valve 41 is opened, and drainage and exhaust are performed until the inside of the processing tank 2 reaches the atmospheric pressure. On the other hand, if the inside of the processing tank 2 is less than the atmospheric pressure, the decompression means 4 and the discharge means 6 are not operated, the steam supply valve 24 is closed and the air supply valve 37 is opened to Restore pressure until Then, the door 10 of the processing tank 2 is opened, the to-be-cooked object 1 is taken out from the processing tank 2, and a series of processes is completed.

  The steam heating apparatus of the present invention is not limited to the configuration of the above embodiment, and can be changed as appropriate. For example, although the example applied to the saturated steam cooking apparatus has been described in the above embodiment, the present invention can be similarly applied to a steam sterilization apparatus for sterilizing a scalpel for operation by steam heating. Or after the said heating process, it can also be set as the steaming cooler which decompresses the inside of the processing tank 2 with the decompression means 4, and performs the vacuum cooling of the to-be-cooked object 1. FIG.

  Moreover, in the said Example, although it was set as the structure which vaporizes soft water with the reboiler 14 using the steam from the boiler 13, the steam from the boiler 13 is directly supplied in the process tank 2 without using the reboiler 14. The same applies to the case. Furthermore, in the said Example, although the steam ejector 28, the heat exchanger 29, and the water seal vacuum pump 31 were used as the pressure reduction means 4, these are examples and can be changed suitably. For example, the steam ejector 28 may be omitted.

  Furthermore, in the above-described embodiment, the temperature control trap 25 is used as the exhaust valve. However, a combination of the temperature sensor 46 and the on-off valve 47 may be used instead of the temperature control trap 25. In this case, as shown in FIG. 2, a short branch pipe 48 is connected to the middle of the steam supply pipe 22 at a position close to the steam supply valve 24, and an electromagnetic valve or the like is connected to the branch pipe 48 as an exhaust valve. An on-off valve 47 is arranged. Therefore, when the on-off valve 47 is opened, the inside and outside of the steam supply pipe 22 are communicated. The opening / closing valve 47 is controlled to open / close based on a detection signal from a temperature sensor 46 provided in the steam supply pipe 22 upstream of the steam supply valve 24. That is, when the temperature is lower than the set temperature, the on-off valve 47 is opened, and when the temperature is higher than the set temperature, the on-off valve 47 is closed. By the way, in FIG. 2, only the middle part of the steam supply pipe 22 is shown, but other configurations are the same as those in FIG. Also in this configuration, only the steam can be supplied into the treatment tank 2 after the air in the reboiler 14 and the steam supply pipe 22 is removed by the exhaust valve 47 including the on-off valve 47.

It is a schematic block diagram which shows one Example of the steam heating apparatus of this invention. It is a figure which shows the modification of the exhaust valve in the steam heating apparatus of FIG. 1, and has shown only the part of the steam supply pipe | tube.

Explanation of symbols

1 To-be-cooked object (object to be heated)
2 Processing tank 4 Pressure reducing means 8 Control means 13 Boiler 14 Reboiler (steam generator)
20 Control pressure switch (Vapor pressure detection means)
22 Steam supply pipe 24 Steam supply valve 25 Temperature control trap (exhaust valve)
46 Temperature sensor (In-pipe temperature detection means)
47 On-off valve (exhaust valve)

Claims (5)

A treatment tank in which an object to be heated is accommodated;
A steam supply pipe for supplying steam from the steam generator into the treatment tank;
A steam supply valve that is provided in the steam supply pipe and opens and closes the pipeline;
An exhaust valve that is provided in the steam supply pipe on the steam generator side from the steam supply valve and opens to communicate with the inside and outside of the steam supply pipe at a temperature lower than a set temperature, and closes the opening at a temperature higher than the set temperature. A steam heating apparatus comprising: Decompression means for sucking and discharging the air in the treatment tank to the outside;
A vapor pressure detecting means for detecting a vapor pressure in the steam generator;
The steam heating apparatus according to claim 1, further comprising: a control unit that controls opening and closing of the steam supply valve based on a detection signal of the steam pressure detection unit. A treatment tank in which an object to be heated is accommodated;
Reboilers that use steam from the boiler as heat source and soft water or pure water as steam;
A steam supply pipe for supplying steam from the reboiler into the treatment tank;
A steam supply valve that is provided in the steam supply pipe and opens and closes the pipeline;
The steam supply valve is disposed on the reboiler side, is provided in the steam supply pipe in the vicinity of the steam supply valve, and has an opening that communicates the inside and outside of the steam supply pipe. An exhaust valve that closes the opening based on temperature;
Vacuuming means for sucking and discharging the air in the processing tank to the outside, and reducing the pressure in the processing tank;
A vapor pressure detecting means for detecting the vapor pressure in the reboiler;
A steam heating apparatus comprising: control means for controlling supply of steam from the boiler to the reboiler and open / close of the steam supply valve based on a detection signal of the steam pressure detection means. The steam heating device according to any one of claims 1 to 3, wherein the exhaust valve is a temperature control trap that operates at a temperature lower than a saturated steam temperature under a pressure at an installation location. The exhaust valve is an on-off valve that is controlled to close at a set temperature or higher based on a detection signal of a pipe temperature detection means that detects a temperature in the steam supply pipe upstream from the steam supply valve. The steam heating apparatus according to any one of claims 1 to 3.

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