JP2005030635A - Steam discharge method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a steam discharge method preventing adhesion of steam generated below an FFU to a filter of the FFU. <P>SOLUTION: In a manufacturing facility 10, a high-cleanliness booth 22 is formed inside a clean room 12. A ceiling face 22A of the booth 22 is provided with the FFUs 44A, 44A disposed side by side in a line in the center, and the FFUs 44B, 44B disposed side by side on both the adjacent sides. Steam discharge ports 46 are formed further outside the FFUs 44B, 44B, and an air filter 48 is set in the steam discharge port 46. The FFU 44 is controlled such that the FFU 44 blows cleaning air at an air velocity larger than the FFU 44B. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a steam discharge method, and more particularly to a steam discharge method used in a production facility for producing cooked packaged cooked rice.
[0002]
[Prior art]
In the packaged cooked rice production facility, a cooked rice container containing rice and water is heated in a rice cooker to cook rice, and then the lid is attached to the cooked rice container by the packaging device (see, for example, Patent Document 1). During cooking, the inside of the cooked rice container becomes hot, so the microorganisms are killed and the cooked rice becomes sterile. Packaging this cooked rice in an aseptic state and preventing the invasion of microorganisms is important for producing packed cooked rice with a long shelf life. Therefore, the area from the rice cooker to the packaging device is required to have a high microbial cleanliness.
[0003]
Conventionally, in an area from a rice cooker to a packaging device, fan filter units (hereinafter referred to as FFU) are densely spread on the ceiling surface. The clean air is down-flowed from the FFU, so that the area is maintained at a high cleanliness. As a result, the cooked rice can be transported and packaged in a sterilized state in a sterilized state, and sterilized cooked rice can be produced.
[0004]
[Patent Document 1]
JP-A-9-187238
[Problems to be solved by the invention]
However, the conventional manufacturing equipment has a problem that a large amount of steam generated from the rice being transported rises against the downflow of clean air and adheres to the FFU filter. When the filter is wetted by the adhesion of vapor, microorganisms propagate in the filter and the microorganisms may be diffused into the room together with clean air. For this reason, conventionally, it has been necessary to frequently replace the FFU filter. Since an expensive filter such as a HEPA filter or a ULPA filter is used as the FFU filter, there is a problem that the running cost is greatly increased by frequently replacing the filter.
[0006]
The present invention has been made in view of such circumstances, and an object of the present invention is to provide a vapor discharge method for preventing vapor generated below the FFU from adhering to the FFU filter.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 is a steam discharge method in which a plurality of FFUs are disposed on a ceiling surface, and steam is discharged from a room having a steam generation source below the FFU. The FFU located at the center of the FFU installation area blows clean air at a higher wind speed than the FFU located at the periphery of the installation area.
[0008]
According to the first aspect of the present invention, since the FFU at the center of the installation area blows clean air at a higher wind speed than the FFU at the periphery, the steam generated below the FFU is guided to the outside of the installation area. , Discharged from the room. Therefore, it is possible to prevent the vapor from adhering to the FFU filter. Thereby, the replacement frequency of the FFU filter can be reduced, and the running cost can be reduced.
[0009]
According to a second aspect of the present invention, in the first aspect of the invention, the plurality of FFUs are characterized in that the number of rotations of a built-in fan is controlled according to the amount of steam generated. Therefore, according to invention of Claim 2, the wind speed of the clean air which blows off from FFU is adjusted according to the generation amount of a vapor | steam.
[0010]
According to a third aspect of the present invention, in the first or second aspect of the present invention, a steam discharge port is formed on a ceiling surface around the installation area, and an air filter is provided at the steam discharge port.
[0011]
According to the invention of claim 3, since the steam discharge port is formed on the ceiling surface around the installation area, the steam generated below the installation area rises while being guided to the outside of the installation area, and then remains as it is. It is discharged smoothly from the outlet. According to the invention of claim 3, since the air filter is installed at the steam outlet, it is possible to prevent dust from entering the room through the steam outlet.
[0012]
According to a fourth aspect of the present invention, in the third aspect of the present invention, the indoor air is exhausted by the exhaust fan through the steam exhaust port. Therefore, according to the fourth aspect of the invention, the indoor air can be sucked and exhausted to the steam discharge port by the exhaust fan, so that the steam can be forcibly discharged from the steam discharge port.
[0013]
According to a fifth aspect of the present invention, in the invention of the third or fourth aspect, the steam discharge port is provided with sterilizing means for the air filter, and the sterilizing means sterilizes the air filter when the FFU is stopped. It is characterized by. Therefore, according to the invention of claim 5, since the air filter is sterilized by the sterilizing means, it is possible to prevent microorganisms from growing in the air filter.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the steam discharge method according to the present invention will be described in detail with reference to the accompanying drawings.
[0015]
FIG. 1 is a perspective view showing the overall configuration of a sterilized cooked rice manufacturing facility to which a steam discharge method according to the present invention is applied.
[0016]
As shown in FIG. 1, the manufacturing facility 10 is mainly composed of a rice cooking device 12, a belt conveyor 14, and a packaging device 16, and these devices are installed inside a clean room 18 of a clean room facility. A booth (corresponding to a chamber) 22 to be described later is formed in the clean room 18, and the belt conveyor 14 and the packaging device 16 are installed in the booth 22.
[0017]
FFUs 24, 24... Are thinned out on the ceiling surface 18 </ b> A of the clean room 18, and the air in the ceiling back space 20 is removed by the FFU 24 and blown out into the clean room 18. A baseboard opening (not shown) is formed in a lower portion of a side wall (not shown) of the clean room 18, and air in the clean room 18 is returned to the return space (not shown) adjacent to the clean room 18 through the baseboard opening. Drawn in). Then, the air sucked into the return space is returned to the ceiling space 20 and blown out again to the clean room 18 by the FFU 24. The clean chamber 18 is purified by such air circulation, and the inside of the clean chamber 18 is maintained at a cleanliness level of about class 100,000. Instead of providing the baseboard opening, the floor surface of the clean room 18 may be grating, and the air in the clean room 18 may be exhausted to the under-floor space through the floor surface.
[0018]
The rice cooking device 12 is a device that cooks rice by heating a rice container 26 containing rice and water. The cooked rice containers 26 are continuously carried into the rice cooker 12 in a state where a plurality of cooked rice containers 26 are placed on the container cassette 28. And it is heated inside the rice cooker 12, rice cooking is performed, and the cooked rice container 26 after the rice cooking is continuously carried out from the carry-out port 12A of the rice cooker 12. The carried-out rice container 26 is conveyed to the packaging device 16 by the belt conveyor 14.
[0019]
The packaging device 16 mainly includes a container separator 30, a conveyor 32, a packaging machine 34, and an unloader 36. The cooked rice container 26 conveyed by the belt conveyor 14 is transferred to the container separator 30 while being placed on the container cassette 28, and the cooked rice container 26 is separated from the container cassette 28 by the container separator 30, and is transferred to the conveyor 32. Reprinted. The conveyor 32 is provided with a recess (not shown) following the shape of the cooked rice container 26, and the cooked rice container 26 is fitted into the recess. Thereby, the cooked rice container 26 is conveyed to the packaging machine 34 while being held on the conveyor 32. The packaging machine 34 attaches a lid (not shown) to the cooked rice container 26 while blowing an inert gas such as nitrogen gas to the cooked rice container 26. As a method for attaching the lid, for example, the cooked rice container 26 is covered with a lid, and the outer peripheral portion thereof is heated to be welded to the cooked rice container 26. Thereby, the cooked rice container 26 is sealed with the lid, and the packaged cooked rice 27 is manufactured. The packed cooked rice 27 is unloaded from the unloading port 38 of the booth 22 by the unloader 36. And it is conveyed by the product conveyor 40 installed in the outer side of the booth 22, is accommodated in cases (not shown), such as cardboard, and is shipped.
[0020]
By the way, in the manufacturing equipment 10 mentioned above, in order to manufacture the packaged cooked rice 27 having a long storage period, it is necessary to seal the cooked rice container 26 carried out from the rice cooker 12 in a sterile state. For this reason, the belt conveyor 14 and the packaging apparatus 16 which are arrange | positioned at the back | latter stage of the rice cooking apparatus 12 are installed in the booth 22 of high cleanliness.
[0021]
A plurality of FFUs 44, 44... Are installed on the ceiling surface 22 </ b> A of the booth 22. These FFUs 44, 44... Are arranged more densely than the FFUs 24, 24. Specifically, they are arranged as shown in FIGS. That is, when the conveying direction of the cooked rice container 26 is a row, the FFUs 44, 44... Are arranged in three rows at the center of the ceiling surface 22A. Here, the FFUs in the center column are 44A, 44A... And the FFUs in the adjacent columns are 44B, 44B. Further, an area where the FFUs 44A and 44B are installed is set as an installation area.
[0022]
The installation area is formed at the center of the ceiling surface 22A, and the belt conveyor 14 and the packaging device 16 (see FIG. 1) are arranged below the installation area. Further, a steam discharge port 46 is formed on the ceiling surface 22A adjacent to the installation area, and the booth 22 and the clean room 18 are communicated with each other through the steam discharge port 46. An air filter 48 composed of a medium performance filter (dust removal rate: 90% colorimetric method) is installed at the vapor outlet 46. Therefore, when the driving of the FFUs 44 </ b> A and 44 </ b> B is stopped, the air filter 48 can prevent dust outside the booth 22 from entering the booth 22. The air filter 48 is not limited to a medium performance filter, and for example, a HEPA filter (dust removal rate: particles 99.997% or more with a counting method of 0.3 μm or more) may be used. Further, as the air filter 48, an antibacterial medium performance filter or an antibacterial HEPA filter may be used.
[0023]
As shown in FIG. 3, each of the FFUs 44 </ b> A and 44 </ b> B includes a casing 50 having an opening in the upper and lower sides, a HEPA filter 52 disposed at a lower portion of the casing 50, and a fan 54 provided inside the casing 50. . By driving the fan 54, the air above the booth 22 is sucked into the casing 50, removed by the HEPA filter 52, and then downflowed into the booth 22. Thereby, the inside of the booth 22 is maintained at a high cleanliness level of about class 100. Note that the air in the booth 22 is discharged from the booth 22 through the baseboard openings 42 and 42 formed in the side walls 22B and 22B of the booth 22.
[0024]
By the way, in each FFU 44A, 44B, the rotational speed of the fan 54 is controlled by the control device 56. At this time, the fan 54 of the FFU 44A is controlled to rotate at a higher rotational speed than the fan 54 of the FFU 44B. Thereby, the wind speed of the clean air which blows off from FFU44A becomes larger than that of FFU44B.
[0025]
The control device 56 is remotely operated by an operation unit 58 provided in the booth 22. Therefore, an operator in the booth 22 can control the rotation speed of the fans 54 of the FFUs 44A and 44B using the operation unit 58.
[0026]
Next, the operation of the manufacturing equipment 10 configured as described above will be described with reference to FIG.
[0027]
By driving the fans 54 of the FFUs 44A and 44B, a down flow of clean air is formed below the FFUs 44A and 44B. At that time, the wind speed of the downflow below the FFU 44A is controlled to be larger than the wind speed of the downflow below the FFU 44B. In addition, since the clean air is down-flowed from the FFUs 44A and 44B, the internal pressure of the booth 22 becomes higher than the internal pressure of the clean chamber 18, so that the air in the booth 22 is discharged from the baseboard opening 42 and the steam discharge port 46. The
[0028]
When a large amount of steam is generated from the cooked rice container 26 in the booth 22 where air supply / exhaust is performed in this way, the steam is guided to the steam outlet 46 while rising, as indicated by a two-dot chain line in FIG. The That is, the steam is pushed out from the central part of the installation area where the wind speed of the downflow is large to the peripheral part where the wind speed of the downflow is small, and is further pushed out of the installation area where there is no downflow. Thereby, since a vapor | steam is induced | guided | derived to the vapor | steam discharge port 46, it can prevent that a vapor | steam adheres to the HEPA filter 52 of FFU44A, 44B.
[0029]
As described above, according to the present embodiment, since the FFU 44A in the center of the installation area blows clean air at a higher wind speed than the FFU 44B in the periphery, the steam can be guided to the steam outlet 46 outside the installation area. It is possible to prevent vapor from adhering to the HEPA filters 52 of the FFUs 44A and 44B. Thereby, since the HEPA filter 52 can be prevented from getting wet, the replacement frequency of the HEPA filter 52 can be reduced, and the running cost can be reduced. In particular, in this embodiment, steam is discharged by controlling the speed of the clean air blown from the FFUs 44A and 44B, so that the lower area of the installation area is kept highly clean while preventing the steam from adhering to the HEPA filter 52. can do.
[0030]
In addition, since the manufacturing equipment 10 of the present embodiment can remotely operate the fans 54 of the FFUs 44A and 44B by the operation unit 58, it is possible to adjust the wind speed of the clean air blown from the FFUs 44A and 44B according to the amount of steam generated. it can. That is, the operator visually determines the amount of steam generated, and operates the operation unit 58 based on this to increase or decrease the rotational speed of the fan 54. For example, when the amount of generated steam is very large, the rotational speed of the fan 54 of the FFU 44A, 44B is increased, and the wind speed of the clean air blown from the FFU 44A, 44B is increased. Thereby, since the force which pushes a vapor | steam outside an installation area becomes strong, even if it is a lot of vapor | steam, a vapor | steam can be guide | induced to the vapor | steam discharge port 46, and it can prevent that a vapor | steam adheres to the HEPA filter 52. On the other hand, when the amount of generated steam is small, the rotational speed of the fan 54 is reduced within a range where the cleanliness of the booth 22 does not fall below an allowable value (for example, class 100). Thereby, running cost can be reduced. In addition, when the generation amount of steam is smaller, the steam can be discharged from the baseboard opening 42.
[0031]
Further, in the above-described embodiment, the air filter 48 is provided at the steam discharge port 46, so that the air that flows back even if the air outside the booth 22 flows back into the booth 22 through the steam discharge port 46. The dust inside can be collected by the air filter 48, and the cleanliness in the booth 22 can be prevented from being lowered.
[0032]
In the embodiment described above, the worker visually confirms the amount of steam generated. However, a sensor for detecting the amount of steam generated is provided, and the fan 54 is automatically set based on the detected value of the sensor. You may make it control.
[0033]
In the above-described embodiment, the wind speed on the FFU 44A side is adjusted to be larger than the wind speed on the FFU 44B side by controlling the rotation speed of the fan 54. However, the method for adjusting the wind speed is limited to this. is not. For example, by installing a fan larger than the FFU 44B as the fan 54 of the FFU 44A, the wind speed may be increased.
[0034]
FIG. 4 shows the steam outlet 46 of the second embodiment.
[0035]
As shown in FIG. 4, a nozzle 60 is provided below the air filter 48, and the nozzle 60 is connected to a sterilizing gas supply source. Here, the sterilizing gas may be any gas that sterilizes the air filter 48. For example, sterilizing agents that are harmless to humans such as hinokitiol are used in addition to high-temperature steam and high-temperature dry air.
[0036]
On the other hand, an exhaust fan 62 is provided above the air filter 48. By driving the exhaust fan 62, the air in the booth 22 is sucked into the steam discharge port 46 and is forced out of the booth 22.
[0037]
In the second embodiment configured as described above, when the FFUs 44 </ b> A and 44 </ b> B are stopped, the exhaust fan 62 is driven to perform forced exhaust and the sterilizing gas is injected from the nozzle 60. Since the injected sterilizing gas is forcibly exhausted by the exhaust fan 62, it passes through the air filter 48 and is discharged out of the booth 22. As a result, the air filter 49 is sterilized and microorganisms can be prevented from growing in the air filter 48.
[0038]
In the second embodiment, the steam in the booth 22 can be forcibly discharged to the steam outlet 46 by driving the exhaust fan 62 during the operation of the FFUs 44 </ b> A and 44 </ b> B. Therefore, it is possible to reliably prevent the vapor from adhering to the HEPA filters 52 of the FFUs 44A and 44B.
[0039]
The method for sterilizing the air filter 48 is not limited to the second embodiment described above. For example, an ultraviolet irradiation lamp is installed instead of the nozzle 60, and ultraviolet rays are irradiated from the ultraviolet irradiation lamp to the air filter 48. May be sterilized.
[0040]
FIG. 5 is a perspective view showing the configuration of the booth 22 of the third embodiment.
[0041]
As shown in the figure, a punching metal 64 is installed above the air filter 48. The punching metal 64 is detachably mounted so that it can be replaced with a punching metal having a different aperture ratio. The aperture ratio of the punching metal 64 is set according to the amount of clean air blown by the FFUs 44A and 44B.
[0042]
In the third embodiment configured as described above, since the punching metal 64 is installed above the air filter 48, appropriate airflow resistance can be given to the air passing through the steam discharge port 46. Accordingly, air with an appropriate air volume can be exhausted from the steam exhaust port 46, and the air volume to be exhausted is too large, and the cleanliness in the booth 22 is lowered, or the air volume of the exhaust air is too small to generate steam. It is possible to prevent problems that cannot be exhausted.
[0043]
In the third embodiment described above, the punching metal 64 is installed, but any member that can adjust the ventilation resistance of the air flowing through the steam discharge port 46 may be used. For example, two punching metals 64 and 64 may be arranged in an overlapping manner so that one punching metal 64 is fixed and the other punching metal 64 is slidably arranged. In this case, the aperture ratio can be adjusted by shifting the positions of the openings of the two punching metals 64 and 64.
[0044]
FIG. 6 is a perspective view showing a booth 22 of the fourth embodiment, and FIG. 7 is a side sectional view thereof.
[0045]
As shown in these drawings, in the fourth embodiment, steam discharge ports 68 are formed in the side walls 22B and 22B of the booth 22. In this embodiment, it is preferable that the steam outlet 68 is disposed above the steam generation source (the cooked rice container 26). Further, the FFUs 44 </ b> A and 44 </ b> B are preferably disposed on the entire ceiling surface 22 </ b> A of the booth 22.
[0046]
As shown in FIG. 7, the FFU 44A is controlled to blow clean air at a higher wind speed than the FFU 44B. As a result, the steam is pushed out toward the side walls 22 </ b> B and 22 </ b> B and guided to the steam discharge port 66. Therefore, the steam can be discharged to the outside of the booth 22 with the shortest distance.
[0047]
In the fourth embodiment described above, a member for adjusting the exhaust air volume, for example, a punching metal or a damper for fine adjustment of the exhaust air volume may be installed at the steam outlet 68. Thereby, since the air volume of the air exhausted from the steam outlet 68 can be adjusted to an appropriate value, it is possible to prevent the cleanliness in the booth 22 from being lowered.
[0048]
In addition, a dust removing means, for example, a medium performance filter (dust removal rate: colorimetric rate 90%) may be installed at the steam outlet 68. Thereby, the dust outside the booth 22 can be prevented from entering the booth 22, and the inside of the booth 22 can be maintained at a high cleanliness. When the amount of air exhausted from the steam outlet 68 is small, a HEPA filter with a large pressure loss (dust removal rate: particles with a counting method of 0.3 μm or more 99.997% or more) is used instead of the medium performance filter. It may be provided.
[0049]
In the first to fourth embodiments described above, the FFUs 44A and 44B are arranged in three rows. However, the present invention is not limited to this. For example, the FFUs 44A and 44B may be arranged in five rows as shown in FIG. Here, the FFU of the most central column is 44A, the FFUs of the adjacent columns are 44B and 44B, and the FFU of the outermost column is 44C and 44C. In this case, it is preferable to control so that the FFU 44A blows out clean air at the highest wind speed and the FFU 44C blows out clean air at the lowest wind speed. Thereby, the steam is gradually pushed out to the outside and is discharged from the steam discharge port 46, so that the steam can be prevented from adhering to the HEPA filters 52 (see FIG. 3) of the FFUs 44A to 44C. Thus, when multiple rows of FFUs 44 </ b> A to 44 </ b> C are arranged, it is preferable to control so that the wind speed of the clean air gradually decreases as the distance from the center of the installation area increases.
[0050]
FIG. 9 shows an example in which the wind speed of clean air is controlled by one FFU 70. The FFU 70 shown in FIG. 9 is provided with a punching plate 68 below the HEPA filter 52. The punching plate 68 has the largest aperture ratio at the center portion, and the aperture ratio becomes smaller toward the peripheral portion. Therefore, the clean air blown out from the FFU 70 has the highest wind speed at the center and the lower the wind speed at the periphery. By arranging one FFU 70 configured in this way on the ceiling surface 22 </ b> A of the booth 22, the effect of preventing vapor from adhering to the HEPA filter 52 can be obtained.
[0051]
【The invention's effect】
As described above, according to the steam discharge method according to the present invention, since the FFU at the center of the installation area blows clean air at a wind speed larger than that of the FFU at the periphery, the steam generated below the FFU is It is guided outside and is discharged from the room. Therefore, it is possible to prevent the vapor from adhering to the high-performance filter of the FFU, so that the replacement frequency of the FFU filter can be reduced, and the running cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a perspective view showing the structure of a sterilized cooked rice production facility to which a steam discharge method according to the present invention is applied. FIG. 2 is a perspective view showing the internal structure of a booth. Sectional view [FIG. 4] A side sectional view showing a steam discharge port of the second embodiment. [FIG. 5] A perspective view showing an internal structure of the booth of the third embodiment. [FIG. FIG. 7 is a side sectional view of the booth in FIG. 6. FIG. 8 is a side sectional view of the booth in which FFUs are arranged in five rows. FIG. 9 is a side sectional view of the FFU having different internal structures. [Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Manufacturing equipment, 12 ... Rice cooking device, 14 ... Belt conveyor, 16 ... Packaging device, 18 ... Clean room, 20 ... Ceiling space, 22 ... Booth, 24 ... FFU, 26 ... Rice container, 28 ... Container cassette, 30 ... Container separator, 32 ... Conveyor, 34 ... Packaging machine, 36 ... Unloader, 38 ... Unloading port, 40 ... Product conveyor, 42 ... Baseboard opening, 44A, 44B ... FFU, 46 ... Steam outlet, 48 ... Air Filter, 50 ... casing, 52 ... HEPA filter, 54 ... Fan, 56 ... Control device, 58 ... Operation unit

Claims (5)

In the steam discharge method in which a plurality of FFUs are disposed on the ceiling surface and the steam is discharged from a room having a steam generation source below the FFU,
A steam discharge method, wherein the FFU located at the center of the FFU installation area blows clean air at a higher wind speed than the FFU located at the periphery of the installation area. The steam discharge method according to claim 1, wherein the plurality of FFUs are controlled so that the number of rotations of a built-in fan depends on the amount of steam generated. The steam discharge method according to claim 1, wherein a steam discharge port is formed on a ceiling surface around the installation area, and an air filter is provided at the steam discharge port. The steam exhaust method according to claim 3, wherein the indoor air is exhausted by the exhaust fan through the steam exhaust port. The steam discharge method according to claim 3 or 4, wherein the air discharge port is provided with a sterilization unit for the air filter, and the air filter is sterilized by the sterilization unit when the FFU is stopped.

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