JP3988132B2 - Small steam sterilizer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a steam retort sterilizer for heat sterilizing packaged foods and canned foods.
[0002]
[Prior art]
Conventionally, retort sterilizers that heat and sterilize packaged foods, canned foods, and the like with steam are mixed and jetted with compressed air or hot water, as disclosed in, for example, Japanese Patent Application Laid-Open Nos. 1-211477 and 7-184615. The temperature distribution in the sterilization tank is made uniform by this method.
Most of these devices are used as production machines in factories, and sterilization tanks must be certified for Type 1 pressure vessels stipulated by the Industrial Safety and Health Act.
[0003]
On the other hand, there is no need to purchase large production retort sterilizers for the development and prototyping of foodstuffs in laboratories and test laboratories, and maintenance is difficult and workability is poor even if purchased. There is. However, small steam sterilizers are widely used at present because the devices for controlling pressure and temperature are complicated and expensive when a small tester with the same functions and performance as the production machine is manufactured. Absent.
[0004]
[Problems to be solved by the invention]
Therefore, the present invention has a function that enables sterilization of small quantities of packaged foods and canned foods to have the same quality in the same way as the production machine even in relatively small stores, laboratories and test rooms, etc. The challenge is to provide a steam-heated compact sterilizer that is a sterilization tank equivalent to a small pressure vessel that does not require installation notification or annual regular inspection.
[0005]
In addition, the temperature distribution in the sterilization tank is uniform regardless of the sterilization temperature from 60 ° C to 150 ° C, and the sterilization tank can be easily cleaned. An object of the present invention is to provide an inexpensive compact sterilizer that can perform rotary sterilization.
[0006]
[Means for Solving the Problems]
The invention according to claim 1 is a steam type sterilizer that accommodates a tray on which an object to be sterilized is placed in a sterilization tank and sterilizes the object to be sterilized in the sterilization tank. The sterilization tank is provided with a spray nozzle for supplying cooling water to the upper position of the tray and a liquid level sensor for detecting the cooling water level, and the sterilization tank has compressed air. A small steam sterilizer was connected to an air tank equipped with piping and degassing piping.
[0007]
The invention of claim 2 is provided with an opening provided with an open / close lid on one side of the cylindrical horizontal sterilization tank, a fan for blowing the gas in the sterilization tank on the opposite side, and the gas can circulate in the sterilization tank. A small steam sterilizer equipped with a U-shaped partition plate that is detachable and has a vent hole for the fan.
[0008]
According to a third aspect of the present invention, there is provided a hollow rotating shaft that can be rotated horizontally in a cylindrical horizontal sterilization tank, a basket support base that is detachable from the rotating shaft, and the rotating shaft that is rotated forward and reverse. A small steam-type sterilizer provided with rotational drive units that alternately rotate about 360 ° was used.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
The first embodiment of the present invention will be described below with reference to FIG.
The cylindrical horizontal sterilization tank 1 with one end sealed is provided with an opening provided with an opening / closing lid 2 at the other end, and the tray 3 on which the article R to be sterilized is placed is housed and sterilized.
[0010]
A steam pipe 4 is connected to the sterilization tank 1 and connected to a steam source such as a boiler via a steam valve 5.
[0011]
6 is a cooling water pipe, one is connected to a water supply source such as a water supply via a cooling water valve 7, and the other is connected to a spray nozzle 8 provided above the tray 3 in the sterilization tank. Yes.
[0012]
Reference numeral 9 denotes a connecting pipe that connects the sterilization tank 1 and the air tank 10, and a compressed air pipe 11 provided with a compressed air valve 12 and a deaeration pipe 15 provided with a deaeration valve 14 are connected to the air tank 10. ing.
[0013]
A liquid level sensor 18 for sensing the liquid level of the cooling water is provided above the tray 3 in the sterilization tank, and a drain pipe 16 having a drain valve 17 is connected to the bottom of the sterilization tank 1. In addition, a pressure sensor 19 and a temperature sensor 20 for detecting the pressure and temperature in the sterilization tank are provided on the upper part of the sterilization tank.
[0014]
In the present embodiment, the packaged food is sterilized as follows using the retort sterilizer configured as described above.
[0015]
First, the packaged food is stored in the sterilization tank, and then the steam valve 5 is opened to supply steam to the sterilization tank 1 up to a predetermined sterilization temperature. On the other hand, in order to make the pressure in the sterilization tank higher than the pressure in the packaging container of the packaged food R, the compressed air valve 12 is opened and compressed air is supplied until a predetermined pressure is reached. The steam valve 5, the compressed air valve 12 and the exhaust valve 17 are operated according to the signals of the pressure sensor 19 and the temperature sensor 20 and an instruction from a control panel (not shown) to control the sterilization process to a predetermined sterilization temperature and sterilization pressure. Do. When opening and closing each valve during the sterilization process using a small sterilization tank of around 60 liters, the temperature and pressure in the sterilization tank overshoot from the set value, and the fluctuation range of the temperature and pressure increases. By providing the air tank 10, the overshoot is alleviated and the fluctuation range is reduced.
[0016]
Next, after the sterilization is finished, the cooling water valve 7 is opened and closed intermittently, and cooling water is sprayed from the spray nozzle 8 to cool the packaged food R. At this time, the vapor in the sterilization tank is condensed and the pressure drops, and the compressed air valve 12 is opened by the signal from the pressure sensor 19 to supply the compressed air. Although the pressure in the sterilization tank decreases during the time lag from when the pressure sensor 19 senses the pressure until the compressed air is supplied, the pressure drop is reduced by replenishing the compressed air in the air tank 10. Can be minimized.
[0017]
Next, in the cooling process, the cooling water supplied from the spray nozzle 8 stays in the sterilization tank, and when the water level of the cooling water comes into contact with the liquid level sensor 18 provided above the tray 3, the drain valve 17 is opened and sterilized. Drain the cooling water in the tank. The drain valve 7 is closed when the water level is lowered to some extent by an instruction from a timer or other liquid level sensor (not shown). The packaged food R is evenly cooled by performing full water cooling by repeating the water supply from the spray nozzle 8 and the vertical fluctuation of the cooling water level. When the pressure in the sterilization tank becomes higher than the set pressure during this cooling, the deaeration valve 14 opens, and when it becomes lower, the compressed air valve 12 opens to maintain a predetermined pressure. However, when the volume of the sterilization tank 1 is small, the amount of residual air in the sterilization tank decreases, and it becomes impossible to follow the fluctuation of the water level and the time lag of supply / exhaust, and the pressure fluctuation becomes large. The cooling process can be performed with almost no pressure change due to the relaxation action of the air in the tank 10.
[0018]
Next, a second embodiment of the present invention will be described with reference to FIGS.
FIG. 2 is a vertical cross-sectional view of the sterilization tank 1, and FIG. 3 represents a cross section taken along line XX of FIG. A fan 21 and a partition plate 22 for circulating gas are provided in the sterilization tank on the sealed side of the cylindrical horizontal sterilization tank 1.
[0019]
The partition plate 22 is formed with a side plate 23 provided along the longitudinal direction of both sides of the cylinder of the sterilization tank 1 and a bottom plate 24 that partitions the fan 21 and the tray 3 into a U-shape. And a guide ring 25 are provided.
[0020]
In addition, the U-shaped partition plate 22 is fixed in the sterilization tank at several locations on the bottom plate 24 by fastening bolts 27 and the like so that it can be easily attached to and detached from the sterilization tank 1.
[0021]
The fan 21 is connected to a motor 29 provided outside the sterilization tank 1 through a shaft 28, and the shaft 28 is sealed by a shaft seal 30.
[0022]
The steam and compressed air supplied into the sterilization tank during the sterilization process are forced to circulate in the direction of the arrow in the figure by the partition plate 22 through the fan 21. In pasteurization at 100 ° C or lower, the ratio of air increases and the temperature distribution in the sterilization tank is difficult to be uniform. However, by circulating the mixed gas of steam and air by turning the fan 21, the temperature distribution becomes uniform and the sterilization is poor. Will not occur.
[0023]
Further, since the partition plate 22 can be easily attached and detached, cleaning and cleaning in the sterilization tank can be performed easily and in a short time.
[0024]
Next, a third embodiment of the present invention will be described with reference to FIG.
FIG. 4 is a cross-sectional view of the rotary sterilization tank. The support base 31 is detachably attached to the flange portion 34 of the rotary shaft 35, and the basket 32 is fixed to the support base 31 to give a rotational motion.
[0025]
The basket 32 is loaded with the article R to be sterilized and pressed by the presser lid 33 so that the article to be sterilized R does not move, and is fixed to the support base 31. The support base 31 is attached with a basket 32 to perform a rotational sterilization process and gives a rotational motion to the article R to be sterilized. However, when the stationary sterilization process is performed, it can be removed and the stationary tray 3 can be used.
[0026]
The rotary shaft 35 is a hollow shaft that penetrates the sealed side of the sterilization tank 1 and can perform forward rotation and reverse rotation of about 360 ° alternately by a rotation drive unit 39 provided outside the sterilization tank. The mechanism of the rotation drive unit is based on a rotation system using a worm and a worm wheel, but may be another known mechanism. About 360 ° means an angle at which the article to be sterilized R is most easily flow-stirred, and usually means an angle of 270 ° to 360 °.
[0027]
Reference numeral 36 denotes a cable temperature sensor, one of which is inserted into the article to be sterilized R through the hollow portion of the rotary shaft 35, and the other is connected to a measuring instrument 38 outside the sterilization tank. The cable temperature sensor 36 is sealed by a packing gland 37 at the hollow end of the rotating shaft 35.
[0028]
Even when sterilization is performed while rotating the article to be sterilized R, the cable temperature sensor 36 can only be twisted at a maximum angle of 360 °, and can be connected to the measuring instrument 38 with a single cable, and a complicated connection fitting is used. Without sterilization, sterilization can be performed while rotating the article R to be sterilized with a simple structure.
[0029]
【The invention's effect】
Since the present invention adopts the above-described configuration, first, since the sterilization tank has a volume corresponding to a small pressure vessel, it is easy for the user to maintain and manage the sterilizer and to improve the work efficiency. improves. Further, by connecting the air tank to the sterilization tank, the pressure fluctuation is reduced, and the sterilization process can be stably performed under the same conditions as the production machine.
[0030]
Second, by providing a fan and partition plate in the sterilization tank and forcibly circulating a mixed gas of steam and air, the temperature distribution can be made uniform in the entire sterilization temperature range, and the partition plate can be attached and detached. Since the structure can be made simple, the inside of the sterilization tank can be easily cleaned.
[0031]
Thirdly, by providing a hollow rotating shaft that rotates 360 ° alternately between forward rotation and reverse rotation, it is possible to connect the temperature sensor in the sterilization tank and an external measuring instrument with a single cable. In addition, the sterilization can be performed at a low cost with a simple structure by attaching and detaching the support base directly to the rotary shaft.
[Brief description of the drawings]
FIG. 1 is a sectional view showing an entire apparatus according to a first embodiment of the present invention.
FIG. 2 is a longitudinal sectional view of a sterilization tank according to a second embodiment of the present invention.
3 is a cross-sectional view taken along line XX in FIG.
FIG. 4 is a sectional view of a rotary sterilization tank according to a third embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Sterilization tank 2 ... Open / close lid 3 ... Tray 4 ... Steam piping 5 ... Steam valve 6 ... Cooling water piping 7 ... Cooling water valve 8 ... Spray nozzle 9 ... Connection pipe 10 ... Air tank 11 ... Compressed air pipe 12 ... Compressed air valve 14 ... Deaeration valve 15 ... Deaeration pipe 16 ... Drain pipe 17 ... Drain Valve 18 ... Liquid level sensor 19 ... Pressure sensor 20 ... Temperature sensor 21 ... Fan 22 ... Partition plate 25 ... Guide ring 26 ... Vent 28 ... Shaft 29 ..Motor 31 ... support base 32 ... basket 34 ... flange portion 35 ... rotating shaft 36 ... cable temperature sensor 38 ... measuring instrument 39 ... rotation drive R ... Object to be sterilized

Claims (3)

In a steam type sterilizer that accommodates a tray on which an object to be sterilized is placed in a sterilization tank and heat sterilizes the object to be sterilized in the sterilization tank, In the sterilization tank, a spray nozzle for supplying cooling water to the upper position of the tray and a liquid level sensor for detecting the cooling water level are provided, and the sterilization tank is provided with a compressed air pipe and a deaeration pipe. A small steam sterilizer characterized by connecting tanks. An opening with an open / close lid is provided on one side of the cylindrical horizontal sterilization tank, and a fan that blows the gas in the sterilization tank is provided on the opposite side, and the gas can circulate in the sterilization tank. 2. A small steam sterilizer according to claim 1, wherein a U-shaped partition plate having a mouth is provided. A hollow rotating shaft that can be rotated horizontally in a horizontal horizontal sterilization tank, a basket support base that is detachable from the rotating shaft, and a rotational drive that rotates the rotating shaft forward and reverse alternately about 360 ° outside the sterilization tank. A small steam sterilizer according to claim 1, further comprising a portion.

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