JPH11244359A - Steam sterilizer and its driving method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable disinfection in a short time and to generate saturated steam by eliminating the air in a sterilization chamber with a less amount of water. SOLUTION: On the bottom of the sterilization chamber 30 of main body 1, a lump of metal 4 is mounted. The metallic part 4 is previously heated by electric heaters 5a and 5b. After setting the object 14 to be sterilized on the shelf 13 of the chamber 30 when water is supplied to the bottom of the chamber 30 to be vaporized by touching the metallic part 4. After the air in the chamber 30 is speedily eliminated by the steam, valve 10 of ventilating pipe 8 is closed. Next, the metallic part 4 and the water 12 are heated by the electric heaters 5a and 5b, then the object 14 is sterilized at the temperature of the saturated steam in the chamber 30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steam sterilizer for sterilizing contaminated articles in a hospital or the like with steam.

[0002]

2. Description of the Related Art In a hospital or the like, a steam sterilizer having a built-in electric heater is used to sterilize contaminated articles. The conventional apparatus includes an electric heater 23 at the bottom of the sterilization chamber 22 of the main body 21 as shown in the cross-sectional view of FIG. At the time of use, the bottom of the sterilization chamber 22 is filled with water 25 by a water supply means (not shown), the electric heater 23 is heated to generate steam, and the air in the sterilization chamber 22 is discharged by an exhaust means (not shown) to sterilize. The chamber 22 was filled with saturated steam, and the electric heater 23 was further heated to raise the temperature of the sterilization chamber 22 to a sterilization temperature, and the object placed on the shelf 24 was sterilized.

In such an apparatus, the amount of water 25 supplied to the sterilization chamber 22 must be such that the electric heater 23 is completely submerged even at the end of its operation. When the temperature inside the sterilization chamber 22 is directly increased by the heat generated from the electric heater 23, the electric heater 2
4 is damaged or the temperature in the sterilization chamber becomes uneven, so that the entire object to be sterilized cannot be sterilized uniformly. For this reason, much more water is needed than the amount of water that actually becomes saturated steam. For example, when about 18,000 cc of saturated steam at 132 ° C. and 2 atm is liquefied, it becomes about 20 cc. That is, in a sterilization room with an internal volume of 18,000 cc, it is sufficient to have about 50 cc of water including the generated steam for exhaust. However, 300-500cc of water is actually used for the above reasons.

Here, for example, if a groove for accommodating a heater is provided on the inner bottom of the main body 21, most of the water can be evaporated while the electric heater 23 is submerged. However, since the inside of the main body 21 becomes high pressure during sterilization,
Such a structure of the main body 21 causes a problem in strength.
It is also conceivable that a water storage tank is provided inside the main body part 21 separately from the main body part 21, and the shape of the water storage tank is the same as the above example. However, such an apparatus has a complicated overall structure, which makes it difficult to manufacture and increases the manufacturing cost.

On the other hand, since the conventional apparatus required such a large amount of water 25, it took a long time to heat the water 25 and fill the sterilization chamber 22 with the saturated steam at the sterilization temperature. . That is, it takes a long time to sterilize using this type of sterilization apparatus.

[0006]

As described above, the conventional apparatus requires a large amount of water, and requires a long time before sterilization.

SUMMARY OF THE INVENTION The present invention has been made in view of such conventional problems, and an object of the present invention is to provide an apparatus capable of rapidly sterilizing with a small amount of water and a method of operating the same.

[0008]

According to a first aspect of the present invention, there is provided a steam sterilization apparatus comprising: a main body having a sterilization chamber; water supply means for supplying water to a bottom of the sterilization chamber; Exhaust means for discharging, heat generating means arranged at the bottom of the sterilization chamber, and a heat storage member which is arranged in the sterilization chamber close to the heat generating means and heated by the heat generating means,
It is a structure provided with.

In such a configuration, the actual volume at the bottom of the sterilization chamber is reduced by the volume of the heat storage member. Therefore, when a certain amount of water is supplied to the bottom of the sterilization chamber,
Compared to the case without the heat storage member, the one with the heat storage member can keep the water level higher. Therefore, the necessary saturated steam can be generated with a small amount of water without exposing the heating means from the water surface. Furthermore, in such a configuration, if the heat storage member is previously heated by the heat generating means, steam is generated in a short time when water is supplied.

[0010] The steam sterilizer according to the second aspect is the first aspect.
The apparatus according to the above, further comprising a heat retaining means for keeping the sterilization chamber warm.

In such a configuration, since the sterilization chamber is kept warm, the evaporation of water is further promoted.

[0012] The steam sterilizer according to the third aspect is the first aspect.
Alternatively, the apparatus according to item 2 further includes a sensor that detects the temperature of the heat storage member.

In such a configuration, since the temperature of the heat storage member is detected by the sensor, the temperature of the heat storage member can be controlled by the sensor.

According to a fourth aspect of the present invention, there is provided a steam sterilizer.
The steam sterilizer according to any one of claims 3 to 3,
The heat storage member is a metal lump.

In such a configuration, since the heat storage member is rich in heat conductivity, heat storage is quickly performed.

According to a fifth aspect of the present invention, there is provided a method for operating a steam sterilizer according to any one of the first to fourth aspects, wherein the heat storage member is first heated by the heat generating means, and then the sterilization chamber is sterilized. Put the thing, then supply water into the sterilization chamber by the water supply means, contact this water with the heat storage member to generate steam,
Next, the inside of the sterilization chamber is evacuated by the exhaust means until the inside of the sterilization chamber is filled with steam, and further, heat is generated in the heating means to raise the saturated steam in the sterilization chamber to the sterilization temperature.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the overall configuration of a steam sterilizer according to an embodiment of the present invention, and FIG. As shown in these figures, the main body 1 has a substantially cylindrical shape, and the inside thereof is a sterilization chamber 30. An opening 2 is formed at one end of the main body 1, and the opening 2 is openable and closable by a door 3. The sterilization chamber 30 is provided with a substantially semi-cylindrical metal block 4 along the bottom of the sterilization chamber 30. The metal block 4 has two grooves 4a, 4b in the longitudinal direction on the bottom side, and 1
It has a long hole 4c. A pair of electric heaters 5a and 5b are arranged in the grooves 4a and 4b of the metal block 4, respectively, and are attached to the main body 1. These electric heaters 5a and 5b are supplied with electric power from the outside via conducting wires 50a and 50b. A metal lump temperature sensor 7 is inserted into the elongated hole 4c of the metal lump 4. The metal lump temperature sensor 7 detects the temperature of the metal lump 4 and outputs a detection signal to the outside via a conductor 70. A shelf 13 for mounting an object to be sterilized 14 is provided above the metal block 4 inside the main body 1. An electric heater 6 for keeping the sterilization chamber 30 warm is provided on the outer periphery of the main body 1.
Is provided. As the above-mentioned metal lump 4, for example, a corrosion-resistant alloy containing iron or copper as a main component and manufactured by casting is used.

The present apparatus also includes an indoor temperature sensor 31 for detecting the temperature in the sterilization chamber 30, a control unit 32,
It has a water level sensor 35 for detecting the water level inside. The detection signal of the room temperature sensor 31 is transmitted to the control unit 3 through the conductor 33.
2 The detection signal of the water level sensor 35 also reaches the control unit 32. This control unit 32
Controls the electric power supplied to the electric heater 6 through the conducting wire 60 based on the detection signal of the indoor temperature sensor 31 when the apparatus is prepared for sterilization.
From the above, the temperature is set to a temperature within the sterilization temperature range, and the power supplied to the electric heaters 5a and 5b is controlled so that the temperature of the metal block 4 becomes the set temperature. The controller 32 controls the power supplied to the electric heater 6 and the electric heaters 5a, 5b based on the detection signal of the indoor temperature sensor 31 during sterilization of the present apparatus, so that the temperature in the sterilization chamber 30 is reduced. The sterilization temperature is set. Switching between the sterilization preparation mode and the sterilization mode in the control unit 32 is performed by an instruction signal input by an operator.

Further, one end of an exhaust pipe 8 for discharging air and steam in the sterilization chamber 30 is connected to an upper portion of the main body 1, and the exhaust pipe 8 is provided with a valve 10. Valve 10 is
It opens and closes automatically by sensing the steam temperature. In this example, it closes when the steam temperature exceeds 100 ° C, and opens when it is lower than 100 ° C. A water supply / drain pipe 9 for supplying and discharging water to / from the sterilization chamber 30 is provided at the bottom of the main body 1.
Is connected, and a valve 11 is provided in the water supply / drain pipe 9. This valve 11 is controlled by the control unit 32,
The water from the reservoir is supplied to the sterilization chamber 30 or
This is a switching valve for discharging water or steam in the inside to the outside or simply closing the water supply / drain pipe 9. Here, the exhaust pipe 8 and the valve 10 constitute exhaust means, and the water supply / drain pipe 9 and the valve 11 constitute water supply means.
The steam discharged through the valve 10 is cooled and liquefied, and then returned to the water tank, and the water discharged through the valve 11 is also returned to the water tank.

Next, the operation of the device configured as described above will be described.
The operation method will be described. When performing sterilization using this apparatus, the operator sets the control unit 32 to a sterilization preparation mode. Thereby, the control unit 32 determines that the temperature of the metal block 4 is 100 ° C.
The electric heaters 5a, 5
b to control the power to be supplied. Further, the control unit 32 controls the power supplied to the electric heater 6 for keeping heat so that the temperature in the sterilization chamber 30 becomes a temperature between 100 ° C. or higher and the sterilization temperature.

Next, the operator opens the door 3, inserts the object to be sterilized 14 from the opening 2, and places it on the shelf 13. Further, the operator closes the door 3 and puts the control unit 32 in the sterilization mode. Accordingly, the control unit 32 controls the valve 11 to supply the water 12 into the main body 1 and also controls the electric heaters 5a and 5b and the electric heater 6 for keeping the temperature in the sterilization chamber at the sterilization temperature. To control. At this time, metal lump 4 already has 100
Since the water 12 is heated to a temperature of not less than ° C., the water 12 supplied into the sterilization chamber 30 comes into contact with the metal lump 4 and becomes a vapor at the same time, and the air in the sterilization chamber 30 is rapidly discharged through the exhaust pipe 8. When the control unit 32 detects that the water level in the sterilization chamber 30 has reached a predetermined water level based on the detection signal of the water level sensor 35, the control unit 32 controls the valve 11 to stop water supply. Valve 10 automatically closes when the steam temperature rises above 100 ° C. Here, the control unit 32 controls the temperature in the sterilization chamber to be the sterilization temperature. Therefore, the inside of the sterilization chamber 30 is filled with the saturated steam at the sterilization temperature.

The operator sets the control unit 32 to a sterilization preparation mode after a lapse of time during which the object 14 can be regarded as sufficiently sterilized. Thereby, the control unit 32 controls the valve 11 to discharge water and steam in the sterilization chamber 30. At this time, since the pressure in the sterilization chamber 30 decreases and the exhaust pipe 8 is in contact with the outside air, the steam in the exhaust pipe 8 is cooled to 100 ° C. or less, and the valve 10 is opened. The operator opens the door 3, takes out the object 14 to be sterilized from the opening 2, and closes the door 3.
Here, since the controller 32 is in the sterilization preparation mode, the controller 32 controls the power supplied to the electric heaters 5a and 5b so that the temperature of the metal block 4 becomes a certain set temperature of 100 ° C. or higher. Also, the control unit 32 controls the temperature in the sterilization chamber 30 to 100
The electric power supplied to the electric heater 6 for keeping heat is controlled so that the temperature becomes a temperature between the temperature of not less than ° C. and the sterilization temperature. Therefore, even after the end of the first sterilization operation, the temperature of the metal block 4 is at least the set temperature of 100 ° C. or higher, even if not immediately thereafter, and the temperature in the sterilization chamber 30 is at least 100 ° C. or higher. Until the temperature is up to. In this state, when the present apparatus is used next time, sterilization can be similarly performed in a short time by performing the above-described sterilization operation. Therefore, the present apparatus can always perform sterilization in a short time even when used continuously or at intervals.

In the present embodiment, most of the volume at the bottom of the sterilization chamber 30 is occupied by the metal lump 4. Comparing this with the case without the metal lump 4, the same amount of water
The water level is much higher when there is a metal lump 4 even if it is at the bottom of 0. Therefore, a large amount of water can be evaporated before the electric heaters 5a and 5b emerge from the water surface. That is, according to the present apparatus, the supplied water can be evaporated in a large amount, so that the amount of supplied water can be extremely small.

In the present embodiment, the temperature of the sterilization chamber 30 and the temperature of the metal lump 4 are controlled by the control unit 32. However, the temperatures detected by the metal lump temperature sensor 7 and the room temperature sensor 31 are displayed on the display. The operator may control while watching this. Further, the operator may control the supply / drainage and exhaust of the sterilization chamber 30. On the other hand, these temperature controls,
The control of water supply and drainage may be performed by individual control units that control each of them. In the above example, the main body 1 is cylindrical, but may be square.

[0025]

According to the device of the first aspect, sterilization can be performed with a small amount of water, and sterilization can be performed in a short time if the heat storage member is heated in advance.

According to the second aspect of the present invention, since the sterilization chamber is kept warm, the evaporation of water is promoted, and sterilization can be performed in a shorter time.

According to the third aspect of the present invention, since the temperature of the heat storage member is detected by the sensor, the temperature of the heat storage member can be controlled by this sensor, and the temperature of the heat storage member can be accurately set to a desired temperature. it can.

According to the device of the fourth aspect, since the heat storage member is rich in heat conductivity, heat is rapidly stored, and this is extremely effective when sterilization is not performed continuously.

According to the method of the fifth aspect, sterilization can be performed with a small amount of water, and sterilization can be performed in a shorter time.

[Brief description of the drawings]

FIG. 1 is a diagram showing an overall configuration of an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the device shown in FIG.

FIG. 3 is a cross-sectional view showing a conventional steam sterilizer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main body part 4 Metal lump (heat storage member) 5a, 5b Electric heater 6 Heating electric heater 7 Metal lump temperature sensor 8 Exhaust pipe 9 Supply / drain pipe 10, 11 Valve

Claims (5)

[Claims] 1. A main body having a sterilization chamber formed therein, water supply means for supplying water to the bottom of the sterilization chamber, exhaust means for discharging gas in the sterilization chamber, and disposed at the bottom of the sterilization chamber. A steam sterilizer comprising: a heat generating unit; and a heat storage member disposed in the sterilization chamber in proximity to the heat generating unit and heated by the heat generating unit. 2. The steam sterilizer according to claim 1, further comprising a heat retaining means for keeping the temperature of the sterilization chamber warm. 3. The steam sterilizer according to claim 1, further comprising a sensor for detecting a temperature of the heat storage member. 4. The steam sterilizer according to claim 1, wherein the heat storage member is a metal lump. 5. A method for operating a steam sterilizer according to any one of claims 1 to 4, wherein the heat storage member is first heated by the heat generating means, and then the object to be sterilized is placed in the sterilization chamber. Water is supplied into the sterilization chamber by the water supply means, and the water is brought into contact with the heat storage member to generate steam. Then, the sterilization chamber is evacuated by the exhaust means until the sterilization chamber is filled with steam. A method for operating a steam sterilization apparatus, characterized in that saturated steam in a sterilization chamber is raised to a sterilization temperature by generating water.