JP4073857B2 - Sterilization gas generator and sterilizer using the same - Google Patents

Description

The present invention relates to a sterilization gas generator and sterilizing gas sterilization apparatus it, and more particularly, to a sterilizing gas sterilization apparatus to control the generation amount of sterilizing gas to generate a sterilizing gas of stable quantitatively.

Conventional sterilization includes heat treatment, chemical treatment, radiation treatment, and the like, and an appropriate sterilization technique is selected depending on the characteristics of the article to be sterilized.

Patent Document 1 describes a technique of sterilization by generating an object to be sterilized in a sterilization chamber in which high-pressure steam is sealed in high-pressure steam sterilization, which is mainly used for medical instruments such as scalpels.

Patent Document 2 describes a method of measuring and controlling an end-time pressure in the sterilization chamber so as not to vary the supply amount of ethylene oxide gas, and calculating and controlling an increase pressure value of the current pressure.

Patent Document 3 describes a technique in which plasma active species are generated and sprayed on a packaging material to be continuously sterilized.

Patent Document 4 describes a closed space sterilization method using formaldehyde gas.
JP 2002-17825 A JP 2002-85531 A JP 2001-54556 A Japanese Patent Laid-Open No. 11-226094

However, in the case of the high-pressure steam sterilization apparatus described in Patent Document 1, since the object to be sterilized becomes high temperature,
There is a problem that it cannot be used for a precision instrument such as an endoscope because it may corrode an object to be sterilized because it uses a material that is vulnerable to heat, changes in quality due to heat, or steam. Further, in the case of the ethylene oxide gas sterilization apparatus described in Patent Document 2, ethylene oxide gas is highly toxic to the human body, carcinogenicity is pointed out, and persistence is high and trace of sterilization for about 2 hours. In addition, there was a problem that a gas removal work of about 15 hours was required. Further, in the case of the low temperature plasma sterilization apparatus described in Patent Document 3, since hydrogen peroxide plasma is used, sterilization of water containing gauze or a mask that absorbs hydrogen peroxide or cellulose products cannot be performed. There is a problem that it is difficult to select an object to be sterilized.

As described above, in the conventional sterilization apparatus, it is necessary to use different sterilization methods depending on the material and properties of the article to be sterilized and the purpose of use.

In order to solve the above-mentioned problems, as a sterilization apparatus that does not select the material and properties of an object to be sterilized using sterilization gas containing various radicals (hereinafter referred to as MR gas) generated by catalytic reaction using methanol as a raw material An MR gas sterilizer was used.
The MR gas is a radical gas having a strong sterilizing effect generated from methanol by a catalyst, has high permeability, and can sterilize the inside of an object to be sterilized even at atmospheric pressure. There is no metal corrosion or plastic deterioration, and there are excellent properties such as non-sterile materials and no sterilized materials remaining, and high safety.

FIG. 8 is a schematic view of a conventional sterilization apparatus using MR gas .

In the conventional sterilizer , first, the methanol stored in the methanol tank 401 is vaporized by the vaporizing heater 402. The vaporized methanol reacts with the catalyst 403 installed above the vaporizing heater 402 and the heater 404 to generate MR gas.

However, in such a method, since the supply amount of oxygen used for generating MR gas is not controlled, the generation amount of MR gas becomes unstable, the quality of sterilization gas is not stable, and sterilization reliability is improved. Had the problem of low.

The present invention solves the above-described conventional problems, and an object of the present invention is to provide a highly reliable sterilization apparatus by controlling the supply amount of methanol and the supply amount of air.

The MR gas generator of the present invention includes a methanol supply tank, a secondary tank that stores methanol supplied from the methanol supply tank, and methanol that pumps methanol supplied from the methanol supply tank through the secondary tank. a supply pump, wherein a vaporization means for vaporizing the methanol feed methanol is pumped by the pump, and evaporation means comprising installing a wire brush pumping passage methanol to assist the vaporization of methanol, the 2 A liquid level holding cartridge for controlling the amount of methanol supplied to the vaporization means to be constant by holding the liquid level of methanol in the next tank constant; and oxygen in the air mixed with the methanol vaporized by the vaporization means It has an oxygen enrichment unit for adjusting the concentration, and the said vaporized methanol air Mixed gas was catalytic reaction while heating the of is obtained and characterized by generating a sterilizing gas containing various radical.

Further, the sterilization apparatus of the present invention is for sterilizing an object to be sterilized using the sterilization gas generator of the present invention, a sterilization gas reserve tank for storing sterilization gas generated by the sterilization gas generation apparatus, and the sterilization gas. A sterilization tank, a pump for introducing sterilization gas into the sterilization tank, an exhaust unit for exhausting the sterilization gas in the sterilization gas reserve tank remaining after sterilization of an object to be sterilized, and the sterilization gas reserve tank through the sterilization gas reserve tank And a solenoid valve that controls the amount of inflow when sterilization gas is introduced into the sterilization tank .

According to the sterilization apparatus of the present invention, it is possible to provide a sterilization apparatus that is safe and does not select an object to be sterilized by using MR gas having high sterilization reliability and no corrosiveness or persistence.

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

FIG. 1 shows a schematic diagram of an MR gas generator in Embodiment 1 of the present invention.

In FIG. 1, the methanol supplied from the methanol supply tank 101 is stored in the secondary tank 103, and its liquid level is kept constant by the liquid level holding cartridge 102, so that the amount of methanol supplied to the generator is constant. To. Methanol stored in the secondary tank 103 is pumped by a methanol supply pump 104 and vaporized through a wire brush 105 installed to assist in vaporizing the methanol as a whole. At this time, the methanol supply pump 104 that pumps methanol operates at a pressure that does not flow backward due to the vaporized methanol pressure. The vaporized methanol is blown up together with the air whose concentration is adjusted in the oxygen-enriched film 112 by the air supply means 108, and is oxidized by the heater 109 to generate the MR gas 111. At this time, the use of the catalyst 110 enables generation of the MR gas 111 at a low temperature. Further, by adjusting the oxygen concentration by the oxygen-enriched film 112, the amount of generation of the MR gas 111 can be accurately controlled. Specifically, an oxygen-enriched film is a silicon film having a thickness of about 0.1 μm, and oxygen is about 2.5 times faster than nitrogen when air passes through the film. The oxygen concentration is enriched from about 21%, which is the normal oxygen concentration in the atmosphere, to about 30% after the passage.

The liquid level holding cartridge 102 is a cartridge that applies substitution with air in which air is introduced from the outside into a methanol supply tank and methanol having the same volume as the introduced air is supplied from the supply tank. When air is introduced into the methanol supply tank 101 from an air introduction port installed in the vicinity of the methanol supply port in the cartridge 102, the methanol and air are replaced, and the methanol is supplied to the secondary tank 103. Yes. When methanol is supplied, the liquid level of the secondary tank 103 rises, and when the air introduction port of the liquid level cartridge 102 is blocked with methanol, the air is not introduced into the methanol supply tank 101. Replacement is interrupted and secondary tank 1
The supply of methanol to 03 is stopped. When the liquid level in the secondary tank drops due to consumption of methanol, air is again introduced from the air inlet and the supply of methanol is started. Thereafter, by repeating this phenomenon, the liquid level of the secondary tank 103 can be kept constant. As a result, the amount of methanol supplied to the generator can always be kept constant, and MR gas can be stably generated.

2, 3, 4, 5, and 6 are MR gas decompression generation mode, sterilization mode, sterilization tank exhaust mode, and sterilization tank, which are a series of operations of the sterilization apparatus according to the first embodiment of the present invention. It is a schematic block diagram for demonstrating operation | movement of the intake mode of this, and the exhaust mode of a reserve tank.

2, 3, 4, 5, and 6, the MR gas generator 201 is a simplified version of the sterilization gas generator shown in FIG.

In FIG. 2, the MR gas generator 201 includes a pump 202, a pump 203, a HEPA filter 209, a methanol tank 211, a heater 212, and a catalyst 213. The HEPA filter is a filter that can remove 99.97% of particles up to 0.3 μm. In addition, the sterilization tank 215 containing the material to be sterilized has an internal temperature set at 35 ° C. + 5 ° C., and the exterior is made of a stainless steel material rich in corrosion resistance. Is high and has a strong cylindrical shape. In the present invention, a stainless steel drum can was used. The article to be sterilized is sterilized while being contained in a bag called a sterilization bag. This is performed in order to simplify the transportation of the sterilized article after sterilization while maintaining the sterilized state. The said sterilization bag is comprised with the raw material which has air permeability which has arrange | positioned several fine holes which cannot pass bacteria. The sterilization gas preliminary tank 214 is set so that the internal temperature is 35 ° C. + 5 ° C. and the humidity is 80% ± 5%.

In the sterilization apparatus configured as described above, the operation of the sterilization tank decompression and MR gas generation mode will be described. Normally, the depressurization of the sterilization tank and the MR gas generation mode proceed simultaneously.

In the decompression / MR gas generation mode, the solenoid valve 206 and the solenoid valve 208 are closed, the gap between the solenoid valves 205 a and c and the gap bc of the solenoid valve 207 are opened, and the sterilization tank 2 is used by using the pump 204.
The inside of the sterilization tank 215 is evacuated by exhausting and depressurizing the air in the sterilization gas preliminary tank 214. Here, the sterilization bag containing the article to be sterilized stored in the sterilization tank 215 is made of a breathable material in which a plurality of minute holes that do not allow passage of bacteria are arranged.
The inside of the sterilization bag is also discharged by making the inside of 15 a vacuum state.

Then, the MR gas generated by the MR gas generator 201 is removed from the sterilization gas preliminary tank 2.
14 is filled. At this time, since the pump 204 operates continuously, there is no reverse flow of sterilization gas into the sterilization tank 215 whose pressure is reduced. By filling the sterilization gas reserve tank 214 with MR gas, the air exhausted from the sterilization tank 215 to the sterilization gas reserve tank 214 and the air previously filled in the sterilization gas reserve tank 214 are pressurized by the inflow of MR gas. Is discharged to the outside through the exhaust unit 217.

  Next, in FIG. 3, operation | movement is demonstrated about sterilization mode.

In the sterilization mode, MR gas is generated by the MR gas generator 201 and the spare tank 2
14, the mode in which the inside of the electromagnetic valve 205 is filled is followed by the electromagnetic valve 205 between bc, the electromagnetic valve 206 and the electromagnetic valve 2
07 and the solenoid valve 208 are opened.

Here, in the above-described decompression / MR gas generation mode, since the inside of the sterilization tank 215 is in a vacuum state, the MR gas filled in the sterilization gas reserve tank 214 flows into the sterilization tank 215,
The object to be sterilized is sterilized. At this time, between bc of the electromagnetic valve 205 and the electromagnetic valve 208 are open, MR gas flows from the sterilization gas reserve tank 214 into the sterilization tank 215, so that the outside air is sucked into the sterilization gas reserve tank 214 and sterilized. Prevent decompression of the gas reserve tank 214. The intake port for the outside air and the introduction port for introducing the sterilization gas from the sterilization gas reserve tank 214 to the sterilization tank 215 are installed separately, and the sterilization gas reserve tank 214 has a sufficiently larger capacity than the sterilization tank 215. Since the sterilization tank 215 is filled with the sterilization gas before the outside air flows, the sterilization tank 215 has a structure in which the outside air is not mixed. Further, by shutting off the valve 216, H from the exhaust filter 217 due to the decompression of the sterilization gas reserve tank 214 is reduced.
Prevents intrusion of outside air that has not passed through the EPA filter. In addition, the flow rate of the MR gas can be limited by PWM control of the solenoid valve 206. PWM control is a method of controlling by changing the ratio of the time when the solenoid valve is opened and closed, and an intermediate amount of gas between the fully opened state and the completely closed state of the solenoid valve It is possible to create the same state that is being supplied. The sterilization bag placed in the sterilization tank 215 is supplied with the sterilization tank 215 in the aforementioned decompression / MR gas generation mode because the sterilization tank 215 is decompressed and the air in the sterilization bag (not shown) is discharged. It becomes possible to efficiently penetrate the gas into the sterilization bag.

  The sterilization tank exhaust mode, which is the next mode of the sterilization mode, will be described with reference to FIG.

The solenoid valve 205 is opened between a and c, the solenoid valve 206 is closed, the solenoid valve 207 is opened between bc and the solenoid valve 208 is closed. Using the pump 204, the MR gas in the sterilization tank 215 is
The spare tank 214 is evacuated until the inside of the sterilization tank 215 is in a vacuum state. The MR gas is discharged to the outside through the exhaust unit 217. At this time, a platinum metal honeycomb catalyst is used as the catalyst contained in the exhaust unit 217. By using platinum metal honeycomb catalyst for oxidative decomposition reaction,
Oxygen and organic substances are adsorbed and activated on the platinum metal honeycomb catalyst, so that the combustible substance can be oxidatively decomposed and rendered harmless.

  The next mode, the intake (sterilization tank) mode, will be described with reference to FIG.

The solenoid valve 205 is opened between ac and the solenoid valve 208, and the solenoid valve 206 is closed. Here, since the inside of the sterilization tank 215 is in a vacuum state in the exhaust pressure reduction (sterilization tank) mode, the HEP
It is possible to take out the object to be sterilized stored in the sterilization tank 215 by sucking outside air through the A filter 210 and returning the atmospheric pressure in the sterilization tank 215 to the atmospheric pressure. Since the sterilization bag is made of a material that does not allow bacteria to pass through as described above, it is possible to prevent bacteria from adhering to the object to be sterilized by inhalation.

The exhaust (preliminary tank) mode, which is the next mode after the intake (sterilization tank) mode, will be described with reference to FIG.

The solenoid valve 205 is opened between ac and the solenoid valve 207 between bc and the solenoid valve 208, and the solenoid valve 206 is closed. Outside air is taken into the sterilization gas preliminary tank 214 by the pump 204 through the HEPA filter 210 for a certain period of time. The MR gas filled in the sterilization gas preliminary tank 214 by the outside air is discharged to the outside through the exhaust unit 217. A platinum metal honeycomb catalyst is used as the catalyst contained in the exhaust unit 217. As described above, by using a platinum metal honeycomb catalyst for the oxidative decomposition reaction, oxygen and organic substances are adsorbed on the platinum metal honeycomb catalyst and activated to oxidize and decompose flammable substances to make them harmless. Can do.

FIG. 7 shows a system configuration for operating the sterilizer according to the first embodiment of the present invention.

In FIG. 7, the MR gas generator control unit 301 performs control of the amount of methanol supplied to the MR gas generator 201 described above, control of the oxygen concentration, control of the heater temperature that promotes the oxidation reaction in the catalyst, and the like. The gas circulation control unit 302 is generated in the MR gas generator 201.
Introduce MR gas into the sterilization tank, and control the solenoid valve, which is a means of selecting the introduction route from sterilization to exhaust. The panel control unit 303 controls display on the 6.5-inch LCD 305 and the like. The numeric keypad / LED unit 304 is an operation panel on which, for example, an operation button and an emergency stop button of the apparatus are arranged. The 6.5-inch LCD 305 is a display unit that displays an operation status of the apparatus and a warning or caution to the administrator. The MR gas generation control unit 301, the gas circulation control unit 302, the panel control unit 303, and the numeric keypad / LED unit 304 each have their own CPU, and information communication between the control units is performed using the UART 306.

Sterilization device according to the present invention, reliable sterilization by use is quantified generated stably the MR gas, you it possible to provide a sterilization apparatus agnostic object to be sterilized.

Schematic of MR gas generator of the present invention Schematic for explaining decompression and MR gas generation mode of the sterilization apparatus of the present invention Schematic for explaining the sterilization mode of the sterilization apparatus of the present invention Schematic for explaining the exhaust (sterilization tank) mode of the sterilization apparatus of the present invention Schematic for demonstrating the suction | inhalation (sterilization tank) mode of the sterilizer of this invention Schematic for explaining the exhaust (preliminary tank) mode of the sterilizer of the present invention Schematic of the system configuration of the sterilization apparatus of the present invention Schematic representation of a conventional sterilizer

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Methanol tank 102 Liquid level holding cartridge 103 Secondary tank 104 Methanol supply pump 105 Wire brush 106 Preheating heater 107 Stopper nozzle 108 Air supply means 109 Heater 110 Catalyst 111 MR gas 112 Oxygen enriched film 201 MR gas generator 202, 203, 204 Pump 205, 206, 207, 208 Solenoid valve 209, 210 HEPA filter 211 Methanol tank 212 Heater 213 Catalyst 214 Sterilization gas reserve tank 215 Sterilization tank 216 Valve 217 Exhaust unit 301 MR gas generator control section 302 Gas circulation control section 303 Panel control unit 304 Numeric keypad / LED unit 305 6.5 inch LCD monitor 306 UART
401 Methanol tank 402 Evaporation heater 403 Catalyst 404 Heater 405 MR gas

Claims (8)

A methanol supply tank;
A secondary tank for storing methanol supplied from the methanol supply tank;
A methanol supply pump for pumping methanol supplied from the methanol supply tank through the secondary tank;
Vaporization means for vaporizing methanol pumped by the methanol supply pump, the vaporization means comprising a wire brush installed in the methanol pressure-feed passage to assist the vaporization of methanol ,
A liquid level holding cartridge for controlling the amount of methanol supplied to the vaporizing means to a constant amount by holding the liquid level of methanol in the secondary tank constant;
Oxygen enrichment means for adjusting the oxygen concentration of the air mixed with the methanol vaporized by the vaporization means ,
A sterilization gas generator for generating a sterilization gas containing various radicals by catalytic reaction while heating the gas mixture of the vaporized methanol and the air. The liquid level holding cartridge is
A methanol supply port to the secondary tank;
An air inlet installed in the vicinity of the methanol supply port,
Outside air is introduced into the methanol supply tank from the air introduction port, methanol having the same volume as the introduced air is supplied from the methanol supply tank to the secondary tank, and the methanol liquid in the secondary tank is supplied. As the surface rises, the air inlet is blocked and the outside air is not introduced into the methanol supply tank, so that the supply of methanol to the secondary tank is stopped, and the liquid level of methanol in the secondary tank is reduced. The sterilization gas generator according to claim 1, wherein when outside air is again introduced from the air introduction port, supply of methanol to the secondary tank is started and the liquid level of methanol in the secondary tank is kept constant. . The sterilization gas generator according to claim 1 or 2, wherein the oxygen enrichment means is a silicon film having a property that oxygen passes faster than nitrogen when air passes. The sterilization gas generator according to any one of claims 1 to 3, wherein an amount of sterilization gas generated is adjusted by adjusting an oxygen concentration of the air and a heater temperature for promoting the catalytic reaction. The sterilization gas generator according to any one of claims 1 to 4 ,
A sterilization gas preliminary tank for storing sterilization gas generated by the sterilization gas generator, a sterilization tank for sterilizing an object to be sterilized using the sterilization gas,
A pump for introducing sterilization gas into the sterilization tank;
An exhaust unit for exhausting the sterilization gas in the sterilization gas reserve tank remaining after sterilization of the object to be sterilized;
A sterilization apparatus comprising: a solenoid valve that controls an inflow amount when sterilization gas is introduced into the sterilization tank via the sterilization gas preliminary tank . The sterilization apparatus according to claim 5, wherein the sterilization tank is made of stainless steel and has a cylindrical shape . The sterilizer according to claim 5 or 6, wherein the exhaust unit detoxifies a flammable substance by oxidative decomposition with a platinum metal honeycomb catalyst . The sterilizer according to any one of claims 5 to 7, wherein the sterilization tank is evacuated before introducing the sterilization gas .

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