JP2005130993A - Mr gas generator and mr gas sterilizer using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an MR gas sterilizer which shows high reliability in sterilization and sterilizes any articles to be sterilized. <P>SOLUTION: The MR gas sterilizer is equipped with an MR gas generator 201 for generating an MR gas by heating a mixed gas of oxygen gas adjusted at a prescribed concentration and methanol gas, an MR gas reserved tank 214 storing the generated MR gas, a sterilization tank 215 for sterilizing the articles to be sterilize by using the MR gas, a pump 204 for introducing the MR gas into the sterilization tank 215, and an exhaust unit 217 for exhausting the MR gas left in the reserved tank 214 after the sterilization of the articles to be sterilized, and an electromagnetic valve controlling the inflow when the MR gas is introduced into the sterilization tank 215 through the MR gas reserved tank 214. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an MR gas generator and an MR gas sterilizer therefor, and more specifically, to an MR gas sterilizer that stably generates a fixed amount of MR gas by controlling the amount of MR gas generated.

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 for sterilization by generating an object to be sterilized in a sterilization chamber, which is mainly used for medical instruments such as a scalpel, and in which high-pressure steam is sealed in high-pressure steam sterilization.

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, MR is a sterilization apparatus that does not select the material and properties of an object to be sterilized using gas containing various radicals (hereinafter referred to as MR gas) generated by catalytic reaction using methanol as a raw material. A 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 shows a schematic diagram of a conventional MR gas sterilization apparatus.

In the conventional MR gas sterilizer, first, methanol stored in the methanol tank 401 is vaporized by the vaporizing heater 402. The vaporized methanol is vaporized heater 40.
2 reacts with the catalyst 403 installed above 2 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 thereof is to provide a highly reliable MR gas sterilization apparatus by controlling the supply amount of methanol and the supply amount of air.

In order to solve the conventional problems, the MR gas generator of the present invention includes a methanol supply tank that supplies methanol to a secondary tank that keeps the methanol liquid level constant, and a secondary tank from the methanol supply tank via the secondary tank. A methanol supply pump for pumping the supplied methanol, a vaporizing means for vaporizing the pumped methanol, and an oxygen enriching means for adjusting the oxygen concentration of the air supplied to mix with the vaporized methanol. And an MR gas is generated by heating a mixed gas of oxygen gas and methanol gas adjusted to a predetermined concentration by the oxygen enrichment means.

The MR gas sterilization apparatus of the present invention pumps methanol supplied from the methanol supply tank through the secondary tank by supplying methanol to a secondary tank that keeps the methanol liquid level constant. A methanol supply pump; vaporization means for vaporizing the pumped methanol; and oxygen enrichment means for adjusting an oxygen concentration of air supplied to be mixed with the vaporized methanol. M which generates MR gas by heating a mixed gas of oxygen gas and methanol gas adjusted to a predetermined concentration by means
An R gas generator, an MR gas reserve tank for storing the generated MR gas, a sterilization tank for sterilizing an object to be sterilized using the MR gas, a pump for introducing MR gas into the sterilization tank, An exhaust unit for exhausting the remaining MR gas in the spare tank after sterilization of an object to be sterilized, and an electromagnetic valve for controlling the amount of inflow when the MR gas is introduced into the sterilization tank via the MR gas spare tank It is equipped with.

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 view of a sterilization gas generator in Example 1 of the present invention.

In FIG. 1, the methanol supplied from the methanol supply tank 101 is the secondary tank 1.
03, the liquid level is kept constant by the liquid level holding cartridge 102,
Keep the amount of methanol supplied to the generator constant. Methanol stored in the secondary tank 103 is pumped by the 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 supplied to the oxygen-enriched film 112 by the air supply means 108.
Is blown up together with oxygen whose concentration is adjusted, oxidized by the heater 109, and M
R gas 111 is generated. At this time, by using the catalyst 110, the MR gas 11 at a low temperature is used.
1 can be generated. 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 with a thickness of about 0.1 μm. When air passes through this film, oxygen passes about 2.5 times faster than nitrogen. By utilizing this property, the oxygen concentration is enriched from about 21%, which is a normal atmospheric oxygen concentration, to about 30% after 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 a series of operations of the MR gas sterilization apparatus according to the first embodiment of the present invention. The MR gas decompression generation mode, the sterilization mode, the sterilization tank exhaust mode, It is a schematic block diagram for demonstrating operation | movement of the suction mode of a sterilization tank, 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 MR gas 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 inside of 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 interval between bc of the electromagnetic valve 205, 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 outside air inlet and the inlet 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 MR gas 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.

The MR gas sterilization apparatus according to the present invention is highly reliable in sterilization by stably generating and using gases containing various radicals generated by catalytic reaction of sterilization gas with methanol as a raw material. It is possible to provide a sterilizer that does not choose

Schematic of MR gas generator of the present invention Schematic for explaining decompression and MR gas generation mode of MR gas sterilization apparatus of the present invention Schematic for demonstrating the sterilization mode of MR gas sterilization apparatus of this invention Schematic for explaining the exhaust (sterilization tank) mode of the MR gas sterilization apparatus of the present invention Schematic for explaining the intake (sterilization tank) mode of the MR gas sterilization apparatus of the present invention Schematic for explaining the exhaust (preliminary tank) mode of the MR gas sterilization apparatus of the present invention Schematic of system configuration of sterilizer of MR gas sterilizer of the present invention Schematic representation of a conventional MR gas 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 (9)

A methanol supply tank that supplies methanol to a secondary tank that keeps the methanol liquid level constant, a methanol supply pump that pumps methanol supplied through the secondary tank, and a vaporizing means that vaporizes the pumped methanol And oxygen enrichment means for adjusting the oxygen concentration of the air supplied for mixing with the vaporized methanol,
An MR gas generator comprising: an MR gas is generated by heating a mixed gas of oxygen gas and methanol gas adjusted to a predetermined concentration by the oxygen enriching means. 2. The MR gas according to claim 1, wherein the MR gas is a gas containing various radicals generated by mixing vaporized methanol and oxygen gas and causing a catalytic reaction to the mixed gas. Generator. The methanol supply tank supplies methanol to the secondary tank from the methanol supply tank by sucking outside air into the methanol supply tank, and makes the methanol supply amount to the vaporizing means constant at the liquid level of the secondary tank. The MR gas generator according to claim 1, wherein the MR gas generator is controlled to a constant amount. The MR gas generation apparatus according to claim 3, wherein the MR gas generation amount is adjusted by adjusting the oxygen concentration by the oxygen enrichment means and the methanol supply amount. A methanol supply tank that supplies methanol to a secondary tank that keeps the methanol liquid level constant, a methanol supply pump that pumps methanol supplied through the secondary tank, and a vaporizing means that vaporizes the pumped methanol And oxygen enrichment means for adjusting the oxygen concentration of the air supplied for mixing with the vaporized methanol,
An MR gas generator for generating MR gas by heating a mixed gas of oxygen gas and methanol gas adjusted to a predetermined concentration by the oxygen enrichment means, and an MR gas reserve tank for storing the generated MR gas And a sterilization tank for sterilizing an object to be sterilized using the MR gas,
A pump for introducing MR gas into the sterilization tank, an exhaust unit for exhausting MR gas in the MR gas reserve tank remaining after sterilization of the sterilization object, and MR in the sterilization tank via the MR gas reserve tank A solenoid valve that controls the inflow of gas when it is introduced;
An MR gas sterilization apparatus comprising: 6. The MR gas sterilizer according to claim 5, wherein the MR gas generation amount is adjusted by adjusting the oxygen concentration by the oxygen enrichment means and the methanol supply amount. 6. The sterilization apparatus according to claim 5, wherein the sterilization tank has a cylindrical shape made of stainless steel having high corrosion resistance. 6. The MR gas sterilizer according to claim 5, wherein the exhaust unit has a catalyst for decomposing MR gas into water and carbon dioxide. 6. The MR gas sterilizer according to claim 5, wherein the sterilization tank is evacuated before introducing MR gas.

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