JPH05161827A - Filter unit for fluid discharged from high pressure steam sterilizing device - Google Patents

Abstract

PURPOSE:To prevent the contamination of the outside with bacteria by placing a hydrophilic element on the gravity side of a hydrophobic element when a substance having possibility containing microbiological contaminant is passed through a filter consisting of both elements from a high pressure steam sterilizing device. CONSTITUTION:A hydrophobic element 1 and a hydrophilic element 2 are set to the discharge piping routes 17, 18 of a high pressure steam sterilizing device 11 in such a state that the hydrophilic element 2 is positioned on the gravity side with respect to the hydrophobic element 1. When air, steam and condensed water are discharged, air and steam are filtered by the hydrophobic element 1 of a filter element 3 and also filtered by hydrophilic element 2 not wetted with condensed water. After the elements 1, 2 are wholly wetted with condensed water, air and steam are discharged only from the hydrophobic element and condensed water is discharged only from the hydrophilic element. Therefore, air, steam and condensed water can be smoothly discharged.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a filter assembly for removing microorganisms from a potentially microbial-containing fluid discharged from a high pressure steam sterilizer to sterilize and discharge the fluid.

[0002]

2. Description of the Related Art Conventionally, high-pressure steam sterilization (autoclave sterilization) has been used as an effective means of sterilization in industrial fields such as the pharmaceutical industry, food industry, and biochemistry, microbiology, and genes dealing with microorganisms and cells. It is widely used in research fields such as engineering. In recent years, bio-hazard facilities specializing in genetic engineering have been installed in various places, but it will take every possible measure to prevent the unpredictable life forms created by genetic recombination from leaking out of the experimental facility. It was born from the idea of trying. The atmospheric pressure in the laboratory is lowered from the outside to prevent the air in the laboratory from flowing out, and the indoor air is filtered and sterilized by an air filter to prevent microbial air pollution inside and outside the room. The instrument used in the experiment is sterilized by a sterilization method according to the purpose to eliminate microbial risk, and then discarded or reused.

The high pressure steam sterilization method is most commonly used for the above-mentioned applications, but in order to complete the sterilization effect, the residual air in the can body of the high pressure steam sterilizer is discharged to the outside of the can body before sterilization. The operation of substituting with steam is essential. At this time, air and steam are discharged out of the can body together with condensed water (drain). It is pointed out that some sort of sterilization is necessary because the discharged fluid has a possibility of microbial contamination derived from the substance to be sterilized in the can. Currently, biohazard facilities are classified into classes according to the risk of living organisms to be handled, but special measures are taken at facilities with relatively moderate risks such as P-1 and P-2 levels. The fact is that there is no such thing, and establishment of a highly safe microbial contamination control technology is desired in advanced biological risk management facilities such as P-3 and P-4 levels. Up to now, some large machines have built-in special equipment to sterilize the exhaust drain by high-pressure steam again and sterilize it, but this is due to the large size of the re-steamer and the initial cost. The expansion to small and medium-sized machines has not progressed due to the increase in the number of vehicles. Therefore, a technique for sterilizing discharged liquid by a simple method with a small installation volume including a large machine is desired.

A general sterilization cycle using a high-pressure steam sterilizer will be described with reference to FIG. 4. First, the object to be sterilized is put into the can 11 of the high-pressure steam sterilizer, and then the can 11 has a pressure resistant structure. The lid 14 is closed and the water 15 immediately below the sterilized product is heated by an electric heater 16 to generate steam. Then, for complete sterilization, a discharge pipe 17 communicating with the can body 11 located above the can body until the inside of the can body 11 is filled with saturated steam.
The air in the can is discharged as the internal pressure of the can increases.
Then, steam is generated as the water 15 in the can body is heated, and only steam is eventually discharged after a situation in which air and steam are mixed. At this time, the fluid actually discharged is a mixture of air, steam, and condensed water generated by cooling the steam in the discharge pipe 17 path. At this point, the valve 13 installed in the pipe connecting the can body 11 and the discharge path 17 is closed, the vapor pressure in the can body rises, and sterilization is performed at a predetermined temperature for a predetermined time. Heater-1 after sterilization
When 6 is cut and the internal pressure of the can falls to a predetermined pressure,
The discharge valve 13 is opened, and the residual pressure discharges air, steam, and condensed water out of the can body. One cycle is completed when the inside of the can returns to atmospheric pressure. In large-scale high-pressure steam sterilizers mainly used for industrial purposes, it is common to blow pressurized steam directly into the can instead of heating the water in the can with an electric heater. This cycle is the same except for the difference.

[0005]

DISCLOSURE OF THE INVENTION The present invention, in the above-mentioned sterilization cycle, has a possibility of containing microbiological contaminants derived from the substance to be sterilized, which is discharged outside the can of the high-pressure steam sterilizer, and steam. SUMMARY OF THE INVENTION It is an object of the present invention to provide a filter assembly that effectively filters condensed water and prevents microbial contamination to the outside.

That is, since these exhaust exhausts are exhausted in the same exhaust pipe in the state of air, vapor, and liquid, it is necessary to set a filter capable of efficiently filtering fluids in all of these states. .. There are basically hydrophobic and hydrophilic filters, but hydrophobic filters
Although air and steam can be filtered when this is used for,
The condensed water cannot be filtered, and when the condensed primary water of the filter housing the filter (the filtered liquid side of the filter) is filled with the condensed water, air and steam are also blocked by the liquid and cannot be filtered. On the other hand, when the hydrophilic filter is used for this purpose, air and steam can be filtered when the filter is not wet with water, but once the filter is wet with condensed water, neither air nor steam can be filtered at all. , The predetermined exhaust cannot be discharged. A hydrophilic filter wet with water
The filter has a property that the gas cannot be filtered unless it is filtered at a pressure higher than the bubble point derived from the pore diameter (the gas pressure value when the liquid satisfying the pore diameter is pushed out by the gas against the surface tension).

It is to be noted that a filter having a pore size of 0.2 μm or less is required for removing microorganisms, and a bubble point value when the filter is wet with water is about 3 kg / cm ² or more. The discharge pressure is generally 0.5 kg /
Since it is less than cm ² , no gas is discharged from the filter once wet with water. The valve that separates the inside of the can from the outside is located in the discharge piping path and generally operates in conjunction with a sensor that detects the temperature or pressure inside the can, so that the air inside the can is not completely replaced with saturated steam. As a result, the path is closed and complete sterilization cannot be performed.

Further, since the filter in this application is placed in the discharge piping system in the sterilizer and the installation space is limited, it is necessary to make the shape compact, and the primary side of the filter receives microbial contamination. Since there is a possibility that there is a possibility that there is a possibility that there is a possibility that there is a possibility that there is a replacement of the filter-element from the filter at the time of filter-replacement, to eliminate the danger to humans, the filter-element is integrated, and the filter-unit can be replaced with a capsule shape There is a need to.

[0009]

To achieve the above object, the present invention provides a fluid inlet 5 for supplying a discharged fluid from a high-pressure steam sterilizer 11 to a housing 4, and a supplied fluid which is filtered and discharged. A hydrophobic element 1 having a fluid outlet 6 for allowing the hydrophobic filter 1a to be incorporated between the fluid inlet 5 and the fluid outlet 6, and a hydrophilic filter-2a.
And the hydrophilic element 2 in which the hydrophilic element 2 is incorporated are made to communicate with each other through the filtrate channel 10 formed in the central portion by disposing the hydrophilic element 2 on the gravity side.
0 is connected to the fluid outlet 6. In addition, the hydrophobic filter-1a and the hydrophilic filter-2
The pore diameter of a is in the range of 0.2 μm to 0.01 μm.

[0010]

With the above construction, the filter unit of the present invention, as shown in FIG. 4, has the high-pressure steam sterilizer 11 and the discharge pipe passages 17 and 18 in which the hydrophilic element 2 is placed on the gravity side with respect to the hydrophobic element 1. It is set in the state of being located at.
At the beginning of the autoclave cycle, as described above, air,
Water vapor and condensed water are discharged, but by the filter unit according to the present invention, air and water vapor of the fluids in these states are filtered by the hydrophobic element 1 of the filtration element 3 and hydrophilic not yet wet with condensed water. The sexual element 2 is also filtered and discharged. After the hydrophilic element 2 is completely wet with the condensed water, the air and water vapor are discharged only from the hydrophobic element 1. Further, the condensed water is discharged only by the hydrophilic element 2. At this time, if the filter element 3 is formed of only the hydrophilic element 2, air and water vapor will not be filtered at all from the time when all the elements are wet with the condensed water (in a so-called air-lock state), and the fluid flow. Will stop.

When the filter element 3 is formed of only the hydrophobic element 1, the air and water vapor can be filtered, but the condensed water is not filtered at all, so the condensed water is accumulated inside the unit and the filter element 3 is submerged. Also in this case, the flow of fluid stops. Further, even when the hydrophobic element 1 is used on the gravity side with respect to the hydrophilic element 2, it is the same as the case where only the hydrophilic element 2 is used from the time when the condensed water submerges the hydrophobic element 1. In this case, the fluid flow also stops.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described based on the embodiments shown in the drawings.
As shown in FIG. 1, FIG. 2 and FIG. 3, the high pressure steam sterilizer exhaust fluid filter unit comprises a filter element 3 composed of a hydrophobic element 1 and a hydrophilic element 2 and a filter housing 4 part accommodating the filter element 3. To be done. The filtration element 3 has a large filtration area per volume,
The filter is pleated in a chrysanthemum shape, and both ends are liquid-tightly sealed. The outside of the filter element 3 is the primary side of filtration, and the liquid filtered by the pleated filter is at the center of the filter. -It has a structure that flows out from the core. The filtration element 3 is composed of a hydrophobic element 1 incorporating a hydrophobic filter-1a on one side and a hydrophilic element 2 incorporating a hydrophilic filter-2a, and a filtrate channel 10 formed in the center of each other through the hydrophobic element 1. It is in communication. This filtration element 3 and a filtration housing 4 having a fluid outlet 6 that accommodates the filtration element 3 and communicates a filtrate flow path 10 of the fluid with the filtration element 3, and a fluid inlet 5 that supplies the filtration fluid to the primary side of the filtration element 3. It consists of.

Hydrophobic filter-1a used for these
And the pore size of the hydrophilic filter-2a is 0.2 μm to 0.0
It must be in the range of 1 μm. If the pore diameter is larger than 0.2 μm, microorganisms such as bacteria and viruses may leak, and if the pore diameter is smaller than 0.01 μm, a predetermined filtration amount cannot be obtained. To set a small hole diameter,
In order to satisfy the filtration amount, it is necessary to increase the filtration area of the filtration element. However, if the filtration areas of the hydrophobic filter-1a and the hydrophilic filter-2a are increased, the volume of the filtration element 3 increases and the installation volume also increases. This is unsuitable because it cannot be made compact because it requires a large amount. In addition, even the smallest microorganisms generally present are 0.1 μm
It can be removed with a 0.2 μm filter, and it is considered that a pore size of 0.01 μm or less is unnecessary even if the removal rate of microorganisms due to the coexistence of a surfactant and the production of new microorganisms are taken into consideration.

The material of the filter-1a of the hydrophobic element 1 is silicon, polytetrafluoroethylene (PTF).
Any essentially hydrophobic microporous membrane made of E), polyvinylidene fluoride (PVDF), polypropylene (PP) or the like can be suitably used. Further, even a microporous film made of an essentially hydrophilic material can be similarly used if it is made hydrophobic by making the film water-repellent by a surface water-repellent agent such as silicon or PTFE. .. Among these, the material particularly preferably recommended for this application is a PTFE microporous membrane which is excellent in repeated thermal resistance.

The material of the filter-2a of the hydrophilic element 2 is an essentially hydrophilic microporous membrane made of regenerated cellulose or nylon, or a microporous membrane made of an essentially hydrophobic material. However, cellulose acetate, polysarsan, polyethersalsan, PVDF, PTFE, which is made into a hydrophilic film by hydrophilicizing the film by hydrophilic treatment such as coating with a surfactant or chemical surface modification, P
Any P-made microporous membrane or the like can be suitably used. An example of a method of manufacturing these filtration elements 3 is a filter-
Pleated with a plastic net or non-woven fabric support material to form an accordion shape, and then filter each
The end portion of is subjected to heat sealing or the like to be integrated to form a cylindrical shape. A cylindrical wire-mesh center core which serves as the filtrate flow channel 10 is set in the central portion, and a reinforcing cylindrical wire-mesh outtube is set on the outer periphery, and liquid-tight end plates 7 are provided at both ends of the cylinder.
Take the step of integrating 8. In order to secure the filtrate flow channel 10, at least one end of the end plate is required to be open at the central portion where it is joined to the center core inner diameter portion.

As the hydrophobic (or hydrophilic) element 1 (or 2), an end plate having one end of the end cap opened is used, and the filtrate flow channel 10 is open only on one side. On the other hand, the hydrophilic (or hydrophobic) element 2 (or 1) is an element in which the filtrate channel 10 is open at both ends. The filtrate passage opening of the hydrophobic element 1 and the filtrate passage opening of one of the hydrophilic elements 2 are liquid-tightly integrated to form a filtration element 3 having a common filtrate outlet. As an example of the method for manufacturing a filter unit including the filtration element 3, the filtrate liquid outlet 3a of the assembly of the filtration element 3 is described.
Is fluid-tightly integrated with the fluid outlet 6 of the filtration housing 4.

The filtration housing 4 has a fluid inlet 5, which is formed by liquid-tightly integrating the outer shell member covering the entire filtration element 3 and the filtration housing 4. Further, the filter unit is not limited to the form in which the inlet and outlet of the liquid are located above and below the inside of the filtration housing 4 as shown in FIGS. 2 and 3, and the hydrophobic element 1 of the filter element during filtration is used.
On the other hand, if the structure is such that the hydrophilic element 2 is positioned on the gravity side, it can be similarly used. For example, when the filter unit is in the state shown in FIG. 2, the opening of the hydrophilic element 2 having the filtrate opening at one end and the end of the hydrophobic element 1 having the filtrate opening at both ends are liquid-tight. An integrated filter element 3 is used. Center
The core, the outtube, the end plate and the housing member can be made of metal or plastic.
A heat-resistant thermoplastic resin such as P, PVDF, polycarbonate, etc. can be particularly preferably used because it has heat resistance to the exhaust steam of high-pressure steam sterilization and the welding work is easy during manufacturing.

[0018]

[Experimental Example 1] As a hydrophilic filter-2, a poly (ether sulfone) hydrophilic membrane (manufactured by Toyo Roshi Kaisha, Ltd., pore size: 0.2)
(μm) is incorporated into the filter element 3 in which 0.1 m ^{2 is} incorporated, and as the hydrophobic filter-1, a filter element 3 in which a PTFE membrane (manufactured by Japan GORE-TEX Co., Ltd., pore diameter: 0.2 μm) is incorporated into 0.5 m ² is hydrophobic. The element 1 was integrated so as to be located on the upper side, and this was housed in the filtration housing 4 made of PP to form a filter unit. The external dimensions of this filter unit are 80 mm in diameter and 200 in total length.
mm.

[0019]

[Experimental Example 2] As a hydrophilic filter-2, a nylon membrane (manufactured by MSI Co., Ltd., pore size: 0.1 μm) was used in an amount of 0.05 m ^2.
As the incorporated element and hydrophobic filter-1,
A filtration element 3 incorporating 0.05 m ^{2 of a} PP membrane (manufactured by Ube Industries, Ltd., pore size: 0.05 μm) was integrated so that the hydrophobic element 1 was located above,
The filter unit was made by putting it in a housing made of steel.
The outer dimensions of this filter unit are 80 mm in diameter and 130 mm in total length.

[0020]

[Experimental Example 3] As a hydrophilic filter-2, a polyerither-sulfone hydrophilization membrane (manufactured by Toyo Roshi Kaisha, Ltd., pore size: 0.
2 μm) was incorporated to prepare 0.1 m ^{2 of} the filter element 3. The external dimensions of this filter unit are 80m in diameter.
m, total length 130 mm.

[0021]

[Experimental Example 4] As a hydrophobic filter-1, a PTFE membrane (manufactured by Japan Gore-Tex Co., Ltd., pore size: 0.2 μm)
m) 0.1 m ² incorporated into the filter element 3 only PP
It was housed in a housing made of the same and a filter unit was prepared in the same manner as in Experimental Example 1. The outer dimensions of this filter unit are 80 mm in diameter and 130 mm in total length.

[0022]

[Experimental Example 5] As a hydrophilic filter-2, a poly (ether sulfone) hydrophilic membrane (manufactured by Toyo Roshi Kaisha, Ltd., pore size: 0.2)
filter element 3 incorporating 0.05 m ² ) and a PTFE membrane (manufactured by Japan Gore-Tex Co., Ltd., pore diameter: 0.2 μm) of 0.05 m ² as the hydrophobic filter-1.
The built-in filter element 3 was integrated in the same manner as in Experimental Example 1, except that the hydrophobic element 1 was located at the bottom when used, and the filter element was housed in the PP filter housing 4 to form a filter unit. The outer dimensions of this filter unit are 80 mm in diameter and 130 mm in total length. The above-mentioned 5 types of filter units were attached to the end portion of the discharge pipe of a high-pressure steam sterilizer (manufactured by Hirayama Seisakusho Co., Ltd.) having an internal capacity of 60 liters and subjected to a test. The results are shown in Table 1 and Table 2.
Shown in. Table 1 shows the types of filter units and the amount of discharged fluid.

[0023]

[Table 1]

From the results shown in Table 1, the sterilization in Experimental Examples 3, 4, and 5 has less amount of air, vapor, and condensate than those in Experimental Examples 1, 2 and no filter, and the high pressure is high. This suggests that sterilization may be performed without the saturated steam state inside the steam sterilizer can. Table 2 relates to the sterility of the exhaust fluid.

[0026]

[Table 2]

The sterility of the discharged fluid in Table 2 above is determined by spraying dry bacterial cells of the heat-resistant spore-forming bacterium Batillus subtilis onto the inner surface of the can of the high-pressure steam sterilizer and the discharge pipe in front of the filter unit to normally perform sterilization operation. I went. The pipe after the filter unit liquid outlet was put into a liquid medium (triptycease soy broth medium) so that all the discharged fluid including gas came into contact with the liquid medium. The amount of the medium was set to 5 liters so that the temperature of the liquid medium became high and the number of collected bacterial cells was not affected. After sampling the discharged liquid,
The medium was cultivated at a temperature of 32 ° C. for 7 days, and the presence or absence of bacteria was determined by the turbidity of the medium. From the results shown in Table 2, it can be seen that the installation of the filter is effective for sterilizing the discharged fluid.

[0028]

INDUSTRIAL APPLICABILITY As described above, according to the present invention, the air, steam, and condensed water, which may be discharged from the can of the high-pressure steam sterilizer, may contain microbiological contaminants derived from the substance to be sterilized. 3 utilizes the characteristics of both the hydrophobic and hydrophilic elements, and the hydrophilic element 2 is positioned on the gravity side with respect to the hydrophobic element 1, so that air, water vapor,
Condensed water can be discharged smoothly. At that time, air containing microbiological contaminants derived from the substance to be sterilized by using a filter having a pore size of 0.2 μm to 0.01 μm,
The steam and condensed water can be completely filtered and discharged to the outside. Further, since the filter element is made compact, the device can be downsized, and the filter element can be replaced biologically safely and easily.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention, in which (a) is a partial cutaway perspective view and (b) is a partial vertical cross-sectional side view of a filtration element.

FIG. 2 is a schematic vertical sectional view of the present invention.

FIG. 3 is a schematic vertical sectional view of the present invention.

FIG. 4 is a schematic diagram of an exhaust fluid filtration system of a high pressure steam sterilizer.

[Explanation of sign]

 DESCRIPTION OF SYMBOLS 1 Hydrophobic element 1a Hydrophobic filter-2 Hydrophilic element 2a Hydrophilic filter-3 Filtration element 4 Filtrate housing 5 Fluid inlet 6 Fluid outlet 7 End plate 8 End plate 9 Connection part 10 Filtrate flow path 11 High pressure steam sterilizer 12 Sterilized object 13 Valve 14 High pressure steam sterilizer lid 15 Water 16 Heater 17 Fluid introduction pipe 18 Fluid discharge pipe

Claims (2)

[Claims] 1. A fluid inlet (5) for supplying an exhaust fluid from a high pressure steam sterilizer (11) to a filter housing (4),
A hydrophobic element (6) having a fluid outlet (6) through which the supplied fluid is filtered and discharged, and incorporating a hydrophobic filter (1a) between the fluid inlet (5) and the fluid outlet (6). 1) and a hydrophilic element (2) incorporating a hydrophilic filter (2a), the hydrophilic element (2) is arranged on the gravity side, and the filtrate channel (10) is formed in the center part of each other. ), The central part filtrate flow path (10) is connected to the fluid outlet (6), the high pressure steam sterilizer discharge fluid filter unit. 2. The high pressure steam sterilizer exhaust fluid filter unit according to claim 1, wherein the hydrophobic filter (1a) and the hydrophilic filter (2a) have a pore size in the range of 0.2 μm to 0.01 μm.