JP5104530B2 - Centrifuge - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a centrifuge that rotates a rotor by reducing the pressure in the chamber, and more particularly, to a centrifuge that shortens the evacuation time in the chamber.

  For example, when the rotational speed of a rotating body reaches 20,000 revolutions per minute, the temperature of the rotating body rises due to windage, the sample inside the sample is denatured, or the output of the drive device is insufficient. In some cases, the rotation speed cannot be increased to Therefore, in some centrifuges, the inside of the chamber is decompressed with a vacuum pump to reduce the influence of windage loss. Particularly, in a centrifuge called a so-called ultracentrifuge having a maximum rotation speed of 40,000 revolutions or more per minute, the temperature rise due to windage increases, so the degree of vacuum in the rotation chamber is further increased. Therefore, an oil diffusion vacuum pump that can obtain a high vacuum (the ultimate pressure of the pump alone is approximately 0.0001 Pa or more) is used.

  Since the oil diffusion vacuum pump requires a back pressure of about 20 Pa to operate, it has a simple mounting structure and does not require special handling as an auxiliary pump for obtaining this back pressure, and it is easy to obtain a high vacuum. An oil rotary vacuum pump is used.

  On the other hand, vacuum pumps include not only oil rotary vacuum pumps, but also dry vacuum pumps such as diaphragm vacuum pumps and scroll vacuum pumps. Diaphragm vacuum pumps are inferior in ultimate vacuum, until the required back pressure is reached. The scroll-type vacuum pump has a drawback in that it takes time, and until recently, there has been a difficulty in sealing performance, so that it cannot be used for this type of centrifuge.

  In such a centrifuge, if a sample leaks from the rotating body into the chamber during rotation, the sample is sucked into the vacuum pump together with air and discharged from the vacuum pump to the outside of the device. If the sample is pathogenic or toxic, it may be discharged as it is, which may cause a biohazard that can infect humans or laboratory animals in the room.

  Therefore, when separating a biological sample with high risk, in order to reduce the risk of sample discharge, as described in Patent Document 1 and Patent Document 2, piping of a pipe connecting a centrifuge chamber and a vacuum pump is used. There is a biohazard measure to prevent the sample from being released to the outside of the centrifuge by connecting a filter in the middle and capturing it with a filter while it is sucked into the vacuum pump even if a dangerous sample leaks into the chamber. Generally taken.

  A filter used in this type of centrifuge is called a HEPA filter (High Efficiency Particulate Air Filter), and a filter having a collection rate of 99.97% or more for particles having a particle size of 0.3 μm is generally used. Is.

Japanese Utility Model Publication No. 62-36532 JP 59-32966 A

  As a biohazard measure, in a centrifuge incorporating a HEPA filter, the filter also prevents the flow of air instead of collecting particulates, so the time to decompress the chamber is slower than a centrifuge that does not incorporate a HEPA filter. There's a problem. This conventional centrifuge will be described with reference to FIG.

  In FIG. 5, a centrifuge 201 has a frame 202 having a substantially square cross-sectional shape when viewed from above, and a titanium alloy for holding a sample container (not shown) such as a sampling tube in the frame 202. Alternatively, a rotor 205 made of aluminum alloy or the like, a motor 204 for applying a rotational driving force to the rotor 205, and a space for accommodating the rotor 205 partitioned by the chamber 203 are provided. The inside of the chamber 203 is depressurized by two vacuum pumps that operate during operation of the rotor 205. This decompression can reduce heat generation due to friction with the remaining air while the rotor 205 is rotating.

  An oil diffusion vacuum pump 206, vacuum pipes 208a and 208b, and an oil rotary vacuum pump 213 are arranged in the vacuum path, and a HEPA filter 212 is attached between the vacuum pipes 208a and 208b. In the centrifuge using the oil rotary vacuum pump 213, the HEPA filter 212 is usually connected between the oil diffusion vacuum pump 206 and the oil rotary vacuum pump 213. The provision of the HEPA filter 212 at this position is based on the structural reason of the oil rotary vacuum pump 213. Even if it is desired to provide the HEPA filter 212 behind the oil rotary vacuum pump 213, the expected performance cannot be maintained. Because.

In the case of the oil rotary vacuum pump 213, since oil mist is discharged together with exhaust from the discharge port, it is common to connect an oil mist trap 214 for capturing the oil mist to the discharge port. It is not realistic to connect the HEPA filter without connecting the oil mist trap 214. Even if a HEPA filter is connected behind the oil mist trap 214, the oil mist trap 214 cannot be expected to collect 100% of the oil mist, so the HEPA filter is likely to be clogged. Another problem is sterilization. That is, when the HEPA filter is provided on the discharge port side of the oil rotary vacuum pump 213, the oil rotary vacuum pump 213 needs to be sterilized in order to sterilize the chamber and the vacuum path. However, there outlet of the pump portion of the oil-rotary vacuum pump 213 is in the oil, inhaled biological sample from that would be released into the oil, sterilization that Do difficult. Therefore , it is not practical to connect a HEPA filter to the discharge port side of the oil rotary vacuum pump 213.

  For the above reasons, the HEPA filter 212 must be connected between the oil diffusion vacuum pump 206 and the oil rotary vacuum pump 213 as shown in FIG. Since the pressure is negative with respect to the atmospheric pressure, only 101.3 kPa (1 atm) is generated at the maximum. For this reason, when a HEPA filter having a large flow resistance is connected, the time required to reach the back pressure at which the oil diffusion vacuum pump operates becomes longer, and the time required to reach a high vacuum is significantly greater than when the HEPA filter 212 is not provided. It was increasing.

  Further, in this type of centrifuge, it is often necessary to keep the temperature of the sample at a constant temperature, for example, 4 ° C., and the chamber 203 is generally provided with a bowl 203 d for heat exchange. A semiconductor element called a thermo module 210 is attached to the bowl 203d, and the bowl 203d is cooled or warmed by the thermo module 210. In addition, there is also a type in which a tube is wound around the bowl, and the temperature of the bowl is lowered by flowing a refrigerant with a refrigerator. However, since moisture in the air is condensed on the surface of the bowl, the vacuum pump sucks and exhausts the condensed moisture together with the air in the chamber. This moisture is trapped in the HEPA filter 212, evaporates under reduced pressure, and part of the water flows back into the chamber 203, which hinders improvement in the degree of vacuum in the chamber 203.

  As described above, the centrifuge 201 with the HEPA filter 212 added between the oil diffusion vacuum pump 206 and the oil rotary vacuum pump 213 has an advantage that there is no fear of discharging dangerous particles outside the apparatus, but the vacuum exhaust time Has the disadvantage of becoming longer. In a centrifuge having an oil diffusion vacuum pump with an exhaust speed of about 100 L / sec and an oil rotary vacuum pump of about 160 L / min, the pump normally starts to operate until the vacuum level in the chamber reaches 1 Pa. While it takes about 10 to 20 minutes, a centrifuge equipped with a HEPA filter between the oil diffusion vacuum pump and the oil rotary vacuum pump may take more than one hour, and the user has a long waiting time. This is a factor that reduces the efficiency of centrifugation.

  Accordingly, an object of the present invention is to prevent a delay in evacuation time in a centrifuge equipped with a filter.

  Still another object of the present invention is to provide a centrifuge capable of performing sterilization of the vacuum path and the vacuum pump without any trouble even if the installation position of the filter is moved to the downstream side of the vacuum path.

  Of the inventions disclosed in the present application, typical features will be described as follows.

  According to one aspect of the present invention, a rotor that is rotationally driven by a motor while holding a sample, a chamber that houses the rotor, a vacuum pump that depressurizes the chamber, and a vacuum pipe that connects the chamber and the vacuum pump And using a dry vacuum pump as the vacuum pump, and collecting a biological sample on the discharge port side of the dry vacuum pump without providing a filter in the vacuum piping from the chamber to the dry vacuum pump A filter having a filter was provided, and the air in the chamber was discharged to the outside through the filter. For example, a HEPA filter may be used as a filter having the ability to collect a biological sample. As the dry vacuum pump, for example, a scroll type dry vacuum pump is used, and a valve for closing the flow path is preferably provided in the inlet side vacuum piping of the scroll type dry vacuum pump.

  According to another feature of the invention, a second vacuum pump is further provided in the vacuum piping from the chamber to the dry vacuum pump. For example, an oil diffusion vacuum pump or a mechanical booster vacuum pump is preferably used as the second vacuum pump.

  According to still another aspect of the present invention, a pressure gauge is provided between the discharge port of the dry vacuum pump and the filter. A buffer tank may be provided between the discharge port of the dry vacuum pump and the filter, and a pressure gauge may be provided in the buffer tank to measure the buffer tank pressure. The measured value of the pressure gauge is monitored by the monitoring means, but the monitoring means may be configured to have the function in the control unit that controls the whole centrifuge, or with a monitoring function that issues an alarm when the set pressure is exceeded The pressure gauge may be used. The monitoring means is configured to issue an alarm when the measured pressure value exceeds a predetermined pressure.

According to the first aspect of the present invention, since a dry vacuum pump and an oil diffusion vacuum pump are used as the vacuum pump , the time required for vacuum suction can be reduced and a high degree of vacuum can be achieved . In addition, since a filter having the ability to collect a biological sample is connected to the discharge port of the dry vacuum pump, the evacuation time of the centrifuge can be shortened without increasing the vacuum flow path resistance. Furthermore, since there is no filter in the vacuum pipe, there is no problem that moisture trapped in the filter causes a decrease in the degree of vacuum.

  According to invention of Claim 2, since a filter is a HEPA filter, a favorable collection rate can be achieved with respect to a biological sample.

  According to the invention of claim 3, since the dry vacuum pump is a scroll type dry vacuum pump, even when the chamber and the vacuum exhaust system are sterilized, for example, formalin gas is injected into the chamber and the vacuum pump is used. By sucking, gas can reach the inside of the pump as well as piping from the chamber as well as a dry vacuum pump, so that it can be sterilized reliably.

  According to the invention of claim 4, since the valve for closing the flow path is provided at the inlet of the scroll-type dry vacuum pump, the valve is closed if the power supply is interrupted due to a power failure or the like. By doing so, it is possible to prevent the sucked air from flowing back from the scroll-type dry vacuum pump into the chamber.

According to the invention of claim 5 , since the pressure gauge is provided between the discharge port of the dry vacuum pump and the filter, it is easy to use the pressure gauge to clog the filter due to suction of dust, dust and the like. Can be confirmed.

According to the invention of claim 6 , since the buffer tank is provided between the discharge port of the dry type vacuum pump and the filter, the instantaneous pressure rise can be reduced, and the influence of pulsation hindering the pressure measurement can be eliminated, Compared to the case where there is no tank, the number of cases where the pressure temporarily increases to reach a predetermined pressure is reduced, and the effect of extending the filter replacement cycle can be expected.

According to the seventh aspect of the present invention, when the pressure is monitored and the predetermined value is exceeded, an alarm is issued. Therefore, when the user neglects to periodically replace the filter, Even when the filter is clogged faster than expected due to suction, etc., it is possible to detect clogging of the filter before the pipe is disconnected or the filter is damaged, and it is possible to prevent dangerous substances from leaking out of the machine.

  The above and other objects and novel features of the present invention will become apparent from the following description and drawings.

  Hereinafter, a centrifuge according to an embodiment of the present invention will be described with reference to FIG. In FIG. 1, the main points different from the conventional example shown in FIG. 5 are that the vacuum pump is changed from the oil type (oil rotary vacuum pump 213) to the dry type and the installation position of the HEPA filter is changed.

  In FIG. 1, a centrifuge 1 includes a frame 2, a chamber 3, a motor 4, a rotor 5, a scroll-type dry vacuum pump 7 (first vacuum pump), and an oil diffusion vacuum pump 6 (second vacuum). Pump), vacuum pipes 8a and 8b, and a HEPA filter 12. The frame 2 forms a skeleton and an outer shell of the centrifuge 1, and an operation panel 15 is disposed on the upper part thereof. A plastic cover 14 is provided on the upper portion of the frame 2, and a hole 14 a for accessing a rotor chamber 3 a described later is formed in the cover 14. In the chamber 3, for example, a bowl 3 d made of an aluminum material is installed so as to surround the rotor 5. Between the bottom of the bowl 3d and the bottom member of the chamber 3, a thermo module 10 for temperature control is sandwiched. The thermo module 10 is controlled by the control device 9, and the cold heat is transmitted to the bowl 3d formed of a material having high thermal conductivity (for example, aluminum). When the degree of vacuum of the rotor chamber 3a is low, the temperature inside the rotor chamber 3a The rotor 5 is cooled or warmed through the air to maintain a uniform temperature (eg, 4 ° C.), and when the degree of vacuum in the rotor chamber 3a is high, the rotor is similarly driven by radiation heat transfer between the bowl 3d and the rotor 5. 5 is kept at a uniform temperature. As a result, when the windage loss during rotation of the rotor 5 is large, the temperature rise is cooled, and control is performed so that the temperature rise of the sample container in the rotor 5 due to high-speed rotation during centrifugation does not occur. The temperature of the rotor 5 is detected by a temperature sensor (not shown) fixed to the bottom member of the chamber 3 and measured by the control device 9.

  In the upper part of the chamber 3, a hole 3b that connects the rotor chamber 3a and the hole 14a is formed, and a door 16 that closes the hole 3b and seals the rotor chamber 3a is provided. The door 16 is provided with a sensor (not shown) that detects opening and closing, and the closing state of the door 16 is monitored. A through hole 3c that communicates the inside and outside of the rotor chamber 3a is provided in the lower portion of the chamber 3. The motor 4 has an output shaft 4a, and a shaft case 4b is provided so as to cover the output shaft 4a. The motor 4 is elastically fixed to the frame 2 so that the housing of the motor 4 is positioned below the chamber 3. The shaft case 4b penetrates the through hole 3c and projects into the rotor chamber 3a. In the through hole 3c, the shaft case 4b is sealed by a seal member (not shown), and the airtightness of the rotor chamber 3a can be maintained.

  The rotor 5 is formed with a plurality of holes 5a for inserting a sampling tube or the like into which a sample is inserted, and is connected to the output shaft 4a of the motor 4 and rotated. In the present embodiment, the rotation speed of the motor 4 is, for example, 40,000 rotations or more per minute, and the sample is centrifuged by the centrifugal force generated by this rotation. Normally, when the rotor 5 rotates at high speed under atmospheric pressure, the rotor 5 generates heat due to windage. Further, the high rotation of the rotor 5 is suppressed by atmospheric resistance under atmospheric pressure. Therefore, it is necessary to extract the air in the chamber 3 during the centrifugal separation to make a vacuum state and to suppress windage loss.

  The oil diffusion vacuum pump 6 has a suction side connected to the rotor chamber 3a, and a discharge side connected to the suction port 11a of the scroll type dry vacuum pump 7 via the vacuum pipes 8a and 8b and the valve 81. The oil diffusion vacuum pump 6 is a known device that includes liquid oil inside and discharges air in the rotor chamber 3a by evaporation / condensation inside the oil. Since the oil diffusion vacuum pump 6 requires a certain amount of back pressure (about 20 Pa) in order to operate, an auxiliary pump is required to obtain this back pressure. It functions as an auxiliary pump for the diffusion vacuum pump 6.

  What is important here is that a dry type vacuum pump (scroll type dry vacuum pump 7) is used as a vacuum pump on the rear stage side. By using a dry type vacuum pump, it is no longer necessary to provide an oil mist trap on the discharge side, and a HEPA filter 12 can be provided at that position. The HEPA filter 12 can be provided at an arbitrary position downstream of the discharge port 11b of the dry type vacuum pump, and is connected via the pipe 13 in this embodiment. The HEPA filter 12 is fixed to a part of the frame 2 by a fixing member.

When the installation position of the HEPA filter 12 is arranged on the most downstream side of the vacuum path, sterilization in the scroll-type dry vacuum pump 7 must be considered when the rotor chamber 3a and the vacuum path are sterilized. It has been a dry-type vacuum pump, since it does not also used sealability is good oil, can be easily sterilized by simply adding a sterilizing gas in the path leading to the HEPA filter 12 from the rotor chamber 3 a. The sterilizing gas is, for example, formalin gas.

  If the scroll-type dry vacuum pump 7 is used, if the power supply is cut off due to a power failure or the like, the sucked air flows back from the scroll-type dry vacuum pump 7 and returns to the rotor chamber 3a. There is a fear. Therefore, in this embodiment, the valve 81 is provided upstream of the scroll-type dry vacuum pump 7, and in such a case, the valve 81 is shut off and the vacuum path can be closed. As the valve 81, for example, an electromagnetic valve can be used.

According to the present embodiment, it is not necessary to provide a HEPA filter in the vacuum pipe even when taking measures against biohazards, so that the vacuum exhaust time in the chamber 3 can be shortened. Normally, when a HEPA filter is incorporated in a pipe connecting the chamber 3 and the first vacuum pump, the pressure sucked through the HEPA filter is only 101.3 kPa (1 atm) at maximum. On the other hand, the pressure resistance (positive pressure) of this type of filter is 101.3 kPa or more.
The HEPA filter (trade name: HEPA Capsule 12144) sold by Corporation has a container made of resin such as polypropylene or nylon and can withstand a maximum pressure of 340 kPa. Even if the flow path resistance is large, a pressure of three times or more is applied, and quick exhaust is possible as compared with the case where it is arranged on the suction side of the vacuum pump. Further, the pressure resistance can be further increased by using a HEPA filter contained in a metal container.

  The air in the chamber 3 sucked by the two vacuum pumps is finally exhausted from the discharge port 12a through the HEPA filter 12 to the outside of the centrifuge 1. Even if a virus or fungus with pathogenicity or toxicity is mixed in the vacuum pipes 8a and 8b, it is captured by the HEPA filter 12, so that the discharge of the virus or fungus into the atmosphere can be prevented. Biohazard prevention effect can be expected. Furthermore, even when replacing the HEPA filter, if formalin gas is injected from the inlet (not shown) of the sealed chamber 3 and discharged from the HEPA filter into the water, it is safe and reliable from the chamber 3 to the HEPA filter. Since sterilization is possible, there is no problem in ensuring safety when replacing the filter. The inlet for injecting gas is closed so as not to affect the degree of vacuum in the chamber 3 during normal use.

  Next, a second embodiment of the present invention will be described with reference to FIG. 2 are the same as those in FIG. 1, and therefore, the repeated description is omitted. Unlike the centrifuge of FIG. 1, the centrifuge 1a shown in FIG. 2 does not have the oil diffusion vacuum pump 6 corresponding to the second vacuum pump, and the chamber 3 and the scroll-type dry vacuum pump 7 have vacuum pipes 108a and 108b. It communicates directly at. A valve 81 is provided between the vacuum pipes 108a and 108b, and the vacuum flow path can be shut off. The air in the chamber 3 sucked by the scroll type dry vacuum pump 7 is exhausted to the outside of the centrifuge 1 through the HEPA filter 12 connected to the discharge port 11b by the pipe 13.

  As described above, according to the above-described embodiment, since there is no HEPA filter between the chamber 3 and the scroll-type dry vacuum pump 7 which is the first vacuum pump, the HEPA filter does not become a resistance to vacuum exhaust. In addition, there is no possibility that moisture condensed in the bowl 3 d corresponding to the evaporator for heat exchange is captured by the HEPA filter in the vacuum path and the moisture flows back into the chamber 3. Therefore, a good vacuum state can be realized without worrying about a decrease in the degree of vacuum.

  According to the second embodiment, when replacing the HEPA filter 12, for example, a sterilization pipe (not shown) is provided in the chamber 3, and a sterilizing gas such as formalin gas is injected into the chamber and is exhausted by a vacuum pump. Thus, the flow path for discharging the air in the chamber 3 can be sterilized to every corner, and the contaminated HEPA filter 12 can be handled safely. The sterilization piping is sealed with a valve or the like during normal use.

  Both the oil diffusion vacuum pump 6 and the scroll-type dry vacuum pump 7 are hermetically sealed from the outside except the suction port and the discharge port, and there is no fear of gas leaking from the inside of the pump to the outside. In addition, the scroll type dry vacuum pump 7 includes a pump having a suction port called a gas ballast valve for introducing air from the outside into the pump compression chamber so that moisture is not condensed inside the pump compression chamber depending on the type. However, if the gas ballast is closed, the inside of the pump can be maintained, so there is no risk of gas leakage.

  Next, a third embodiment of the present invention will be described with reference to FIG. 3 are the same as those in FIG. In FIG. 3, a pressure gauge 17 a is provided in a part of the pipe connecting the scroll-type dry vacuum pump 7 and the HEPA filter 12, and the output of the pressure gauge 17 a is input to the control device 9. It was configured to monitor the pressure on the input side. Therefore, in this embodiment, the shape of the discharge port 11c of the scroll type dry vacuum pump 7 is formed by a member that branches into a T shape.

  Here, when the HEPA filter 12 is regarded as a circular pipe having a pipe resistance, the pressure difference P before and after the HEPA filter 12 is P∝λ · v2. Here, λ is the pipe resistance, and v is the flow velocity. That is, v increases at the start of evacuation when there is a large amount of gas (air) in the chamber 3, so the pressure between the scroll-type dry vacuum pump 7 and the HEPA filter 12 is large immediately after the start of evacuation. As the air becomes leaner, the pressure decreases as the exhaust fluid decreases. On the other hand, the rotor 5 holding the sample is stopped immediately after the start of evacuation or starts to rotate, so that the pressure between the scroll-type dry vacuum pump 7 and the HEPA filter 12 should be less than that of the HEPA filter 12. Even if the allowable value is exceeded, an abnormality can be determined immediately after the start of operation. When a predetermined pressure is reached during the operation of the centrifuge 1b, an alarm is turned on on the operation panel 15. As a result, it is possible to replace the filter before there is a possibility of sample leakage, that is, before the rotor rotates at high speed.

  In addition, when a predetermined pressure is reached, an alarm may be generated and the vacuum pumps (6, 7) may be stopped. Furthermore, when the rotor 5 has started rotating, the rotor 5 may be stopped.

  Further, when the pressure increases and approaches a predetermined pressure, the valve 81 is closed. When the pressure decreases, the valve 81 is opened again to operate the scroll-type dry vacuum pump 7, and when the pressure approaches the predetermined pressure again, the valve 81 is opened. You may make it repeat these, when is closed.

  As described above, even if the pressure between the scroll-type dry vacuum pump 7 and the HEPA filter 12 rises to an allowable value or more due to clogging of the HEPA filter 12, the user can immediately know the abnormal state. The HEPA filter 12 can be replaced at an appropriate time. Therefore, even if the user neglects to replace the filter regularly, or when the filter is clogged faster than expected due to suction of dust, dust, etc., before the pipe 13 comes off or the HEPA filter 12 is damaged. It can be detected in advance and can prevent dangerous substances from leaking out of the machine.

  Next, a fourth embodiment of the present invention will be described with reference to FIG. 4 differs from FIG. 3 in that an arbitrarily shaped buffer tank 18 having an appropriate capacity is provided between the scroll-type dry vacuum pump 7 and the HEPA filter 12, and the pressure gauge 17b is replaced with a buffer tank. 18 was attached. The buffer tank 18 is, for example, a stainless cubic or cylindrical container, and has a sufficiently higher pressure resistance than the HEPA filter 12. The HEPA filter 12 is connected to the outlet side of the buffer tank 18 via a pipe 19b.

  By using the buffer tank 18 in this way, even if a sudden fluid movement (increase in the flow velocity) occurs at the start of evacuation, the pressure increase can be mitigated, and temporarily compared with the case where there is no tank. The number of cases in which the measurement by the pressure gauge is erroneously performed such that the pressure increases and reaches a predetermined pressure is reduced. As a result, since the instantaneous pressure rise can be reduced, the effect of extending the filter replacement period can be expected, and the leakage of exhaust gas due to damage to the pipes 19a and 19b and the HEPA filter 12 can be more effectively prevented.

  As mentioned above, although demonstrated based on embodiment which shows this invention, this invention is not limited to the above-mentioned form, A various change is possible within the range which does not deviate from the meaning. For example, a mechanical booster vacuum pump may be used instead of the oil diffusion vacuum pump 6, or the vacuum pump may be configured in three stages and the HEPA filter may be provided on the discharge side of the most downstream vacuum pump.

  In addition, a pressure gauge with an alarm function may be used to issue an alarm such as a buzzer when the set pressure value is reached. If comprised in this way, it is not necessary to change the structure by the side of the control apparatus 9, and monitoring of a pressure value is easily realizable.

It is a schematic sectional drawing of the centrifuge which concerns on embodiment of this invention. It is a schematic sectional drawing of the centrifuge which concerns on the 2nd Embodiment of this invention. It is a schematic sectional drawing of the centrifuge which concerns on the 3rd Embodiment of this invention. It is a schematic sectional drawing of the centrifuge which concerns on the 4th Embodiment of this invention. It is a schematic sectional drawing of the centrifuge by a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1a, 1b, 1c Centrifuge 2 Frame 3 Chamber 3a Rotor room 3b Hole 3c Through-hole 3d Bowl 4 Motor 4a Output shaft 5 Rotor 5a Hole 6 Oil diffusion vacuum pump 7 Scroll type dry vacuum pump
8 Vacuum piping 9 Control device 10 Thermo module 11a Suction port 11b, 11c Discharge port 12 HEPA filter 13 Piping 14a Hole 15 Operation panel 16 Door 17a, 17b Pressure gauge 18 Buffer tank 19a, 19b Piping 201 Centrifuge 202 Frame 108, 208a, 208b Vacuum piping 203d Bowl 204 Motor 205 Rotor 210 Thermo module 212 HEPA filter 213 Oil rotary vacuum pump 214 Oil mist trap

Claims (7)

A rotor that is rotationally driven by a motor while holding the sample;
A chamber containing the rotor;
A dry vacuum pump for reducing the pressure in the chamber;
An oil diffusion vacuum pump provided between the chamber and the dry vacuum pump;
Between said chamber and the oil diffusion vacuum pump, and a centrifuge having a vacuum pipe connecting between said oil diffusion vacuum pump said dry vacuum pump,
A centrifuge characterized by providing a filter having a capability of collecting a biological sample on the discharge port side of the dry vacuum pump, and discharging the air in the chamber to the outside through the filter.   The centrifuge according to claim 1, wherein the filter is a HEPA filter.   The centrifuge according to claim 2, wherein the dry vacuum pump is a scroll type dry vacuum pump.   The centrifuge according to claim 3, wherein a valve for closing the flow path is provided at an inlet of the scroll-type dry vacuum pump. The centrifuge according to any one of claims 1 to 4 , wherein a pressure gauge is provided between a discharge port of the dry vacuum pump and the filter. 6. The centrifuge according to claim 5 , wherein a buffer tank is provided between a discharge port of the dry vacuum pump and the filter, and the pressure gauge is provided in the buffer tank. The centrifuge according to claim 5 or 6 , wherein monitoring means for monitoring a measured value of the pressure gauge is provided, and the monitoring means issues an alarm when the measured value exceeds a predetermined pressure.

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