JP3772640B2 - Centrifuge - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to the safety of a centrifuge that handles flammable samples.
[0002]
[Prior art]
Conventionally, a centrifuge having a rotor that can be rotated at a high speed by a driving device and can store a sample is used for sample separation work or the like. There are various types of samples to be accommodated, but depending on the work content, there are cases in which flammable organic solvents are handled. In this case, the operator is working while paying careful attention not to ignite, but the risk of the sample igniting and exploding for some reason was not zero. For example, if a spark occurs when the rotating rotor cover is detached and a flammable sample leaks out of the tube containing the sample, and the metallic cover and the rotor collide at high speed, this spark is applied to the sample. The case where it ignites is raised. Therefore, it is conceivable to reduce the air amount (oxygen amount) by rotating the rotor in a vacuum or in a reduced pressure state to make it difficult to ignite, but in this case, the rotor is rotated in a vacuum state as described above. There is a problem that the rotor chamber of the machine and the rotor itself need to have a vacuum resistant configuration, and the handling and the configuration of the centrifuge are complicated. The original purpose of evacuation is to reduce the windage loss of the rotating rotor.
[0003]
Japanese Utility Model Laid-Open No. 03-59053 discloses a device for rotating a rotor in an inert gas atmosphere, thereby suppressing the risk of ignition. However, even if the inert gas is sealed in the rotor chamber, there is a possibility of ignition if the oxygen concentration increases due to air entering from the outside during the rotor rotation due to some factor. In addition, since the inert gas filling level is checked by the operator's eyes and ears, if it is overlooked due to a human error even though the inert gas filling level is low There is a risk of ignition.
[0004]
[Problems to be solved by the invention]
As described above, when handling flammable organic solvents, the rotor is rotated under an inert gas atmosphere, and the filling degree of the inert gas is checked visually or audibly. There is a problem in that there is a risk of ignition if it is overlooked even though the degree of gas filling is low.
[0005]
An object of the present invention is to solve the above problems, confirm that the atmosphere in the rotor chamber is replaced with an inert gas, and if this replacement state is lower than a predetermined initial condition, there is a risk of ignition. Therefore, it is to provide a centrifuge excellent in safety to prevent ignition by stopping automatically.
[0006]
[Means for Solving the Problems]
The purpose is to fill the rotor chamber that rotates the rotor containing the sample with inert gas so as not to ignite, and to monitor that the rotor chamber is always filled with a certain inert gas. This is achieved by stopping the operation of the centrifuge when the possibility of ignition exceeds a certain value.
[0007]
A centrifuge provided with a drive device, a rotor that can be rotated by the drive device and can contain a flammable organic solvent, a rotor chamber that houses the rotor, and a supply means for filling the rotor chamber with an inert gas Is achieved by measuring the oxygen concentration in the rotor chamber and providing a control unit for stopping the driving device when the measured value exceeds a predetermined value.
[0008]
A centrifuge provided with a drive device, a rotor that can be rotated by the drive device and can contain a flammable organic solvent, a rotor chamber that houses the rotor, and a supply means for filling the rotor chamber with an inert gas Is achieved by measuring the inert gas concentration in the rotor chamber and further providing a control unit for stopping the driving device when the measured value falls below a predetermined value.
[0009]
A centrifuge provided with a drive device, a rotor that can be rotated by the drive device and can contain a flammable organic solvent, a rotor chamber that houses the rotor, and a supply means for filling the rotor chamber with an inert gas Is achieved by measuring the concentration of the sample leaking into the rotor chamber and providing a control unit for stopping the driving device when the measured value exceeds a predetermined value.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
This embodiment will be described with reference to FIGS. FIG. 1 is a partially longitudinal side view showing a centrifuge in the present embodiment, and FIG. 2 is a flowchart showing a processing method after gas concentration detection in the centrifuge. The centrifuge main body holds a sample to be centrifuged, and a driving motor 2 that is a driving device that rotationally drives a rotor 1 that rotates at high speed, a rotor chamber 3 that houses the rotor 1, a door 4 that can close the rotor chamber, and a drive Control unit 5 for controlling the centrifuge body such as motor 2, operation unit 6 for operating / inputting the main body, supply port 7 for introducing inert gas into rotor chamber 3, discharge port 8 for discharging inert gas, A gas cylinder 9 for supplying an active gas, an oxygen concentration meter 10 for measuring the oxygen concentration in the rotor chamber 3, a buffer tank 11 for stably measuring the oxygen concentration, a communication passage for connecting and communicating the rotor chamber 3 and the buffer tank 11 12 is comprised. As an operation procedure of the centrifuge having such a configuration, an operator first opens a valve of the gas cylinder 9 and causes an inert gas to flow into the rotating chamber 3. The oxygen concentration or inert gas concentration in the rotating chamber 3 or the buffer tank 11 is measured with a densitometer, and if it is determined that there is no problem, the drive motor 2 of the centrifuge is started by operating the start switch. Separation work can be started. Of course, when there is a problem in density, the drive motor 2 is controlled not to start even if the operator presses the start switch. Alternatively, if the operator has pressed the start switch once before reaching the predetermined concentration, the drive motor 2 may be controlled to be automatically started when the concentration has no problem. As another method, the drive motor 2 may be set at a constant rotational speed without any problem during concentration measurement, and if there is no problem in concentration, acceleration control may be performed from there. The valve opening and closing of the gas cylinder 9 is manually operated by an operator, but may be controlled to be automatically opened and closed as necessary.
[0011]
The sample is loaded into the rotor 1 and separated by centrifugal force due to high speed rotation. In general, in order to take in and out the sample, the rotor 1 is generally composed of a rotor body 13 for holding the sample and a rotor cover 14 for reducing windage loss during high-speed rotation and preventing leakage of the sample to the outside. Occasionally, the rotor cover 14 may be detached from the rotor body 13 during high-speed rotation due to insufficient mounting of the rotor cover 14. In this case, when the rotor cover 14 moves away from the rotor chamber 3, the tube containing the sample is damaged, the sample is scattered in the rotor chamber 3, and sparks generated by the contact between the rotor cover 14 and the rotor body 13 etc. If the sample is flammable, there is a risk of flammable explosion. Therefore, as a measure against ignition, the rotor chamber 3 is filled with the inert gas from the gas cylinder 9 containing the inert gas such as nitrogen gas, argon gas and helium gas through the supply port 7. There is a method of rotating the rotor 1. In addition, if the confidentiality in the rotor chamber 3 is good, it is only necessary to fill the inert gas once. However, since the inert gas may leak from the rotor chamber 3 over time, the rotor chamber 3 may be used if possible. It is more effective to continuously flow an inert gas into the inside. The inert gas that has entered the rotor chamber 3 is discharged out of the centrifuge body through the discharge port 8 communicating with the buffer tank 11, but there is no confirmation that the interior of the rotor chamber 3 has been replaced with the inert gas. In this embodiment, in order to enhance safety, that is, to confirm that the rotor chamber 3 is filled with the inert gas without any problem, the communication passage 12 is provided between the rotor chamber 3 and the discharge port 8. A buffer tank 11 is provided. Then, the oxygen concentration in the buffer tank 11 is measured by the oxygen concentration meter 10, and when the measured value exceeds a predetermined constant value, the control unit 5 controls to stop the drive motor 2. In other words, it is determined whether or not the gas is replaced with an inert gas, and the operation of the centrifuge body is controlled to continue unless the gas is replaced with a predetermined constant oxygen concentration. The reason for obtaining the confirmation of the substitution state with the inert gas by measuring the oxygen concentration is that the degree of ignition to the sample is greatly influenced by the oxygen concentration of the atmosphere, and the inert gas concentration is measured. This is because it is easier to measure the oxygen concentration than to do it. Of course, the inert gas concentration may be directly measured, and when the measured value is equal to or less than a predetermined value, the control unit 5 may be controlled to stop the drive motor 2, and the flammability leaked from the rotor 1 may be controlled. The concentration of the sample may be measured, and the control unit 5 may be controlled to stop the drive motor 2 when the measured value exceeds a predetermined value.
[0012]
In the present embodiment, the densitometer 10 is provided not in the rotating chamber 3 but in the buffer tank 11, because this can perform more stable concentration measurement. In the rotating chamber 3, the air is disturbed by the rotation of the rotor 1, so that the pressure is not stable and measurement is difficult, and since the rotating chamber 3 is cooled by the cooling device, moisture is present because there is moisture. However, if the concentration meter 10 is provided above the buffer tank 11, moisture is accumulated below, so that stable concentration measurement can be performed without any problem. Further, when the densitometer 10 is provided in the rotating chamber 3, there are difficulties in the location and assembly configuration of the densitometer 10, but when the densitometer 10 is provided in the buffer tank 11, the assembly configuration is independent of the pressure difference. It can be easily provided. In other words, as described above, measuring a stable gas concentration in the buffer tank 11 rather than measuring a gas concentration in the rotating chamber 3 or in a thin pipe can create a more stable environment and accurately measure it. This is possible. In addition, although the inert gas discharged | emitted from the discharge port 8 is discharged | emitted outdoors, you may collect | recover through a filter etc. as a biohazard countermeasure depending on the case.
[0013]
From the above, it is confirmed that the atmosphere in the rotor chamber 3 is replaced with an inert gas, and if the replacement state is lower than a predetermined initial condition, there is a risk of ignition. By controlling to automatically stop, it is possible to provide a centrifuge excellent in safety that can prevent a flaming accident.
[0014]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, the centrifuge excellent in the safety which can prevent the ignition to a sample can be provided by confirming that the atmosphere in a rotor chamber is filled with the inert gas.
[Brief description of the drawings]
FIG. 1 is a partially longitudinal side view showing a centrifuge according to the present invention.
FIG. 2 is a flowchart showing a processing method after gas concentration detection of a centrifuge according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 is a rotor, 2 is a drive motor, 3 is a rotor chamber, 4 is a door, 5 is a control part, 6 is an operation part, 7 is a supply port, 8 is a discharge port, 9 is a gas cylinder, 10 is an oximeter, 11 A buffer tank, 12 is a communication path, 13 is a rotor body, 14 is a rotor cover, and 15 is a tube containing a sample.

Claims (3)

  A driving device; a rotor that can be rotated by the driving device and that can store a flammable organic solvent; a rotor chamber that houses the rotor; and a supply unit that fills the rotor chamber with an inert gas. The centrifuge further comprises a controller for measuring the oxygen concentration in the rotor chamber and stopping the driving device when the measured value exceeds a predetermined value.   The centrifuge according to claim 1, further comprising a concentration meter for measuring an oxygen concentration in a buffer tank communicating with the rotor chamber.   The centrifuge according to claim 1, wherein the inert gas is nitrogen gas.

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