JP2010209987A - Ejector device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To safely and efficiently discharge liquefied gas stored in a container in a device comprised for resolving risk work in transferring liquefied gas such as liquid nitrogen in a container such as a cryopreservation container to another container. <P>SOLUTION: The ejector device includes straight pipe like liquefied gas lead-out pipe 15 dipped in a substantially erected state in the liquefied gas, an ejector part 14 attached to a lower end of the liquefied gas lead-out pipe to suck up the liquefied gas, a liquefied gas blow-up preventing valve 16 connected to an upper part of the liquefied gas lead-out pipe and closed full time, a liquefied gas outflow pipe 21 connected to the liquefied gas blow-up preventing valve to send the liquefied gas to another container, a driving gas lead-in pipe 11 supplying driving gas to the ejector part, a nitrogen gas cylinder 4 connected via a check valve 10 to the driving gas lead-in pipe, and a valve opening and closing part opening the liquefied gas blow-up preventing valve when necessary. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an ejector apparatus used for discharging a liquefied gas such as liquefied nitrogen stored in a container such as a cryopreservation container for cryopreserving a sample such as a cell or a fungus.

In a cryopreservation container, a large number of ampoules containing specimens such as bacteria are stored in a storage rack, and the storage rack etc. is not a sealed pressure container but an open structure with a lid. It has become.
When the lid is opened and the storage rack is taken in and out, moisture in the air enters the cryopreservation container and becomes ice and accumulates on the bottom of the container. If the amount of ice is small, there is no problem.
For this reason, in order to remove ice from the cryopreservation container, it is necessary to periodically pump out liquefied nitrogen in the container.

  Conventionally, in order to pump out 196 ° C. liquefied nitrogen stored in a cryopreservation container, gloves for cryogenic temperatures are attached and a beaker or a handle is used. The gloves for liquefied nitrogen are so thick that it is difficult to stably beak a beaker or handle. For this reason, liquefied nitrogen was spilled on the floor, the floor material was frozen and damaged, or the spilled liquefied nitrogen gasified and filled the room, leading to the risk of lack of oxygen.

Also, the inside of the cryopreservation container during the liquefied nitrogen pumping operation was filled with water in the surrounding air in the form of a mist, so that the liquid surface position of the liquefied nitrogen could not be visually confirmed, and there was a risk of frostbite.
The most dangerous thing is that this pumping-out operation leads to a posture of leaning over the opening of the cryopreservation container. This posture has a very high risk of oxygen deficiency, and there is a risk that the oxygen deficiency will cause crumble and fall into the cryopreservation container.

JP 2004-76825 A JP 2006-313004 A

  The present invention was made to eliminate dangerous work when transferring liquefied gas such as liquefied nitrogen in a container such as a cryopreservation container as described above to another container, and the liquefied gas stored in the container Is intended to be safe and efficient.

To solve this problem,
The invention according to claim 1 is an ejector device that is immersed in a liquefied gas in a container and pumps up the liquefied gas by an ejector action,
A straight tubular liquefied gas lead-out pipe immersed in the liquefied gas in an almost upright state, an ejector part that is attached to the lower end of the liquefied gas lead-out pipe and sucks up the liquefied gas, and is connected to the upper part of the liquefied gas lead-out pipe at all times. A liquefied gas blow-off prevention valve that is closed, a liquefied gas outflow pipe that is connected to the liquefied gas blow-off prevention valve and delivers liquefied gas, a drive gas supply pipe that supplies drive gas to the ejector section, and this drive gas An ejector apparatus comprising: a drive gas supply source connected to a supply pipe via a check valve; and a valve opening / closing part that opens the liquefied gas blow-off prevention valve when necessary.

The invention according to claim 2 is characterized in that the valve opening / closing portion is formed of an air cylinder, and a pipe for branching from the driving gas supply pipe to send the driving gas is connected to the air cylinder. The ejector device according to claim 1.
According to a third aspect of the present invention, a foot valve is arranged in a pipe connecting the check valve and the driving gas supply source, and the air cylinder is operated by operating the foot valve, and the liquefied gas ejection preventing valve is installed. 3. The ejector device according to claim 2, wherein the ejector device is opened and closed.

  The invention according to claim 4 is characterized in that the ejector portion is inserted into a dome-shaped cap attached to the lower end of the liquefied gas outlet tube, and the cap and the liquefied gas outlet tube, A substantially cylindrical ejector body in which a drive gas introduction port is formed, a nozzle connected to the drive gas introduction port of the ejector body and ejecting the drive gas toward the liquefied gas outlet tube, and the nozzle connected to the nozzle The ejector device according to claim 1, further comprising a connector that sends driving gas from the driving gas supply pipe to a nozzle.

  The invention according to claim 5 is characterized in that a plurality of leg-like bases extending downward are further attached to the lower end of the cap, and the bases are in contact with the bottom of the container. The ejector device according to claim 4.

  According to the present invention, dangerous work when transferring liquefied gas such as liquefied nitrogen in a container such as a cryopreservation container to another container is eliminated, and the liquefied gas stored in the container is discharged safely and efficiently. it can.

It is a schematic block diagram which shows an example of the ejector apparatus of this invention. It is the block diagram of the partial cross section which shows the ejector part in this invention in detail. It is a block diagram which shows the valve | bulb opening / closing part in this invention. It is a perspective view which shows the support stand used in this invention.

FIG. 1 shows an example of an ejector apparatus according to the present invention. In this example, a description will be given of a state in which liquefied nitrogen in a cryopreservation container is pumped out.
In FIG. 1, the code | symbol 1 shows a cryopreservation container. This cryopreservation container 1 is a vacuum insulated container, in which liquefied nitrogen 3 having a temperature of -196 ° C is stored, and the inside of the container 1 is kept at a low temperature.
The amount of liquefied nitrogen stored varies depending on the size of the container 1 and the storage method, but is about 50 to 400 liters. Samples such as cells and fungi are stored in a storage rack (not shown), and then stored in the cryopreservation container 1 for cryopreservation.

Driving gas nitrogen gas from a nitrogen gas cylinder 4 as a driving gas source passes through a pipe 6 through a pressure reducing valve 5 and is sent to a foot valve 7, and further passes from a pipe 8 through a connection joint 9 to a driving gas introduction pipe 11. Sent to.
The driving gas introduced into the driving gas introduction pipe 11 is divided into two parts, and a part thereof is sent to the ejector unit 14 through the check valve 10. The remaining driving gas is sent to the air cylinder 19 and used for the operation of the air cylinder 19.

  The ejector section 14 is connected to the lower end of the liquefied gas outlet pipe 15. The liquefied gas lead-out pipe 15 is a straight pipe and is provided in an almost upright state in the liquefied nitrogen in the cryopreservation container 1, and the liquefied nitrogen sucked up from the ejector section 14 flows into the liquefied gas lead-out pipe 15. .

As shown in FIGS. 2A to 2C, the ejector unit 14 includes a dome-shaped cap 13 attached to the lower end of the liquefied gas outlet tube 15, and a lower end portion of the cap 13 and the liquefied gas outlet tube 15. Are connected to the drive gas introduction port 35 of the ejector body 24, and a substantially cylindrical ejector body 24 in which a plurality of liquefied gas introduction holes 34, 34... And a drive gas introduction port 35 are formed. The nozzle 23 is configured to eject the driving gas toward the liquefied gas lead-out pipe 15, and the connector 36 is connected to the nozzle 23 and sends the driving gas from the driving gas supply pipe 11 to the nozzle.
The nozzle 23 affects the ejector action, and it is preferable to use a nozzle having a shape that increases the suction height of liquefied nitrogen.

With this configuration, the driving gas from the driving gas introduction pipe 11 is ejected from the nozzle 23 toward the liquefied gas outlet pipe 15 at a high speed, so that liquefied nitrogen is sucked into the liquefied gas introduction holes 34, 34,. The air then flows in and flows upward along the flow of the driving gas.
Further, a plurality of leg-like bases 12, 12... Extending downward are attached to the lower end of the cap 13, and the bases 12, 12... Are in contact with the bottom of the cryopreservation container 1. The base 12 is made of an aluminum material so as not to damage the inner bottom surface of the cryopreservation container 1 having a vacuum heat insulating structure. Further, the remaining amount of the liquefied nitrogen 3 can be minimized by the effect of the cap 13.

As shown in FIG. 3, a liquefied gas blow-off prevention valve 16 is connected to the upper end of the liquefied gas outlet pipe 15, and a liquefied gas outflow pipe 21 is connected to the liquefied gas blow-off prevention valve 16 through a connection joint 18. Has been.
Of this liquefied gas outflow pipe 21, the base end portion located on the connection joint 18 side is composed of a stainless steel pipe 21a and a heat insulating material 20 for heat insulating coating. The distal end portion is composed of a flexible hose 22 and is connected to the proximal end portion via a connection joint 18.
The flexible hose 22 is for facilitating the transfer of the liquefied nitrogen pumped up to the vacuum heat insulating container 2, and improves workability by providing flexibility.

  As the liquefied gas ejection preventing valve 16, a ball valve made of stainless steel having a small pressure loss is used. When using a ball valve, the space formed by the ball valve main body, the ball seat, and the ball is in a sealed state, and when used for liquefied gas, measures to prevent liquid sealing must be taken. As a countermeasure against this liquid sealing, a hole having a diameter of about 2 mm is formed on the central axis through which the liquefied gas flows from the upstream ball surface in the closed state to the vent hole of the ball.

  The valve handle 25 of the liquefied gas blow-off prevention valve 16 is linked to the tip of the piston rod 19a of the air cylinder 19 via a connecting rod 26, and the piston rod 19a of the air cylinder 19 moves forward and backward. The valve handle 25 is rotated so that the liquefied gas ejection preventing valve 16 is opened and closed. Further, the connecting rod 26 has a function of preventing the cold heat transmitted from the liquefied gas blowing-up prevention valve 16 via the valve handle 25 from being transmitted to the piston rod 19a and preventing the freezing thereof.

  The air cylinder 19 is attached to a protective cover 17. In this example, a single-acting type incorporating a spring is used, and when the driving gas from the driving gas introduction pipe 11 is supplied to the air cylinder 19. When the piston rod 19a moves forward, the liquefied gas ejection prevention valve 16 opens, and when the driving gas is released, the piston rod 19a moves backward and the valve 16 closes. Besides this, a double-acting air cylinder may be used.

The protective cover 17 has a rectangular parallelepiped frame with a metal mesh 27, and the piston rod 19a, the connecting rod 26, the liquefied gas blow-off prevention valve 16 and a part of the liquefied gas outlet pipe 15 are accommodated therein. Thus, the valve opening / closing part 28 is configured.
The inside of the protective cover 17 can be visually confirmed through the wire mesh 27, the operation state of the liquefied gas blow-off prevention valve 16 can be easily confirmed, and the air permeability is maintained, so that the member housed inside can be iced. It can also prevent accidents such as fingers being pinched.

Such an ejector device is assembled and used in the form shown in FIG. 1 in a use state, but when not in use, the connection joints 9 and 18 can be separated and disassembled, and can be transported in this state.
Further, in the state shown in FIG. 1, it is necessary to keep the liquefied gas outlet pipe 15 almost upright. For this reason, the support frame shown in FIG. 4 is actually used.

In this support frame, two telescopic rails 29 and 29 connected to each other by a thumbscrew 30 so as to be orthogonal to each other are placed on the upper opening of the cryopreservation container 1 until the stopper 31 hits the outer edge of the opening. The rails 29 and 29 are contracted and the thumbscrews 30 and 30 are tightened and fixed.
The support 33 supports the proximal end portion of the liquefied gas outflow pipe 21 in FIG. The support 33 also has an extendable structure, and the height is adjusted according to the size of the cryopreservation container 1 and is fixed with the thumbscrew 30.
Since the support frame is assembled at the upper opening of the cryopreservation container 1 in which the liquefied nitrogen 3 is stored, a structure that does not drop tools and parts is required. For this reason, a thumbscrew that does not require a tool is employed, and a treatment that prevents the head on the male screw side from being crushed and a treatment that prevents the wire 32 from being dropped is applied depending on the location of use.

Next, the usage method of this ejector apparatus is demonstrated.
First, the support frame shown in FIG. 4 is attached to the mouth of the cryopreservation container 1. Then, the ejector device is assembled in a usage pattern as shown in FIG. 1, and the driving gas introduction pipe 11 and the liquefied gas outlet pipe 15 are immersed in the liquefied nitrogen 3 in the cryopreservation container 1.
Next, the foot valve 7 is stepped down to be opened, and the driving gas is fed into the driving gas introduction pipe 11 through the pipe 8 and the connection joint 9. As a result, the liquefied nitrogen is sucked up from the ejector section 14 and the air cylinder 19 is operated simultaneously to open the liquefied gas blowing-off prevention valve 16 so that the liquefied nitrogen is liquefied gas outlet pipe 15, liquefied gas blowing-off prevention valve 16, It is transferred to the vacuum insulation container 2 through the liquefied gas delivery pipe 21 and the flexible hose 22. When the foot valve 7 is not depressed and closed, the supply of the driving gas is stopped, the liquefied gas ejection preventing valve 16 is closed, and the transfer of liquefied nitrogen is stopped.

According to such an ejector apparatus, the liquefied nitrogen 2 in the cryopreservation container 1 can be safely and efficiently transferred to the vacuum heat insulating container 2, and no electric power is required. Further, the “spouting phenomenon” described later can be prevented.
When the liquefied nitrogen 3 stored in the cryopreservation container 1 is handled, a frostbite accident may occur unless the liquefied nitrogen has a “spout phenomenon”.
The “spout phenomenon” means that when the lower tip of a hollow tube at room temperature is immersed in liquefied nitrogen stored in the cryopreservation container 1 or the like in a vertical direction, it is liquid with nitrogen vaporized from the tip of the upper tube. The phenomenon that nitrogen blows up, and when the portion immersed in liquefied nitrogen is cooled to the same temperature as liquefied nitrogen, the “spout phenomenon” ends.

When the liquefied nitrogen stored in the cryopreservation container with the upper part opened is to be pumped out by the ejector method, safety measures against this “spout phenomenon” are essential.
In the present invention, the check gas 10 is attached to the drive gas introduction pipe 11 of the drive nitrogen gas inflow line, and the liquefied gas blow-off prevention valve 16 that is normally closed is attached to the liquefied nitrogen discharge pipe 15 of the liquefied nitrogen outflow line. Due to this safety measure, even if the ejector portion 14 at room temperature is immersed in liquefied nitrogen, the “squirting phenomenon” does not occur because the check valve 10 and the automatic opening / closing valve 28 are closed.

Since the “spout phenomenon” occurs at the moment when the ejector device is immersed in liquefied nitrogen, if the check valve 10 and the valve 16 are removed, the drive gas introduction pipe 11 and the liquefied gas lead-out pipe 15 Liquefied nitrogen may erupt, resulting in a major accident of lack of oxygen and frostbite.
Therefore, a reliable safety measure against the danger is an integrated structure in which the check valve 10, the drive gas introduction pipe 11, the ejector section 14, the liquefied nitrogen outlet pipe 15, and the automatic opening / closing valve 28 cannot be easily disassembled. It is necessary to become.

Specific examples will be described below.
The amount of liquefied nitrogen discharged is detected by placing the 100-liter cryopreservation container 1 storing liquefied nitrogen on a scale and measuring the weight.
The nitrogen gas cylinder 4 is filled with nitrogen gas having an internal volume of 47 liters and a pressure of 15 MPa, and this nitrogen gas is decompressed to 0.9 MPa by the pressure reducing valve 5. By recording the primary pressure of the pressure reducing valve 5, the necessary nitrogen gas amount as the driving gas can also be measured.

First, the part centering on the ejector part 14 where the connecting joint 9 and the first connecting joint 18 are not coupled was immersed in liquefied nitrogen. At this time, it was confirmed that there was no occurrence of the “spout phenomenon” which was a concern.
Next, the apparatus is assembled as shown in FIG. 1, and finally the scale of the scale is set to zero to complete the test preparation.
The operation is very safe because it is only necessary to step on the foot valve 7 with one foot and it is not necessary to approach the cryopreservation container 1.
In addition, the air cylinder 19 was replaced with a double-acting type, and the same inspection was performed, but the same safety as that of the single-acting type could be confirmed if the driving nitrogen gas pressure was a little.

As a result of the test, 40 liters (32.3 kg) of liquefied nitrogen in the cryopreservation container 1 could be transferred in a required time of 258 seconds. At this time, the nitrogen gas consumption for transport was 1.5Sm ³ at equivalent pressure 32 MPa.
Converting this data, the derivation capacity of liquefied nitrogen is 9.3 liters / minute, and the nitrogen gas consumption is 0.0375 Sm ³ (nitrogen gas) / liter (liquefied nitrogen).
Moreover, 180 liters of liquefied nitrogen can be derived with one nitrogen gas cylinder, and the required time is about 20 minutes.

It was confirmed that the apparatus was sufficiently effective in practice by preparing the necessary number of nitrogen gas cylinders according to the amount of liquefied nitrogen stored in the cryopreservation container.
In addition, this apparatus can be applied to liquefied argon and liquefied oxygen other than liquefied nitrogen, and can be used without any trouble even in the absence of electric power.

1 .... Cryopreservation vessel, 2 .... Vacuum insulation vessel, 3 .... Liquid nitrogen, 4 .... Nitrogen gas cylinder, 5 .... Pressure reducing valve, 6, 8, ... Tube, 7, ... Foot valve, 9, 18, ... · Connection joint, 10 ·· Check valve, 11 · · Drive gas introduction pipe, 12 · · Base, 13 · · Cap, 14 · · Ejector section, · · · Liquefied gas outlet tube, 16 · · Prevention of liquefied gas spout Valve, 17 ... Protective cover, 19 ... Air cylinder, 19a ... Piston rod, 20 .... Heat insulation, 21 ... Liquid gas outflow pipe, 21a ... Stainless steel pipe, 22 .... Flexible hose, 23 ... Nozzle 24 ··· Ejector body, 25 · · Valve handle, 26 · · Connecting rod, 27 · · Wire mesh, 28 · · Valve opening and closing part, · · · Rail, 30 · · Thumb screw, · · · Stopper, 32 · · · Wire, 3 ... support, 34 ... liquefied gas introducing hole, 35 ... driving gas inlet 36 ... connector

Claims (5)

An ejector device that is immersed in a liquefied gas in a container and pumps the liquefied gas by an ejector action,
A straight tubular liquefied gas lead-out pipe immersed in the liquefied gas in an almost upright state, an ejector part attached to the lower end of the liquefied gas lead-out pipe and sucking up the liquefied gas, and connected to the upper part of the liquefied gas lead-out pipe A liquefied gas ejection preventing valve that is closed; a driving gas supply pipe that supplies driving gas to the ejector section; a driving gas supply source that is connected to the driving gas supply pipe via a check valve; and the liquefied gas An ejector device comprising a valve opening / closing part that opens a blow-off prevention valve when necessary.   2. The ejector apparatus according to claim 1, wherein the valve opening / closing part is composed of an air cylinder, and a pipe for branching from the driving gas supply pipe to send the driving gas is connected to the air cylinder.   A foot valve is arranged on a pipe connecting the check valve and the driving gas supply source, and the air cylinder is operated by operating the foot valve to open and close the liquefied gas ejection preventing valve. The ejector device according to claim 2.   The ejector portion is inserted into a dome-shaped cap attached to the lower end of the liquefied gas outlet tube, and the cap and the liquefied gas outlet tube, thereby forming a liquefied gas inlet and a driving gas inlet. A substantially cylindrical ejector body, a nozzle connected to the drive gas introduction port of the ejector body and ejecting drive gas toward the liquefied gas lead-out pipe, and a nozzle connected to the nozzle from the drive gas supply pipe 2. The ejector device according to claim 1, wherein the ejector device comprises a connector for sending driving gas to the nozzle.   The ejector device according to claim 4, wherein a plurality of leg-like bases extending downward are further attached to the lower end of the cap, and the bases are in contact with the bottom of the container.

Images