JPS5915692B2 - gas centrifugal separator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention particularly relates to a gas centrifugal separator capable of discharging different component gases to the outside of a rotating drum.

A gas centrifugal separator is known as a device that separates a mixed gas of heavy gas components and light gas components into each component gas.

This gas centrifugal separator generally houses a rotating cylinder for gas separation and a motor that rotates this rotating cylinder at an ultra-high speed in a vacuumed case, and the rotating cylinder is rotated at an extremely high speed. The gas to be separated is introduced into the rotary shell and separated into a heavy gas component layer and a light gas component layer by the high centrifugal force field inside the rotating shell, and each separated component gas is separately discharged to the outside of the rotating shell. .

To achieve a higher separation rate, a plurality of gas centrifugal separators are usually connected in a cascade so that the separation process can be repeated many times in series.

However, conventional gas centrifugal separators have the following problems.

That is, as mentioned above, the rotary cylinder is operated in a high vacuum atmosphere for the purpose of reducing windage loss and separating it from other gas systems.

Therefore, the case in which the rotary cylinder is housed and the piping system connected thereto must be sufficiently airtight.

However, in reality, it is extremely difficult to maintain this airtightness.

For example, when separating JF6, etc., it is necessary to connect dozens of gas centrifuges in a cascade, so even if the amount of leakage per unit is extremely small (even if it is small, the entire The amount of leakage, that is, the amount of air entering the separation system, is large.

When air enters the separation system in this way, the quality of the separated gas inevitably deteriorates because the air is mixed into each component gas.

Furthermore, if processing oil, cleaning liquid, water, etc. adhere to the inner surface of the case or piping during processing and assembly, these vaporized gases will also be mixed into each component gas, further degrading the quality of the separated gas.

Similarly, decomposition products of bearing oil can degrade the quality of the separated gas.

In conventional apparatuses, almost no measures have been taken against the mixing of these different component gases, so there is a strong possibility that only so-called poor quality component gases will be obtained.

The present invention was made in view of the above circumstances, and its purpose is to be able to discharge different component gases from inside the rotating barrel, improve the quality of the separated gases, and also to make it possible to cut gases using the above-mentioned discharge system. The object of the present invention is to provide a gas centrifugal separator that can also be regulated.

Hereinafter, details of the present invention will be explained with reference to illustrated embodiments.

FIG. 1 shows an example in which the present invention is applied to a scoop tube extraction type device, and this device is constructed as follows.

That is, in the figure, 1 is a case, and this case 1 has a cylindrical part 2 whose axis is parallel to the direction of gravity,
Upper and lower lids 3 that airtightly cover the upper and lower end openings of this cylindrical portion 2
, 4.

A rotary trunk is rotatably housed in the case 1.

The rotating body consists of a cylindrical body 6, an upper and lower end plate γ, 8 that closes the upper and lower end openings of the cylindrical body 6, and an upper end plate 7 that is fixed to the inner surface of the cylindrical body 6 so as to face the upper end plate 7. An annular upper partition plate 10 that forms a light gas component collection chamber 9 between the annular upper partition plate 10 and a heavy gas component collection chamber 11 that is fixed to the lower end plate 8 so as to face the lower end plate 8. It is composed of an annular lower partition plate 12.

The side wall of the lower partition plate 12 is provided with a plurality of holes 13 along the circumferential direction for introducing heavy gas components into the heavy gas component collection chamber 11.

A shaft member 14 coaxially protrudes from the center of the outer surface of the lower end plate 8, and the tip of the shaft member 14 is connected to a thrust bearing 15 fixed to the inner surface of the lower lid 4. .

Further, a rotor 17 of an axial air gap motor 16 that applies rotational power to the rotary drum 5 is fixed to the outer surface of the lower end liquid 8, and a stator 18 of the motor 16 is fixed at a stationary position opposite to the rotor 17. It is.

On the other hand, an annular permanent magnet 19 magnetized with the illustrated polarity is fixed on the outer surface of the upper end plate 7, and a magnetic bearing 1 is mounted on the inner surface of the upper lid 3 facing the permanent magnet 19.
An annular permanent magnet 21 constituting the is fixed.

Thus, holes 22.23 are coaxially provided in the center of the upper cover 3 and the upper end plate 7, and these holes 22.23
Through this, scoop pipes 24 and 25, a feed pipe 26, and a different component gas exhaust pipe 27, which will be described next, are inserted into the rotating cylinder (inside the rotating cylinder J without contacting it).

The scoop pipe 24 is inserted into the rotary shell 5 parallel to the axis of the rotary shell 5, extends to the vicinity of the inner surface of the lower end plate 8, and is then bent at a nearly right angle to open the air inlet 24a to the heavy gas component. It is located at the periphery of the gathering room 11.

In addition, the scoop pipe 25 is also inserted parallel to the axis of the rotary shell 5 and bent at a nearly right angle near the inner surface of the upper end plate 7, so that the inlet 25a is connected to the periphery of the light gas component gathering chamber 9. It is located.

The feed pipe 26 has a double pipe structure with the scoop pipe 24, and extends to the center of the rotating barrel, and the tip thereof is airtightly closed.

A plurality of discharge holes 28 are provided in the side wall near the tip.

On the other hand, the different component gas discharge pipe 27 is inserted along the axis of the rotary drum 5, and its open end 27a is located at the center of the gas inlet of the light gas component collection chamber 9.

Note that the portions where the scoop pipe 25, the feed pipe 26, and the different component gas discharge pipe 27 pass through the hole 22 are kept sufficiently airtight.

Further, numeral 29 in the figure indicates a molecular pump that sufficiently lowers the pressure of the atmosphere with which the outer surface of the rotary drum 5 comes into contact.

In the apparatus configured as described above, the feed pipe 26 is connected to the gas to be separated supply system, the scoop pipe 24 is connected to the heavy gas component recovery system, and the scoop pipe 25 is connected to the light gas component recovery system. Further, the different component gas exhaust pipe 27 is connected to a recovery system (not shown) via an exhaust pump (not shown) for use.

Next, the operation of the above-mentioned constituent device will be explained.

First, when the axial air gap motor 16 is driven to rotate the rotary drum 5 at an extremely high speed, the molecular pump 29 exhibits its function, and the atmosphere with which the outer surface of the rotary drum 5 comes into contact is maintained at a sufficiently low pressure.

In this state, a gas to be separated consisting of a heavy gas component and a light gas component is introduced into the feed pipe 26, and the exhaust pump connected to the different component gas discharge pipe 27 is driven.

The gas to be separated introduced into the feed pipe 26 passes through the discharge hole 2
8 into the rotary cylinder 5, and circulates within the rotary cylinder as shown by solid line arrows in the figure.

During this time, the heavy gas components gather near the inner surface of the cylindrical body 6, and the light gas components gather inside.

Then, the heavy gas component enters the heavy gas component collection chamber 11 through the hole 13 provided in the lower partition plate 12, and is then discharged to the outside through the scoop pipe 24.

Further, the light gas component enters the light gas component collection chamber 9 through a hole provided in the center of the upper partition plate 10, and is then discharged to the outside through the scoop pipe 25.

Here, taking as an example a gas with a relatively large mass, such as UFa, as the gas to be separated, let us consider a case where the airtightness of Case 1 is impaired and air enters the separation system, that is, a leak phenomenon occurs.

Since the air component is lighter than the UF 6, it gathers at a position close to the axis in the rotary trunk nostril and easily enters the light gas component gathering chamber 9.

However, as in this embodiment, a dissimilar component gas discharge pipe 27 is provided with its open end located on the axis, and the gas in the rotary cylinder 5 is discharged by a pump through this discharge pipe 27. Since the air component that has entered is discharged out of the device through the exhaust pipe 27, there is no risk of air getting mixed into the light gas component, and even if a leak phenomenon occurs, the separated gas will not be contaminated. It is possible to prevent the deterioration of the quality of the separated gas.

Similarly, oil that adhered during processing and assembly of case J and rotary cylinder 5,
Even if gases vaporized from water or decomposed gases such as bearing oil get mixed in, these gases are lighter than UF6 and tend to gather near the axis of the rotating body 5, so these gases are also different. Since the component gases are discharged through the component gas discharge pipe 27, it is possible to prevent the separation gas from being contaminated by the above gases.

Further, by controlling the amount of gas discharged through the different component gas discharge pipe 27, the cut can be adjusted, so that stable operation can be performed at all times.

Note that since the gas discharged through the different component gas discharge pipe 2γ also contains so-called effective components, these discharged gases may be separated again to extract only the effective components.

FIG. 2 shows another embodiment of the present invention, in which the same parts as in FIG. 1 are designated by the same reference numerals.

Therefore, the explanation of the overlapping parts will be omitted.

In this embodiment, the installation of a different component gas discharge pipe is omitted, and instead, the discharge direction of the molecular pump 29 is set downward in the figure.
In addition, a molecular pump 30 is newly provided between the lower end edge of the rotational load capacity and the inner circumferential surface of the cylindrical portion 2, and the discharge direction of this molecular pump 30 is set upward in the figure.
29 to exhaust the different component gases to the outside of the rotating body 5 through the hole 23 provided in the upper end plate 7, and the exhausted gas is extracted by a pump (not shown) through the exhaust port 31 provided in the side wall of the cylindrical portion 2. We are trying to direct them to the collection system.

With such a configuration, not only can the same effects as those of the above embodiments be expected, but also a state in which decomposed gases such as oil adhering to the inner surface of the case 1 and bearing oil do not enter into the rotating body 5. Since the separated gas is discharged to the outside, deterioration in the quality of the separated gas can be reliably prevented.

FIG. 3 shows yet another embodiment of the present invention, which is a molecular pump 30 in the embodiment shown in FIG.
Instead, the exhaust port 31 is connected to the molecular pump 29 and the upper lid 3.
It is located between.

Even with this configuration, the same effects as in each of the embodiments described above can be obtained.

FIG. 4 shows still another embodiment of the present invention.
The same parts as in FIGS. 3 to 3 are indicated by the same reference numerals.

This embodiment shows an example in which the present invention is applied to what is called a W-type end plate extraction type.

As is well known, in the end plate extracting type, molecular pumps 29 and 30 are provided on the outer periphery of the upper and lower ends of the cylindrical body 6 so that the discharge directions are opposite to each other. For example, a light gas discharge hole 41 is provided in the upper end plate 7, and a heavy gas discharge hole 42 is provided in the lower end plate 8.
are provided, and the heavy gas and light gas discharged from these discharge holes 41 and 42 are discharged through discharge ports 43 and 44 provided in the cylindrical portion 2.
I am trying to extract them separately via .

In this embodiment, holes 45 and 46 are coaxially provided in the center of the upper end plate 7 and the center of the upper lid 3, and a cylinder 47 is provided protruding outward from the periphery of the hole 450. A cylinder 48 is protruded from the periphery of the hole 460 so as to fit into the cylinder 47 without contact, and a molecular pump 49 for sealing is formed on the opposing surface of the cylinder 48 and cylinder 47.

Further, a guide tube 50 is disposed inside the cylinder 47 with a predetermined gap between it and the cylinder 47, and one end side of the dissimilar gas exhaust pipe 51 is fitted into the guide tube 50 without contact. ing.

The different component gas discharge pipe 51 is fixed to the inner surface of the cylinder 46 via a support member 52, and a molecular pump 53 for sealing is formed on the outer surface of the part fitted into the guide cylinder 50. .

Then, the double separated gas is transferred to the different component gas discharge pipe 51 and the cylinder body 4.
6 and the space between the guide cylinder 50 and the cylinder body 4T, and is introduced around the upper part of the rotary cylinder 5.

Further, the light gas component is guided to a guide plate 54 provided on the lower surface of the guide tube 50 in the figure, and is discharged to the outside of the rotary cylinder j through the light gas discharge hole 41. The heavy gas is discharged to the outside of the rotary drum 5 through the heavy gas discharge hole 42.

Furthermore, the light different component gases that have entered the rotary drum 5 are exhausted through the different component gas discharge pipe 51 by a pump (not shown).

Therefore, the same effects as those of the embodiments described above can be expected.

FIG. 5 shows still another embodiment of the present invention, and this embodiment shows an example in which the present invention is applied to an end plate extracting type, which is called a P type.

In the case of the P type, the upper end plate 7 is provided with a heavy gas exhaust hole 42, and the lower end plate 8 is provided with a light gas exhaust hole 41.

(If the direction of gas supply to be separated is reversed, the above relationship will also be reversed.

) In this embodiment, the guide tube 50 is extended along the axis to the center of the rotary drum 5 to discharge the different component gases.

Of course, even with this configuration, the same effects as in the embodiment described above can be expected.

In addition, the vicinity of the suction port of the different component gas exhaust pipe may be bent to provide a pumping effect.

Further, when actually incorporating this device into a cascade, only a portion of this device may be incorporated, and the method of incorporation can be freely selected.

As described in detail above, according to the present invention, even if gases of different components are mixed in, this gas can be extracted, so there is no risk of degrading the quality of the separated gases.1. It is possible to provide a gas centrifugal separator that is particularly effective when connected in a cascade.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of one embodiment of the present invention, and FIGS.
The figures are longitudinal sectional views of different embodiments of the invention. 1...Case, body...Rotating body, 15
...Thrust bearing, 16...Axial air gap motor, 27,51...Different gas discharge pipe, 29゜30...Molecular pump, 3
L43, 44...Discharge port.

Claims (1)

[Claims] 1. In a gas centrifugal separator in which a mixed gas of a heavy gas component and a light gas component is introduced into a rotating barrel for gas separation and separated into each component gas using a high centrifugal force field in the rotating barrel, the above-mentioned a first exhaust system for discharging the gas that has gathered around the periphery of the rotary shell out of the rotary shell as a heavy gas component; a second discharge system for discharging the component to the outside of the rotating body;
A gas centrifugal separator comprising: a third exhaust system for discharging gas collected near the axis of the rotary shell as a different component gas to the outside of the rotary shell.