JPS5953090B2 - centrifuge rotating barrel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotating barrel of a centrifuge, and particularly to a baffle structure suitable in terms of strength and separation performance.

Among centrifuges, so-called scoop-type centrifuges in which gas separated within a rotary barrel is extracted through a scoop tube require a baffle to form a scoop chamber and control the flow of gas.

Two baffles are required: a product baffle for extracting product gas from the upper part of the rotating shell, and a waste baffle for extracting waste gas from the lower part of the rotating shell.

Particularly when the waste gas is a heavy gas, it is required to introduce the waste gas into the scoop chamber from a position as close as possible to the outer periphery of the rotary drum.

Baffle structures that have been conventionally attempted to meet the above requirements will be explained with reference to the drawings.

FIG. 1 shows an example of this. 1 is a shell, 2 is an end plate, and 3 is a hollow disk-shaped baffle welded inside the shell. This baffle 3 has holes 4 for guiding waste gas to the scoop chamber 5. A plurality of them are provided on the same radius.

As mentioned above, it is better for the radial position of the hole to be as close to the outer circumference as possible.

However, since drilling a hole in a welded part poses a problem in terms of strength, it is not possible to position the hole sufficiently toward the outer periphery.

Therefore, a method is used in which a rim 3a is provided on the outer periphery of the baffle and the outer periphery of the rim is brought as close as necessary to the contents of the barrel.

FIG. 2 shows another conventional example, in which the baffle 3 is formed in a cross-sectional shape, and the end of the cylindrical portion is joined to the end plate 2 by welding.

A plurality of holes 4 for guiding waste gas to the scoop chamber are provided in the cylindrical portion.

In this conventional example, waste gas is introduced into the scoop chamber 5 from a location close to the outer periphery of the barrel by narrowing the gap between the outer diameter of the cylindrical portion and the inner diameter of the barrel.

The conventional structure described above has the following points to be improved.

In the example shown in FIG. 1, the baffle is joined to the shell by welding, but the welded portion generally has various metallurgical or geometrical defects, making the strength unreliable.

Particularly in products that rotate at high circumferential speeds, such as rotary cylinders, it is required to minimize the number of welded parts to improve strength and reliability.

In addition, a hole is required to guide the waste gas into the scoop chamber, but since the rotating cylinder rotates at a high circumferential speed of 400 m/s or more, a high circumferential stress of 100 kg/m4 or more is generated in the baffle. It is undesirable from the viewpoint of strength to provide holes in areas where such high stress occurs.

If a hole is provided, stress will be concentrated at the edge of the hole, and the stress will be approximately three times that of the state without a hole, so the stress at the edge of the hole will reach an elastic stress of more than 300 kg/mm, which is similar to maraging steel. Even if a material with a high yield point is used, plastic deformation will occur, and if the rotation speed increases and decreases repeatedly, there is a risk of failure due to low cycle fatigue.

Similar drawbacks can be pointed out in the conventional example shown in FIG.

In this example, the baffle is welded to the end plate, but the body is also welded to the end plate, and both welds must be very close together due to construction.

If the welds are close together, the welds exert a thermal influence on each other, causing coarse grains and other factors that reduce strength.

Furthermore, in the conventional example shown in FIG. 2, the cylindrical part is essentially a useless part from the viewpoint of the function of the baffle, and there are disadvantages in that extra material is used and extra time is spent on processing.

An object of the present invention is to eliminate the above-mentioned drawbacks of the prior art and to provide a rotary cylinder that is highly reliable in terms of strength and has high separation performance.

In order to achieve this object, in the present invention, the baffle is formed into a cross-sectional shape, and a bulge is formed in the cylindrical part, and a bulge is also formed in the rotating body, and both bulges are formed. The baffle is characterized by a structure in which the baffle is fixed within the rotating body by fitting together.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 3 is a longitudinal sectional view showing one embodiment of the present invention, FIG. 4 is an enlarged view of the contact portion between the baffle and the shell, and FIG.
XX sectional view in the figure, and FIG. 6 is a YY sectional view in FIG.

In these figures, the end plate 2 is fixed to the shell 1 by welding.

The baffle 30 is annular with an L-shaped cross section.
Several bulges 30a are formed in the cylindrical portion to bulge outward.

On the other hand, the shell 1 is formed with a shallow bulge 1a that bulges outward over the entire circumference at a position where the baffle 30 is attached.

The baffle 30 is fixed to the body 1 by press-fitting the bulge 30a of the baffle 30 into the bulge 1a of the body 1 or cooling it.

As shown in FIGS. 4 to 6, the outer diameter of the baffle 30 is smaller than the inner diameter of the barrel 1, and the gap A between the two except for the swollen portion 30a serves as a passage for heavy component gas. Become.

The outer diameter of the bulge 30a provided in the cylindrical portion of the baffle 30 is slightly larger than the inner diameter of the bulge 1a provided in the shell 1, so that the baffle 30 and the shell 1 can be bonded together by press-fitting or cooling. After being assembled, the baffle 3 is firmly fixed to the shell 1 when at rest.

In this structure, when the shell 1 starts rotating, the shell 1 expands outward due to centrifugal force, and the baffle 30 also expands outward, but because the radius of the shell 1 is slightly larger than the cylindrical part of the baffle 30, The centrifugal force acting on both is slightly larger on the shell 1, and as the circumferential speed increases, the difference in radial displacement between the two becomes larger, causing the bulge 30a of the baffle 30 and the bulge on the shell 1 to increase. It is conceivable that a gap is formed between the portion 1a and the portion 1a.

However, since the baffle 30 has an L-shaped cross section, the cylindrical portion is inclined as shown in FIG. This is compensated for by the displacement of , and the baffle 30 continues to be fixed to the shell 1 even during rotation.

It is sufficient that the cylindrical portion of the baffle 30 has a length necessary to form the radial bulge 30a, and if it is too long, the above-mentioned inclination cannot be expected.

The present invention is not limited to the embodiments described above, and various modifications and applications are possible.

For example, by forming several bulges that bulge inward on the body 1,
A bulge that bulges inward over the entire circumference may be formed in the cylindrical portion of the baffle, and both bulges may be squeezed together.

In addition, the shape of the bulge in the torso is not formed around the entire circumference,
It may be provided only at a location corresponding to the swollen portion of the baffle.

Further, as shown in FIG. 8, the rotating cylinder can be constructed by reversing the direction of the baffle 31.

However, the structure of the embodiment shown in FIGS. 3 to 7 is advantageous in the following points.

First, the full circumference outward bulge of the barrel can be easily accomplished with existing equipment.

Second, it is easier to maintain balance if there are bulges all around.

Thirdly, the work of fitting the baffle can be easily performed.

As explained above, according to the present invention, since the baffle is fixed to the shell without using welding, a rotating shell with high reliability in terms of strength can be obtained.

Furthermore, since no holes are used as gas passages, strength reliability including low cycle fatigue is improved.

Further, since the gas passage is formed in the gap between the cylindrical portion of the baffle and the barrel, it can be set as far as necessary on the outer circumferential side, and a rotating barrel with good separation performance can be obtained.

Furthermore, since the axial length of the baffle is sufficient as long as it is sufficient to form the radial bulge, there is an advantage that less material is required and processing is relatively easy.

[Brief explanation of the drawing]

1 and 2 are vertical cross-sectional views showing a conventional example of a rotary cylinder, and FIG. 3 is a vertical cross-sectional view showing an embodiment of a rotary cylinder according to the present invention.
Fig. 4 is an enlarged vertical sectional view of the main part of Fig. 3, Fig. 5 is a sectional view taken along line XX in Fig. 4, and Fig. 6 is a sectional view taken along line Y-X in Fig. 4.
FIG. 7 is a vertical cross-sectional view showing deformation during rotation, and FIG. 8 is a vertical cross-sectional view of a rotating drum showing another embodiment of the present invention. 1...Body, 1a...Bulge, 2...
...End plate, 6...Scoop tube, 30...
...Baffle, 30a...Bulge, 31...
...Baffle.

Claims (1)

[Scope of Claims] 1. In a centrifugal separation rotary body comprising a body, an end plate, and a baffle, a bulge that bulges in the radial direction is formed in a part of the body in the axial direction, so that the cross section is L-shaped. A radial bulge is formed in the cylindrical portion of the formed baffle, and this bulge is press-fitted into the bulge of the body, thereby fixing the baffle within the body. A centrifugal rotary cylinder characterized in that a gap is formed between the outer surface of the cylindrical part and the inner surface of the cylinder. 2 A bulge that bulges outward over the entire circumference is formed in a part of the axial direction of the barrel, an arbitrary number of bulges that bulge outward are formed in the cylindrical portion of the baffle, and the bulge is The centrifugal separation rotary cylinder according to claim 1, characterized in that the cylinder is press-fitted into a bulging portion of the cylinder.