JP3016733B2 - Seal structure near the rotation support part of the centrifuge - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seal structure in the vicinity of a rotary support portion of a centrifugal separator including a bowl supported by a pair of main bearings and rotatably rotatable in a casing disposed therebetween. In particular, the present invention relates to a seal structure in the vicinity of a rotation support portion of a centrifugal separator for preventing lubricating oil and liquid and their mist from flowing from a main bearing to a casing.

[0002]

2. Description of the Related Art A centrifuge is used to separate a solid / liquid mixture into a solid and a liquid. FIG. 4 shows an example of a conventional centrifuge.

[0003] As shown in the figure, a conventional centrifugal separator 20 includes a gantry 22, a pair of main lubrication systems 24 and 24, which are fixedly mounted on the gantry 22, and axially opposite ends. A pair of main bearings 24 having portions 26a, 26a
A bowl 26 supported rotatably at a high speed about a horizontal axis, a casing 28 provided liquid-tight around the bowl 26, a screw conveyor 30 rotatably supported inside the bowl 26, and a main bearing. 24 and a feed pipe 32 extending through one of the bowl shafts 26a and introducing the solid / liquid mixture into the bowl 26 via the inside of the screw conveyor 30, and the bowl 26 and the screw conveyor Each of the motors 30 includes a motor 34 having a speed reducer 34a that rotates the motor 30 at a predetermined speed.

[0004] The bowl 26 has shaft portions 26a at both ends in the axial direction.
In the middle of 26a, there is a cone portion 26b whose inner diameter gradually increases and a cylindrical portion 26c having a constant inner diameter. A solid discharge port 26d for discharging solids is provided at the tip of the cone portion 26b, and a separated liquid discharge port 26e for discharging the separated liquid is provided at a predetermined radial position at the rear end of the cylindrical portion 26c. I have.

[0005] As the solid / liquid mixture supplied from the liquid supply pipe 32, for example, there is a plating solution containing slime in a solid state, which will be described later, and this plating solution is passed through the screw conveyor 30 into the bowl 26. Lead. The bowl 26
It rotates at several thousand revolutions per minute and applies a maximum of 3500 G of centrifugal force to the material pressed against the inner wall of the bowl 26.

As a result, the heavy solid is pressed against the inner wall of the bowl 26 in close contact, while the liquid is located on the center side. The solid pressed against the inner wall of the bowl 26 is transferred by the screw conveyor 30 to the cylindrical portion 26.
c to the cone 26b, and is discharged out of the bowl 26 from the solid discharge port 26d.

On the other hand, the separated liquid is discharged from a separated liquid discharge port 26e provided at a predetermined radial position at the rear end of the cylindrical portion 26c. The solid and the separated liquid are discharged to the outside of the centrifuge 20 through a solid discharge passage 28a and a separated liquid discharge passage 28b provided in the casing 28, respectively.

In the centrifuge 20, the bowl 2
The main bearings 24 that support the motor 6 are rotated at an extremely high speed, and are of a splash lubrication type. In such a main bearing 24 of the splash lubrication system, the inside of the housing surrounding the rotating component is filled with oil droplets and mist. Therefore, in the one-stage labyrinth seal mechanism provided on the shaft portion 26a, there is a possibility that the lubricating oil leaks to the casing side through a slight gap or the separated liquid in the casing 28 leaks to the housing side of the main bearing 24. Was.

[0009]

By the way, the technology of electrotin plating is as follows: canned cans, tableware, toys, terminals of electronic parts,
Widely used in connectors and the like. In such an electrotin plating technique, continuous filtration has conventionally been performed as a means for removing slime (tetravalent tin oxide) from a plating solution.

FIG. 5 is a block diagram of a conventional continuous tin electroplating system. In this system, the plating solution flowing out of the plating cell 40 using the insoluble anode is circulated to the plating cell 40 through the plating solution circulation tank 50. In the plating solution circulation tank 50, an organic acid, a surfactant and the like are added in order to maintain a predetermined plating solution composition.

On the other hand, a part of the plating solution is withdrawn from the plating solution circulation tank 50, and metal tin is dissolved in the tin bath 52 for replenishing tin. Immediately below the molten tin bath 52, oxygen is blown to raise the dissolved oxygen. The solution in which the metal tin is dissolved passes through the precipitation tank 54, the oxide is removed by the filter 56, and the separated solution is finally returned to the plating solution circulation tank 50.

The disadvantages of this system are that it is difficult to completely remove the slime by the filter, and that the filter must be replaced or backwashed frequently to prevent the filter from being clogged. . The disadvantage is that
This is remarkable in a plating system exposed to a highly oxidizing atmosphere in which slime is easily generated, for example, a vertical plating system in which an insoluble anode and a tin supply tank are combined.

Japanese Patent Publication No. 3-35395 discloses a plating cell 40 comprising a pair of electrolytic cell main bodies 42, 42 for accommodating a pair of vertical electrodes 42a, 42a disposed opposite each other at a predetermined interval. And an electrolytic cell 44 for receiving the electrolyte flowing out of the vertical electrode pair 42a. The strip S is caused to travel vertically downward between one of the vertical electrode pairs 42a, 42a, and the other vertical electrode pair 42a, The vertical type electroplating apparatus which performs electroplating by running vertically between 42a is described (see FIG. 6).

The combination of the insoluble anode and the tin supply tank has advantages such as the stabilization of the distance between the electrodes and the separate preparation of tin ions as shown in Japanese Patent Publication No. 3-35395. are doing. On the other hand, a highly oxidizing atmosphere is present at two places, that is, the insoluble anode surface and the tin supply tank, which has the disadvantage that slime is easily generated.

[0015] The present applicant filed on August 9, 1996,
In such a plating system, a patent application was filed for an invention relating to a method for removing oxides, which comprises separating an oxide (slime) present in a tin plating solution extracted from a tin plating cell by a centrifugal separator. Was.

If the conventional centrifugal separator as described above is used as it is in the above-described method for removing oxides, the plating solution and the mist thereof separated in the casing 28 pass through the gaps slightly and pass through the main bearing 24 side. And plating solution mixed into the bearing 24 may cause baking.

Conversely, oil droplets and mist filling the inside of the housing of the main bearing 24 may leak to the casing through a small gap, and may contaminate the tin plating solution, which is a separating solution. is there. Contamination of the tin plating solution with the lubricating oil is a fatal defect in the technique of electrotin plating and is unacceptable.

The above-mentioned demand is a common demand in the case where the separated liquid is a liquid that causes seizing of the main bearing and in all the use modes in which contamination of the separated liquid with the lubricating oil is not allowed.

Accordingly, the present invention is directed to a centrifugal separator in which the lubricating oil from the main bearing to the casing and the separated liquid from the casing to the main bearing and their mist can be almost completely blocked. An object is to provide a seal structure.

Another object of the present invention is to provide a seal structure in the vicinity of a rotary support portion of a centrifuge which can be manufactured at a low cost with a simple structure.

[0021]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a centrifugal separator including a bowl rotatably supported by a pair of main bearings at a high speed in a casing disposed therebetween. A seal structure in the vicinity of the rotation support portion, wherein a seal member arranged around a shaft portion of the bowl is provided on a shaft portion of the bowl between the main bearing and the casing.
A pair of phosphors provided in parallel that project radially inward
And the pair of rings, and insert the
Of an annularly provided shaft with one ring attached
A pair of labyrinth seal mechanisms composed of a concave portion, air supply means for increasing the pressure in a section defined by the pair of labyrinth seal mechanisms higher than in the casing and in the main bearing, and the casing from the main bearing side An oil seal that seals the inflow of lubricating oil into the casing and prevents the separated liquid on the casing side from flowing out to the main bearing side.

According to a second aspect of the present invention, there is provided a seal structure near a rotary support portion of a centrifuge including a bowl supported by a pair of main bearings and rotatably rotatable in a casing disposed therebetween. The bowl shaft is located on the casing side of the bowl shaft between the main bearing and the casing.
Project radially inward from the sealing member
A pair of rings provided in parallel and
One ring inserted in between
And a recess of a shaft portion provided in an annular shape having a ring.
A labyrinth seal mechanism comprising been, the main bearing side of the shaft portion of the bowl, the outlet of the main bearing side of the casing side of the separated liquid together to seal the flow of lubricating oil from the main bearing side to the casing A seal provided with an oil seal for preventing the pressure, and an air supply means for increasing the pressure in a portion defined by the labyrinth seal mechanism of the shaft portion and the oil seal higher than in the casing and in the main bearing. Provide structure.

[0023]

The third aspect of the present invention is the first or second aspect.
In the seal structure according to the above, in the seal structure at the rotation support portion of the centrifuge, the centrifuge is a gantry, a pair of main bearings of a splash lubrication system fixedly installed on the gantry, and both ends in the axial direction A shaft portion, a cone portion having an inner diameter that gradually increases, a solid material discharge port for discharging solid matter, and a separation liquid discharge port for discharging separation liquid, the shaft part having a horizontal shaft as the center by the pair of main bearings. A bowl supported rotatably at high speed, a casing provided in a liquid-tight manner around the bowl, and a screw conveyor for rotatably supporting the separated solid inside the bowl and feeding the separated solid to a solid discharge port,
A liquid supply pipe extending through one of the main bearing and the bowl shaft to introduce the solid / liquid mixture into the bowl via the inside of the screw conveyor, and a bowl and the screw conveyor respectively. And a driving means for rotationally driving at a speed.

According to the first aspect of the present invention, a pair of labyrinth seal mechanisms and a pressure at a portion defined by the pair of labyrinth seal mechanisms are applied to the shaft of the bowl between the main bearing and the casing. By providing the air supply means higher than the inside of the shing and the inside of the main bearing, an air flow is formed from a portion defined by the pair of labyrinth seal mechanisms to the inside of the casing and to the main bearing.

Thus, the flow of air in the opposite direction is prevented, and the separated liquid mist in the casing and the lubricating oil mist in the main bearing do not leak to the part defined by the pair of labyrinth seal mechanisms. become unable.

Further, by providing an oil seal on the shaft of the bowl between the bearing and the casing, the separated liquid and the lubricating oil in the liquid state are stopped at this portion, and the separated liquid from the casing to the main bearing is stopped. The movement and the movement of the lubricating oil from the main bearing side to the casing are sealed. By effectively sealing both the mist and liquid separated liquid and lubricating oil, the leakage of separated liquid from the casing side to the main bearing and the leakage of lubricating oil from the main bearing side to the casing are almost complete. To block.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a seal structure in the vicinity of a rotation support portion of a centrifuge according to the present invention will be described in detail based on the illustrated preferred embodiment.

First, an outline of an electrotin plating system using a centrifugal separator employing a seal structure according to the present invention will be described. FIG. 2 is a block diagram of an electrotin plating system using a centrifugal separator employing the seal structure according to the present invention. FIG. 1 is an enlarged sectional view of a main part of a seal structure according to the present invention employed in the centrifuge shown in FIG.

The illustrated centrifuge 10 and the plating cell 40 have basically the same configuration as the conventional centrifuge and the plating cell 40 shown in FIGS. 4 and 6, and according to the same principle, The plating solution is separated into a slime and a separation solution, and the strip S is tin-plated. The plating solution circulation tank 50 and the molten tin tank 52 have the same configuration and operation as those of the conventional electrotin plating system shown in FIG. Therefore, a detailed description of these components will be omitted.

When compared with the conventional electro-tin plating system shown in FIG. 5, the feature of the electro-tin plating system shown in FIG. 2 is that the plating solution is removed by the centrifugal separator employing the seal structure according to the present invention. The dehydrated slime (stannic oxide) is separated into a separated plating solution which is not contaminated by the lubricating oil, and the separated solution is separated into a plating solution circulation tank 5.
The point is to return to 0 and reuse.

For the purpose of use in which contamination of the separated solution by the lubricating oil is not allowed, such as the electrotin plating technique,
It is essential to use a centrifuge 10 employing a seal structure according to the present invention described later. The same applies to a separated liquid in which the main bearing is seized due to leakage of the separated liquid to the main bearing.

The first of the features of the seal structure according to the present invention is as follows.
As shown in FIG. 1, the main bearing 12 and the casing 1
4, a pair of labyrinth seal mechanisms 17 and a pair of labyrinth seal mechanisms 17
The pressure in the section defined by the casing 14
And an air supply port 18 which is higher than the inside of the main bearing. An air supply source (not shown) is connected to the air supply port 18. In the present invention, the air includes all gases such as lubricating oil and an inert gas that does not adversely affect the separated liquid separated by the centrifuge 10.

As a result, the air pressure in the section defined by the pair of labyrinth seal mechanisms 17
It becomes higher than the air pressure inside and inside the casing 14, and an air flow toward the main bearing 12 and the casing 14 is formed. This prevents the air flow in the opposite direction,
The lubricating oil mist inside the main bearing 12 and the plating solution mist inside the casing 14 form a pair of labyrinth seal mechanisms 17.
Can no longer leak into the area defined by the Specifically, it is preferable that the pressure is higher than the pressure inside the main bearing 12 by about 0.5 kg / cm ² .

The main bearing 12 shown in FIG.
The bearing is of the splash lubrication type to support the bearing so that it can rotate at high speed. An oil pan 12a is provided at the bottom of the main bearing 12, and lubricating oil stored in the oil pan 12a is scraped up by a splash rod 16b fixed to a bowl shaft 16a to supply lubricating oil to rotating parts. I do.

In the illustrated preferred embodiment,
As shown in FIG. 3, the labyrinth seal mechanism 17
Is provided by a labyrinth seal formed between a cylindrical sealing member 15 disposed around the bowl shaft 16a and a sleeve member 13 fixed to the outer peripheral surface of the bowl shaft 16a.

More specifically, a pair of parallel rings 15 projecting radially inward from the seal member 15
a, 15a, and one ring 1 which receives the pair of rings 15a, 15a and is inserted between them.
And a concave portion 13b provided in an annular shape having 3a. Of course, such a recess may be formed directly on the outer peripheral surface of the bowl shaft 16a. Thereby, an effective labyrinth seal can be obtained with a simple configuration.

The second feature of the seal structure according to the present invention is that
Bowl shaft 16a between main bearing 12 and casing 14
And an oil seal 19 is provided. In the illustrated preferred embodiment, the oil seal 19 is provided at an intermediate portion of the main bearing 12 on the side of the virulence seal mechanism 17 and the air supply port 18. Therefore, most of the air supplied from the air supply port 18 flows into the casing 14 side, so that the plating solution can be almost completely sealed.

Since the oil seal 19 can effectively seal not only the liquid state but also the mist state of the lubricating oil and the plating solution, the oil seal 19 does not mix with the oil seal 19 as a boundary. In the present embodiment, the lubricant in the liquid state and the plating solution are removed by the labyrinth seal mechanism 17, and then the lubricant and the plating solution in the mist state are sealed by the oil seal 19.

The bowl shaft 16 of the oil seal 19
The mounting position on a is not limited to this embodiment,
For example, by providing between the labyrinth mechanism 17 and the main bearing 12, or between the labyrinth mechanism 17 and the casing 14, a sealing effect can be independently provided for the lubricating oil and the plating solution.

Labyrinth seal mechanism 17 on the main bearing 12 side
Alternatively, an oil seal 19 may be used. The labyrinth seal mechanism on the casing 14 side is
It is good to provide a step.

When a centrifugal separator is used in the above-described electric tin plating system, slime (stannic oxide) separated as a dehydrated solid is an extremely hard substance. Therefore, when the slime is moved to the solid matter discharge port side of the bowl by the screw conveyor, the slime always comes into frictional contact with the blade surface of the screw conveyor.

Therefore, it is preferable to use a detachable ceramic liner having particularly excellent wear resistance for this portion. On the other hand, it is preferable to use a highly corrosion-resistant metal such as SUS316L for the bowl. The bowl has a welded portion such as a boundary between the cone portion and the cylindrical portion, and is for preventing corrosion caused by carbon deposited on the welded portion.

The seal structure of the centrifugal separator according to the present invention comprises:
The shaft portion of the bowl between the main bearing and the casing, said bowl
Radially inward from the seal member placed around the shaft
A pair of rings provided in parallel and protruding from
One that accepts the ring and is inserted in the middle
A ring-shaped recess having an annular ring
A pair of labyrinth seal mechanisms formed, air supply means for increasing the pressure in a section defined by the pair of labyrinth seal mechanisms higher than in the casing and the main bearing, and lubricating oil from the main bearing side to the casing And an oil seal that seals the inflow of liquid and prevents the separated liquid on the casing side from flowing to the main bearing side, thereby effectively sealing the separated liquid and the lubricating oil in the mist state and the liquid state. This has an effect that leakage of the separated liquid from the casing side to the main bearing and leakage of the lubricating oil from the main bearing side to the casing can be almost completely prevented.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view of a main part of an embodiment of a seal structure in a rotation support portion of a centrifuge according to the present invention.

FIG. 2 is a block diagram of an electrotin plating system using a centrifuge employing a seal structure according to the present invention.

FIG. 3 is an enlarged sectional view of the labyrinth seal mechanism shown in FIG. 2;

FIG. 4 is a schematic sectional view showing an example of a conventional centrifuge.

FIG. 5 is a block diagram of a conventional continuous filtration type electrotin plating system.

FIG. 6 is a cross-sectional view illustrating details of the plating cell of FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Centrifuge 12 Main bearing 13 Sleeve member 13a Ring, 13b recess 14 Casing 15 Sealing member 15a Ring 16 Bowl 16a Bowl shaft 17 Labyrinth seal mechanism 18 Air supply port 19 Oil seal

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F16J 15/447 F16C 33/80 B04B 1/20 B04B 7/00

Claims (3)

(57) [Claims] 1. A seal structure in the vicinity of a rotation support portion of a centrifuge including a bowl supported by a pair of main bearings and rotatably rotatable in a casing disposed therebetween, wherein the main bearing and the casing are provided. the shaft portion of the bowl between, 該Bo
Radial direction from the seal member placed around the urn shaft
A pair of rings provided in parallel protruding inward,
Accepts a pair of rings and is inserted between them
An annular recess of the shaft having one ring
A pair of labyrinth seal mechanisms, air supply means for increasing the pressure in a section defined by the pair of labyrinth seal mechanisms higher than in the casing and the main bearing, and the main bearing side. And an oil seal for sealing the inflow of lubricating oil from the casing into the casing and preventing the separated liquid on the casing side from flowing out to the main bearing side. 2. A seal structure near a rotation support portion of a centrifugal separator including a bowl supported by a pair of main bearings and rotatably rotatable in a casing disposed therebetween, wherein the main bearing and the casing are provided. A seal disposed around the bowl shank on the casing side of the bowl shank between and
One set provided in parallel protruding radially inward from the member
Accept the pair of rings and the pair of rings and
Provided in an annular shape with one ring inserted in the middle
A labyrinth seal mechanism comprising a recess of the shaft portion; and a casing for sealing the inflow of lubricating oil from the main bearing side to the casing on the main bearing side of the shaft portion of the bowl. An oil seal for preventing the separated liquid on the side from flowing out to the main bearing side; and a pressure in a portion defined by the labyrinth seal mechanism of the shaft portion and the oil seal from the inside of the casing and the inside of the main bearing. A seal structure characterized by comprising: an air supply means for increasing the pressure; 3. The seal structure for a rotary support portion of a centrifuge according to claim 1 , wherein the centrifuge comprises a gantry and a pair of splash lubrication systems fixedly installed on the gantry. A main bearing, a shaft portion at both ends in the axial direction, a cone portion having an inner diameter gradually increasing, a solid material discharge port for discharging solid matter, and a separation liquid discharge port for discharging a separation liquid, wherein the shaft part has the pair of main shafts. A bowl rotatably supported around a horizontal axis by a bearing; a casing provided in a liquid-tight manner around the bowl; solids rotatably supported and separated inside the bowl for discharging the solids; A screw conveyor that feeds into an outlet; a liquid supply pipe that extends through one of the main bearing and the bowl shaft to introduce a solid / liquid mixture into the bowl via the inside of the screw conveyor; To, seal structure, characterized in that it is configured with a driving means for rotating the bowl and screw conveyor at each predetermined speed.