JPS5813221B2 - Self-discharging centrifugal drum - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a self-discharging centrifugal drum having a piston slider delimiting a separation chamber and a solids chamber on one side to control the discharge opening in the peripheral wall of the drum. and the discharge opening allows selective partial or total discharge, and the closed chambers of the centrifugal drum are arranged in a plurality of sections located one after the other in the radial direction and connected via passages. divided, sealed with respect to adjacent drum parts and adapted to be supplied with a closing liquid, and also provided with at least one discharge valve for total discharge, and for partial discharge. At least one discharge valve is arranged on the outer periphery of the centrifugal drum for the purpose of discharging, the discharge passage of the discharge valve being connected to a passage extending from the outer closed chamber section, and the discharge passage of the discharge valve is connected to the passage extending from the outer closed chamber section, and of the type in which the passage connecting the outer closed chamber section has a constriction point.

A centrifugal drum of this type is known from German Patent Application No. 2704903 and has two closed chambers located one after the other and connected via a closable channel. These closed chamber sections are arranged between the piston slide and the adjacent drum section and are filled with closing liquid before the centrifuge is put into operation.

The closure chamber consisting of these two closure chamber sections has larger dimensions in the radial direction than the drum interior, so that when the closure chamber is completely filled, the piston slide can be removed from the side of this closure chamber. The closing pressure acting on the drum is greater than the drum filling pressure acting in the opening direction from the other side.

To discharge the solids, the closing liquid is discharged from the section of the closing chamber at full rotational speed of the drum via a liquid-controlled centrifugal valve and the closing pressure below the piston slide is thereby reduced.

Under the pressure of the drum filling, the piston slider then moves into an open position which releases the outlet.

Depending on the type and viscosity of the solids to be separated, it may be advantageous to carry out a so-called partial discharge over a relatively short period of time or to carry out a complete discharge over a relatively long period of time.

In the case of partial evacuation, the drum is opened only briefly and the closing liquid is discharged from the outer closing chamber section, preferably via a liquid-controlled centrifugal valve.

In the case of this partial discharge, only a portion of the solids collected in the solids chamber is discharged, while the remaining solids remain in the drum as a liquid spill-preventing ring.

This prevents large amounts of centrifugation liquid, which is often a useful liquid, from being discharged and wasted along with the solids.

In the case of this partial evacuation, only the outer section of the closure chamber is drained of the closure liquid, so that the duration of the opening of the self-emptying drum and its opening width are limited.

This is because the closure liquid in the other section of the closure chamber remains.

As soon as the free liquid level in the separating chamber recedes until its opening pressure is less than the closing pressure of the closing liquid remaining in the closing chamber after the discharge of the solids has begun, the piston slide moves back into the closing position. .

The greater the closing pressure of the closing liquid retained in the closing chamber, the faster the drum will reclose and the less solids will be released during each opening process.

In the case of full evacuation in this known design, not only the outer chamber section but also the inner chamber section is evacuated.

For this purpose, the liquid-controlled centrifugal valve itself, which is arranged in the discharge channel connecting the two closed chamber sections, opens under the action of the liquid pressure located on the flange of the centrifugal valve. And as soon as the outer closed chamber section is evacuated, the discharge passage for emptying the inner closed chamber section is also opened.

In this type of construction, in the case of partial evacuation, the outer closed chamber section is evacuated, and in the case of complete evacuation, both the outer and inner closed chamber sections are evacuated.

In such an evacuation process, as long as closing liquid is present in the respective closing chamber section, the residual pressure in the closing chamber section is exerted on the piston slide.

Moreover, in the case of total evacuation, the evacuation process of both categories is particularly slow.

This is because the closing liquid from the inner closing chamber section must also first be conveyed through the passage into the outer chamber before being discharged from the drum.

This leaves the outer chamber under relatively high hydraulic pressure for a relatively long period of time.

However, rapid evacuation of the closed chamber is essential in order to ensure that the evacuation gap for solids is quickly opened wide.

As a result, the solids initially located in the solids chamber are evacuated and only then can the remaining useful liquid be evacuated.

This slow opening of the drum means that during the emptying process the useful liquid is first drained away by the fragile solids ring in the solids chamber, but there is a risk that residual solids will remain in the drum. The remaining amount can lead to dangerous imbalance of the drum.

In order to eliminate this risk, the opening process must be instantaneous, which is not possible with the construction of this known centrifugal drum.

The object of the invention is to design a self-emptying centrifugal drum of the construction type mentioned at the outset in such a way that partial and full discharge can be carried out quickly.

This problem is solved in the embodiment of the invention in which the discharge valves provided on the outer periphery of the centrifugal drum for total discharge extend from the radially outer ends of the inner closed chamber section and the outer closed chamber section and are arranged separately. This solution is achieved in that the discharge passage for the discharge valve which is in contact with the discharge passage provided for the partial discharge and which is provided for partial discharge extends from the inner diameter of the outer closed chamber section.

Due to the arrangement of separate drain valves for partial and full draining, the inner closed chamber section and the outer closed chamber section can be drained of the closing liquid in the shortest possible way and very quickly in the case of full draining, and the piston The closing pressure on the underside of the slide is likewise quickly reduced.

In the case of partial drainage, as soon as the discharge valve evacuates the associated discharge channel, the fluid connection between the two closed chamber sections is established by means of a throttle point arranged in the channel connecting the two closed chamber sections. is interrupted, whereby a significant pressure drop occurs in the outer closed chamber section and moves the piston slide very quickly into the open position.

On the other hand, a residual closing pressure is maintained by the liquid that is present below the piston slide in the outer closed chamber section, so that the piston slide returns again very quickly to its starting position.

In such a process, only a very small amount of closing liquid is discharged from the closing chamber.

Depending on the position of the throttle point, the closing pressure can be reduced by more than 50% during this partial evacuation process.

Next, embodiments of the present invention will be described with reference to the drawings.

In the drawing, reference numeral 1 shows a separation chamber with a dish-shaped insert, and reference numeral 2 a solids chamber, which is bounded on its upper side by a drum lid 3 and on its lower side by a piston slide 4. With its axial movement, the piston slide 4 opens and closes the outlet 5 of the drum part 6 for discharging the solids.

The drum part 6 and the drum lid 3 are connected by a closure ring 7.

Closed chambers are arranged between the piston slide 4 and the adjacent drum part 6, which in the illustrated embodiment are located radially one after the other and are sealed with respect to each other 2. The piston slide 4 is divided into two sections, an inner closed chamber section 8 and an outer closed chamber section 9, in which the piston slide 4 is divided into parts 10 and 10'.
In addition to the conventional guide of the drum part 6 , it is additionally guided by a section 11 of the adjacent drum part 6 and sealed by a sealing ring 12 .

In order to carry out the total evacuation, the evacuation passage 13 is opened from the radially outer ends of the inner closed chamber section 8 and the outer closed chamber section 9.
and 14 extend, and these discharge passages 13, 14
is opened and closed by a discharge valve 15.

These discharge valves 15 close the discharge passages 13 and 14 under the action of centrifugal force during operation.

The operation of such a valve 15 is known, for example, from U.S. Pat. No. 4,054,244.

In order to open this drain valve 15 , control liquid is supplied to the drain valve 15 via a channel 18 via a supply channel 16 and an annular channel 17 .

For partial evacuation, a discharge channel 19, which is designed as an annular channel, extends from the inlet of the outer closed chamber section 9 and opens into an annular channel 20. is assigned to a discharge passage 22 which is connected to a discharge valve 21 .

Extending from the inner closed chamber section 8 in the radial direction from its outer end is one or more discharge channels 23 in which a throttle point 24 is arranged, the throttle point 24 having an annular shape. It opens into the passage 20.

The discharge ducts with these constriction points can be arranged in the piston slide 4 or in the drum part 6, in which the discharge ducts and the constriction points are labeled. Illustrated at 23' and 24'.

In order to control the discharge valve 21, which also acts under centrifugal force, it is supplied with control liquid via the supply conduit 25, the annular channel 26 and the channel 27.

Filling the closed chamber with control liquid takes place via supply conduit 28, annular channel 29 and channel 30.

The mode of operation of this self-discharging centrifugal drum is as follows.

That is, in the case of full evacuation, a control liquid is supplied via the supply conduit 16 through the annular channel 17 of the centrifugal drum, which control liquid also flows through the channel 18 and further through the channel 1.
The discharge valve 15 opens under the action of the liquid pressure generated in the discharge valve 8 .

Via the discharge channels 13 and 14, the inner and outer closed chamber sections 8 and 9 are suddenly discharged, so that the piston slide 4 is forced downwardly under the influence of the overpressure created in the separating chamber 1 and the solids chamber 2. is moved axially into the open position and the drum fill is discharged via the discharge gap 5.

For total discharge, one or more discharge valves 15 with corresponding discharge channels 13 and 14 can be arranged.

For the closing process, closing liquid is passed through the supply channel 28 into the annular channel 29 to refill the closing chamber sections 8 and 9.

For partial evacuation, a control liquid is supplied via the supply channel 25 and the annular channel 26 to the channel 27, the liquid pressure generated in this channel 27 being applied to the drain valve 2.
Open 1.

Under the action of centrifugal force, the discharge passage 22 and the annular passage 20
is expelled abruptly, in which case the fluid connection between the inner closed chamber section 8 and the outer closed chamber section 9 through the throttle point 24 is broken.

This is because the throttling point 24 is supplemented with less closing liquid than the liquid that is discharged via the discharge channel 22 and the discharge valve 21.

As a result, the liquid pressure in the outer closed chamber section 9 is reduced very rapidly, so that the piston slide 4 moves axially downwards under the action of the pressures generated in the separation chamber 1 and the solids chamber 2. Moreover, a certain amount of the drum fill is discharged via the discharge opening 5.

However, since liquid remains annularly in the outer closed chamber section 9 and thus a constant hydraulic pressure continues to be maintained, the piston slide 4 is again moved very rapidly into the upper closed position.

In this case, the opening stroke of the piston slide is smaller than in the case of full evacuation.

With this partial evacuation, the amount of liquid discharged from the closed chamber is extremely small.

This is because mainly only the closed liquid from the discharge passage 22 and the annular passage 20 is discharged from the drum.

This means that during this downward movement of the piston slide, only a portion of the liquid present in the outer closed chamber section below the piston slide is displaced into the annular channel 20 which was initially discharged therebelow.

Depending on the position of the blocking zone 11 and the throttling point 24 between the inner chamber section 8 and the outer chamber section 9, the pressure drop in the outer chamber section can be greater than 50%.

Very little closing liquid is therefore required for the closing process after partial evacuation, which closing liquid is supplied to the closing chamber via supply channel 28, annular channel 29 and channel 30.

For partial evacuation, a corresponding evacuation channel 2 is also required.
One or more discharge valves 21 may be provided.

It is also conceivable to provide more than two closed chamber sections.

The complete and partial evacuation process can take place via a control device not shown, and the full evacuation process can also be connected to the partial evacuation process, in which case the evacuation process can be carried out even more quickly. .

[Brief explanation of drawings]

The drawing is a partial vertical sectional view showing an embodiment of a centrifugal drum according to the present invention. 1... Separation chamber, 2... Solid matter chamber, 3.
...Drum section, 4...Piston slider, 5...Discharge port, 6...Drum part,
7...Closing ring, 8...Inner closed chamber section, 9...Outer closed chamber section, 10, 10',
11... part, 12... seal ring, 13, 14... discharge passage, 15......
Discharge valve, 16... Supply passage, 17...
Annular passage, 18... passage, 19... discharge passage, 20... annular passage, 21......
Discharge valve, 22, 23, 23'...Discharge passage, 2
4, 24'... Throttle point, 25... Supply passage, 26... Annular passage, 27...
Passage, 28... Supply passage, 29... Annular passage, 30... Passage.

Claims (1)

[Scope of Claims] 1. A self-discharging centrifugal drum, comprising a piston slider that limits a separation chamber and a solids chamber on one side to control a discharge port on the peripheral wall of the drum; The outlet makes it possible to selectively carry out partial or total evacuation, and the closed chamber of the centrifugal drum is divided into a plurality of sections located radially one after the other and connected via passages. , sealed with respect to the adjacent drum parts and adapted to be supplied with a closing liquid, and also provided with at least one discharge valve 15 for full discharge, but also for partial discharge. For this purpose, at least one discharge valve 21 is arranged on the outer periphery of the centrifugal drum, the discharge passage 22 of which discharge valve 21 being connected to a passage 19 extending from the outer closed chamber section 9 and the inner closed chamber section 9. Channel 2 connecting chamber section 8 with outer closure section 9
3, 23' with throttling points 24, 24', a discharge valve 15, which is arranged on the outer periphery of the centrifugal drum for total discharge, connects the inner closed chamber section 8 and the outer closed chamber. A discharge valve 21 extends from the radially outer end of the section 9 and is connected to separately arranged discharge passages 13, 14 and is further provided for partial discharge.
A self-draining centrifugal drum, characterized in that a discharge passage 22 for the pump extends from the inner diameter of the outer closed chamber section 9. 2. The self-discharging centrifugal drum according to claim 1, wherein an annular passage 20 is assigned to the discharge passage 22. 3. Self-emptying centrifugal drum according to claim 2, wherein the discharge passage 19 of the outer closed chamber section 9 is constructed as an annular passage. 4. The self-discharging centrifugal drum according to claim 3, wherein the annular passage 19 opens into the annular passage 20. 5 Throttle points 24, 24 extending from the inner closed chamber section 8;
The discharge passages 23, 23' having the same diameter as the annular passage 2
5. The self-discharging centrifugal drum according to claim 4, which has an opening in the middle. 6. A channel 23 extending from the inner closed chamber section 8 and connected to the annular channel 20 and the outer closed chamber section 9 and having a throttle point 24 is arranged in the piston rider 4. self-discharging centrifugal drum. 7. A channel 23' extending from the inner closed chamber section 8 and connecting to the annular channel 20 and the outer closed chamber section 9 and having a throttle point 24' is arranged in the adjacent drum part 6. The self-discharging centrifugal drum according to paragraph 5.