FR2612425A1 - OUTPUT DEVICE IN A CENTRIFUGAL SEPARATOR - Google Patents

Abstract

TO CONSTANTLY MAINTAIN A LOW LEVEL OF THE LIQUID IN A TURBINATION CHAMBER 26 OF A CENTRIFUGAL ROTOR, THE LIQUID BEING PUMPED INTERMITTENTLY FROM THIS BLOWER CHAMBER TO A RECEPTION LOCATION OUTSIDE THE ROTOR, IT IS LIMITED TO THE FLOW OF LIQUID FROM THE SEPARATION CHAMBER 7 TO THE TURBINATION CHAMBER 26 OF THE ROTOR AND, AT THE SAME TIME, TO DISCHARGE A LIMITED FLOW OF LIQUID FROM THE TURBINATION CHAMBER 26 THROUGH A CALIBRATED OUTLET. ACCORDING TO THE INVENTION, A VALVE 35 WHICH CAN BE ACTUATED INTERMITTENTLY IS PROVIDED TO CLOSE THE CALIBRATED OUTLET 37, 38 FROM THE OUTLET CHAMBER 26 DURING THE PERIODS OF TIME DURING WHICH THE LIQUID IS PUMPED FROM THE OUTLET CHAMBER 26 RECEPTION LOCATION OUTSIDE THE ROTOR.

Description

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  Output device in a centrifugal separator.

  The present invention relates to a centrifugal separator comprising a rotor forming an inlet for a mixture of two liquids of different densities, which must be separated, a separation chamber communicating with said inlet, a first outlet for a first separated liquid, this outlet communicating with a first part of the separation chamber, and a second outlet for a second separated liquid, which comprises an outlet chamber which communicates via a calibrated opening with a second part of the separation chamber, the centrifugal separator comprising in addition stationary elements extending into the outlet chamber and forming both an outlet pipe which is provided with means arranged to open and close a connection between the outlet chamber and a receiving location outside the rotor , and a calibrated output arranged to discharge a limited current of liquid since the exit chamber when the pipeline

exit is closed.

  A centrifugal separator of this type is described in US-4,622,029.

  The particular arrangement of a calibrated aperture in the connection between the rotor separation chamber and the rotor exit chamber and a calibrated output for discharging a limited flow of liquid from the exit chamber, when the outlet is closed, serves to constantly maintain a level of liquid as low

  as possible in the exit room.

  The object of the present invention is to further improve the output device of a centrifugal separator of this type, so as to give the stationary elements a greater pumping effect for pumping the liquid from the outlet chamber to the receiving location outside the rotor, without the stationary elements being immersed in the liquid in the outlet chamber deeper than necessary, when the connection between the exit chamber and the receiving location is -2- closed. According to the invention, this object is achieved by means of an intermittently operable valve arranged to close said calibrated outlet when the outlet pipe is opened to establish the connection between the outlet chamber and the location of the outlet.

  reception outside the rotor.

  Thanks to the invention, it is possible to optimize, independently of one another, the two different functions of said stationary elements, namely 1) to maintain a liquid level in the outlet chamber as low as possible when the outlet pipe is closed, and 2) pumping the liquid from the outlet chamber to the receiving location outside the

  rotor as efficiently as possible.

  Within the scope of the invention, the calibrated output and the valve for intermittently closing it can be completely separated from the outlet pipe, in which case a separate closure valve is mounted therein. It is further possible to have the calibrated output from the outlet pipe while providing two separate closure valves in the calibrated outlet and the outlet pipe respectively. But in a preferred embodiment of the invention, only one valve is used for the two valve functions required. The calibrated output then starts from the outlet pipe, the last mentioned valve being arranged to establish, in a first position, a connection between the outlet chamber and the receiving location outside the rotor and, simultaneously, close a connection between the output chamber and the calibrated output, and in a second position close the connection between the output chamber and the receiving location and simultaneously establish a

  connection between the outlet chamber and the calibrated outlet.

  Preferably, said valve is mounted outside the rotor, the calibrated output being connected inside the rotor to return the liquid from the outlet chamber for example to the chamber of

rotor separation.

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  The invention will be described in more detail with reference to the accompanying drawing which schematically shows a preferred embodiment. In the drawing is shown a centrifugal separator comprising a rotor consisting of two parts 1 and 2, which are held together by means of a locking ring 3. The rotor is supported by a shaft

Training 4.

  In the rotor is provided a sliding member 5 which is movable axially back and forth to establish a tight seal by applying against an annular liner 6. A separation chamber 7 is limited between the sliding member 5 and the part upper rotor 1, and a chamber 8 provided to contain what is called a control liquid is limited between the element

  sliding 5 and the lower part 2 of the rotor.

  A means 9 is arranged to send control liquid in a space 10 defined inside the part 2 of the rotor, where a duct 11 leads to said chamber 8. A small section pipe 12 extends from of the part of chamber 8 which is radially outmost and passing through part 2 of the

rotor towards the outside of the rotor.

  In the separation chamber 7 is mounted a set of conical separation discs 13. These are based on what is called a distributor 14 which forms in the lower part of the rotor and with

  a conical plate 15 an inlet 16 to the separation chamber 7.

  The upper part of the distributor 14 surrounds a central space inside the rotor, in which a stationary tube 17 extends for feeding a mixture of components to be separated at

inside the rotor.

  On the set of discs contained in the separation chamber (only a few discs 13 are shown in the drawing) rests a conical top disc 18 which is thicker than the discs 13 and which extends radially outwardly into the chamber of separation being a little longer than said disks. The disk 18 forms a pipe 19 with the upper part 1 of the rotor and comprises a through hole 20 at a level which is just about that of the edges

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  external separation discs.

  In the upper part of the rotor, the upper disk 18 comprises two annular flanges 21 and 22 directed radially inwards, which form between them a chamber 23. The upper flange 22 extends radially inwards over a distance a little longer than the collar 21. Above the upper flange 22, the upper part 1 of the rotor supports an annular flange 24 directed radially inwards and which extends radially inwards over a distance one longer than the collar 21 which is the lowest. Between the flanges 24 and 22 is constituted a space 25 communicating via the pipe 19 with the chamber of

separation 7.

  Between the highest part of the part 1 of the rotor and the flange 24 supported by it is constituted a chamber 26 which communicates with said space 25 by a calibrated opening 27

formed in the collar 24.

  As previously described, the inlet tube 17 supports a coaxial tube 28 which surrounds it, which supports at its lower end what is called a turbine disk 29.

  is mounted inside the chamber 23 previously mentioned.

  The tube 28 supports on its side a coaxial tube 30 which surrounds it, which supports at its lower end a turbine disk 31. The turbine disk 31 is mounted in the chamber 26 mentioned above and comprises several pipes 32 - distributed around the turbines - which communicate via an annular pipe 33 with an outlet pipe 34. The outlet pipe 34 is connected to an inlet of a valve 35 which is connected at its side by a first outlet to a conduit 36 and a second outlet to a return line 37. The latter forms a passage which opens through the calibrated opening 38 in the space 25. The aforementioned turbine disk 29 includes turbines 39 which communicate via an annular pipe 40 with a pipe 41. In the pipe 41 are mounted detection means 42 of a conventional type

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  whatever to detect if a certain liquid that flows through the

  line 41 contains fractions of another liquid.

  Control equipment 43 is connected via leads 44 and 45 to sensing means 42 and valve 35, respectively. The valve 35 is shown in the drawing in the form of a gate valve comprising a slide comprising two parts 46 and 47 respectively. In the drawing, the drawer is shown in an upper position in which the drawer portion 47 establishes communication between the outlet line 34 and the return line 37. By a signal from the control equipment 43, the drawer can being moved downwards to a lower position in which the portion 46 of the spool prevents this communication between the outlet pipe 34 and the return pipe 37 but establishes against the communication between the outlet pipe 34 and the pipe 36. Driving 36 leads to a receiving location, not shown, for the liquid having been separated in the rotor and having been collected in the radially outermost part of the

separation chamber 7.

  The centrifugal separator described above can be used for the purification of oil, for example heavy fuel oil, by removing it from water and solid particles. A mixture of these components, heated to about 100 ° C., is sent into the centrifugal rotor via line 17, from which it flows via line 16

in the separation chamber 7.

  At this stage, the chamber 8 located between the sliding element 5 and the rotor part 2 is filled with control water, so that the sliding element 5 is kept pressed against the packing 5. A small amount of control water constantly leaves the chamber 8 through the hole 12, but a corresponding amount of water of

  new order is continuously provided by means 9.

  In the separation chamber 7, the separated oil moves towards the center of the rotor and flows into the chamber 23, from where it is pumped by the impeller 29 through the pipes 39 and 40 to at the outlet duct 41. The radially inwardly directed annular collar 21 forms an overflow outlet for the separated oil from the separation chamber, which is why the liquid level in the separation chamber

  is determined by the position of the inner edge of the flange 21.

  The separated oil flows towards the center of the rotor, also passing through line 19 between the upper disc 18 and the rotor part 1. From the pipe 19, the oil enters the central space 25 where a free surface of the liquid is formed at the same

  level only in the separation chamber 7.

  A certain amount of oil passes through the calibrated opening 27 formed in the flange 24 to reach the chamber 26. From there, the oil is pumped by the turbine disk 31 through the pipes 32 and 33 and out through line 34 to go to valve 35. In a starting position, valve 35 is in the position shown in the drawing and the oil thus continues to be pumped through valve 35 and return line 37 to return through the opening 38 in the central space 25. From there, the oil can again flow into the chamber 26 through the opening 27. By appropriately sizing the openings 27 and 38, can maintain the surface of the liquid in the chamber 26, during the operation of the rotor, at a desired level radially outwardly

  of the free surface of the liquid contained in the space 25.

  If the return line 37 and / or the perforated flange did not exist, the level of the liquid in the chamber 26 would be the same

  at this point only in the space 25 and in the separation chamber 7.

  This would mean that a relatively large portion of the surface of the turbine disk 31 would have been in contact with the oil rotating inside the chamber 26, which means that the temperature in

  this room would have risen undesirably.

  When after a certain period of operation a sufficient quantity of separated water has been collected in the radially outermost part of the separation chamber so that the interface layer between the oil and the water is located at the At level A in the separation chamber, fractions of water begin to accompany the separated oil and exit through line 41. This is detected by the means 42 which emits a signal applied to the control equipment 43. On the other hand, the control equipment 43 responds by adjusting the valve 35 so that the outlet line 34 is kept in communication with the line 36 for a predetermined period of time. During this period of time, a sufficient quantity of separated water is allowed to leave the separation chamber 7 via the pipe 19 and the flow-determining opening 27 formed in the collar 24 so that the layer of interface between the oil and the water in the separation chamber reaches a level B. When the valve 35 has returned to its position shown in the drawing, the water present in the chamber 26, the space 25 and the pipe 19 returns to this stage in the separation chamber 7, the oil then flowing through the hole 20 formed in the upper disc 18 and filling again said spaces to the levels

which are shown on the drawing.

  The separated water may be discharged intermittently from the separation chamber 7 in the manner described above. In general, the solid particles separated in the separation chamber need to be evacuated more rarely. This is achieved by an occasional interruption of the control water supply passing through the supply means 9. The control equipment 43 may be programmed for example so that every fourth time a signal is emitted and indicates that the interface layer between the oil and the water in the separation chamber has reached the level A, the valve 34 is maintained in the position shown in the drawing, while the control water supply by the means 9 is occasionally interrupted. The sliding element 5 is thus made to move axially downwards and to provide an open slot between itself and the lining 6. The separated solids and a desired quantity of water then leave the separation chamber 7 passing through this slot and the openings of the part 2 of the rotor which are located

  radially outside the slot.

  By determining the size of the calibrated opening 38, it is possible to start from a certain desired size of the opening 27 and a certain desired level for the liquid in the chamber 26 when the valve 35 is in the position shown in the drawing. The flow rate passing through the opening 27 can be determined by acting on the pressure difference prevailing in the liquid bodies on the respective sides of the collar 24, in the region of the opening 27. the oil in the chamber 26 is maintained, it is necessary that exactly the same flow that passes through the opening 27 also passes through the opening 38. When said openings 27 and 38 have been dimensioned correctly and when the arrangement described has been put into operation, the surface of the liquid in the chamber 26 automatically adjusts to the desired level. The arrangement is therefore self-controlled. Thanks to the invention, it is possible according to the needs to give the aperture 38 relatively large dimensions without this having a negative influence on the capacity of the turbine disk 40 to pump the water to the location of reception at

the outside of the rotor.

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Claims (4)

  A centrifugal separator comprising a rotor forming an inlet for a mixture of two liquids of different densities, which must be separated, a separation chamber (7) communicating with said inlet, a first outlet (23) for a first separated liquid, this outlet communicating with a first portion of the separation chamber (7), and a second outlet for a separate second liquid, which includes an outlet chamber (26) which communicates via a calibrated opening (27) with a second portion of the separation chamber (7), the centrifugal separator further comprising stationary members extending into the outlet chamber (26) and forming both an outlet pipe (34, 36) which is provided with means arranged to open and close a connection between the outlet chamber (26) and a receiving location outside the rotor, and a calibrated outlet arranged to discharge a limited current of liq uide from the outlet chamber (26) when the outlet pipe (34, 36) is closed, characterized by a valve (35) operable intermittently and arranged to close said calibrated outlet (37, 38) when the pipe outlet (34, 36) is provided for establishing the connection between the outlet chamber (26) and   the receiving location on the outside of the rotor.   Centrifugal separator according to Claim 1, characterized in that the calibrated outlet (37, 38) starts from the outlet pipe (34, 36) and in that said valve (35) is arranged in a first position to establish the connection between the outlet chamber (26) and the receiving location outside the rotor and, simultaneously, to close the connection between the outlet chamber (26) and the calibrated outlet (37, 38), and in a second position to close the connection between the outlet chamber (26) and the receiving location, and simultaneously, to establish the connection between the chamber   output (26) and the calibrated output (37, 38).   Centrifugal separator according to Claim 2, characterized in that the valve (35) is mounted on the outside of the rotor and that the   calibrated output (37, 38) is connected to the inside of the rotor.   4. Centrifugal separator according to any one of the claims - 10 -   preceding, characterized in that said first outlet (23) communicates with a central portion of the separation chamber (7) while the outlet chamber (26) communicates with a portion   peripheral of the separation chamber (7).