Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B04—CENTRIFUGAL APPARATUS OR MACHINES FOR CARRYING-OUT PHYSICAL OR CHEMICAL PROCESSES
  • B04B—CENTRIFUGES
  • B04B3/00—Centrifuges with rotary bowls in which solid particles or bodies become separated by centrifugal force and simultaneous sifting or filtering
  • B04B3/02—Centrifuges with rotary bowls in which solid particles or bodies become separated by centrifugal force and simultaneous sifting or filtering discharging solid particles from the bowl by means coaxial with the bowl axis and moving to and fro, i.e. push-type centrifuges
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B04—CENTRIFUGAL APPARATUS OR MACHINES FOR CARRYING-OUT PHYSICAL OR CHEMICAL PROCESSES
  • B04B—CENTRIFUGES
  • B04B15/00—Other accessories for centrifuges
  • B04B15/08—Other accessories for centrifuges for ventilating or producing a vacuum in the centrifuge
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B04—CENTRIFUGAL APPARATUS OR MACHINES FOR CARRYING-OUT PHYSICAL OR CHEMICAL PROCESSES
  • B04B—CENTRIFUGES
  • B04B3/00—Centrifuges with rotary bowls in which solid particles or bodies become separated by centrifugal force and simultaneous sifting or filtering
  • B04B3/02—Centrifuges with rotary bowls in which solid particles or bodies become separated by centrifugal force and simultaneous sifting or filtering discharging solid particles from the bowl by means coaxial with the bowl axis and moving to and fro, i.e. push-type centrifuges
  • B04B3/025—Centrifuges with rotary bowls in which solid particles or bodies become separated by centrifugal force and simultaneous sifting or filtering discharging solid particles from the bowl by means coaxial with the bowl axis and moving to and fro, i.e. push-type centrifuges with a reversible filtering device
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B04—CENTRIFUGAL APPARATUS OR MACHINES FOR CARRYING-OUT PHYSICAL OR CHEMICAL PROCESSES
  • B04B—CENTRIFUGES
  • B04B7/00—Elements of centrifuges
  • B04B7/02—Casings; Lids
  • B04B7/06—Safety devices ; Regulating

Definitions

• the invention relates to an inverting filter centrifuge for separating liquid-solid mixtures with a rotatingly driven centrifugal drum, with a reversible filter cloth arranged on the centrifugal drum, with a filtrate housing for receiving and removing the liquid-solid mixture by centrifuging into the centrifugal drum Inverted filter cloth separated liquid filtrate, with a solid housing for receiving and discharging the solid separated from the liquid-solid mixture while rotating the centrifugal drum with the filter cloth turned out (filter cake) and with an annular gap surrounding the edge of the centrifugal drum in the area of the filtrate housing and the solid housing.
• An inverting filter centrifuge of this type is known from DE-37 40 411 AI.
• the centrifugal drum In order to achieve the greatest possible separation effect when working with such a centrifuge, the centrifugal drum is usually operated at the highest possible speed, which leads to very high peripheral speeds at the drum edge. Since tumbling movements of the centrifugal drum occur in these centrifuges due to inevitable unbalance, an annular gap has been provided between the rotating centrifugal drum and the stationary housing in the area of the filtrate and solids space, which can also contain a flexible, elastic seal (DE-34 30 506 C2 ). If the centrifugal drum is set in rapid revolutions within such an annular gap, the annular gap must be at least so large that the tumbling movement of the drum which occurs at maximum unbalance does not cause the rotating centrifugal drum to come into contact with stationary ones Housing parts leads. If a seal is used in the annular gap, it may only bear lightly on rotating machine parts due to the high peripheral speed of the centrifugal drum and the heat that occurs when touched.
• the base piece carrying the filter cloth becomes like a plunger in moved the solids housing into it.
• the dry solid is thrown into the solid housing.
• the gas in this housing is enriched with solid aerosols by dusty portions of the solid.
• a transfer of filtrate into the solids housing and vice versa of solids in the filtrate housing is highly undesirable because of the contamination involved, but was previously unavoidable because of the annular gap between the centrifugal drum and the machine housing, even if the annular gap contained a seal.
• the object is achieved in a generic inverting filter centrifuge by the invention in that protective devices in the form of sealing gas generating devices are provided on the inverting filter centrifuge, with the aid of which a sealing gas stream which is effective in two directions and can generate an undesirable gas can be generated in the annular gap surrounding the rim of the drum Effectively prevents the passage of gaseous, liquid and / or solid substances in the direction of the filtrate housing and / or solid housing.
• the invention is therefore based on the general idea of a solution to establish a pressure difference between the filtrate housing and the solid housing in order to generate a gaseous medium flow, which precludes an undesirable mass transfer between these housing regions.
• an overpressure or underpressure is generated directly in the centrifugal drum and not in the filtrate or solids housing.
• the pressure generated in the centrifugal drum can also have an effect in the surrounding filtrate housing, this prevents the passage of gaseous, liquid and / or solid substances between the filtrate and solid housing.
• FIG. 1 shows schematically an inverting filter centrifuge with a closed centrifugal drum.
• FIG. 2 shows the inverting filter centrifuge from FIG. 1 with the centrifugal drum open;
• 3 and 4 are partial views in the area of the dot-dash circle X in FIG. 1;
• FIG. 5 shows a modified embodiment of an inverting filter centrifuge with an open centrifugal drum
• FIGS. 6 and 7 are partial views of modified embodiments of inverting filter centrifuges in the area of the dot-dash circle X in FIGS. 1 and
• Fig. 8 shows a further modified embodiment of an inverting filter centrifuge with a closed drum.
• the 1 and 2 comprises an inverted filter centrifuge, a schematically indicated, enclosing the drive part of the centrifuge (not shown on the right in these figures), the machine housing 1, in which a hollow shaft 3 in bearings 4, 5 is rotatably supported on a stationary machine frame 2 is.
• the hollow shaft 3 can be put into rapid circulation by means of a motor (not shown). It extends beyond the machine frame 2, the bearing 4 and a partition 6, which closes the machine housing 1 at the front and is tightly connected to the machine frame 2, and has an axially running keyway (also not shown) in which a wedge piece 9 is axially displaceable is.
• This wedge piece 9 is rigid with an inside of the hollow shaft 3 slidable shaft 12 connected. The shaft 12 therefore rotates together with the hollow shaft 3, but is axially displaceable in the latter.
• a pot-shaped centrifugal drum 16 is flanged with its bottom 17 in a rotationally fixed manner.
• the centrifugal drum 16 has radially extending passage openings 18 on its circular cylindrical side wall.
• the centrifugal drum 16 is open on its end face opposite the bottom 17.
• the edge of an essentially circular cylindrical filter cloth 22 is tightly clamped on a flange-like opening edge 19 by means of a retaining ring 21.
• the other edge of the filter cloth 22 is correspondingly tightly connected to a base piece 23 which is rigidly connected to the displaceable shaft 12 which freely penetrates the base 17.
• a centrifugal chamber cover 25 is rigidly fastened via stud bolts 24, leaving a space free, which tightly closes the interior of the centrifugal drum 16 by resting on its opening edge 19 in FIG. 1 and in FIG. 2 together with the base piece 23 by axially pushing out the Shaft 12 is lifted free of the centrifugal drum 16 from the hollow shaft 3.
• the filter cloth 22 is turned inside to the centrifugal drum 16, in Fig. 2 this cloth is turned inside out.
• a filtrate housing 10 and a solids housing 11 connect to the machine housing 1 in the region of the centrifugal drum 16. Both housings are sealed off by corresponding walls. In the vicinity of the opening edge 19 of the centrifugal drum 16, the filtrate housing 10 and the solids housing 11 are separated from one another by an annular end wall 14. The opening of this annular end wall 14 surrounds the outer edge of the centrifugal flow, leaving an annular gap 15 free. mel 16. This annular gap is so large that the centrifugal drum can perform small wobbling movements at high speed without touching the inside of the opening formed in the annular end wall 14.
• known circular, self-contained seals 41 could be arranged in the annular gap 15, which consist of elastic, highly flexible material, are embedded in the partition wall 14 and loosely grind on the outer edge of the drum 16, so that these tumble movements in the necessary dimensions can perform (Fig. 4).
• the filtrate housing 10 serves to receive and discharge a liquid filtrate which has penetrated the passage openings 18 of the centrifugal drum 16 and the filter cloth 22.
• a discharge line 7 with a shut-off valve 71 connected to the filtrate housing 10 is provided to discharge the filtrate.
• a filter cake deposited on this cloth and present as a solid can be discharged via a discharge line 8 of the solid housing 11 after the filter cloth 22 has been turned inside out, the line 8 being tightly closable by a shut-off valve 81.
• a filling tube 26 which serves to supply a suspension to be broken down into its solid and liquid components into the interior of the centrifugal drum 16 (FIG. 1) and in the one in FIG. 2 shown operating state penetrates into a bore 27 of the displaceable shaft 12, the displacement of the shaft 12 and thus the opening and closing of the centrifugal drum 16 via (not shown, also shown on the drawing on the right) drive motors, for example hydraulic, done.
• the inverting filter centrifuge takes the position shown in FIG. 1 on.
• the displaceable shaft 12 is retracted into the hollow shaft 3, as a result of which the bottom piece 23 connected to the shaft 12 lies near the bottom 17 of the centrifugal drum 16 and the filter cloth 22 is inserted into the drum in such a way that it covers the passage openings 18 inside it .
• the centrifugal chamber cover 25 has placed tightly on the opening edge 19 of the centrifugal drum 16. With a rapidly rotating centrifugal drum 16, suspension to be filtered is introduced continuously via the filling tube 26.
• the liquid constituents of the suspension enter the filtrate housing 10 as filtrate through the filter cloth 22 and the passage openings 18 and are passed there by a baffle plate 36 into the discharge line 7 connected to the filtrate housing 10.
• the solid particles of the suspension are retained in the form of a filter cake by the filter cloth 22.
• the filling tube 26 has penetrated into the bore 27 of the shaft 12 through corresponding openings in the cover 25 or in the base piece 23.
• the filter centrifuge is brought back into the operating position according to FIG. 1 by pushing back the shaft 12, the filter cloth 22 turning back in the opposite direction. In this way, operation of the centrifuge with a continuously rotating centrifugal drum 16 is possible.
• the rotating centrifugal drum 16 in the filtrate chamber 10 acts like a fan, which leads to a pressure drop directed from the filtrate housing 10 into the solid housing 11 and thus to a gas flow from the filtrate housing 10 into the solid housing 11, as a result of which the annular gap 15 undesirable substances, in particular liquid aerosols and evaporated liquid, can get into the solid housing 11.
• means or protective devices are provided in order to achieve a constant gas overpressure in the solid housing 11, with the aid of which a constant flow of a gaseous barrier medium, for example air, can be generated through the annular gap and which leads to an undesired transfer of gaseous and in particular prevents liquid substances from the filtrate housing 10 into the solid housing 11.
• a compressed gas source pressure pump
• a gas inlet connection 51 provided on the solid housing 11 and introduces a gaseous medium, for example air or an inert gas, into the solid housing 11 in the direction of the arrow.
• the excess pressure used in the solid housing 11 can be, for example, 5 to 50, preferably 10 to 30, mbar.
• the filtrate housing 10 has a further connection piece 52, which in the simplest case is open to the atmosphere. A pressure equalization can thus take place via the annular gap 15 with the formation of a correspondingly directed gas flow, the gas flow preventing foreign particles from passing from the liquid housing 10 into the solid housing 11.
• shut-off valves 71, 81 in the discharge lines 7 and 8 are closed as required.
• shut-off valve 54 in the case shown.
• the shut-off valve 54 is provided in the gas suspension line 53 and is kept closed during the generation of this overpressure.
• FIGS. 3 and 4 show again schematically and clearly.
• 3 shows the annular gap 15 between the partition 14 and the edge of the centrifugal drum 16 in accordance with the circular area X in FIG. 1 1, that is to say when the centrifugal drum 16 is closed, a gas stream directed into the filtrate housing 10 in the direction of arrow I is generated, air being able to serve as the barrier medium, for example.
• the solid is thrown off the inverted filter cloth 22, a flow of gaseous barrier medium is caused through the annular gap 15 in the direction of arrow II.
• FIG. 4 shows the annular gap 15 with two sealing strips 41 which surround the centrifugal drum 16 in an annular manner, as shown in FIG. 4.
• the respectively associated pipe connecting pieces 52 and 51 serving for the gas outlet can also be connected to vacuum lines (suction pumps).
• suction pumps The mode of operation, namely the generation of a flow from a gaseous barrier medium in the annular gap 15, does not change anything here.
• FIG. 5 shows a modified embodiment of an inverting filter centrifuge, in which, however, only the structure and arrangement of the gas suspension line 53 have been changed compared to the embodiment according to FIGS. 1 and 2.
• this line also comprises a further shut-off valve 55.
• the line 53 has a further branch 56 into the solid matter housing 11 with an additional shut-off valve 57 and a dust or solid matter filter 58.
• the inverting filter centrifuge according to FIG. 5 can be used in the same way as the inverting filter centrifuge according to FIGS. 1 and 2.
• the barrier medium flows through the annular gap 15 in the direction from the filtrate housing 10 to the solid housing 11 when the solids discharge, ie with the centrifugal drum 16 open (FIG. 5)
• the shut-off valve 57 is then opened.
• the gaseous barrier medium supplied via the pipe socket 52 flows out of the filtrate housing 10 through the annular gap 15 into the solid housing 11, from there via the opened shut-off valve 57 into the dust filter 58, where solid particles are retained, and finally via the gas suspension line 53 into an exhaust gas line 59.
• the exhaust gas line 59 can contain a pressure holding valve 61, which serves to maintain a certain pressure in the overall system.
• the flow of the gaseous barrier medium in the annular gap 15 in the desired direction can be generated either by overpressure or by underpressure in one of the spaces forming the filtrate housing or the solid housing. Combinations of overpressure and underpressure in these rooms are also possible.
• the gas discharged from the solid housing 11 via the exhaust line 59 can be reprocessed. If you are working with a sealing gas flow in the opposite direction, i.e. the gas is not drawn from the solid housing 11 but from the filtrate housing 10, the valve 55 is opened when the valves 54, 57 are closed and the gas is also introduced into the exhaust line 59 for the purpose of conditioning. In this case, for example, the gas can be introduced via the pipe socket 51 into the solid housing 11, the pipe socket 52 being sealed tightly.
• a single line 64 is provided in the partition wall 14, which in turn e.g. can be thought of as a radial branch from a ring line surrounding the centrifugal drum 16 and connected to a pump.
• the two flows of the barrier medium in directions I and II each start from a single opening in opposite directions.
• the annular gap 15 in FIG. 7 in turn contains two annular sealing strips 41 which surround the drum 16 and are fastened in the partition wall 14.
• the introduction of the barrier medium via line 64 takes place between the sealing strips 41. It is also possible not to direct the introduction of the gaseous barrier medium into the annular gap 15 according to FIGS. 6 and 7 in both directions I and II, but depending on the working state of the inverting filter centrifuge either only in direction I or only in direction II.
• the gas flows flowing in the directions I and II can be generated either by overpressure in the lines 62, 63, 64, or also by underpressure in the respective spaces receiving the flows, namely either the filtrate housing 10 or the solid housing 11.
• FIG. 8 finally shows a last embodiment of an inverting filter centrifuge.
• the pressure drop required for the sealing gas flow can also be achieved without additional gas feed, as described in the previous embodiments.
• a suction pump P can be switched into the gas suspension line 53, which sucks gaseous medium out of the filtrate housing 10 via a liquid separator 91 and the opened shut-off valve 55, with the shut-off valve 57 and open shut-off valve 54 into the solids housing 11 feeds and thus maintains a constant, self-contained flow of barrier medium through the annular gap 15 (arrow I in Fig. 3 and 4).
• the pipe socket 51 is closed in this case.
• the invention could also be formulated as a method, for example in the sense that a current is generated in the annular gap 15 from a gaseous barrier medium, which prevents foreign substances from passing between the filter and solid housing 10, 11.

Landscapes

• Centrifugal Separators (AREA)
• Lubrication Details And Ventilation Of Internal Combustion Engines (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=7810995

Family Applications (1)

Country Status (12)

Families Citing this family (20)

Family Cites Families (8)

• 1996
  • 1996-11-08 DE DE19646038A patent/DE19646038C2/de not_active Expired - Fee Related
• 1997
  • 1997-10-21 AT AT97912208T patent/ATE219390T1/de not_active IP Right Cessation
  • 1997-10-21 RU RU99111966/13A patent/RU2188081C2/ru not_active IP Right Cessation
  • 1997-10-21 JP JP52208598A patent/JP2001503327A/ja not_active Ceased
  • 1997-10-21 CN CN97199559A patent/CN1092085C/zh not_active Expired - Fee Related
  • 1997-10-21 EP EP97912208A patent/EP0936948B1/fr not_active Expired - Lifetime
  • 1997-10-21 DK DK97912208T patent/DK0936948T3/da active
  • 1997-10-21 DE DE59707571T patent/DE59707571D1/de not_active Expired - Fee Related
  • 1997-10-21 ES ES97912208T patent/ES2175370T3/es not_active Expired - Lifetime
  • 1997-10-21 KR KR1019997004071A patent/KR100339774B1/ko not_active IP Right Cessation
  • 1997-10-21 WO PCT/EP1997/005804 patent/WO1998020980A1/fr active IP Right Grant
  • 1997-11-05 TW TW086116455A patent/TW344680B/zh active
• 1998
  • 1998-06-26 US US09/105,778 patent/US5988398A/en not_active Expired - Fee Related

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events