DE4408803C1 - Polymer split fluid flow filter control unit - Google Patents

Abstract

In a unit which controls the flow of fluid within two or more passages, the novelty is that the control unit incorporates common fluid inlet (10) and flow passages (5, 6) to o the outlet (11). Each partial fluid flow passage (5, 6) has a filter (1, 2). The control unit has one or more valves (3, 4) linked to passages (10, 5, 6, 11) which filter the fluid flowing into the passages (10, 5, 6, 11), depending upon the position of the valves (3, 4). The filter assembly (1, 2) is rinsed clean by the fluid, or the fluid entering one of the passages (5, 6), while the other filter (13) is rinsed clean.

Description

The present invention relates to a control device for at least two partial fluid streams with the features of the preamble of claim 1.

There is a common problem in the art that fluid flows need to be filtered. To solve this problem, it is known, for example, a corresponding filter device to be arranged in a fluid channel, the fluid then Filter device happens in such a way that the Fluid containing unwanted particles are filtered off. In addition, there are corresponding filter devices at which the main fluid flow, starting from a common one Fluid supply channel, divided into several fluid subchannels becomes. Seen in the direction of flow, downstream of the fluid subchannels then the partial fluid streams are again in a common Fluid discharge channel summarized. In the fluid subchannels  filter device known for example from EP-A 0 250 695 then filters are arranged, each filter then optionally flowed through by both partial fluid streams simultaneously or just a filter from the corresponding fluid sub-stream is flowed through, while the other filter in this Production position backwashed with the fluid and thus brisk is generated. To such a different mode of operation to allow in the known filter device are the Filters arranged in appropriate filter support bodies where is slidably mounted on each filter support body, so that the filters out of their filtering position by a shift can be transferred to a rinsing or regeneration position, such that in this filter position the filter with a Atmosphere open flush channel is connected so that the Particles filtered off by the filter when the Filters are discharged to the outside.

The known filter device described above has one relatively complex structure. This is due to the fact that a large number of subchannels have to be aligned with one another since otherwise there is a risk that current dead zones train that will eventually clog the filter can lead.

The present invention has for its object a Control device for at least two partial fluid flows for Ver to provide a particularly simple structure sits.  

This object is achieved by a Steuereinrich tion with the characterizing features of claim 1 solved.

The control device according to the invention for at least two Partial fluid streams has a common fluid supply channel and a common fluid discharge channel, the fluid supply channel with the fluid via at least two fluid subchannels driving channel is connected. Every fluid subchannel is with it control device according to the invention a filter device orders, the control device according to the invention further ren has at least one valve device. This mind At least one valve device is one of the channels (Fluid supply channel, fluid discharge channel, fluid subchannel) net and designed such that depending on the position of the Valve device the fluid flowing in the channels fil triert, the filter device flushed through the fluid or in a subchannel the fluid fil flowing in this channel is trated while the filter is flushed through the fluid becomes.

In other words, the control device according to the invention designed such that they flow simultaneously through the Filters and thus a separation of the unwanted particles the fluid, a flushing of the separated particles of min at least a filter or at the same time a filter and there with a cleaning of a fluid flow from unwanted particles allows while the other filter or filters is flushed out by the fluid.  

The control device according to the invention has a number of Advantages. So it should first be noted that the inventions control device according to the invention a particularly simple construction has, since only a few channels are required here, to enable the three operating positions listed above chen. This is due to the fact that in contrast to the beginning State of the art in the invention Control device consciously separate the valve device from the filter device is arranged. By such a ge separate arrangement of filter device and valve device it is also possible to use a particularly trouble-free to drive the control device according to the invention lichen. Another advantage of the control unit according to the invention direction can be seen in the fact that when the Ven tileinrichtung only this and not the filter at the same time direction must be replaced overall, so that the ent speaking repair relatively inexpensive and with less Effort can be done. As a major advantage of Control device according to the invention can be seen that this Control device allows for a change of color or the material of the liquid to be filtered, in particular when using the control device in plastic extrusion , an easy and unproblematic rinsing of the tax direction. This not only leads to savings in terms of production time, but also in particular to reduce it reduction of wrong productions or wrong colors.  

A first, particularly suitable and simple in its structure Design variant of the control device according to the invention provides that the valve device is assigned to one of the channels net and is designed such that depending on the position the valve device optionally that flowing in the channels Fluid is filtered or in at least one subchannel flowing fluid is filtered while the in the other sub-channel or the other sub-channels flowing Fluid flushes the filter or filters. In other words, he allows this first embodiment of the invention Control device thus two modes of operation, one Operating mode depends on the position of the valve device directs the fluid flows through the control device such that from this the undesired foreign particles are removed by means of the filter be filtered. In the second operating position is single Lich a partial fluid flow through at least one subchannel flows, filtered while simultaneously over the corresponding Position of the valve device, the second partial fluid flow, the also flows in at least one other fluid subchannel, deflected such that at the same time that in the at least one other fluid sub-channel arranged flushed further filters becomes. This first variant of the invention Control device has the additional advantage that here the fluid flow from the common fluid supply channel to the common fluid drainage channel during the flushing of the fil ter does not have to be interrupted, which then gave way tig is when the control device according to the invention at Ex trudder is used for the extrusion of thermopla plastics are used.  

Another preferred embodiment of the fiction moderate control device provides that the control device two fluid subchannels and two fluid valve devices has, with each fluid sub-channel assigned a valve device is arranged. This other embodiment of the fiction moderate control device allows in particular the above continuous operation described. Are at for example, in this embodiment, the two valves facilities in a first position, the stream Partial fluid flows separated by the two Fluid sub-channels, which leads to the fact that from the fluid sub-flows who filters out the unwanted particles contained in the fluid the. By transferring one of the two valve devices gene in a second position is achieved that the fluid flows direction in the associated with this valve device Subchannel is reversed, so that accordingly in this Fluid subchannel arranged filters backwashed and thus from separated particles is washed away. At this time the fluid flowing in the other fluid subchannel continues filtered. The same applies analogously if the one Ven tileinrichtung is transferred to the second position while the other valve device remains in the first position, as is specifically the case with an execution example below game is explained.

Another embodiment of the control unit according to the invention direction includes a valve device between a he Most position in which a fluid flow from the fluid supply channel to the  Fluid discharge channel, a second position in which a fluid flow from fluid discharge channel in the direction of the Fluidzufuhrka nal and from there to the atmosphere and a third digit in which a fluid flow from the fluid supply channel into the atmosphere sphere takes place, is feasible. The first serves here Position of the valve device, as already be above wrote that the fluid flow to remove imm desired particles the filters arranged in the subchannels flows through while in the second position of the valve direction a reversal of a partial fluid flow towards the Fluid supply channel is effected, whereby the filter or Filter of separated particles is washed away or who the. The third position of the valve device serves that when starting the control device according to the invention Quantities of fluid seen in the direction of flow of the fluid the valve devices are arranged, towards the atmosphere can be drained so as to prevent that already in the Start-up operation a large amount of particles to be filtered get to the filters. Such a valve device bie is particularly useful when the invention Control device downstream of a conveyor, for example as a screw conveyor, and upstream of a nozzle of an Ex truders for thermoplastic materials is arranged.

Basically, the tax in accordance with the invention direction provided valve devices designed arbitrarily provided that it is ensured that they reproduced the previous ones enable functions. It is particularly suitable but if the control device according to the invention a valve  has device which has a cylindrical housing bore and includes cylindrical valve body, the cylindrical Ven tilkörper axially displaceable in the cylindrical housing bore is stored that a sealing engagement between the cylin The valve body and the wall of the cylindrical housing bore the valve device. The cylindrical housing bore of the valve body pers is with two, radially opposite, for connection to appropriate sub-channel sections verse suitable holes hen. The valve body has a first bore, which as radially over the entire diameter of the valve body fende through hole is formed, said first Through hole ensures that in the first position the Valve means a fluid flow from the common fluid supply channel to the corresponding fluid subchannel takes place. Des furthermore, the cylindrical valve body has an axial one Distance from the first through hole arranged second Hole on, with the second hole only radially over extends a partial diameter of the valve body. These second bore opens axially through the valve body per extending first drain channel, the first drain channel is open to the atmosphere. Here, this represents second hole in connection with the axially extending first drain channel sure that in the second position the Valve device (backwashing position) with the of each because of the detached particles of the fluid flow can be led outside to the atmosphere, so that the ge Desired cleaning of the filter is done. By an axial Ver displacement of the cylindrical valve body relative to the zy it is then possible that the valve is  direction from the first position in which the first passage hole in the valve body with the two holes in the valve body housing bore is aligned and in which a fluid flow through the respective Fluid subchannel in the direction of the corresponding filter instead finds, can be transferred to the second position, in which second position the second hole in the valve body with only one of the two holes in the valve housing bore is aligned. Here at is one of the two holes in the valve housing bore Bore seen downstream in the Ven tilgehäusebohr is arranged. As already explained above is then carried out via the second provided in the valve body Hole and the adjoining and also in Valve body arranged drain channel the discharge of the cleaning the filter with particle-laden fluid flow to the atmosphere.

In a development of the embodiment described above form of the valve device, the valve body has a third, radial only over a partial diameter of the valve body ongoing bore. This third hole opens into a second axially extending through the valve body Drain channel or in a fluid side channel, the second Drain channel or the fluid side channel open to the atmosphere is. The third hole is seen above the valve body preferably with an axial distance from the first through hole and the second bore and radially opposite the second hole arranged so that only an axial Ver shift the valve body relative to the valve housing bore is the third hole with the one in the valve  Housing bore arranged bore that leads to the fluid supply channel points to brin to cover gen. In other words, is by an axial displacement Exercise of the valve body relative to the valve housing bore the previously be Written third position of the valve device adjustable. In this third position of the valve device, the fluid to the atmosphere located upstream of the valve device sphere to be discharged, so that in start-up mode Fluid drain from the control device according to the invention possible is.

A particularly suitable development of the previously described Design variant of the control device according to the invention provides that the second and / or provided in the valve body third bore has an elliptical cross section. This enables an axial displacement the valve body relative to the valve housing bore a meterable Partial amount of the fluid flow to the first and second discharge channels or can be supplied to the fluid side channel. Furthermore prevents the elliptical cross-section of the second or third hole that a spon when discharging the fluid flow Tan pressure drop in the fluid flow occurs, so that undesirable Faults, such as pressure surges, can be avoided.

In addition to the elliptical shape described above design of the second and / or third hole or instead this configuration there is a possibility that the second and / or third bore and / or the first and / or second Ab flow channel and / or the fluid side channel an area points in which the cross section of the bore, the fluid side ca  nals or the drainage channel is tapered and / or tapered. This also ensures that the amount of Atmo spherical fluid flow discharged limited or limited is, so that such training is an adaptation of control according to the invention to the respective conditions possible.

To training in the control device according to the invention preventing flow dead zones, sees one particularly advantageous development of the Steuerein invention direction that in the connection area of the fluid supply channel with the fluid subchannels increase the turbulence of the fluid existing facility is provided. This will in particular suitably further ensures that all Fluid sub-channels that in the connection area of the Fluidzufuhrka branch off, always supplied with the same amount of fluid become. Depending on the respective fluid, devices that increase the turbulence of the fluid, for example as a sieve or as a protruding into the connection area jumps or baffles can be formed.

As already mentioned several times above, the invention is invented control device according to the invention, in particular in the case of extruders set for the extrusion of thermoplastics be used. The control device then becomes the Art trained and verse with suitable mounting elements hen that the control device in a position downstream of the Feed screw of the plastic extruder and upstream of the nozzle the same is arranged. Because one of the  like extruder inevitably in front of the nozzle a considerable Fluid pressure is built up on the arrangement of a Fluid discharge channel associated additional valve device ver to be waived.

However, the control device according to the invention for others Purposes, it is recommended to use the fluid drainage channel assign a further valve device, this further Valve device at least a first valve position in which the amount of fluid through the fluid discharge channel is not limited, and a second valve position in which the fluid amount of fluid to be conveyed is limited got to.

A special embodiment of the tax according to the invention device provides that each of the two fluid sub-channels a first channel located downstream of the fluid supply channel has section, wherein the first channel section under a Angle α from 120 ° to 160 ° relative to the fluid supply channel is arranged that seen in the fluid flow direction each connects a second channel section, the at the second channel sections are essentially parallel fen, and that seen in the direction of fluid flow each third channel section follows, which is at an angle β of 120 ° to 140 ° from the second channel section relative to the common one men fluid discharge channel is arranged inclined. A derar term arrangement and design of the fluid sub-channels sure that the same amount of fluid through each fluid subchannel is transported, especially when the fiction  appropriate control device in an extruder for thermoplastic Plastics is used.

In a further development of the previously described embodiment of the control device according to the invention is in every first channel section a valve described in the sense above direction provided.

To ensure that the associated with each fluid subchannel Filter device is easily accessible, it is recommended to use this Filter device in development of the previously described concrete embodiment in the second channel section to po sition.

Advantageous further developments of the control unit according to the invention direction are specified in the subclaims.

The control device according to the invention is described below a specific embodiment in connection with the drawing tion explained in more detail. Show it

Fig. 1 is a schematic side sectional view of the control device in a first position,

Fig. 2 is a sectional view taken along line AB in Fig. 1,

Fig. 3 is a schematic side sectional view of the control device in a second position,

Fig. 4 is a sectional view taken along line AB in Fig. 3,

Fig. 5 is a side sectional view of the control device in a third position and

Fig. 6 is a sectional view taken along line AB in Fig. 5.

In Figs. 1 to 6 the same parts are provided with the same reference numerals.

The embodiment of the control device shown in FIGS . 1 to 6 each has a fluid supply channel 10 , from each of which a first fluid subchannel, generally designated 5 , and a second fluid subchannel, generally designated 6 , branch off. The two fluid subchannels 5 and 6 open into a common fluid discharge channel 11 .

A filter device 1 or 2 is assigned to each fluid subchannel 5 or 6 , the filter 13 being perpendicular to the fluid flow direction indicated by arrow 14 .

This fluid subchannel 5 or 6 has a first Kanalab section 7 , an adjoining second Kanalab section 8 and a third channel section 9 , the first channel sections 7 being arranged relative to the fluid supply channel at an angle α of approximately 140 °. The two second channel sections 8 of the two fluid sub-channels 5 and 6 run parallel, while the third channel sections 9 are arranged relative to the fluid discharge channel 11 at an angle β of approximately 130 °.

A valve device 3 and 4 are arranged in each first channel section 7 of the fluid subchannels 5 and 6 .

As is apparent from FIGS. 1 and 2, each valve means 3 and 4 respectively of a cylindrical valve housing bore 15, the valve housing bores store 15 a disposed within the valve housing bores cylindrical valve body 16 and 17 respectively. The valve bodies 16 and 17 are arranged within the cylindrical valve housing bores 15 in a fluid-tight manner and are axially displaceable relative thereto in the direction of arrow 23 and vice versa.

Each cylindrical valve body 16 or 17 has a first through hole 18 which extends radially over the entire cross section of the valve body 16 or 17 . With axia lem distance from each valve body 16 or 17, a second, radially extending only over a partial diameter Boh tion 19 is provided, the second bore 19 in a through the valve body 16 or 17 axially extending drain channel 20 opens is open to the atmosphere.

In addition to the bores described above, the valve body 17 has a second bore 21 axially above the first through bore 18 , which extends only partially radially over the diameter of the valve body 17 and opens into a connecting channel 22 .

As already described above, the valve bodies 16 and 17 are mounted axially displaceably in the direction of the arrow 23 or vice versa, within the valve housing bore 15 .

The embodiment of the control device shown in FIGS . 1, 3 and 5 is preferably used in connection with an extruder for thermoplastics. For this purpose, the control device is angeord net on the extruder that seen in the direction of flow of the thermoplastic material, the control device is positioned downstream of the screw conveyor of the extruder and upstream of the nozzle, such that the thermoplastic material via the fluid feed channel 10 of the control device by means of Feed screw is fed and is then extruded downstream of the fluid discharge channel 11 through the nozzle positioned there. When passing through the control device, the thermoplastic liquid plastic can then be freed of unwanted particles via the filter 13 .

The mode of operation of the control device is explained in more detail below with reference to FIGS . 1 to 6 for the application in extrusion of thermoplastic liquid plastic.

In Figs. 1 and 2, an operating state of the Steuerein direction is shown how this takes place during the current Extru decoding process.

Via the fluid supply channel 10 , the liquid thermoplastic cal plastic is supplied to the control device, the valve devices 3 and 4 being in a first position, as is shown in FIGS. 1 and 2. In the water first position, the passage openings 18 provided in the valve bodies 16 and 17 are aligned with the corresponding inner diameter of the first channel sections 7 of the two fluid sub-channels 5 and 6 . The result of this is that in this first operating position both fluid sub-channels are flowed through by the liquid plastic, so that the filters 13 can separate the undesired particles contained therein from the two fluid sub-streams. After bringing together the partial fluid flows in the common fluid discharge channel 11 , the liquid plastic is conveyed into the nozzle (not shown) and shaped there accordingly.

As soon as the filters 13 are loaded with particles and regeneration (backwashing) of a filter is required, one of the valve devices 3 and 4 is moved into a position as shown in FIGS. 3 and 4 using the example of the valve device 4 . In this second position of the valve device 4 , the second bore provided in the valve body 17 is aligned with the second channel section 8 of the second fluid subchannel, so that a path to the atmosphere is opened via the bore 19 and the subsequent discharge channel 20 . Due to the fact that the ge not shown nozzle of the extruder builds up a back pressure in the system, the liquid plastic supplied via the first fluid subchannel 5 is partly returned to the nozzle and partly via the third channel section 9 of the second fluid subchannel 6 , which causes the overall direction of fluid flow in the two th fluid subchannel 6 is reversed. This direction of flow direction change in the second fluid channel has the effect that the filter 13 arranged in the fluid subchannel 6 is freed of particles, so that the liquid plastic loading with particles via the second and partly first channel section 8 or 7 , the second bore 19 and the drain channel 20 Atmosphere is dissipated. This in turn causes cleaning of the filter 13 provided in the second fluid subchannel 6 without the supply of thermoplastic material to the nozzle being interrupted un.

After backwashing the filter 13 arranged in the second fluid subchannel 6 , the valve body 17 is brought back into the position as shown in FIG. 2. Hereinafter, an axial displacement takes place of the valve body 16 in the position shown in Fig. 4 for the valve body 17 position so that in analo ger, the disposed in the first partial fluid duct 5 Fil ter can be backwashed 13, as described above for the filter 13, is arranged in the second fluid subchannel 6 , has been written.

FIGS. 5 and 6 show a third position of the Ventilein direction 3 and 4 again. This third position shows a start position, in this start position the possibility is opened upstream of the control device in the direction of flow of the plastic seen residues of the same to the atmosphere. In this third position, the valve device 3 is closed as a result of the axial displacement of the valve body 16 into the position shown in FIG. 6, while the valve body 17 of the other Ventilein device 4 is in a position in which the third bore 21 , the Connection channel 22 and the fluid side channel 12 of the liquid plastic can be discharged to the atmosphere without this liquid plastic flowing through the Filterein devices 1 and 2 . This prevents an extreme loading of the filter from taking place at the start of the extrusion, which would lead to an immediate clogging of the filter.

Claims (13)

1. Control device for at least two partial fluid streams, characterized in that the control device has a common fluid supply channel ( 10 ) and a common fluid discharge channel ( 11 ), the fluid supply channel ( 10 ) over at least two fluid partial channels ( 5 , 6 ) with the Fluid discharge channel ( 11 ) is connected that each fluid sub-channel ( 5 , 6 ) a Fil tereinrichtung ( 1 , 2 ) is assigned and that the Steuerein direction has at least one valve device ( 3 , 4 ) which in this way at least one of the channels ( 10 , 5th , 6 , 11 ) is assigned and designed such that, depending on the position of the valve device ( 3 , 4 ), the fluid flowing in the channels ( 10 , 5 , 6 , 11 ) filters the filter device ( 1 , 2 ) through the fluid flushed or in a sub-channel ( 5 , 6 ) the fluid flowing in this channel is filtered, while the other filter ( 13 ) is flushed out by the fluid. 2. Control device according to claim 1, characterized in that the valve device ( 1 , 2 ) is assigned to at least one of the channels ( 5 , 6 ) and is designed such that depending on the position of the valve devices ( 1 , 2 ) flowing in the channels fluid is filtered, or in at least one sub-channel, is filtered flowing fluid, while at the same time in the other part channel (6; 5) (5 6) or flushes and the flowing at the part channels fluid to the filter (11). 3. Control device according to claim 1 or 2, characterized in that the control device has two fluid sub-channels ( 5 , 6 ) and two valve devices ( 3 , 4 ), wherein each fluid sub-channel ( 5 , 6 ) is assigned a valve device ( 3 , 4 ) . 4. Control device according to one of the preceding claims, characterized in that the valve device ( 3 , 4 ) between rule's first position in which a fluid flow from the fluid supply channel ( 10 ) to the fluid discharge channel ( 11 ), a second position in which a fluid flow from the fluid discharge channel ( 11 ) in the direction of the fluid supply channel ( 10 ) and from there to the atmosphere, and a third position in which a fluid flow into the atmosphere can be brought. 5. Control device according to claim 4, characterized in that the valve device ( 3 , 4 ) has a cylindrical housing bore ( 15 ) and a cylindrical valve body ( 16 , 17 ), that the cylindrical valve body ( 16 , 17 ) axially displaceable in the cylindrical housing bore ( 15 ) is mounted that the cylindri cal housing bore ( 15 ) is provided with radially opposite suitable for connection to corresponding sub-channel sections ( 7 , 8 ) and that the valve body ( 16 , 17 ) with egg ner radially extending over the entire diameter first through hole ( 18 ) and at an axial distance therefrom is provided with a second, radially only ver over a partial diameter running bore ( 19 ), the second bore ( 19 ) in an axially through the valve body ( 16 , 17 ) he extending drain channel ( 20 ) which is open to the atmosphere. 6. Control device according to claim 5, characterized in that the valve body ( 16 , 17 ) has a third, radially only over a partial diameter bore ( 21 ), the third bore opening into an axially extending through the valve body second drainage channel, the is open to the atmosphere. 7. Control device according to claim 5 or 6, characterized in that the second and / or third bore ( 19 , 21 ) has an elliptical cross section. 8. Control device according to one of claims 5 to 7, characterized in that the second and / or third bore ( 19 , 21 ) and / or the first and / or second drainage channel ( 20 ) has a loading area in which the cross section the bore or the drain channel is tapered. 9. Control device according to one of the preceding claims, characterized in that in the connecting region of the fluid supply channel ( 10 ) with the fluid sub-channels ( 5 , 6 ) is provided a device which increases the turbulence of the fluid. 10. Control device according to one of the preceding claims, characterized in that the control device is suitable Bracket elements for attaching the control device in egg ner position downstream of the screw conveyor of a plastic extruder ders and upstream of the nozzle of the plastic extruder. 11. Control device according to one of the preceding claims, characterized in that each of the two fluid sub-channels ( 5 , 6 ) has a first, downstream of the fluid supply channel ( 10 ) arranged channel section ( 7 ), the first channel section ( 7 ) at an angle α is arranged from 120 ° to 160 ° relative to the fluid supply channel ( 10 ), that a second Kanalab section ( 8 ) connects to it, as seen in the fluid flow direction, the two second Kanalab sections ( 8 ) running essentially parallel, and that in the fluid flow direction seen in each case a third Kanalab section ( 9 ) follows, which is arranged at an angle β of 120 ° to 140 ° from the second channel section ( 8 ) relative to the common fluid discharge channel ( 11 ) inclined. 12. Control device according to claim 11, characterized in that in each first channel section ( 7 ) a Ventilein direction ( 3 , 4 ) is provided. 13. Control device according to claim 11 or 12, characterized in that in each second channel section ( 8 ) each Weil a filter device ( 1 , 2 ) is positioned.