METHOD AND DEVICE FOR SEPARATION OF PARTICLES

Abstract: The invention claims a process and a filtering device for continuous separation of particles from in a conduit flowing fluid (3), at which the fluid on entering the apparatus is given a rotational movement by means of a rotation inducing member (7) and that the flow of the fluid is caused to pass through a filter which is arranged at the downstream end of the apparatus, at which the filter comprises a filtering surface (20.1) and a filter surface (20.2), the filtering surface extending along the rotational axis of the fluid and the filter surface being so placed as to form a downstream barrier for the non-filter fluid, whereby in the event of a sudden increase of pressure in the fluid, the filter surface during an initial stage allows a potent rotational movement to build up synchronously with the separation of the torn-away particles being effected against the filter surface (20.2), whereby the rotational movement of the fluid is given enough time to stabilize and the torn-away particles are forced away from the filtering surface and whereby said particles by the movement of the liquid concurrently are moved in the longitudinal direction of the device towards the filter surface.

Description: METHOD AND DEVICE FOR SEPARATION OF PARTICLES. The present invention relates to a method for continous separa¬ tion of solid particles from in a conduit flowing fluid and a device for continous separation of said solid particles from said fluid. This method and this type of device is designed to be used in the field of sprinkler installations i.e. as a filter used to protect the sprinkler installations from being clogged. It may also be used in other fields where a continous, unobstructed flow of some type of a fluid through narrow passages or orifices, e.g. sprinkler nozzles, injection nozzles, needle nozzles a. s. o., e.i. in cases when a failure in the flow cannot be accepted. This means that the flow must be freed of all particles to guarantee that there will be no blocking of the flow. Filters for separating particles from flowing fluids, i.e. water, oil etc. are well known in the art. The types of filters commonly used aFe mechanical filters, to be precise filters having surface media filters of different types, i.e. (rotary) drumfilter, bagfilters etc. The disadvantages connected with these commonly known filters is that they get clogged very soon if there are any particles in the fluid and from experiments it has been shown that the time for clogging almost solely depends on the surface area of the filter, and when the filter is clogged the flow will be obstructed. In order to show the general state of the art, we now look to GB-A-1 134 304, in which an apparatus for separating solids from streams of liquids is known. This apparatus is meant for separating e.g. mussels from sea water for use in condensers and cooling water systems in steam boiler plants. The apparatus comprises a pipe or a pipe section for the liquid flow, and a filtering screen arranged in the pipe or pipe section, the screen having a form which is that of a surface portion of a three-dimensional body having a base and an apex and said surface portion extending from the perimeter of the base to the apex and converging from the base to the apex, the screen being so arranged that the direction along the altitude from the apex to the base is a possible flow direction through the pipe or pipe section, and the base being sealed to the interior wall of the pipe or pipe section, (i.e. the flow 13 meeting the apex of the cone, the base of which covers the whole flow area) the annular gap between the inner wall of the pipe or pipe section and the base end region of the screen just upstream the base being widened to form a substantially toroidal duct, and there being pipe portions opening into the duct substantially tangentially to the circumferential torus axis so that a washing medium can be introduced into, and screened particles removed from, the toroidal duct by way of said pipe portions. In this apparatus the solids entrained by liquid flow travelling in the apparatus in a direction from the screen apex to the screen base can be engaged by the screen and slide substantially along the inclined plane of the screen surface. At the end of the screen, namely at the screen region adjacent the screen base, where the screen Is connected to the inner wall of the pipe or pipe section, the screened solids pass into the toroidal duct. At least one of the pipe portions can open into the duct in a direction along the torus axis opposite to that in which at least one other pipe portion opens. An annular flow can then be produced in the duct by means of said at least one pipe portion. This annular flow entrains the solids floated into the duct and discharges them through said at least one other tangentially directed pipe portion. It is also possible to arrange inclined guide vanes at the apex end region of the screen in order to impart a certain amount of spin to the arriving flow, and to cause solids of relatively high density to be driven out into the pipe region near its wall, so that relatively easy discharge into the toroidal duct is guaranteed. These guide vanes are connected to the pipe wall and to the screen and " serve at the same time to hold the apex of the screen since in the case of large pipe diameters, such as are required for cooling water supply in steam power plant, the screen is also of a considerable length and thus needs additional stabilisation at its pointed end. As a result, solids of relatively considerable mass are carried outwardly towards the inner wall of the pipe line and as a result pass more easily into the toroidal duct. If mussel fragments or other substances have accumulated on the screen, the screen can easily be cleaned in the following way. A shut-off gate valve upstream of the screen is closed and an annular flow produced in the toroidal duct by means of said pipe portions. As a result, the water column remaining in the pipe is also rotated, so that the particles which have become stuck on the screen are projected outwards by the action of contrifugal force and can easily be discharged after the shut-αff valve has been opened. This means that this filter has to be shut-off at intervals to clean the filter, which we will see is not possible to allow in the applications for which the filter according to our invention is provided for. This type of apparatus is not fit for the application we have in mind, since it is very important for the present purpose that there never is a possibility of the filter ever being clogged, especially not when as a result of a sudden change of pressure in the fluid particles may be torn away in the conduit and obstruct the filter area very easily. In EP-A-00 25 628 is shown an other conventional type of filter for liquids with automatic cleaning of the filtering element. This filtering element has the shape of a hollow cylinder, the bottom of which is closed and which cylinder is made from filter cloth. The upper part of the filter is so formed that the liquid flows down on the outside of the cylinder, passes through the filter cloth from the outside to the inside, and thereafter moves upwards and finally flows out of the outlet of the filter. During this sequence the particles entrained in the liquid are trapped in a known manner on the filter cloth. Eventually the particles fall off the filter cloth and settle out on the bottom of the filter. This filter is provided with a cleaning device in the shape of a ring provided with vanes or plates. These vanes or plates are placed at a fixed angle with regard to the longitudinal axis of the element, in such a way that the fluid, which is to be filtered makes a rotational or twirling movement around the filter element before it flows through the filter. There is in this filter no way to let the fluid build up a potent rotational movement, which is the aim of our invention and to take care of the impact of a sudden preassure increase in the fluid which with all certainty brings along among other things air, torn-away- particles and such and still give the fluid an unabstructed passage through the filter, since in all cases the flow hits a solid surface at the downstream end of the filter receptable, which will disturb the motion of the fluid, unsettle the particles and therethrough not keep the particles away from the filter. In connection with sprinkler installations provided for fire extinguishing purposes the problems in connection with clogging are normally not to great, since the nozzles of the sprinklers have a diameter, which is not too susceptible to clogging. However, there are a number of applications, where a very fine spray, almost atomized, is desirable and in which instances it might also be desirable to limit the necessary amount of water (liquid), soas not to have to dispose of more than necessary. One type of fire, which is thought of in this context is one where burning oil is spread over a vast area. To fight this burning oil with water, when the oil is spread over an extensive area must be done by a concurrent pouring of water over all of the burning surface. On manually pouring water on the burning oil there is a great risk of the oil continuing to burn on top of a layer of water. Sprinkler installations are considerably more efficacious, but makes It a necessity that all sprinklerheads are in function when using water as a fire extinguishing medium. If one or more of these sprinklerheads is out of order, the burning oil in all likelihood will continue to burn, floating on top of a layer of water. This of course involves larger damages due to fire and water and results in a more extensive loss of production capacity, as well as other. risks. It is well known, that when using conventional sprinkler installa¬ tions, every sprinkler head gives quite a large amount of water per unit of time and where it is necessary, as above, that substantially all sprinklerheads are in function, the total amount of water therefore has to be minimized in order to on the one hand avoid unnecessary damages on the place or machinery, which is supposed to be protected by the fire-fighting installation caused by water and on the other to minimize the total amount of possibly contaminated water, which has to be taken care of. In order solve these and .other problems the water has to be almost atomized. We have therefore tested sprinklerheads having spray nozzles, which atomize the water to small drops or to a mist, which nozzles gives a better fire extinguishing ' effect and which nozzles also allows a limiting of the necessary amount of water. In that connection the nozzles, which in this case have an approximate diameter of 1,2 mm have proven to be very susceptible to clogging. The spray nozzles also show further atomizing means inside the nozzles, which means also are very susceptible to that same phenomena. In commonly used sprinkler installations temperature-responsive fuses are arranged, i.e. each sprinkler has its own fuse, which opens at a chosen temperature e.g. 70 Oc . Tne pipe line system is in these instances waterfilled and pressurized. In the event of a possible damage on the sprinkler, the water spurts uncontrolled, which is also the case In the event of damage to the pipes enough to break them. In installations where such a failure cannot be accepted, a system where all sprinklers are released at the same time may be usable. The pipe line system is in these cases waterfilled and pressurized up to a main stop valve (there may of course be a number of those). After the main stop valve up to the nozzles the pipeline system is empty, i.e. not waterfilled. At a signal from a fire alarm or the like the main stop valve opens. The pipeline system is filled with water and water starts to spray from the sprinkler nozzles. In cases where failure of the sprinklersystem is to be avoided, it is thus appropriate to construct a system of empty pipelines having a main stop valve. The water supply -lines may sometimes exhibit lengths up to around one kilometer. These pipes are usually galvanized pipes, which means that there is danger of scaling of the galvanization layer or rust flakes and moreover, the water which always has a unique composition at every location may, in spite of water supply plant and water treatment, have such a composition as to give solid deposits of e.g. CaCθ3 or the like, which may be spread all over the system. This type of particles will with all certainity be torn away and will very soon fill the sprinkler spray nozzles (in practice it has been shown that 96 of 126 sprinkler heads very soon malfunctioned because of the clogging). This implies that some form of separation of these particles has to be effected before the water enters the sprinkler nozzles. This cannot be accomplished by means of conventional filters because of the fast congestion of these and the necessity of a continous flow through the filter. These problems are not only prevailing in connection with sprinkler installations, but may of course have relevance in all types of flows, which are polluted in the sense of particles being entrained in the flow and where the flow is supposed to flow through narrow passages or orifices, e.g. needle or ball valves or the like, in instances, when the flow must not be obstructed. Confere e.g. fuel feed. The problem not only exists when the flow exhibits a density which is less than the density of the particles but also when the flow exhibits a density which is greater than that of the particles. It should also be pointed out that in commonly used filters the capacity of the filter is determined by the filter surface and in the device according to the invention the capacity is a question instead of how much space is available for particles to settle in before they clog the filter. The present invention is aimed at avoiding the disadvantages of known filtersy.stems in regard to continousiy separating particles from a fluid flow, whereat the device and the parts of the same cooperate to hinder the solid particles to settle on the filter and thus obstruct the passage of the fluid. This aim is attained through a process for continous separation of particles from in a conduit flowing fluid, at which the fluid on entering the apparatus is giving a rotational movement by means of rotation inducing means and that the flow of the fluid is caused to pass through a filter which is arranged at the downstream end of the apparatus, at which the filter comprises a filtering surface and a filter surface, the filtering surface extending along the rotational axis of the fluid and the filter surface being so placed as to form a downstream barrier for the non-filter fluid, whereby in the event of a sudden increase of pressure in the fluid, the filter surface during an intitial stage allows a potent rotational movement to build up synchronously with the separation of the torn-away particles being effected against the filter surface, whereby the rotational movement of the fluid is given enough time to stabilize and the torn-away particles are forced away from the filtering surface and whereby said particles by the movement of the liquid concurrently are moved in the longitudinal direction of the device towards the filter surface. The invention also claims a filtering device for continous separa¬ tion of solid particles from a fluid flowing in a conduit. The apparatus being placed in a housing comprising an upstream , end and a downstream end and the flow of the fluid rotation inducing means provided at the upstream end, which gives the flow of the fluid a rotational movement around the rotational axis, and provided at the downstream end of the device a filter having a filtering surface essentially parallell with the rotational axis of the flow of the fluid and a filter surface so provided as to constitute a downstream barrier for the" non-filtered flow. In a preferred embodiment of the device the housing may be constituted by the conduit in which the device is arranged. In a further embodiment, the device is provided with a bulge downstream at the in the direction of the flow furthest away part of the filter, said bulge provided to constitute a space for collecting the solid particles, and means provided for drainage of the solid particles in connection with said space. In a further embodiment of the device the filtering surface constitutes a part of a self supported filter. In yet another embodiment of the device the filtering surface constitutes a part of a filter having one in the center of the device, essentially parallell to the rotational axis of the flow arranged the filtering surface supporting slotted stay tube said tube having a rigidly mounted plate provided with holes, which plate covers the flow area, at which the stay tube and the plate on the upstreams side of the flow carries a filter of which the filtering surface covers said tube and the filter surface is carried by said plate provided with holes. The rotation inducing means may be provided inside the housing or in the conduit upstream of the filtering surface which conduit forms the housing or on the wall of the housing of the filtering device at the inlet thereof. In a further embodiment of the device the rotation inducing means are arranged on the stay tube or on the self-supported filter at the upstream end of the same. In yet another embodiment of the device there is provided between the rotation inducing means and the filter a conical member is, the position and the basal radius of which can be monitored to regulate the flow of the fluid. This filtering device may be used either solely or in a combination of a plurality of said devices as a protectional filter for easily damaged components. It may also be used as a filter placed in front of sprinkler nozzles in a sprinkler installation, at which the filter has a mesh size, which is less than that of the nozzle opening diameter. It has to be observed that on account of the density of the particles as compared with that of the fluid there are two distinctly different cases. If the particles are denser than the fluid, the particles will move outwards, and accumulate on the inside surface of the device e.g. the inside of the housing. If the particles are less dense than the fluid the opposite will occur, e.g. the particles will move towards the center of the device. Some preferred embodiments of the invention will now be described below, with reference to the accompanying drawings, wherein: Fig. 1. shows an embodiment of the separating device in accordance with the invention, for use in connection with sprinklers. Fig. 2. shows an embodiment in accordance with the invention for use in a main supply line (the rotation inducing means not shown). 8 Fig. 3. shows an embodiment in accordance with the invention having a stay tube, filtering surface and rotation inducing means in the form of a screw. Fig. 4. shows an embodiment in accordance with the invention with rotation inducing means having a different shape than the one in Fig. J. Fig. 5 shows an embodiment in accordance with the invention similar to the one In Fig. 2. but with a third type of rotation inducing means. Fig. 6. shows an embodiment in accordance with the invention of the filter part of the device having two different types of discharge means for discharge of more or less settled solid particles. ' Fig. 7. shows an embodiment similar to the one in Fig. 6. Figs 8, 9, 10a and 10b show embodiments according to the invention of the filter part of the device for combination with different types of rotation inducing means. Figs 11-12 show examples of embodiments in accordance with the invention of the rotation inducing means in the form of vanes or fixed screws. The device shown in Fig. 1. is a preferred embodiment of the invention as used in a sprinkler provided with spray nozzles of the type that gives a mist. The device comprises a filter housing 1, which at the end 5 of the housing opens into a sprinkler nozzle 17. This nozzle 17 has several orifices 18 having an approximative diameter of 1.2 mm. At the upstream end 4 of the device rotation inducing means 7, here in the form of a fixed screw is arranged. In this embodiment the the rotation inducing means (7) is a fixed screw, which screw 7 is attached to, alternatively fixedly rests on a slotted stay tube 10 having a slot 11. At the downstream end of the stay tube 10, which moreover is the downstream end 5 of the device, the tube is equipped with a rigidly mounted plate 13, provided with holes therethrough. The plate 13 also may be held against the housing by the sprinkler nozzle 17. The filter is placed on the upstream side of the plate 13 and the stay tube, i.e. the filtering surface 20.1 and the filter surface 20.2. The device functions in the following way. The inflowing fluid is designated by reference numberal 3, and the direction of the flow is indicated by the arrow. When the flow has passed the fixed screw 7 i.e. the rotation inducing means, at the place designated by the reference numeral 6 and the particles, which in case said particles show a higher density than the fluid will move outwards towards the inside of the filter housing, the rotational motion of the particles continous also below the screw, i.e. in the general direction of the flow. On account of this rotational component to the over-all movement of the particles, said particles will tend to follow the inside of the housing and settle against this, which means that the filter will show a higher degree of tolerance as to obstruction (clogging). The particles will settle at the place indicated by reference numeral 15 and be compacted. Thus the water will flow unobstructed through the filtering surface 20.1 and thereafter through the slotted stay tube (the stay tube may of course also have holes arranged in it). The uppermost part of the slot, that is the part furthest away from the nozzle, at referense numeral 12, may . as a safety measure be left uncovered ' by the filtering surface or may be covered depending on the demands raised by the situation. The mesh size of the filter parts is to be <1.2 mm (this measurement of course depends on the orifices of the spray nozzle, in this case the spray nozzle having orifices of 1.2 mm are used. The mesh size should of course be decided on in dependence of the application. The filtering surface 20.2 is provided because when the main stop valve in the water supply pipes is opened following happens. First a lot of air is pressed out of the pipes and leaves the system very fast. Thereafter a- turbulent waterfront mixed with air will follow, which front will in all certainty tear away particles from the inside of the up-to-then empty pipes and which front will entrain most of the particles. These first in the water- air mixture entrained particles will be pressed against the "bottom" 20.2 at the start of the process. The filter surface 20.2 which is not parallell to the pipe might at this time become totally covered, something which will not have any consequences since after the initial phase of the process the rotational movement of the fluid will have fully developed and the flow will pass unobstructed through the filtering surface 20.1. The great advantage of this device according to figur 1 is the simplicity with which an existing installation may be supplemented with the rotation inducing means and filter according to the invention. This is easily done by removing existing sprinklerheads, inserting the rotation inducing means and the filter in accordance with the invention and thereafter placing the sprinklerhead back in its old place. The old spriπklerhead may of course also be replaced by the device shown in figur 1 with a mounted sprinkler including the spray nozzles. This means that in excisting installations may at a reasonably low cost, and moreover using easily manufactured components and with a small amount of work, the safety as regards to fire defense be raised in a very simple and economical manner. Another preferred embodiment of the device in accordance with the invention is shown in figur 2. This embodiment may be placed in the main water supply pipe to the sprinkler installation above and is then used as a primary filter to the filters placed at the sprinklers. The device contains a filter housing 1, which may conviniently be placed in a main water supply pipe. The device may of course be fitted into the pipe in different ways e.g. as shown in the figure by means of one or more flange joints 2. At the upstream end 4 of the filter a cone 14 having its apex pointed in the reverse direction of the flow is placed. This cone 14 is provided with rotation inducing means, preferably vanes (at 9 not shown). Into this cone the stay tube 10, provided with a slot 11 or holes, opens. The stay tube 10 is rigedly fastened to the bottomplate 13 provided with holes (it may of course be fastened in many different ways). Said plate is placed at the downstream end 5 of the device. At the upstreams side of the plate 13 a filter 20.1, 20.2 is provided surrounding the stay tube 10 supported on the plate 13. The stay tube 10 may of course be omitted and a self supporting filter used instead. The settled particles are indicated at 15. The functioning of the device is mainly the same as that of the device shown in figur 1. The cone 14 may, if appropriate, be mounted in such a way as to be movable. The movement of the cone 14 in the upstream or downstream direction may be used to regulate the flow through the filter in order to attain a suitable rate of flow for the separation procedure. For the same purpose the cone 14 may be so designed that its basal diameter is adjustable. A combination of these two embodiments having different designes of their rotation inducing means is of course possible. This embodiment is also easily manufactured and shows low manufacturing- and installation costs, and gives of course the same benefits as to five prevention as the first embodiment. Mounting of the device according to figur 2, naturally means that it will take even longer time before an eventual clogging of the filters combined with the sprinklers. In figur 3, 4 and 5 different embodiments of the already shown embodiments are depicted. In figur 3 is shown a filterhousing 1 and arranged therein at the upstream end 4 thereof rotation inducing means 7 having a central support 19 carrying a band in the form of a helix. The arrow designated 3 show the flow of the fluid. The central support 19 rests upon in a fixed way or is fixedly fastened to the stay tube 10, in which a slot 11 is arranged. Around the stay tube 10 and surrounding it is a filtering surface 20.1 arranged and at the downstream end 5 of the device fastened to the filtering surface component 20.1 is the filter surface component 20.2. In figur 4 is shown another form of the cone 14 and arranged thereon a rotation inducing member 7. In figur 5 is shown yet how another type of rotation inducing member 7 may be arranged on the cone 14 and a somewhat different design of the filter housing 1. What is told about the basal diameter of the cone and the adjustment of it in connection with figur 2 naturally applies also here. In figur 6 and 7 is shown how the discharge means 25 and 26 are meant to function. In figur 6 is shown a discharge means provided with a tapping cork or the like and 26 an open discharge with a small, but constant drainage and in figur 1 there is provided a tapping cork 25 with the filter housing arranged in another direction. The filter in figur 8 is arranged in a housing 1, which in this case is a pipe, in which a circular stay tube 10 is concentrically arranged in relation to the pipe 1. Surrounding the stay tube 10 the filtering surface 20.1 is arranged and the downstream and of the filter is provided by the filter surface 20.2. This filter is designed for cases when the particles show a higher density than the fluid. The filter in figur 9 is in the same way arranged in a housing 1, which in this case is a pipe in which a filter is arranged which is made up by two concentrically with the pipe walls arranged circular walls of which the outer one of the two is the filtering surface 20.1. This filter also has a filter surface 20.2 as a bottom. This filter is designed for the particles 15 showing a lesser density than the fluid. In experiments using the embodiment according to figur 1 it has been noticed that about 90 % of the particles, when the particles consist of a mixture of sand, earth and particles of a extremely light material (frigolit) sticks to the bottom (in this mass of particles there are also some of the extremely light ones) and the remainder of the very light particles continue to spin around in the flow at a small distance from the filtering surface. In case the distribution of particles is such, that particles both denser and less dense than the fluid are present, problems may be foreseen. To solve this problem there is yet another type of filter shown in figur 10a, b. The filter shown in figur 10a, is a combination of the two earlier (figur 8, 9) shown filter types. In figur 10b is shown a section of the filter in figur 10a along the line A-A. The filter is placed in a housing 1, here pipe, in which four with the pipe concentrically arranged circular walls are placed, of which at least two are made up by filtering surfaces 20.1. These walls are at the bottom of the downstream end of the filter connected to each other two by two and thereby form two concentrically arranged filters. In this filter separation may be performed of particles 15a showing a lesser density than the fluid and particles 15b having a higher density than the fluid. The bottom forming connection, preferably is constituted by filter surfaces 20.2. In figur 11a - lie and figur 12a - 12b is schematically shown different types of rotation inducing means consisting of fixed screws or vanes. In figur 11a is shown a band in the form of a helix placed around a central support 19. In figur lib there is a form of a double helix around a central support 19. In figur lie there is a band in the shape of an helix but without a support. In figur 12a and b the rotation inducing means consists of vanes arranged on a central support 19. The helixes in figur 11a - lie may of course be modified within the scope of the invention by varying the pitch within the helix, varying the number of turns, changing the pitch angle and so on. The vanes in figur 12 a and 12b may also of course be changed as to angle of pitch, profile, number of vanes and so on. It is of course within the scope of the invention to mount the filter and the chosen rotation inducing means in the filter housing 1, which may be a part of the pipe forming a part of the conduit carrying the flow, each one separately or as a unit. Within the scope of the invention is also the fact that these rotation Inducing means of different forms, mounted on the stay tube, the cone, the inside of the filter housing or in any other appropriate way depending on the situation, must not necessarily occupy the whole flow area but a space may be left there between as long as the rotation inducing means fills its purpose. As regards to the method it is pointed out that the f iltring surface not necessarily must be parallell with the walls as shown in the described embodiments of the device. The only limiting provisions as regards the surface Is, that when the particles in their motion are forced away from the filtering surface and concurrently towards the downstream end of the filter, they do not come in contact with the filtering surface. For example should in figur 1 the perimeter of the filtering surface 20.1 upper part (furthest away from the filter surface) preferably be greater than the perimeter down at the filter surface 20.2, i.e. that part of the filter which formes the filtering surface may show one towards the downstream and generally tapering form. Within the scope of the invention it is thus possible to vary the rotation inducing means and their shape and the shape of the filter in accordance with the character of the flow and the type of particles involved. The described embodiment shall not in any way be thought to be anything but examples of embodiments and shall therefore not be considered to in any way limit the process or the device according to the submitted claims, but merely constitute illustrative embodiments thereof.

Claims: CLAIMS 1. Process for continous separation of solid particles from a fluid ' flowing in a conduit characterized in that the fluid on entering the apparatus is given a rotational movement by means of rotation inducing means and that the flow of fluid is caused to pass through a filter, which is arranged at the downstream end of the apparatus, at which the filter comprises a filtering surface and a filter surface, the filtering surface extending along the rotational axis of the fluid and the filter surface being so placed as to form a downstream barrier for the non-filtered fluid, whereby in the event of a sudden • increase of pressure in the fluid the filter surface during an initial stage allows a potent rotational movement to build up, synchronously with the separation of the tornaway particles being effected aganst the filter surface, whereby the rotational movement of the fluid is given enough time to stabilize and the tornaway particles are forced away from the filtering surface and whereby said particles by the movement of the liquid concurrently are moved in the longitudinal direction of the device towards the filter surface. 2. Filtering device for continous, separation of solid particles from a fluid flowing in a conduit- characterized . by the 'apparatus being placed in a housing (1) comprising an upstream end (4) and a downstream end (5), and the flow of the fluid (3) rotation inducing means (7) provided at the upstream end (4), which gives the flow of the fluid a rotational movement around a rotational axis, and provided at the downstream end of the device a filter having a filtering surface (20.1) essentially parallell with the rotational axis of the flow o the fluid and a filter surface (20.2) so provided as to constitute a downstream barrier for the non-filtered flow. 3. Device according to claim 1 characterized in that the housing (1) constitutes the conduit in which the device is arranged. 4. Device according to any of the claims 2-3characterized In that a bulge is provided downstreams, at the in the direction of the flow furthest away part of the filter, said bulge provided to constitute a space (24) for collecting the solid particles (15), and means provided for drainage (25, 26) of the solid particles in connection with said space (24). 5. Device according to any of the claims 2-4characterized in that the filtering surface (20.1) constitutes a part of a self-supported filter. 6. Device according to any one of the claims 2 - 4 characterized in that the filtering surface (20.1) constitutes a part of a filter having one in the center of the device, essentially parallell to the rotational axis of the flow arranged the filtering surface (20.1) supporting slotted stay tube (10), said tube having a rigidly mounted plate (13) provided with holes, which plate covers the flow area, at which the stay tube (10) and the plate (13) on the upstreams side of the flow carries a filter of which the filtering surface (20.1) covers said tube (10) and the filter surface (20.2) is carried by said plate (13) provided with holes. 7. Device according to any one of the claims 2 - 6 characterized in that the rotation inducing means (7) is provided inside the housing (1) or in the conduit upstream of the filtering surface which conduit forms the housing or on the wall of the housing (1) of the filtering device at the inlet thereof. 8. - Device according to any one of the claims 2 - 7 characterized in that the rotation inducing means (7) are arranged on the stay tube (10) or on the self-supported filter at the upstream end of .the same. 9. Device according to any one of the claims 2 - . 8 characterized in that between the rotation inducing means (7) and the filter a conical member is provided, the position and the basal radius of which can be monitored to regulate the flow of the fluid. 10. Use of the filtering device according to any of the claims 2 - 9 either solely or in a combination of a plurality of said devices as a - protectional filter for easily damaged components. 11. Use of the filtering device according to any one of the claims 2 -9 as a filter placed in front of sprinkler nozzles in a sprinkler installation, at which the filter has a mesh size, which is less than that of the nozzle opening diameter.

Inventors: BJOERK LENNART, BJOERK, LENNART
Applicants: BJOERK LENNART, BJOERK, LENNART
Application year: 1989
Main classification: A62C35
IPC codes: B01D29, B01D33