DE2311284A1 - VALVE ARRANGEMENT FOR REWINDING AIR OR GAS FILTERS - Google Patents

Description

Dipl.-Ing. H. MITSCHERLICH 8 MDNCHEN

Dipl.-Ing. K. GUNSCHMANN Steinsdorf, t _ra ee 10

Dr. rer. nat. W. KÖRBER »(Mil) ·» «« Dipl.-Ing. J. SCHMIDT-EVERS

PATENT LAWYERS 7 MARCH 1973

ROLF JOHAN FLEBU 231 1 2 8 A

Bj / rnsvikveien 25

Slependen, Norway

Patent application Valve arrangement for backwashing air or gas filters

The invention relates to valve assemblies that it in the case of tube filters used to keep air or gases out, such a filter can be used for backwashing to supply serving air so that an impact effect is achieved.

r <ei one of the known methods for cleaning the i'filter hoses of hose filters of the known type is the Air used for backwashing is fed to the filter bags in a direction that corresponds to the seal is opposite in which the air to be cleaned or that supplied during normal operation will. In particular, it is known that such backwashing can be effected by having nozzles, each of which has a filter hose one is assigned, supplies compressed air. A compressed air flow generated in this way has an injector effect off, so that air is entrained from the area around the nozzle on the clean side of the filter hose, üie together with the supplied compressed air causes the filter hose in question is filled with air more or less abruptly in order to cause a flow movement, aie in connection with the air flowing in the opposite direction from the inside of the filter hose to its outside

309837/0961 original inspected

231 i284

flows causes which is on the outside of the filter i chlauchs deposited soot layer causes falling down. In a serious one-eighth part of this cleaning method, a large amount of energy must be expended in order to supply a sufficient amount of compressed air to the filter to be cleaned; This is primarily due to the low efficiency achieved when the filter bags are filled with compressed air and with air entrained on the clean side of the liter, and also to the fact that the valves and the compressed air lines cause high pressure losses. Another significant disadvantage of this known method is that when certain filter hoses are leaking or damaged in some other way, so that the air on the clean side of the filter has a certain dust content, the compressed air nozzles set dusty air in motion, which into the The filter hoses are blown in so that the filter hoses gradually clog on their clean side. In such a case it is necessary to remove all filter bags and clean them thoroughly; this is a time consuming and costly job.

"Is this backwashing method used to clean filter hoses applied, one must also take into account the fact that the air used for rewinding is again must be filtered, and that this increases the load on the active filter surface. At a glance on this it is of the achievement of a perfect cleaning Apart from the filter hoses, it is very important that you are in the right position, the amount of backwashing air used to reduce as much as possible.

The invention is based on the observation that the Duration of the backwash process for the cleaning effect of is of relatively minor importance, but it is important that the backwashing air is supplied in such a way that it exerts a short-term Sioßffekt on the filter fabric to

309837/096 1

to cause the deposited layer of dust to peel off and. falls down. Ls is known for supplying back-flushing air to use a valve arrangement for filter hoses, which includes a poppet valve that can be actuated by axial movement to establish a connection to close or open to an air duct for filtered air or to a source for the backwash air leads. However, such an arrangement does not enable the short-term generation which is aimed at by the invention a supply of backwashing air serving to harm the negative effects, and in addition, this arrangement results in considerable losses in that the backwash air partially escapes via the line for discharging the filtered air, as long as the valve disk is in a middle position. From the patent 845 599 it is known to have two valves to provide with a common actuating device in such a way that a valve for discharging filtered air before is closed when a backwash air valve is opened. This prevents backwashing air from being lost as a result goes that it escapes in a direct way via the line for discharging the filtered air. With this well-known Arrangement, however, the valve movement is brought about on magnetic Vie ge, so that you have a very robust and expensive Construction needed to be able to apply the large actuating forces that are required to the to bring about rapid valve movement, which is a prerequisite for the intermittent supply of the backwash air, which is aimed at by the invention.

The invention is now intended to provide a valve assembly of the type which has a valve for dispensing having filtered air and a backwash air valve, in which basically one valve is open while the other is closed and vice versa, and in which the backwash air valve is designed as a poppet valve in its closed position the pressure difference between the pressure of the backwash air and the pressure of the

309837/0961

is exposed to filtered air, so this pressure differential will help keep the backwashing air valve closed to keep. In this respect, this arrangement corresponds to that according to the above-mentioned patent specification. in the In contrast to this known arrangement, however, the mode of operation of the valve arrangement is based on the invention the use of a compressed air cylinder to actuate the "Valves through the intermediary of one of the valves sam associated, axially movable piston rod.

Generally speaking, the invention has provided a valve assembly which enables the Backwash Iu ft in the manner described above to be fed in abruptly, so that the filter bags are cleaned; here the filter bags become one in such a way but that there are only minimal losses and at the same time it is possible to have one with low losses To use inexpensive, reliable operating device of simple construction. According to the invention this is primarily achieved by the fact that the valve disc of the Ruckspulluftventxls through the piston rod under Mediation of a spring is actuated, the ~ in the closed position of the "valve against the further The differential pressure mentioned above acts, and its spring force increases as soon as the "valve is filtered for dispensing Air is opened, as well as in that the compressed air cylinder is dimensioned and arranged so that a Compressed air supply forms so that the cylinder comes into effect in the manner of an air spring when the I-aicksyülluftventils is opened bring about a rapid movement of the piston rod.

Invention and advantageous details of the invention are described below with reference to cal drawings explained in more detail using exemplary embodiments. It shows

1, 2 and 3 an embodiment of a valve arrangement in three different working positions, respectively

309Ö37 / 0961

231Ί28Λ

in longitudinal section; and

Fig. 4 in an enlarged ν certain cross-section Design features of valves which can be used in a valve arrangement according to FIGS. 1 to 3.

In Fig. 1 is a valve assembly according to the invention in their normal operating position, i.e. while purging air or a gas. To the one shown Arrangement includes a filter chamber 1, which contains several filter bags, of which only one partially is indicated, also an upper channel 2, which is in "connection with several filter bags, and a Outlet duct 3 for discharging the filtered air. Furthermore, a backwash air duct 4 is shown in Fig. 1 to 3, which makes it possible to supply backwashing air to the filter system to clean the filter hoses. The valve order according to the invention it makes it possible to introduce backwash air from the backwash air duct 4 directly into the filter bags, without the backwash air in the filter being mixed with filtered air, and in such a way that only short duct sections are required, so that only low losses occur. Therefore you can use a blower Provide low drive power in order to convey the backwash air. In many cases it is even possible without a get along with such a blower, since the prevailing vacuum in the filter is sufficient to provide the required length of the backwashing air suck in.

The "valve arrangement according to FIGS. 1 to 3 includes a Valve plate 5 »together with a valve seat 6 Kückspülluftventil forms, and also is another Valve plate 8 available, which together with a seat 9 forms a valve for discharging the filtered air. That -uücKr: purge air valve is used to direct the backwash air to the upper i-onal 2 to be supplied so that the backwashing air in the fiI-tercchiluche is introduced into the i-filter chamber in order to reduce the Clean the filter hoses and the valve for dispensing

309837/096 1

filtered air is opened or closed as required, to open or close the opening between the upper duct 2 and duct 3 for discharging filtered air close, which depends on whether the filter is in operation to purify air or whether the filter hoses are to be cleaned.

The movement of the valve disc is brought about by a compressed air cylinder 10, to which a piston rod belongs, at the lower end of which the lower valve disk 8 is attached. The upper valve plate 5 is slidably guided on the piston rod 11 and works with it Coil spring 7 together, which is supported with its lower end on the upper side of the lower valve disk 8. According to FIGS. 1 to 3 ΐε-t also a tubular stop voranden, which surrounds the lower part of the piston rod 11, is connected to the lower valve disk 8 and a Has length which is slightly greater than the distance between the valve seats 6 and 9 · The compressed air cylinder 10 has two connections 12 and 13 for supplying compressed air.

In the normal operating position of FIG. 1 is located the piston rod 11 is in its lowest position, and the valve for discharging filtered air is open, there the lower valve disk 8 assumes a position at a distance from the underside of the associated valve seat 9. In the upper channel 2, therefore, a negative pressure has priority, and the air or gas to be united is passed through the filter hoses are sucked through, so that the filtered-out dust is on the outer surfaces of the filter hoses deposits. In the backwash air duct, on the other hand, there is a relative overpressure, and the upper valve disk 5 is in Plant held on its seat 6 as it is exposed to the difference between the two pressures. The dimensions the different lines are chosen in practice so that that it is only necessary to cause a valve movement, the piston pin 11 along a relative short distance in axial direction; to be moved. However

309837/0961

the compressed air cylinder 10 preferably has a stroke length on, which is considerably larger than that required for the actual valve movement, and that working in the cylinder According to FIG. 1, the piston is in a central position between the ends of the cylinder as long as the filter system is in operation to filter air.

If compressed air is supplied to the underside of the piston in the cylinder 10 via the connection 1 $, the piston rod 11 moved upwards to the lower valve disk 8 of the valve for discharging filtered air after to move up and bring it to rest on the seat 9, so that the valve disc 8 is in its closed position approaching. During this movement, the upper valve disk 5 remains displaceable along the piston rod 11 is, initially in its closed position in contact with the seat 6, since on him the pressure difference between the upper Channel 2 and the kick scavenging air channel 4 act, while at the same time the spring 7 between the two valve disks 5 and 8 is partially compressed. During this movement of the piston rod 11 and the lower valve disk In addition, a higher air pressure builds up under the piston in the compressed air cylinder 10.

As soon as the lower valve disk 8 approaches its closed position, the upper valve disk 5 is through the Stop 14 is lifted from its seat 6 so that the pressures in the upper channel 2 and the Eückspülluftkanal 4 balance. This leads to a considerable reduction in the resistance to further upward movement of the upper valve disk 5 is opposed, and the compressed or tensioned spring 7 causes in connection with the air spring action which the compressed air exerts on the underside of the piston in the cylinder 10, that the upper valve disk 5 after at high speed is thrown up and lifted from its seat 6, while at the same time the lower valve disk 8 very quickly

309837/0981

carries out the remaining part of its closing movement.

5 shows the position of the parts of the valve arrangement for the EaIl that both valve plates have moved upwards, so that the kick-purge air valve has been opened is to enable a blast of compressed air to be applied to the filter bags. During the cleaning process which occurs during a short predetermined period of time, therefore, the compressed air exerts an impact on the inner surfaces of the filter bags, so that on the outer surfaces Dust layers deposited on the filter bags are shaken off. Also flows during the dismissal period a certain part of the itüciispülluftamt out of each filter hose through the hose wall to the outside, and this provides an additional cleaning effect improved. As soon as the cleaning period is over, compressed air is supplied via port 12 on the top of the piston in the cylinder 10, and thereby the valve discs are moved in the opposite direction, i.e. the upper valve disk 5 is moved downwards in order to bring it to bear against its seat 6, and the lower valve disk 8 is lifted down from its seat 9. Thus, the plate 5 of the Eüc-purge air valve is at the end its closing movement quickly brought into contact with the seat 6. For a brief moment may possibly a certain amount of the Eücispülluft escape into the discharge channel 3, but during this stage of the working cycle, this is irrelevant.

It is obvious that the basic mode of operation of the valve arrangement just described follows the invention can also be achieved with the help of constructions that are more or less of the Ausführungsbei game according to Fig. 1 to 3 differ. For example you can arrange both valve plates so that they slide on the piston rod; in this case the Driving movement of the piston rod on each valve disc

309837/096 1

transferred by a separate spring. Here it is possible to choose the relevant distances and to train the springs so that the valve zürn .Delivery of the filtered Air is closed before the backwash air valve is opened to clean the spring hoses. Finally, in contrast to FIGS. 1 to 3, where a standing arrangement is shown to arrange the valve assembly horizontally or in any other position.

Fig. 4 shows further details of a preferred embodiment of a valve which can be used in any or each of the "valves of the arrangement of Figs. 1 to 3. However, Fig. 4 relates primarily to an embodiment in which the valve disk is longitudinal The piston rod is displaceable so that it corresponds to the plate 5 of the valve according to Fig. 1 to 3 for the delivery of backwashing air. According to Fig to increase ntiltellers v _e. in the valve plate 15 is installed in the mastics an assembly, to which belongs an inner guide sleeve 22 which is slidably guided on a piston rod 21, further comprising a secured to the valve plate outer sleeve 23 as well as a between the two sockets arranged body made of rubber or the like he line to make the construction flexible, so that the valve disk 15 can also firmly rest against the valve seat 16 if the axis of the valve determined by the piston rod 21 should for any reason be inclined relative to the plane of the valve seat. A valve designed according to FIG. 4 is more suitable for the purposes of the invention, because better sealing is ensured in its closed position, and more favorable flow conditions result in its open position. These two factors are necessary for the achievement of the rapid veritil movements of Lecieutunr; which are necessary in order to

- -ίο -

to achieve the cleaning effect aimed at by the connection in the filter bags.

Finally, it should be noted that even filter in ^u U sing are where the filter surfaces have no tubular in shape, but are designed as in Hehrnen eingebau te flat filter surfaces, of course, the invention can also with such filters apply, ie its applicability is not limited on tubular or tubular filter surfaces.

iraterite claims 309837/0961

Claims (4)

P A ϊL K T A K ö P K υ G h E Valve arrangement for the impulsive introduction of Eück-Sülluft in filters intended for purifying air or gases with a valve for discharging filtered air and a laickspüluftventil, where basically one Valve is open when the other valve is closed and vice versa, and when the backwash air valve is on The poppet valve is in its closed position of the pressure difference between the pressure of the Ioick flushing air and the pressure of the filtered air is exposed, so that this Pressure difference contributes to the backwash air valve being closed to hold, and both valves with the help of a compressed air cylinder mediated by a axially movable piston rods assigned to them can be actuated, characterized in that that the valve disc (5) of the iSück flush air valve passes through the The piston rod (11) is actuated by means of a spring (7), the spring force of which in the closed position of the back flushing air valve counteracts the pressure difference and increases when the valve for discharging the filtered air is closed, and that the compressed air cylinder (10) is dimensioned and set up so that a compressed air supply can accumulate in it, which is suitable for Kind of an air spring to come into effect and so the piston rod when opening the Imckspüluftventils during the to give a quick movement to the last part of their movement. 2. Valve arrangement according to claim 1, characterized in that the valve disk (8) of the Valve for discharging the filtered air is attached to the piston rod (11), and that the Hückspüluftventil (5 »6) lets open a little before the valve to the 309837/0961 - 12 - 23 ί ί? 8Α Dispensing of filtered air at the beginning of a flush period is closed. 3 valve arrangement according to claim 1 or 2, characterized in that with the valve disk (S) of the valve for discharging filtered air, a stop (14) is rigidly connected, which serves to open the valve disc (5) to raise the loickspülluftventils shortly before the time by closing the valve to release filtered air. 4. Valve arrangement according to one of claims 1 to 3 » characterized in that one or each valve disk (15) on the piston rod (21) by means of a elastic assembly (22, 23, 24) built into the center of the valve disk is slidably guided. 5 valve arrangement according to one of claims 1 to 4, characterized in that the valve opening of the Rücr.spülluftventils and / or valve for dispensing filtered air is provided with an elastic, profiled element (16) extending along its belt which is shaped in such a way that it dampens the shocks exerted by the valve disc (15) and that it helps the air flow through the valve opening with as little loss as possible to let pass. l> he patent attorney: 309837/096 1 Blank page