US2576656A - Apparatus for cleaning hose filters - Google Patents

Description

Nov. 27, 1951 s. w. WALLIN 2,576,656

APPARATUS FOR CLEANING HOSE FILTERS Filed Aug. 16, 1949 4 Sheets-Sheet 1 A J %WWW 322/ w AZ??? 1 J Nov. 27, 1951 s. w. WALLIN APPARATUS FOR CLEANING HOSE FILTERS 4 Sheets-Sheet 2 Filed Aug. 16, 1949 mm mm L %A% Wd Nov. 27, 1951 s. w. WALLIN 2,576,656

APPARATUS FOR CLEANING HOSE FILTERS Filed Aug. 16, 1949 4 Sheets-Sheet 4 20 45 24 24 FIG. 9

aw/V i u MHZ???" J Patented Nov. 27, 1951 2,576,656 APPARATUS FOR CLEANING HOSE FILTERS Sven Werner Wallin, Jonkoping, Sweden, as-

signor to AB Svenska holm, Sweden Fliktfabriken, Stock- Application August 16, 1949, Serial No. 110,634 In Sweden April 21, 1948 4 Claims. I

The present invention relates to a method and arrangement for periodical cleaning during operation of a section of the hose filter at a time by hose filters divided into section for gaseous media.

The method according to the invention is in the first place characterized by that the difference in pressure of the gas before and after passing the hose filters, when the pressure of the purified gas with a certain value is below the pressure of the not purified gas, as an impulse may affect an arrangement which actuates driving members which partly send a counterdirected current of fresh air through the hose filters in one section and partly close the normal outlet for purified gas from this section, and after a certain period of time, when the pressure difference is considered to be equalized, will stop the counter-directed current of air, will open the normal outlet for the purified ga from the section and stop the driving members because the decreased pressure diiTerence will restore the impulse affected arrangement to the original position. According to still another characteristic feature of the method the counter-directed current of air may partly be conducted to and utilized for the operation of a vibrator shaking the deteriorations from the hose filters of the closed section.

The arrangement for the performing of the method relates to different sections of chambers with vertically downwards hanging hose filters within each section, which hose filters open out in a lower chamber, common to all the sections, which chamber is provided with inlet openings for the gaseous medium which is to be purified, which chamber sections each by itself, by means of an opening in the chamber wall, open out into a box, which, by means of an opening provided with a closing arrangement is connected with an outlet pipe common to all boxes for the purified medium, and what is most characteristic for this arrangement according to the invention is, that the lower chamber and the outlet pipe for the purified medium each by means of a pipe are connected to a pressure-difference gauge which is arranged to begin to deviate at a certain pressure difference and thus start one or more driving members which member or members partly start an air driving arrangement for injection of fresh air in a pressure chamber, provided with closing members for the same number of openings from the pressure chamber as the hose filter has sections and boxes connected thereto, which open- Jugs are each connected to a box, partly start an arrangement which is arranged to open in proper turns and during a certain period of time keep open the closing members for the openings from the pressure chamber mentioned to the boxes and thereafter close these closing members again, which boxes by means of a separating Wall are divided into two compartments communicating with each other, one of which by means of openings mentioned is connected to partly the hose filter chamber section and partly the outlet pipe for purified medium and the other compartment by means of likewise mentioned openings is connected to the pressure chamber, in which latter compartment is disposed a screen, possible to operate by the air from the pressure chamber and swingably journalled, which screen by means of its swinging is arranged to affect the opening and closing of the closing arrangement for the opening between the second compartment of the box and the outlet pipe for the purified medium. Other characteristic features of the arrangement according to the invention are evident from an embodiment closer described in the following and shown in the drawings.

The invention involves the advantage that the arrangement, used for the cleaning of the hose filters, automatically is set in function and in proper turn cleans one hose filter section at a time. The cleaning of one section is thus eifected without stopping the operation of the plant which is so managed that the other section or sections in the meantime takes over the function of the section being cleaned. The cleaning proceeds during a certain period of time and is thereafter intercepted. Thereafter the other section or sections are cleaned in proper turns in the same manner with interruptions between each cleaning. Cleaning of one section is thus only done when it is necessary and is efiected automatically in such a way that the pressure diiference of the medium before and after passing the filter may be the impulse which actuates the cleaning arrangement in section after section. Another advantage is that the air which is led in for cleaning of the hoses in the filter also is used for the operation of a vibrator shaking the hoses being cleaned. The above mentioned use of the pressure difference as impulse for actuating the cleaning arrangement furthermore involves a simplifying of the whole cleaning arrangement and makes a manual con trol of the arrangement unnecessary. In addition to this a special advantage lies in the fact that the movable parts of the arrangement have been enclosed, that is, protected from dust, exterior deteriorations thus not being able to disturb the operation. In certain case the movable parts may even be immersed in an oil bath.

The invention is illustrated in one of its embodiments in the accompanying drawings.

Figure 1 shows schematically a cross section through a gas purifying plant.

Figure 2 is a side view of the same plant; and

Figure 3 is an end view of Figure 2 viewed from the left side.

Figure 4 shows a vertical section in a larger scale; and

Figure 5 shows ahorizontal section in a -iarger scale of the arrangement for opening and closing of the closing members for fresh flushing air for the sections. Figure 4 is a section of Figure 5 in line IV-IV and Figure 5 is a section of Figure 4 in line V-V. Figures 6 and 7 aresections in a larger scale of the pressure difierence gauge.

Figure 6 is a section of Figure '7 in line VI--VI and Figure '7 is a section of Figure 6 in line Figures 8 and 9 are sections in a larger scale of the -box with the closing arrangement between the filter chamber and the outlet pipe. Figure 9 is a section of Figure 8 in line IXIX. Figures '10 and 11 are sections in a larger scale of the vibrator for the hoses.

ure 10 is a section of Figure 11 in line X-X and "Figure 11 is a section of Figure 10in line XI-XT.

The plant shown in Figures 1, 2 and 3 consists of thr'eecasings i, 2 and 3, forming filter chamhers, separated from each other, and designated 1A, 2A and 3A although only chamber in may be seen in the drawing. The casings l, 2 and 3 rest on and are connected to alower outlet chamber 4, the walls of which are designated 5. In casings l, 2'a-nd 3,-which are uniform, there is an upper plate?) which rests on springs 7, disposed oninteriorli'sts 8 in the casings. The plate constitutes acarrying member for hoses s, hanging down vertically in the casings. The hoses 9 are fastened to the plate 3 by forcing th'ein on annular elements 11) arranged on the lower side of the plate. Hoses 9 may be made of molesk'in oranyother convenient filter material. The lower ends of the'hoses'extend through an upper wall to the lower outlet chamber l, for this purpose being provided fwith*ho1es H, corresponding to thehose's, in which holes are arranged annularmembersfl, around which the lower ends "of the hoses are to be fastened. On the plate '6 is disposed a vibrator 1-3. From the lower part of chamber 1 an "opening 44 leads laterally to a box or outlet chamber [5. 1n the bottom of the inlet "chamber A is disposed an endless screw it which servesthe purpose of transporting away fallen "down deteriorations from chamber d, the 'deteriorations being separated from the medium which is to be purified. 'The medium is introduced into the chamber 4 through -a pipe 'ii and "from there rises in the hoses in all the casings, "is filtered by the hoses and enters the chambers "IA, 2A and-3A from which the purified medium escapes throughopening's M to boxes. or outlet chambers 15. The boxes or chambers 15 are by means 'of an interior separating wall 15a, into two compartments l9 and 20, communicating witheaoh other through an aperture or passage i'8. See especially Figures 8 and 9 showing the box in a larger scale. Compartment 2! has two openings one ofwhi'ch is connected to open- 'ing 14 and the other'one, 2|, is connected to an outlet pipe or duct 22 for purified medium, the outlet pipe being common to all boxes. Openh1g2 I is provided with "avalve '23 supportedby I two arms 24 fixedly arranged on an axis 2'5, rotatably journalled in the box IS, the axis furthermore supporting a screen 26, fixedly attached to and rotatable with the axis 25. The valve 23 consists of a plate, which by means of screws 27, nuts 28 and springs 29 is resiliently journalled in another plate 33, fixedly fastened to the arms 24. The valve 23 and the screen 25, are shown in Figure 8 in partly a full drawn closed position with reference to the valve, and partly a dash-dotted open position.

The compartment i9 is provided with the apertime 18 previously mentioned, constituting a communication between the compartments l9 and 28, an opening 3i connected to a pipe 32 and an opening 33 connected to a pipe 3 1 leading to the vibrator E3. The boxes i5 rest by means of a foot part 35 on and are fixedly fastened to the outletpipe 22 with which the foot part communicates.

From the lower chamber 3 a pipe 33 and from the outlet pipe 22 another pipe 3"? leads to a pressure difference gauge 33. This consists of a housing separated in two compartments 4% and 4'! by means of a vertical partition 35 (see Figures ti and 7 which compartments both are connected with the atmosphere by means of an opening 43 closed with-a lid #32. In the housing in the drawing.

of the pressure gauge 38 is a shaft M, supporting the wings =45 and '43, rotatably journalled. By the rotation of the shaft the wings '45, "is move at a very little distance from the wall or the housing. The shaft is provided with a threaded -projection i? on which a weight 58 is displace'abie by means of threads and a locking nut 49 and possible to lock in order to change the equilibrium of the wings 5346. On the shaft at is furthermore fixedly arranged a mercury switch 58 the connections 5! and 52 of which are taken through holes in the wall of the pressure gauge and lead to one or more electrical -motors,

described in the following.

A housing is designated 53 (seespeciallyFi'gures 4 and 5) which is divided into two chambers completely separated irom each other, one pressure "chamber as and one motor chamber 55. The partition wall between the chambers is designated '56. Chamber 54 is provided with an opening 51 which is connected to a pressure um is, driven by an electrical motor '59 and blowing compressed fresh air into the chamber '55. The starting and stopping of this motor 'is regulated by means of the mercury switch 58, the connections of which lead to the starting device or themot'or although this is not especially shown From the pressure chamber pipes 32 lead to boxes 15, one pipe 3 2 120 each box IS. The ends of the pipes 32 opening out in the pressure chamber are provided with control valves in the shape of adisc 5d, rotatably journalled on an arm iii around a pivot 62. Arm 3| extends through an opening 63 in the partition wall 56 and forms a tight closure to this wall by means of metal bellows 3'4 surrounding the arm, the metal bellows being only slightly sensitive to'pressure from'chamber but letting -the "arm freely rotate around a shaft 65 oom mon to all arms 3 I, shaft 65 being rotat'ably joui' nalledin chamber 55. Arm 6 5 is two-armed and one end supports the valve 69 and-the oth'erend supports a roller 56, rotatabl'y arranged around a pivot 61. The rollers 36 of the arms =61 make contact against a drum H providedw- ith cams 68, 69 and ill, the drum being rotatably 50in"- 'nal-led a'r'ou'nd shaft 12 in the chamber 55, axis 12 being journalled in bearings 13 and 14. The drum is provided with a toothed wheel 75, driven by an endless chain :6 from the chain drive i! belonging to the gearing l8 driven by an electrical motorlil. The starting device of this motor is also connected to the mercury switch 59 as is evident from Figure l and the motor is started andstopped by means of the mercury switch.

1 The screen 26 described in connection with Figures 8 and 9 is formed according to the walls of the housing but leaves a small distance free between the contour of the screen and the wall oi the housing.

The vibrator consists of a housing with an inlet 80 for compressed air and an outlet iii. In the housing of the vibrator as shaft $2 is fixedly arrangedand on this shaft two bearings 33 and 3d are, mounted, supporting a wing 85, set into motion around axis 82 by compressed air thus generating vibrations by means of the compression impacts.

The arrangement according to the invention functions in the following way.

The medium to be purified, enters into the inlet chamber 4 through pipe 11, from which chamber it rises in the hoses 9 and penetrates the walls of the hoses and enters into chamber IA and escapes through the opening it in a purified state. Conditions are analogous for all casings 1,2, and 3. If the hose filters are newly inserted all the valves 23 will assume the open position shown with dash-dotted lines in Figure The purified medium then continues from openlit ing 14 through compartment and out through opening 2! and into and away through outlet pipe 22.

. As long as the pores of the hose filters are not closed by deteriorations the pressure in the let chamber 4 and in the outlet pipe 22 is substantially the same. When one or more of the hoses of the filter sections begin to be plugged the pressure in the outlet pipe 22 will be lower than the pressure in the inlet chamber 4 which results in a pressure diiference between the average pressures in pipes 36 and 37 which difference successively will increase in value. ence in pressure is registered by the wings i5 and 46 which by means of the weight 43 have been adjusted so that the wings balance each other at substantially the same pressure in the pipes 36 and 31, but are moved from this position by counterclockwise rotation of the shaft 44 owing to the efiect of the arising pressure difference, so that on reaching a predetermined pressure difference the shaft 44 has rotated enough so that the mercury switch 5B, which from the beginning I has been open, will close the circuit to the motors 59 and ill. The closing of the circuit from the supply lines A through the main switch A starts these motors. Motor 59 runs the pump 58 blowing compressed air into chamber 54, all the valves 60 of which have been closed in the meantime. As the motor i9 simultaneously runs the gearing l8 and the pinion H and the latter wheel runs the chain 18 and thus the toothed wheel 15, the drum ll will also be set into motion, causing the cam 68 to lift one end of arm 6! and during a certain period of time keeps it lifted up and thereafter to lower it again. The lifting of the arm causes a lowering of the other end, thus opening the control valve on the pipe 32 and letting compressed air pass the opening and enter compartment [9 in box 15. Owing to the effect of the air pressure the screen 2'5 will rotate shaft 25 and thus arms 24 clockwise resulting in that the valve 23 will close the opening 2|. Continued flowing The diff erin of air into chamber compartment '15 results in this air passing through the openings between screen 26 and the interior walls of the chamber compartment and continues through opening it into chamber compartment 28 and from there into chamber IA, through the hose filters in opposite direction to the medium which is to be purified and enters into the lower chamber 4 after having passed the hoses and then cleaned them from adhering deteriorations which fall down into chamber 4 and are transported away by means of conveyor Hi. When screen 26 has moved sufliciently to clear the opening 33 01 pipe 34 the compressed air flows through the pipe to vibrator l3 and runs said vibrator thereby vibrating plate 6 which shakes the hoses and facilitates the cleaning of the hoses from deteriorations. After cleaning the hoses of one section in this manner durin a certain period of time, the pressure difference between the pressure in pipes 36 and 3'! will drop and the wings will return to the original position by means of weight 48 thus causing the mercury switch to break the current to the motors which stop. In the meantime cam 68 of the drum H has passed roller and arm 6| has been lowered, i. e. valve G8 has closed pipe 32 and stopped the communication between the compressed air chamber 54 and box 55. Fresh air then beings to enter box IE again and opens the valve 23, which furthermore on account of its own weight returns to the position with free opening 2!, shown in Figure 8 with dash-dotted lines. The plant now works normally again without cleaning of the hoses until a new pressure difference will appear, actuating the cleaning mechanism again, but this time it is the next section of the filter which is to be cleaned, which procedure thereafter is repeated.

Having now described my invention, what I claim as new, and desire to secure by United States Letters Patent, is:

1. In filter apparatus comprising a plurality of filter casings each having a plurality of vertically extending filter hoses in each thereof and an inlet chamber for the mechanism to be purified underlying said filter casings and arranged so that the medium to be filtered entering said inlet chamber is caused to pass upwardly into said filter hoses and then outwardly through the lat ter into said filter casings, means defining an outlet chamber for each casing for the purified medium, an outlet duct communicatim with each outlet chamber, normally open valve means for closing-oil communication between said outlet duct and said outlet chambers, actuating means for said valve means in each outlet chamber operable in response to a predetermined gaseous fluid pressure to close said valve and simultaneously cause said pressure fluid to flow from said outlet chambers into said filter casings and inwardly through the hose filters therein to clean the same, a source of gaseous pressure fluid, a connection from said source to each outlet chamher, a normally closed control valve for each said connection, cam means constructed to open said control valves one at a time in predetermined sequence, and means responsive to a predetermined differential between the inlet chamber pressure and the outlet chamber pressure operable to actuate said cam means thereby to open said control valves in predetermined sequence and cause the gaseous pressure fluid to flow to the outlet chambers in accordance with the quential opening of said control valves.

2. In filter apparatus comprising a plurality of filter casings each having a plurality ofvertically extending filter hoses in each thereof and an inlet chamber for the mechanism to be purified underlying said filter casings and arranged so that the medium to be filtered entering said inlet chamber is caused to pass upwardly into said filter hoses and then outwardly through the latter into said filter casings, means defining an outlet chamber for each casing for the purified medium, an outlet duct communicating with each outlet chamber, normally open valve means for closingoff communication between said outlet duct and said outlet chambers, actuating means for said valve means in each outlet chamber operable in response to a predetermii'ied gaseous fluid pressure to close said valve and simultaneously cause said pressure fluid to flow from said outlet chambers into said filter casings and inwardly through the hose filters therein to clean the same, a source of gaseous pressure fluid including a pump, a connection from said source to each outlet cham ber, a normally closed control valve for'each said connection, cam means constructed to open said control valves one at a time in predetermined sequence, and means responsive to a predetermined differential between the inlet chamber pressure and the outlet chamber pressure operable to drive said pump and to actuate said cam means thereby to open said control valves in predetermined. sequence and cause the gaseous pressure fluid to flow to the outlet chambers n accordance with the sequential opening of said control valves.

3. In filter apparatus comprising a filter casing having. a plurality of vertically extending filter.

hoses therein in spaced relationship and an inlet chamber for a medium to be purified underlying said filter casing and arranged so that the medium to be filtered is caused to pass upwardly into said filter hoses'and then outwardly through the latter into said filter casing, means defining an outlet chamber for the purified medium communicating with said casing, an. outlet duct communicating with said outlet chamber, normally open valve means for closing-off communication between said outlet duct and said outlet chamber, actuating means for said valve means in the outlet chamber operable in response to a predetermined fiuid pressure to close said valve and simultaneously cause said pressure fluid to i flow from said outlet chamber into said filter casing and inwardly through the hose filter to clean the same, mechanism responsive to a predetermined differential between the inlet cham-- ber pressure and the outlet chamber pressure operable, to discharge into the outlet chamber a gaseous fluid at said predetermined pressure thereby to operate said valve closing means and cause the pressure fluid to now to said filter a 8 casings, said mechanism being aut matically rendered inoperative when the pressure difieren tial falls below said predetermined value, a gasdriven vibrator connected to the hose filters. for shaking them, and a connection to said vibrator from the outlet chamber for conducting a por tion of the gaseous fluid discharged into saidout let chamber to. said vibrator to drive the same.

4. In filter apparatus comprising a plurality of filter casings each having a plurality of vertically extending filter hoses in each thereof and anin let chamber for the mechanism to be purified underlying said filter casings and arranged so. that the medium to be filtered entering said inlet chamber is caused to pass upwardly intosai'd filter hoses and then outwardly through the latter into said filter casings, means defining an outlet chamber for each casing for the purified medium, an outlet duct communicating with each outlet chamber, normally open valve means for closingoiT communication between said outlet duct and said outlet chambers, actuating means for said valve means in each outlet chamber operablein response to a predetermined gaseous fluid pressure to close said valve and simultaneously cause said pressure fluid to flow from said outlet chainbers into said filter casings and inwardly through the hose filters therein to clean the same; mechanism responsiveto a predetermined differential between the inlet chamber pressure and outlet duct pressure operable to discharge into saidoutlet chambers one at a time a gaseous fiuid at said predetermined pressure thereby to operate said valve closing means in said one chamber and cause" the' pressure fiuid to flow to its associated filter casing, said mechanism being automatically rendered inoperative when the pressure difie'rential falls below said predetermined value; a gas driven vibrator connected to the hose filters in" each casing for shaking them, and a conrie'ctio'rr to said vibrator from the associated outlet chain's ber for conducting a portion of the gaseousfluid discharged into said outlet chamber to said vibrator to drive the same.

SVEN' WERNER WALLIN;

REFERENCES, CITED The following references are. of record in the" file of this patent: V

UNITED STATES. PATENTS" Number Name Date- 1",638,067 Szekely Aug. 9, 192? 1,784,339 Clasen" etal'. Dec; 9; I930 1,806,513 Straus-Scharina May' 19,- 1931 1,974,952 Eiben Sept. 25, 1934f 2,276,805 Tolman Mar. 17,1942 2368,78"? Skinner Feb. -6, i945

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