Note: Descriptions are shown in the official language in which they were submitted.
ti4~35
The invention relates to a flushing air valve for
cleaning of at least one hollow filter member, said valve having
a flat valve member whose one side Eorms with its inner portion
the closure of the inlet of a flush:ing air conduit, peripheral
portions of said one side being located adjacent a flushing air
chamber, wherein khe valve member is arranged for movement in a
holding chamber in a direction pexpendicular to said one side,
under the influence of the flushing air, and wherein the holding
chamber is arranged in a continous communication - on the one
hand - with flushing air chamber, through at least one restric-
tor means and - on the other hand - with a control air conduit
adapted to be closed by a control valve. The term "holding
chamber" implies that the main function of such chamber is to
maintian the flat valve member in closed position during normal
operation of the device.
In one flushing air valve of this type known for years the
valve member is made from a rubber diaphragm which is clamped about
its entire periphery between the housing of the holding chamber and ~
that of the flushing air chamber. The valve can be used in flush- ;
ing one or more filter members, ~.g. filter hoses or filter bags. ~-
Air filters with this flushing system have enjoyed an exceptionally
wide use as-they are capable of operating with a small pressure
of the flushing air due to the overall structure of the device. An
overpressure of the maximum of 0~5 atu (a~mospheric excess pressure ;
in kg/cm2) is sufficient for flushing ~ dividual hoses. Thus,
simple air compressors can be used.
An increasingly undesired drawback is in the limitation of
the field of application as the maximum temperature of QperatiOn is
about 150C due to the use of the rubber diaphragm.
In another known embodiment, the diaphragm is not
stretched but is arranged for free movement, On shutting off
the flushing air opening, it sets free the filling of the
flushing air chamber over the control valve. Therefore, the
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c~ntrol ~alve must be of a structure suitable for reversln~
the flow directlon, not merely for shutting off the exhaust
air. Its structure is expensive and its speed o~ response is
too small. As the holding chamber is not in a constant commun-
ication with the ~lushing air chamber, the flushing cannot
be interrupted at a given time by simply closing the control
valve; insteadl pressurized air must be supplied via the
control valve into theholding chamber in order to enable the
re-closlng of the ~lushing alr openlng. In this case, too, the
response speed is smaller so that the duration of the flushing
pulse is difficult to control. In order to secure sufficient
flushing, the duration o~ the flushing pulse must be selected
to be greater than in the first mentioned embodiment, so that
a considerable additional consumption of ~lushing air is
necessaryL In this case the operational temperature is also
llmited.
It is known ~rom the art of digital, pneumatic and
hydraulic control means to employ valves whose valve members
are of the type of a solid plate. They su~er from the same
drawback as the structure described above, namely that they
require a positive control pressure for closing the valve and
oannot be controlled by simply shutting o~f the exhaust air.
Their use is primarily considered ~or h~draulic devices.
They are primarily intended to improve the sealing erfect
and to reduce the oil leakage. Their transforming to the
sizes and speed of pne~atic flushing air valves for air and
gas filters is impossible due to the intolerable noise on the
impact of the plate against the housing of the bu~er chamber.
The ~lushlng air valve according to the inventlon ls
characterized in that the valve member is a plate which has
a small clearanoe with respect to the walls o~ the ~olding
chamber, the plate bein~ guided by a guide provided on the
housin~ of the holdingchamberD the plate being provided
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~t lts race ~dj~cent to the use~l air condu~t with at least
one cyllnder arranged to enter into a hollow of the houslng.
It is then posslble to produce by simple means a
temperature independent flushing nir valve which ls decele-
rated at the end o~ its opening stroke wlthout the need for
a separate part. Nevertheless, the l~ftins o~ the valve member
is e~fected much ~aster th~n in the kno~rn diaphragm valve so
that the pressure of the flushing air can be selected to be
even smallerq Even ~hen flushing a plurality of hoses, the
required pressure of the flushlng air is much smaller than in
the known structures~ In a particularly advanta~eous embodi~
ment, a portion o~ the control air conduit adjacent the holding
chamber is used as the recess to form with the cylindric
member cutout means ~or cutting o~f the exhaust air flow.
In this case, the deceleration by cuttlng off the spent air
conduit is effeoted b~ the valve member itsel~, while the air
ramaining in the holdingchamber acts as a cushioning.
In further advanc1ng this conceptt the cylindric member
can be permanently received in the exhaust air condult to thus
form in cooperation with same a ~uide for the plate. It ~om-
prises a conn~c~ion conduit arranged to commun1cate at its
one end with the control air conduit and with the other, through
a communication passage in the cylindrical member nea~ the
plate, with the holdingchamber. It is possible to arbitrarily
select the wldth o~ the communication passage along its axial
length depending on the desired course of deceleratlon.
Furthermore, the housing of theholding chamber may be
deslgned to comprise a cylindric s~de wall and a cover flxed-
ly secured to same, with the cover comprisin~ the reoess ~or
recelving the cyl~ndric member9 wherein the cover serves the
purpose of a ~ixture on one wall of the flushing air chamber
and the cyl~ndric wall extends lnto ~he flushlng alr chamber.
The valve can thus be mounted on the flushing air chamber as
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a unit. The overR11 height ls mlnlmum a~ th~holdingchamber
ls lo¢~ted inslde the ~lushing air ohamber.
In general tPrms, the present invention provides a
flushing air valve for use in a filtering apparatus comprising
a plurality of hollow filter members, said flushing air valve
: being of the type arranged in a housing for flushing at least
one of said filter members, said flushing air valve including
a flat valve member whose one face is arranged to close by its
inner portion a flushing air conduit, the outside portion
of said one face of the valve member being arranged to face
the interior of a flushing air chamber of said apparatus, said ~:
valve member being movable in a holding chamber in a direction
generally perpendicular to the said one face under the action of
flushing air pressure, said holding chamber being arranged in
a permanent communication with the flushing air chamber through
at least one restrictor means, said holding chamber further
communicating with one end of control air exhaust means arranged
to be selectively opened or closed by a control valve; said
valve member being a plate whose peripheral edge is closely spaced
2~ with respect to a wall of said holding chamber; said valve ~;~
member being provided with guide means secured to said housing
for guiding the movement of said plate in said direction;
the surface of said valve member facing said exhaust means
forming, together with a portion of said valve housing facing
said surface of the valve member, a piston-cylinder arrangement
whose piston is adapted to be slidably received in the cylinder
of said arrangement. :
The present invention further provides a flushing air
valve for use in a filtering apparatus comprising a plurality
of hollow filter members, said flushing air valve being of
the type arranged in a housing for flushing at least one of said
filter members, said flushing air valve including a flat valve
member whose one face is arranged to close by its inner portion
~; a flushing air conduit, the outside portion of said one face of
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the valve member being arranged to face the interior of a
flushing air chamber of said apparatus, ~.aid valve me~er being
movable in a holding chamber in ~ direction generally perpen-
dicular to the said one face under the action of flushing air
pressure, said holding chamber being arranged in a permanent
communication with the flushing air chamber through at least
one restrictor means, said holding chamber further communicating
with one end of a control air exhaust means arranged to be
selectively opened or closed by a control v~lve; said valve
member being a plate whose peripheral edge is closely spaced
with respect to a wall of said holding chamber, said valve
member being provided with guide means secured to said housing
for guiding the movement of said plate in said direction; the
~ace of said valve member facing said exhaust means being provided
with a cylindric member arranged to be received in a recess
provided in the valve housing.
The drawing shows, as an e~ample, four embod~ment~ o~
the ln~entlon.
Figure 1 ls a sectional vlew o~ a hose ~ er provided
with a ~ir~t embod~ment Or the flushing air valve according
to the lnventlon.
Flgure 2 ~hows, on an enlarged scale, a sectional ~iew ~;
: o~ one ~lushing air ~alve of Figure 1.
~igure 3 shows the same embodiment o~ the flushing
alr valve ln sectlonal view correspond~ng to that o~ ~igure 2
Figure 4 shows the third embodlment o~ the ~lushlng
air valve in a ectional vlew corresponaing to that o~ Figure 2.
Flgure 5 shows a sectional vle~ o~ a hose ~ er provided
~lth ~lushing air valves o~ the ~ourth embodiment.
Figure 6 shows, on an enlarged scale, a ~ectlonal view
of ~lushing a~r v~lve o~ Flgure 5.
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1064~35
The houslng 11 of the hose .~ er according to Fl~ures
1 and 2 is dlvlded by partition ~a:lls 12, 13 lnto a cleaning
compartment 14, a clean alr plenum 15 and 9nto a ~lushlng air
chamber 16. In the cleanin6 compartment 14 are arran~ed filter
hoses 1~ closed at thelr bottom en~s 20. They are ~l~ed, by
clamps 21, to sleeves 22 arranged on the intermedlate partitlon
12, to ~orm a passage 23 between the inside o~ the filter
hoses 19 and the clean alr plenum 15. An inlet tube 25 cvmmun-
lcates into the cleanlnE compartmen~ 14. It ls provided with
a discharge olo~ure 26 having a se~m~nt wheel 27, A dlscharge
tube 29 ls ~rrang~d at the outlet o~ the clean air plenum 15,
Into the flushing air chamber 16 communicates ~ pressurlzed
: alr conduit 31. On the top wall 32 of the ~lu~hing a~r chamber
16 are secured by ~eeu~ing meanæ ~ot shown) flushin~ air
val~es 34. To each ~ilter hose 19 is associated one flu~hing ~;
air valve 34. Communicating outwardly rrom the ~lushlng ~ir
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valve 34 ls a ~lushin~ air duct 35 rixedly secured to the
~artition 13 reRchin~ lnto the th~ clean ~ir plenum 1~. It
communicates with same at a spacing ~rom and in the directlon
of the correspondin~ passage 23. l'he houslng 33 forms the
holdin~chRmber 37 for the valve member of the type o~ a plate
38. The bottom side 40 of plate 38 rorms with lts inner
portion 42 a cloæure o~ an inlet 43 of the flushing air
conduit 35. The bottom side 40 ls adjacent to th~ flushing
ai~ chamber 16 ~ith its perlpheral zones 45.
The plate 38 is arranged for mo~ement ~n the holding
chamber 37 in a directlon perpendicular to lts bottom slde
40. It has a small spacing 41 relative to the housln~ 33~
the spaeing thus forming a restrictor means of the type of
a permanent communication between the ~lushing air chamber 16
ana the bu~rer chamber 37.
Theholding chamber 37 communicates with a co~trol air
~onduit 48, which has a oylindric~l recess 49 o~ the b~using
33. The control air conduit 48 is arranged to be closed by a
control valve 51. It communi~ates wlth a chamber 53 of the
control valve 51 whlch includes a ~alve member 54 shown in
a dlagrammatic way. The valve member ls pressed by a spring
55 in the direction of lnlet 56 of an exhaust oonduit 57
whlch communic~tes wlth the atmosphere. An electrlc windln~
59 actuated by eleotrlcal current controllea by a ~ontrol
de~ice (not shown), is used ln pullin~ back the v~lve member
54 to thus open the inlet 56 ~or communlcatlng the aontrol air
conduit 4B with the exhaust conduit 57.
The plate 38 carrles on its upper side 61 a cylindric .
member 62 which is permanently received ln the cylindrical
recess 49 to thus form the guide means ~or the plate 38. It
~ncludes a communlcation conduit 64 termlnating at one end
with the recess 49 and with the other end through a communlcation
openlng 6~ disposed on the cylindrlc body 62 in pro2imity to
plate 38~ ~ith the holding~hamber 37.
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4 5135
The operation ls as followss
The contamlnated air is fed, by a blowing device (not
shown) lnto the cleanlng chamber 14, via the inlet tube 25,
either by compression or by suction. The air penetrates into
the inside of the filter hoses 19 while a portion of the dust
remains deposited on the outslde surface of the filter hoses
19, the maJor portion of the dust ~alling downwards and being
removed by the permanently dr~ven discharge segment wheel 27
from the cleaning compartment 14~ The segment wheel 27 also
serves the purpose of sealing the outlet o~ the compartment.
Clean air flows from the inside of the filter hoses 19
; through the passages 23 into the clean air plenum 15 and
leaves same through the clean air outlet tube 29.
Eventually, the layer o~ dust on the outside surface of
the fllter hoses 19 incre~ses and the resistance to the air
flow of contaminated air is increased accordingly. Therefore,
it is necessary to clean the filter hoses 19 ~rom time to time.
This is effected ln a way ~nown per se so that the indivi~ual
filter hoses 19 are subjectedg one after another, to an impact
pulse, in a predetermined sequence9 the pulse being effected by
a flushing air flow. The flushing air flow from the respective
flushing air conduit passes through the passage 23 into the
inside of the ~ er hose 19. The hose stretches outwardly
and due to the impact acting on the filter material, a desired
portion o~ the deposited layer of dust is removed and discharged
at the bottom, Durlng the cleaning of one of the filter hoses
19, the other filter hoses 19 remain in filtering operation
so that there is no interruption in the vperation of the
overall device~
During the filtering operation of the respeoti~e
filter hose 19~ the winding 59 (Figure 2j remains ~ree of
electric current. Theholding chamber 37 re~ains in a constant
communlcation with the flushing air chamber 16 th~ough the
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33~
ann~llar s~all clearance 41, so th~t there is the sa~e pressure
in both chambers, the pressure correspondin,~ to that ln the
pressurized air conduit 31.
The pressurized flushin air enters through the commun-
ication opening 65 into ~he communication conduit 64, into
the recess 49 and the spent alr condu~t 48 up to the chamber
530 Its action is such tha.t it tends to close the valve member
54. As the upper side 61 of plate 38 has a greater area than
the peripheral zone 45 of its bottom side 40, the plate 38
is pressed by a. ~reater force against the inlet 43 o~ flushing
air conduit 35, the inlet thus bein~ securely closedO
l~hen the respective filter hose 1.9 is to be cleaned,
the control device (not sho~) of the winding 59 subjects
the win~ing to an electric current action pulling back the
valve member 54 against the force of the spring 55 and against
the pressure of the pressurized air p~esent ln the chamber 53.
The pr~sEurized air in theholding chamber 37 can thus ~low
in a pulse manner through the communicatlon opening 65, the
commlmicat~on conduit 64, the recess 49, the control air ~onduit :.
49 and out through the exhaust conault 57. Thus, the pressure ~;
in the holdingchamber 37 is reduced and the pressure of the
flushing air acting at the peripheral zones 45 of the bottom
side 40 o~ plate 38 moves the plate 38 in a stroke motion
until the communication opening 65 enters the recess 49. Due
to the thus effecte* closing o~ the communication opening 65t
the air remaining in the holdingchamber 37 is prevented from ~-
ente~in~ the spent air condult 48 so that it now acts on the
plate 48 by way of deceleratlng effeck, thus preventlng the
plate from striking with a great noise a.gainst the housing 33.
The type of the communication opening 65 can be selected so as
to achieve the requlred course of the slowing down o~ the plate
38.
- The M ushlng air flows by way o~ an impact wa~e from the
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flushin~ air chamber 1.6 to the pl~te 38, through the inlet 43
into the flushln~ air con~1uit 35 and from there ~nto the
inside of the filter hose 19, as cLescribed above~
After a short time, the control dev~ce opens the circuit
of the wlnding 59~ The spring 59 presses the valve nember 54
against the inlet ~6 of the exhaust conduit 57 so that the
control air conduit is closed. Due to the inflow o~ ~lushin~
air from cha~ber 16 through the annular clearance 41, the
pressure in the holdingchamber 37 increases again so that the
plate 38 ls now pressed do~nnwardly to again close the inlet 43.
I~ will be observed that in case of a long duratlon of the
flushing, ~hich in itself is not desirable due to an increased
consumptlon of pressurized air, the pressure in the.buf~er -~:
chamber 37 is again increased due to the closing of the
communication opening 65, to press the plate dotnnwardly. As . .
soon as this communication opening 65 is again opened, the
air from the ~oldingchamber 37 is reduced in pressure due to
the renewed communicat~on with the exhaust conduit 57, thus
bringing the plat0 38 into the state of equilibrium~
In the embodiment of ~ig 3, the plate 38 ca~ries a simple ~ :
short cylinder which, with the plate 38 in closed position, i :
does not reach lnto the recess 49~ Pins 72 fi~ed to the housin~
33 are used in guiding the plate 38.
On the opening movement of plate 38, the oyllnder 71
and the recess 49 form an interruption means for the ~low o~
air into the control air conduit 48.
In the embodiment o~ Fig, 4, the portion of the contr
air conduit 48 ad~acent the ~u~er chamber 37 is not used as
a recess. Separate recesses 82 are provided which are d0signed
in the form o~ gas pockets.
The plate 38 carries cylinders 81 which, at the end of
the openlng stroke, enter into the recesses 82. Due to the
air arrested ~n the closed recesses 82, the cylinders 81
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~3641~35
co-operæte ~ith recesses 82 to fo~m a stroke bu~fer.
In the embodlment of Flgs. 5 and 6t the housing 11
does not have any flushlng alr chamber. A separake flushlng
air chamber ~1 is disposed to the ~side of the filter housing
on a support 92. A ~lushing air conduit 9~ communicates
into a header 96 extending into the cle~n air plenum 1~ and
provided ~ith ~ets 97, ~or slmultaneous cleanlng of an entire
row o~ hose fllters 19~ Obviously, a plurality o~ rows of
filter hoses 19 is disposed in ~he cleaning compart~ent 14,
one after another, so that the flushing air chamber 91 e~tends
in a direction perpendicul~r to the plane of the figure, along
a deslred length.
The structure and operation of the flushing air vs.lve
lol generally corresponds to thàt of ~he embodiment ac&ording
to Figures 1 and 2, t.he control valve for closing the control
air conduit 48 not belng shown, similar to the representation
in Figs. 3 and 4. A major portion of the housin~ 1.03 of the
buffer chs.mber 37 is formed by a cylindric wall 104 and bg
a cover 105 ~ixedly secured to same, the cover 105 havin~ the
recess 49 for receiving the ¢yllndric member 62. The cover
105 ls arranged to be secured by threaded bolts 1.07 to the
upper wall 106 of the flushing air chamber 91, so that the ~.
cylindrlc wall 104 protrudes into the flushing air chamber 91.
Such arrangement enables a simple assembly and reduce~ the
overall height o~ the device as a ma~or portion of the bu~er
chamber 37 is located inside the ~lushing air chamber 91.
Those skilled in the art will readily conceive further
embodiments utillzing the present invention. Such embodiments
may be more or less different from the embodiments disclosed
hereinbefore but would nevertheless fall within the scope of
the present invention as defined in the accompanying claims.
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