Note: Descriptions are shown in the official language in which they were submitted.
~2032~4
E~ECTRO PNEUM~TIC CO~TRVL SYSTEM
FO~ VAL~JE BAÇ; FII,LING APPARATlJS
E~ACKl;iROU~D O~ THE INV~NTION
The present invPntlon relates to the f illing
S of valve bags with particulate ma~eri~l and, more
par~icularly, to a method and system for control1ing
~ novel filling nozzle which eliminate~ the si~ting
of produ~ from the valve bag during and ~fter the
bag filling operation,
Particulate materials are commonly pa~kaged i~
bags that are made from multiple layer6 of p~per and
h~ve a "valve" in one upper corner. The valve provides
an opening through which the material is dispen~ed
during the bag f~lling opecation. ~he valve ~ag i~
typically filled by insertin~ a spou~ or nozzle into
the valve and caus~ ns material to flow through the
nozzle into the bag. Wh~n ~he bag i5 full, the flow
of material is halted and the nozzle is wit~drawn
from the valve ~sually ~y Tnoving the bag away from
20 the nozzle. The val~e is sealed to pre~ent egress
of the material from the bag during shipping and
hand 1 i ng .
~2032~4
The control system of the present
invention is particularly suited for use in conjunction
with the filler sleeve disclosed in U. S. Patent No.
4,387,749, issued June 14, 1983, Frederick A. Donisi.
The filler sleeve comprises an elongated tubular
member which is connec-ted to the top end of the bag.
The tubular member includes an open end which is con-
tiguous with a filler opening provided in the top end
of the bag. The opposed end of the tubular member is
closed, e.g. by heat sealing or folding. A longitudin-
ally extending slit is provided in the tubular member
disposed on the bottom surface thereof. In use, when
the bag is filled by introducing the product by air
flow or by gravity through a filler nozzle which is
inserted into the filler opening and into the tubular
member, the product is deflected downwardly into the
bag thereby inhibiting the likelihood of blow-out of
the side panels. Preferably, the tubular member is
formed from a stretchable material such as poly-
ethylene, so that during the filling of the bag theflow of the product stretches the material. By this
arrangement, when the filling is completed, and the
bag is inverted, the side edges of the slit, which
have been stretched, overlap and the weight of the
product functions to maintain the overlapping relation-
ship thereby preventing the unwanted escape of product
from the bag.
- 2 -
~2032~4
While the filling nozzle of the present invention
i~ particularly suited for use with the slitted
filler sleeve ~isclosed in the afore~entioned co-
pending app1ication, those skilled in the art ~ill
appreciate that the present filling nozzle is also
adaptable ~oe use in con~entional valve bags.
In filling valYe bags, problems have been
en¢ountered in reducing or elimi~a~ing the sifting
and dustin~ problems which o~cux. Typically, some
amo~nt of produc~ will spill from the f illin~ nozzle
on its way into the bag or on lts withdraw from the
bag. Variou~ h~zardous products, such as toxic
chemicals, c~ay, limestone, cement, c~rbon black,
h~rbicides, fungi~ides, and the like are usually
lS packaged in valve ~ags ~nd the elimination of product
sifting and dus~ing pcoblem~ durin~ the filling
oper~ion is therefore imperative. The slit~ed
sleeve enhan~es ba~ performan~e and effe~tively
reduces dustlng, ~ut does ~ot ~ompletely eliminate
the problem. ~urther, ~ifting can occur after the
filling process is comple.ted, e.g. during transit,
if material is entrap~ed in the valve durin~ the
filling proces~, Such entrapment of material can
occur if the filllng n~zzle does not dire~tly discharge
produc~ thro~gh the slitted sleeve. ~aterial can
also ~ecome entrapped if product dribbles out of the
nozzle into the sleeve at the end of the f illing
~ycle.
-3-
~2(:~32~
It would be advantageous to provide an apparatus
for fi}llng a valve bag which dire~ts the flow of
produ~t downwardly into the ~ag, thereby avoiding
the direct discharge of produ~t into the back end of
the v21ve bag sleeve. It would be further advantageo~s
if the apparatu5 and method in~luded a purge system
to ~lear the filling nozzl~ of all produ~t after a
bag has been fill~d, to subs~antially reduce produçt
dribb~e out of the no~le, ~nd ~o clear any pro~uct
from ~he valve sleeve which remains after the ba~
ha~ been filled.
~his invention relates to suçh an apparatus.
-4-
- ~032~4
~3U~l~lA R~ _OF THE I l`~VENT I ON
,~n electro-p~eumatic system for controll ing
the operation of a valve bag ~ill ing nozzle is provided.
The system cornpr ises a programmahle ccntroller having
5 a plurality of output A supply air manifold,
mean~ ~or coupling the manifold to a ~igh pxessure
source of air, and pressu~e regul~ting means coupled
to the manifol~ for providing a~ lea~t one source of
red~ced pressure ai~ are include~. A firs~ solenoid
~ctuated v~lve means coupled to the supply air mAnifold
is ad~pted to be actuated by one output of the programmable
controller fvr providing a ti~ed high pressure blas~
of ai~ for introduction into the filling noz~le
a~ter a valve bag has been filled. A second solenoid-
actuated valve me~ns i~ coupled to the pressurerey~l3t~ng mean~ and ~dapted to be ~ctuated by another
of the progr~mmable controller outputs for providing
a low pressure blast ~f air ~or introduction ex~ernally
of the f ill in~ nozzle after the actu~tion of the
20 f irst soleno~d actua~ed ~ralve. A third solenoid
actuated valve means is coupled to ~he s~pply air
. manifold and adapted to be actuated by an out~ut of
the programm~ble controlle for p~o~id$ng a v~cuum
for int~oduction into the filling nozzle after the
25 actuation of the second solenoid actuated valve.
3Z14
The v~cuum provided by the actuation o~ the
third solenoid actuated valve can be created by a
ventur i . A Ya~uum valve c~an be connected in ser ie
between the venturi and the filling nozzle, A fourth
5 solenoid act~ated valve mean~ can be controlled by
the proyramma~le ~ontroller. to open the vacuum ~alve
a~ter ~he third solenoid actuated valve Treans causes
th~ ~enturi to st~rt produ::ing a v2cuun~.
The provision of an electro-pneumati~ system
10 to con~rol the v~l~e bag ill in~ nozzle provides a
reliable, easily programmed and economical ~pparatus
for filling valve bags~ ~he syste~ elil~inates the
sifting o~ produ~t from the valve bag during and
after the ~ag filling operation by ~learing the
15 filling no2zle of any loo~e produ~t aft~r the b~g
has been fill~d, and by clearing the filling valve
in the bag of extraneou~ product at the completion
of the bag f ill ing cycle,
--5--
120;~ 4
B~IEF DESCRIPTION OF T~E DRAWINGS
Figure ~ is a top plan ~iew, with partial cut-
awayr showing a filling nozzle s~itable for use with
the con~rol syste~ of the p~esent inventio~S
S ~igure 2 is a side plan view, with partial
cut-away, of the nozzle shown in Figure l;
Fig~re 3 is a cross-sectiona~ vie~ taken substantially
along the line 3-3 sho~n in Fi~ure 2
~ig~re 4 is a cross-sectional view taken su~stantially
alonq the lin~ 4-4 shown in Figure 2;
Figure S is a cross-sectional ~iew sho~ing the
noz21e fillin~ a valve b~ thro~gh a s~itted valve
sleeve; and
~ig~re 6 is a ~lock diagram of a ~ontrol sys~em
lS apparat~s in accordance with the present invention.
--7--
32~4
DETAILED DESCRIPTION OF THE INVENT~ON
The overall structure of a Eillin~ nozzle
which can be used in conjunction with the filling
sys~em of the p~esent in~ention is shown in ~igures
1 ~nd 2. The nozzle 10 in~ludes an elo~ate~ tube
which is hollow to provide a material passage lS
~hereth~ough. In filling a valve baS, ~he nozzle is
inse~ted into the bag ~s ~ho~7n in Fi5ure 5. Product
flow~ into end 16 of the nozzle th~ough prcduct
supply conduit 58. The product, which is typical~y
a particulate material, ~merges from the nozzle
through opening 12, The valve baq shown in Fi~ure 5
includes a val~re ~leeve 52 h~vin~ a sli~ 54 therein
throu~h ~hi~h particulate material 56 passes, Once
p~rticulate ~aterial 5~ has passed thr~ugh 51it 54
it is within the interior of bag S~
~ n ~alve bag ~illing noz~le~ of prior design,
the opening ~t which the particulate product eme~ges
for filling the bag is not designed to direct the
flow of material exiting therefrom through ~ slitted
valve sleeve. When suçh prior nozzles are used in
conjunctiOn with a slitted sleeve, such as sleeve 52
shown in Figure 5, product is forced into the closed
end 53 of sleeve 52 ~here it ~n hec~me lodged or
otherwise remain af~er th~ filling of the bag has
been ~ompleted. P~oduct remaining at end S3 of
--8--
~2()32~
v~lve sleeve 52 can later find its way out o~ the
valve sleeve, causing the material (wl~ich may be
hazardous or toxic~ to exit ~rom the bag. Any su~h
leakage of product ~rom the bag is highly undesirable,
S Further, nozzles of prior design can c~use the ~losed
end 53 of valve sleeve 52 to rupture due to ~he
direc~ for~e of material which impa~ts the closed
end.
In the filling nozzle shown, opening 12 ls
10 situated so that when ~he nozzle i5 inserted into a
slitted ~alve sleeve, the produc~ flowing through
the nozzle will be directed through the sli~ and
into the bag, thereby minimizing the risk that the
produ~ will be caugh~ in the close~ end of the
valve sleeve. Th~ design of opening 12, by directing
product downwardly, al~o prevents ~he r~pture of the
closed end c~f the v~l~te sleeve.
The filling no2~1e also in~ludes various means
~or clearing the nozzle of residual parti~ulate
material after the prod~ct flow has ceased, and for
removing any parti~ul~te material which ~nay otherwise
remain in the valve sleeve afte~ the bag has been
fllled. Also provided is means for sealing the
no~zle ~ithin the valve ~leeve of a bag dur ing the
fillin~ operatio~.
~ he sealinq of the nozzle within a valve sleeve
i~ acçomplished by an inflatable rubber boot 14.
Rubbe~ boot 14 is infl~ted by a pressur ized fluid,
_ g _
~2~)3Z~
for example, pxessurized ai~, whi~h is introduced to
the boot through a condui~ 34A Conduit 34 is most
clearly shown in F~ures 2 and 3, and is connected
to a hose 38 by couplin~ 36~ Hose 38 is fed by a
timed source of pressurized ~ir which is caused by
suitable control means ~discussed hereinbelow) to
inflate ru~er boo`t 14 just ~fter the nozzle is
inserted into an emp~y valve ba~, and to deflate
rubber boot 14 ~ust pr ior to the removal of the
filled bag ~om the nozzle. The pressure used to
inflate boot 14 wLll typically be on the order of 3
to 5 pounds per square in~h.
After ~ bag has been filled with product flowins
t~rough the nozzle, and prior ~o the removal of the
lS filled bag from ~he nozzle, a blast Of high pressure
air iS int~oduced into material passage 15 of the
nozzle to clear the no~zle of any partic~late materi~l
remaining therein. The blast of high pressure air
is passed thrDugh hose 46 to ~onduit 42. Hose 46 is
20 coupled to conduit 42 by coupling 44. In the oper~tion
of the filling ~pout, the blas~ of high pressure air
will typically be ~t a pressure on the ~rde~ of 100
pounds pe~ squ ar e i nch .
7~f ter the high pressure bla~t clears mater ial
25 passage 15 of ~ny remaininy produ~t, low pressure
ai~ at a pressure on the order of 5~ pounds per
square inch ~s introduced between the nozzle and the
valve sleeve at ports 20, The ~ow pressure air is
carried to ports 20 by ~onduit~ 18. Conduits ~8 ~re
-10-
~2032~4
coupled, ~hrou~h coupling~ ~2, to hoses 23 which
carry the low p~essure air. The term "l~w pressure"
is used in des~ribinq thiq air source simply to
differentiate it from the hi~h pressure burst of air
5 whic~ is introduced into material passage 15 by
conduit 42 and is u~ed to clear m~terial passage 1
of extraneou~ par~iculate material aE~er a ~ag has
been f illed .
The purpose of providin~ ~ burst of low pressure
10 air between the nozzle and ~he ~alve sleeve into
whi~h the noz~le is inserted is to suspend any particula~e
product mater ial remairlinq in the ba9 sleeve af ter
the ba~ has been filled. ~ny such particl~s ~emaining
in the v~lve sleeve a~te~ the bag has been filled
15 are referred ~0 as l'dribblings". After the dribblin~s
have been su~pen~ed, a vacuum is drawn through cond~it
40. Conduit 40 ~ommunicates with material passasge
15. The vacuum ls d~awn as the nozzl~ is being
removed from the ~a~, and as a result any suspended
dribblings are sucked into material passage ~5, and
through conduit 40 to ~ffect their removal from the
bag. When the nozzle is used ~n conjunctiOn with a
slitted valve sleeve, as shown in Figure 5, the
in~ernal pressure of the aerated product in the~
25 filled bag forces the ~lit to close~ thereby preventing
the vacuum within material passage 15 from sucking
~ny product (other than dribbling5) out of the illed
bag. Thus, slit 54 can be analogized to a one way
- lZ032~14
valve, which allows product to enter, but not exit
rom the b~g. Figure 4 ~learl~ shows the nozzle
opening 1~. and por~s 20 whi~h supply the low pressure
air externally of nozzle 10~
S In order to efect pro~er ti~ing of the vacuum
whi~h is drawn ~rou~h c~nduit 40, a vacu~m valve ~4
is provided. V~cuum valve 24 is controlled by a
vac~um pilot line 2~, ~oupled to valve 24 at port
- 32. A por~ 33 can optionally be provided for pressure
relief or to close the valve, depending on the type
of ~alve which is ~sed for vacuum valve 2~. A ho~e
26 is shown connected to optional port 33. A vacuum
sour~e is conn~ted at end 30 of çonduit 40 through
~ ~oupling 31. The vacuum source can be turned on
1~ prior to the time at which it is desi~ed to draw a
va~uu~ thr~ugh conduit ~0, to enable the vacuum to
re~h i~s full operating cap~ci~y. Then, when it is
desired to draw the va~uum through conduit 40, pressu~i~ed
air is introduce~ into port 32 from vacuum pilot
~0 line 2~ to cause valve 24 to open. When it is desired
to terminate the vacuum in conduit 40, vacuum pilot
line 28 ~h~s valve 24 of~. The vacu~m source attached
at end 30 of condult 40 can comprise a venturl o~r
any other well known va~u~m source.
Figure 6 i8 a blo~k diagram of the control
system 150 of the present inven~ion. The control
system shown in ~igure 6 is connected to a nozzle of
the type shown in Figure5 1 through 5.
~12-
I
- ~203Z~14
A process controller 65 includes a pro~rammable
controller which is conne~ted to a supply voltage
through terminals 62 and 64. An on/off switch 66 iS
provided a!or~g with.a lamp 6~ to indicate that power
S is being supplied to programmable controller 60. An
electro-pneumatic ~ontrol unit 95 is driven by process
controller 65. Electro pneumatic control unit 95
provides the ~tariou~ air pressures which ~re used ~ n
the operation of spoU~ tfillins nozzle) 1~.
lG In filling a v~lve bag ~n accordance with the
present i~vention, rubber boot 14 on spout 10 is
inflated after the spout has been inserted into the
valve of a valve ~ag. In order to initia~e the bag
filling sequence~ an vperator presses start button
15 70 on programn~able contro~ler 60 . Programmabl e
controller 60 has a plurali~ 4f outputs 72, 7~, 76,
~nd 78~ A~ter a val~e ~g i~ placed on spout 10,
~nd s~art buttorl 70 is pressed, output 72 is energlzed
to inflate boot ~4. A la~np ~0 is conne~ted in series
20 ~ith outpu~ 72 to indi~ate that the signal for inflating
boo~ 14 is present. Outpu~ 72 i~ ~onnected from
process controller 65 to elec~ro-pneumati~ control
unit 9S, ~here it is connected to a air pilot solenoid
valve 98. Output 72 cause~ valve g8 to open, allowing
25 low pressure air to pass th~ough hose 38 and coupling
36 on spout 10, thereby inflating boot 14 ~ Pr ior ~o
~emo~al o~ the f ill ing nozzle or spo~t 10 from the
filled valve bag, output 7~ of programmable con~roller
60 turns off, turning off valve 98 and thereby defl~tin:~
30 boot 14.
-13-
~120321~
Air is ~upplied to valve 9~ from pressure
regulator 108. Pressure re~ulator 108 is supplied
with high pres~ure aLr from high pressure air supply
line 110. Typically, the hi~h pressure air supply
S will be at a pres~ure of about 100 pounds per s~uare
inch. Low volume pressure regulator 96 further
regulates the ~ir whi~h inflates boot 14, to ins~re
that the boot does not rupture durihg infl~tion.
The pressure actu~lly ~pplied to rubber boot 14 is
on the order of 3 to 5 pounds per squ~re inch.
~fter b~ot 1~ i~ inflated to effect a seal
between the spout 10 and the valve bag into which it
is inserted, programmable contr~lle~ ~0 will wait
until the valve bag is filled with a product flowing
through ~he spout from supply conduit 58. After the
ba~ is filled, output 7~ from programma~le controller~
60 wi.1 be~ome ene~gized, thereby t~rning on ~
pilot so~enoid valve lOC. When valve 100 tu~ns on,
a h~gh press~e bla~t of air will be transmitted by
hose 46 and through coupling ~4 in spout 10 to clea~
material passage 15 of any produ~t rem~ini~g therein
after the product fl~w through conduit sa has ceased.
Sol~noid valve 100 re~eives high pressure air dire~tly
rom high pr~58ure air supply line ~
A 1~P ~2 i3 provided in series ~ith outp~t 74
of pro~ramm~ble controller 60 to indicate th~t the
output is energized. After the high pressure blast
of air has been provided, outpu~ 7q ~urns off a~d a
low pressure air purge is effected by output.76 of
-14-
~203Zl~
programmable controller ~0. Output 76 has lamp 84
connected in series therewith to indicate ~hen the
output is energized, This outpu~ is c~nnected from
p~ocess controller 65 to a low pressure purge valve
104 in ele~tro-p~eumatic control unit 95. Valve 104
is an air pilot solenoid valve which reoeives a low
pressure ai~ supply from pressure regul~tor 10~.
~en valve 104 is actuated ~y output 76 o~ programmable
controller 60, a low pressure ~las~ of air travels
th~ough hose 23, through coupling 22 and cond~it 18
in spout 10 ~here it exit~ ~hrough po~s 20. This
low pressure blast suspends any dribblin~s le~t in
the valve of the bag ~ft-er the spout has been cleared
by the high pressure purge f rom valve 100 .
Output 7~ o~ programmable con~roller 60, which
15 intiateS the hig~ pre~sure p~rge from ~alve 100, has
a delay relay 88 connected thereto. Output ~9 of
delay relay 88 has ~ lamp ~0 connected in series
the~e~ith to . indicat~ when ~he delay relay output 8
is energized. The energi~ation of output 89 actuate~
~ ven~uri solenoid valve 102 in electro-pneumatic
control unit 9S. venturi ~alve 102, when act~ated,
introduces air at hi~h pressure inta hose 131. Hose
131 is coupled to ven~uri 132 to produce a vacu~ ~t
the output ~hereof. The ou~put of ventlJri 132 is
connected by ho5e 133 to ~oupling 30 on valve 24.
When valve 24 is Off, no vacuum is introduced into
material p~ssage 15 of spout 10 through conduit 40.
-15-
~Z03~4
Delay rel~y B8 actu~tes venturi ~talve 102 a
predetermined ~ilne after butput 74, and hence high
pressure purge valve 100, has been energized. The
predetermined time period e~pire~ before output 78
S of programmable controller 60 becomes energized.
The purpo~e of this is to enahle ventur i 132 to
produce its m~ximum v~cuum before valve ~4 is opened,
Thus, once ~ralve 24 opens, the full vacuum from
venturi 1~2 i~ int~odu~ed to material passasge 15 ln
10 spc~u~ 10 . ~hose Si~ ed ~ n the art will appreciate
that the use of del~y relay 88 enables the present
control syste~ to operate u~ing a progr~mmabl~ controller
with only ~o~r outputs. If a progra~mable ~ontroller
with f ive outp~t~ we~e av~ilabl~, output line 89
which actUateS venturl valve 102 could be ~onnected
~i~ectly to one of the five outputs, thereby o~viat~ng
the need for delay ~elay 88.
After the o~curance of the high pressure purge
and low pressure p~r~e, and d~rin~ She prod~ction of
~ a va~uu~ by vent~ri 132, output 78 of programmable
controller ~0 is energized to a~t'late vacuum pilot
~olenoid valve 1~6 in electro-pneumatic ~ontrol un~t
95, A lamp ~ ~s provide~ in series with output 78
to indicate when thiC output is energized. Vacu~urn
25 pLlot valve 106 is fed by high pressure air supply
linc 110 and when ac~uated, introduces air unde~
high pressure t} rough hose 28 to v~cuu~n valve 24.
- ~203~4
When high pressure air ~s introduced into valve 24,
the valve ope~s an~ applies the vacu~m produced by
venturi 132 ~v mat~r i~l p~ss~gc lS . In this manner,
any drib~lings which ~ave been suspende~ in the bag
valve by the low pressure pur~e are removed therefrom
by suction. Spout 10 is then withd~awn from the
~illed valve bag and a reset si~nal is applied to
programm~ble controller 60 throu~h reset line g~,
indicating that ~he b~g filling cycle has been completed.
The reset signal can, fo~ example, be generated by a
mic~oswitch arrangement loca~ed at the bag filli~g
station. Once programmable controller ~0 ha~ been
rese~, it is ready for the next bag ~illing cycle~
Programm~le controllers, such as programmable
controller 60 shown in Figure 6, are well known in
the art. One such unit is the Micromaster WP6000
prog~ammable controller. Those skilled i~ the art
wi~1 appreciate that other prog~ammable cont~ollers
can be readily ad~pted for use in the Cbntrol sys~em
of the present invention.
Ea~h of air pilot so~enoid valves 98, 100,
02, 104, and 106 ca~ be explo~ion proof valves~ or
alternatively can be regular valves moun~ed in an
explosion proof box. The use of an explosion p~oof
appara~us provides safety for the operat~rs of the
bag filling machiner~. Su~h solenoid vaives typically
include solenoids which, when açtuated ~y an electric
signal, cause a valve coupled thereto to open or
close. Thus, such air pilot solenoid valves are
easi~y controlled by the electricai outputs of a
programmable con~roller such as controller 60 depicted
in Figure 6.
