Note: Descriptions are shown in the official language in which they were submitted.
06 f~PR '92 15:37 MRRKS & CLERKS LONDON P.10 j 2067380 PC~/GB 9 0 1 0 11 5 1 4
~8 10 i~l
1 2~ OcSober 1
CAUSI NG LI QUI D ~ SOL~ D I N~ERACT~ ON
aak~round of the rn~entl~o-n
T~e invontlo~ relat~s generally to causing a liguid ~o
interact with a solld Nor~ally, mas~ t~anRfQr will
occur between the liquid and the ~olld, but thl4 i~ not
n-ce~sarily 80. The mas~ transfer can b~ to or
fro~ the liguia Th~ inventlon may be appliod for
instance to leachiAg, ion~exchsng~, cryst~llisatlon,
drylng, Qpecific solution, ~o~ption, ro~sting,
601id-partlcle-catalysed liqyid-phase reactlons, and
li~uld-solld reaetions, and the appllcatlon of th-s- ¦
proce~ses to che~lcal rcactions ln general Durlng
contac~, ion or othor xchan~e ~ay take pl4ce, or one or !
mo~e compouna~ ~ay be adsorbod, ~b~or~e~ or che~iisorbod,
or relea~6,d; th- co~pouAds will u~ually b- in the, form
of lon~ or ~olQcule~, but th~y could be colloid31 or
other agglome~at~ons, or mixtures or in ,~o~e oth~r
~or~ Any nu~b-r o~ c~o~ical speaies may b~ involved,
d-p-nd~ ng o~ th- r-qulro~Qnt$ of th- particular
proce~8 I~ tho ~nventioA i~ applled to ion exchang-,
lt can b~ u~-d ~or the contact ~tep and/or for the
r--g--DOr--tL OD 0~ ~1 utl o n C tUp.
' , " ' l
._. _~ .. _ _ I
~d 1~
. PCT ~ `dl ~;I,pilc~,t;on
06 RPR '92 15:38 MRRKS & CLERKS LONDON P.11
20B7380 P~i~ g O l ~ 1 '
2 ~ OCt~b~t 1091
Speclflcally, the lnvention ha~ b-en dev-loped ln the
course of ion exchange procedures for removlng nl~ra~e
~rom wat~r, but can ~e partlcularly useful in r-ducing
the hardness of water, selectively removing or rega~nlng !
materials such as pollutants or metals from waeer, a~d
ad~orbing colour
The nor~al procedure i3 to bring the liquid into contact i
with tho solid, separate the llquia from the solia,
regenerate the solid, and bring further li~uld in~o
contaet with the solid The solld, eg th-
so~bing/reloasing substrate, would usually be insolubl-, i
eg r~in, clay, mineral or ~las~
,' 1.
To date, tho standard procedure for operating a
801id~aqueous liquid system was to support the solid ~n i
a colu~n and to operate a batch procedure, pa~sing the
proce~- liguid, clo~ing off the process liguid, passing
r-g-n-rating olution, and then pa--ing the proc~s~
llquid Thl~ procedure wa~ relatively complicatod I -
Furth-r~or-, t~- soild particl- sizes could not be low-rl
th~n round 0 4 to 0 5 m~, otherwi~e ~he sur~ace tenslon¦
o~ water prevented sufficien~ly rapid draining undor
gravlty, and g~n~r~l pr~ctic~ was to use E~articlu 91Z~
of 0 ~ mm upward~ Th- ~olid wa~ usualiy ~ ~h- ~orm of¦
.
baad- (on~ tan~rd bead size was 1 1 mm), which may
" , ,, , . . . _
~1 SUBSTI~UT St~FE T
'136 flPR '92 15:56 MRRKS ~ CLERKS LONDON P. 1
~ "09"04~9~ ' 2n~738~ 1
PCT~GB90~0151
;~a~e had a coatln~ o~ tho reac~ ve mater~al, but
no~mally were completely made of che reaCtlve mAt~rlal.
~he na~ural swel:ing and contractLon of t~e sol~d causes
cracklng and spa.l~n~, and the small part:cles so formed
can c!og ~he bed of solid
, ' ,
As an ~lternatlve eO thls procedure, contlnuous grav:t~
~cttling ~rocedures have been propos~d. In th~s cas~e,
t~.e solid must be of such a slze that the rate of
~esce~t (or different~dl rate in :an up-flowin~ u~d)
Q reason~bly rap~d. The g~neral view is that the be~d
diamcter~ must be at leagt 0.5 mm, for sufficiently
rapld ~cttling. ~hesc procedures are eomplicated
b~c~use b~ads may ~tlck in valv-s or the valving us~d
may crush the ~ds, leading to unwanted clogg~ng and
in uffici~ntly rapid sedimentation. A spoci'lc proposal
has ~-~n made in GB-A-I 070 Z51, provlding a co~nter
current proce~ where the ~olid~ are ln effect in
J ~ o ~ r- is no discussion of tbe ~iz-- of e~
8 ~ ~-ttcles but, ln prietice, it is found that a
~5~ r o ~e l-ast O.S mm is rcguired for successul
oper~tion. As another instance, in EP-A-0 010 969
~ouling and xc~s~iv~ b~ck pz-ssure c~n occur.
~hc ~ep~rat~on o' ~in- solid par~icles can be dificult,
i~ bcing ~mpr~ct~cal to u~e f~lter columns. Thus it ha~
:.
.
06 ~PR '92 15: 38 M~RKS & CLERKS LONDON P lZ
206738~ PC~/G~ 9 ~ / ~1 51 4
2 ~ 10 ~1
~P, ~ctober'!10~l'
beon ~uggested that the part~cle~ can be coagul~t~d or'
aggiomerated~ for instance when u~ing magnetlc par,~cl-
~
It is de~irable to provide a contlnuousl,y operatlng~yste~n ~,rhere tlle concentr~tiorls re~ain fai~ly constant
aAd where the a~ount of solid required is k-pt a~ low as
poss$ble.
The I nvention
. '
The in~ntion provides a method of cau~ing a llqu~d ~0
interact with a ~olid, comprlslng forming a suspen~ion
of p~rticle~ of the solid in the liquid and ~oving the'
olid pa~ticl-J and th- liquld ln tho sam~ direction
whilo th- liquld lnteracts wi~h ~he solid p~rtlcl~s,
romoving liquid fro~ ~he suspensiion, recycling solid
partlcles f,~o~ the suspen3ion aftcr liquid has been
re~oved, a~d regenerating solid particles, some of ehe
~oiid particles being recycled without regeneration
.
Tho $~-ntlon, p~rticularly ~h-n u~lng a combi~atlon o
~ho aoCu~rent ~o~-~ont of the li~uid and dlscrete
p~rtlcl~s o~ tho solld and crosg~low 11~ra~10n (or a .
rolatod barr$er f~ltration method~, can take advaneage
of th- nhano-d k$n-tics of g microre8ins without
drawbaoXs of ~xcessLve pre~sure drop a~d dang-r of
_ . ....... . . I
~Uni: d '~in~.~!,.n P~ n~ Off'ca
I PCT in!e-n~lorlal A~ ication _ SUBSTITUTE SHEET
~;V~. & CLERKS LONDON 2 0 6 7 3 8 ~
V~0 91~1W791 PC'r~G890/~
'oullnc or elogg:n~ '~hlC~. LS Q~per:enced ~ coi~n
arrange~e~es, or ;ne at:r t' on ard _elated ~echan:ca
bloc~sng and losses commoniy assoc~a~ed w~ cont;nuo~s
Sy~ltem5.
The ~ethod of th~ ~nv-ntson is s~mple and e~ic~en~
Plant s~zes can be reduc~d and qu~pment costs lowered
~he ~thod can be conCin~oUs or nearLy continuous I
Sbe inven~1co c~n b- v--o tor con~ac:~n} se-}~ nd ~o: I
~ reg~neration st~ge, or used only ~n a r-generat~on
s~age or only ;n a con~actsng s~age
Normal val~in~ can be incorporatod if de~ir~d becau--
spl~tt:~g or COmmLnut~On of tho part~cles is no Longer
o~ grea~ ~ign~f~cance a~ th- op~ratsng particle Si2~ can ,
~e very s~ll Thus t~e snvention l;ows u-~ of 'in~
m~t-rial, wh~ther it ss origi~ally ~l~e or, bre~ks down
t ~ ~t s~a~ a~ a r-~ult o~ att,ri~ion ~n ~he prqc~ss ¦
~, . , I .
.~'' ' , . ' i .
~' ~h~ particl~s can hav~ ~ny form whlch :s su_tablo, g
'l~ros or platel~ts or the more cra~eson-l ~ph-r~s an~
sph-roids For sphorscal or ~pherosdal particls~ sh- !
s1ze~ can be conssdered as sLeve pass sszeS (g~e~ng :he '
.
06 fPR '9Z 15:39 M~RKS & CLERKS LONDON ~ 2~6738~ P.13 1
PCT/GB 9 0 / a 1 5 1 4
28 lQI 91
6 ~ 8 O¢to~)el 1901
s~o~inal diamete~), and in ge~-ral the siz~ h-rein ar- ¦
si-ve or ~e~h pass siz-s
.'.,. I
Constraints on the maximum size of the pa~ticle- aro
related to the economic and operatlng condltlonJ o f
lndl~dual proce~es by a number of alfferent
paramete~s, such as ~olume, surface aro~, mlni~u~ or
maximu~ presented a~ea, ~axi~um ~re en~ed ar~ ni~u~
dim-n~ion and maximum dlmen~lon Though a st~ndard slze
of about 1 m~ ~or peoiflcally 1 1 mm) can b- u~ed,
partlcularly in larg- plants, the partlcl-s ~r- i
p~ef-rably sm~ll compared to those used in standard
procedures, 80 that the effectlve specific surfac~
14rge~ and the exchange/sorption/solution/reactlon
klnetics ~re more rapid R latlve reduction ln sizc can
lncrea~e th- app~r-nt nu~ber of sites available ~or
~ction but, mor import~ntly, can enhanc~ the react~on
klnQtics ~here is better r~ndom con~act, partlcularly
~t low ¢onc-ntr~t~on~ The partlcle size can b-
o~tial~ed to ~uit th- p~rtlcular proc-Js requ~r-m-ntJ,
but ~olids ¢an b- w ed a~ ~upplied, e ~ with no
preliminary slevlng ~o re~ove fines In g-n-ral, ehe
partlcle slze ls pr-ferably ~aller than that selected
for u--, for ~n~t~nce, in packe~ col~mns or fl~t-r
b-d~ The p~rtlcl- ~iz- ~s preferably le~8 than a~out
0 5, 0 4 or 0 3 am, or le~s than 0 25 or 0 2 mm.
~ ol~l P~o~ Oiflce SU~STITUTE S~EET l
l ?cr~ u~ofial Appli~a~ion
06 PPR ~15:58 ~I~RKS & CLERKS LONDON
.- 206738~
~91J1~791 PCTrGB90/OlSI~ I ¦
Generall~, althouqr. ~e par:;c:es n~ed mot be ~o-med ~y
a Comm~nut~on rechr.~cue, the part;c' e slze can be ~..at
a powdered sollc. Qulte o~een, ~he upper . limlt on
par.,:cle 5~ ze lS that ~mpo~ed :~y seac~ on kinet:~s and
aiso pumpsnc and the energy needed ~o mainta~n 1 ~rg~ ¦
par~zcle ~n suspens~o~. ~here ls not usuaily.a~y
advan~age :~ us:r.g larqe par~:cles, out there is no
reason why they should not be used. ~onethele~s, an
ad~sntage of thc lnv-ntion is that one can u~e p~r:iclo~ ¦
o~ a slze sm~ han nor~al.
There is no theoretlcal low-r limit to ehe p~rt cl~ 51Z-
t~at can be u~-d, though in prict~c~l terms particles o~
;ess ~an about 0. ~ or O. ~ microns ~111 not ~e us-d. .
Th- ~ze of 0.1 m~crons s de~crm~ned ~y ~h~ cut off
5~ze O~ a microfilter, b~t thss size could ~e r-duced
fus'th~r ~ n ul~rafilter were used. A m~.nimum
~rac~ c~l s~Z- of 0.~ or 0.~ mlcrons ~s mor- rc~l~se:c.
H~ ~araclc~ of le~s th~n 50 mscro~ t~nd to torm a
~n~vaeer ~nd be difficult to dew~t~r.
~ ' . ' . I
~o g~ve a Sp-c f:c example, for the ion-exch~ngQ r~sln
used in th~ Exam~le~ below there is no real ~dv~n~ag-
e~n ln haa~ng part~cle sizes le~s ~h~n lOO micron.
Par~cl~ s~i- range~ m~y ~e 50 ~o 120 microns or 100 to '
200 ~lc~on~, or ~or acr~vated carbon lO0 to 600 ~icrons.~
- 06 PPR'9Z 15:58 M~RKS & CLERKS LONDON 2 o 6 7 3 8 ~ P.6
PCT/G890to~ r
Rat~o of Solid to L;~ULd
.he concentratlon or w/w rat:o o solid to l;qu d can ~e ¦
chose~ as approprlate ~or :nstance, some adsor~en~
solids have rela~eiy low capacl;; and nee~ to be us~
in high co~centratlon Some suspensLons ox slu-r~es can
remain fluid at up to 60~ soli~s whilst othors are sol~d
at 2~; the concentratson must be such as to perms~
suspension and pump~n~ Within the need for the
susp-ns~on to re~ain pumpable, the propertles, and
act~al sol,ids conten~, of the ~uspens~on will vary
deoending on the application For instance, the
proport~on of solids may be as low as 0 2% or even
lower, or the propor~lon may be over 20% or ovor 30%.
~n a plant, there can bn different concentrat~ons ;n
different parts, fo: instance in the treatmen~ s;age and!
in the regene~ation stage ~n gener~l, the
concentr~tion of the solid ~n the liquid can b~
relatively low dur~ng the cocurrent movem-nt and
ceton, e g ~elow about 10~ ~/w, preferably fro~ !
S~ down to about 1~ ¦
;~ ~' , i
Contact 5t~e
Any form of turbule~t or other suspension can b- us-d
wh~ ch ehe solid par~ cles and the lLquid are m~xed
06 PPR '92 15:59 MRRKS & CLERKS LONDOI`I ~06738~ P 7 ,,
~'OY1/~79t PCT~GB9~/0151~ ¦
!
:nt~matel~ ~nd randoml~J - ~or Lns~ance, ~ho ~nt~a~
.~lX` n~ ,an be ach~eved eg by ~avlng a tanX ~zh a
', y opeLler ~n it or provldlng a 'l~ldlsed bed Th- ¦
suspens~on n~ed not ~'e a sta~le suspension, le the
solid particles may slnk or rlse ~ there is no flow or
no a~tation, 'he tec~niqu~ ~e~ng ~ type of flu~dzsa~Lon'¦
tech m gue In general terms, :he partlcl-s will be
d~screte; ie not aggr~gated
~he sol~d and `~qu~,d'~ay be put zo~ether prLor co
int-oduction to a chamber where the ~ntim-te and rando~ '
mix:ng occurs However, ln one procedure, after for~na ¦
ehc ~uspenslon, th~ suspension lS p~ssed along a long
supply lin~ with subseantial re~idence ti~e to the
'llt~r in wh~ch the ~ep~rati,on LS effected; the sup~y
line can bo 3~y 1 to 2 5 m lonq In qoner-l, contact
_lm-s ar~ prcfcra~ly gr~ater,than aoout l or 2 mlnuee~
~n~ l-ra than bout 20 m~nuees, say ~bout 4 or 5
~nut~! Tho tim is chos-~ ~s approp~at- to th~
aiz-~, th- d-gre- of agitation, ~nd the
o~ kin-ti cs. . . I .
~
Seoara~ion Sta~c
. . . ! .
ThQ ~cpar~t~on or llquz~ r~oval se~ge can ~ car-led
ou~ ~n any s~:abl- ~ay I: lS not necesSary t~a~ eh~ '
s-para~:on stag- should occu: ~n' a cAamb~r diff-rcn_ I
''' .. . I
92 15 59 MRRK5 8~ CLERKS LONDON PCr~G89~/o~ r
- 0
from that ~n which the conea~ se~ge s carrled ou;
However, ~he m~xture lS pre'erably passed to a filte ,
wh~cl- can be anv suleabie fi!ter ~u. ~s preferably a
crossfLow filter, whlch may be usèd ln a dead-end ~ode
The advantage of using a dead-end mode is that a ~uch -
h~g~er flux can sometlmes ~e'obtaine~,' possibly twen~y
~imes as ~rea~ ' Th~ filter can for instance be as
descri~ed in 5B-A-2'185 906 or US 4 765 906 ~he
sepa~ation s~age can lnvolve thQ s~ep~ of buiid~ ng up a
membrane,'bullding up a cake of .~e contac~ n~ ~a~erLal,
possib1y -egenerat~ng the contactlng m~ter~al and
washing ~t while on the filter, breaking up the cake, e~
with rollers as describe~ ~ GB-A-2 i85 906 or ~5-A-4
765 906, opening up the closed end if Lt is a de~d--nd ',
fil;er and flushinq out; alternatlvely, if ehere lS a
~ag fil~e~, turn~ng the ilter ~nsid~ out wlth an
i~erted me~4e~ such ag a p~ston A flexible filter :s
pre~err-d, neve~thele~s, the f~lter n~ed noe b~ xsbLe
ch-ot filter could be used, and the cake
nely scraped off the filter In some cases, :he
atag~ can occur on or in t~e filter itself, ~'
a~prop~iate to the par~cylar p~ocess; ;n suc~ a case,
the filter c~n be pre-coated, and then coated with thc
solld whiCh is th-n l~mobilised on the filtcr in so~-
way; req n-rat~on can t~en take place on the fileer
'I .
.
.
06 ~R '9Z 15:44 ll~RKS ~ CLERKS LONDON 2 ~ 6 7 3 8 ~ PC~ g ~ 1 4
1 9 1~ 91
11 19 Dec~- 1991
~he u8e of a fllter reduces attr$tlon of ths contact
m~terial, and al~o reduces th- ~f-ct of such attr~ t~ on
ln that llquld cAn be s-moved even with sub micron
p~rtlcles pr-sent The uee of a crossflow filte~ ¦
~nable~ a constant conce~tratlon o th- solid in the
liquid to be m~intained, at least for long p-r~od~ ¦
b-tween ~iltor cleaning o~ratlon-
Yreferably, ~uf~lclent llqu$~ ls lQ~t after the
~eparation for the olid partlcl~- to remain in the for~
of a su-p-n~ion, ~-y a~ a slurry, whloh ~a~ tat-
~recycl$ng
'''' .
At the end of the ~eparation phase, the liquid may pASS
'nto a furth-r cont~ct stAge with the same batch of
ia (but regenerat-d) or a diferent batch o~ solid
R~en-~atLon st~e
.
,ho olid ~ay b- regen rAsed b-for~ r-cyoling, and t~'s
~ay bo ~on at th- s-paratton slte, o~ elsewhQr-
Typic~l reg-n ration will be done by im~er~ion in a
sultabl- fluid, g i~ rsion of ion oxehing- r-sin in
br~n-, but any suieabl- proce-s can bo us-d, ~uch as
caustic or acld washing, leaching, ~a~ elution, he-t~ng,¦
xposur- to light or ot~er electromagnottc r~dla~on,
pA~ge of
06 ~PR '92 16: 00 ~I~RKS & CLERKS LONDON 2 O 6 7 3 8 ~ P. 10
~0 91/04791
PC r/GB90JO 15 .1
.
el~ct~ic current or physLcal shock Further ~a~hlrg o~
f'ushing ~ay be requlred after regeneratlon, to returr
the solid to a su~table ~onditio~ for re-use or d~sposa
For rege~e~ation, a procedure can be used whlc~ ls
~nvent;ve per se The procedure ~5 a ~e~hod of
concacti~g a li~u~d ~ith a solid, co~prising formlng a ¦
suspen ion of tho solid ln a liquid, passing tbe
suspension to a filte~ so that the 11ter holds the
sol~d back, and ~hen passing a liquid through th- f leo~
~n the opposiée dlreccion to remove the solld rom the ¦
filter and for~ a suspensioA ~he filter is preferably¦
_n th- for~ of a bag filtor so that it has a large
retention capacity The method o operation keeps the
filter clean, without requiring any special clean~nq
step as such For regeneration, the solid can ~e
suspended in a ~eak regeneratLng aqent, and then removed¦
fro~ the f$1te~ wlth a StrOAg regenerating ~-nt; for
th~ Jolid can be suspended in ~ f$rst washlng
~n~tAen r-~oved ~ro~ the filter with a socond
~ ~iquia Normally, both procedure~ will be
adopt-d consecutively, in different fi7ters
Reg-n-~ation is p~eferably carried out ~y feed~ng the
solid particl-s ~ro~ the mean~ for remo~ng liquid from
the suspenslon back to a cha~ber ~n which said
06 ~qPR '92 15:~9 M~RKS & CLERKS LONDON 28 1~ s ~,
13 .
suspe w lon ~s m~intaine~, and drawlng su~pen~lon ~so~
saia cha~b~r for ~egeneration; ln otho~ words, t~- ~oll~'¦
par~icles ar- r~cycled withou~ regenerat~on, a s~par~t-
regeneration loop ~eing maintained An alternatlve is
to provide a bleed-off for removing a proportlon of the ¦
so}id p~ticl~ ~s they ar~ recycled to the ~u8p-n-10~ ,
c~amber ¦ '
!
eturn Sta~e
~he last stage 1~ the r-tur~ stago, when the regenerat-d¦
or unregenerated solid may be returned to the ~tart ~ !
the proc-du~o o~ reintroduction at a controlle~ or
measu~e~ r to, if the solid doe~ not remain ln ~$tu
throughout
rn a continuo~s proc~dure, there may be a slo~ bl--d-off !
of the ~olid partlcles for dischargs or regeneration, 1,
which $s replac-d by a slow feed o~ solid parelcle~
wSllst the ~a~or portion of the solid particle~
r--clrculate~ The Jolid particl-~ ca~ be r~cycl-d on
avor~g- at l-a~t about twice before r~generatiOn or
disch~rge, g a~out three or ~our times La~ge
recirculatlon ~mp~ove~ the ut~l~sation of th- so~id by
u~lng lts full capacity, enabl~s hlgher'conc-nt~ations
of ~olid to b~ u~ed, ~nd makes the quality of th-
p~oduct more conslstent
I
ad ~ oJ,~m Pete:~t Offlce SUBStlT~JtE SHEE~ I
~J~ ~
06 PPR ~9Z 1~:01 MRRKS & CLERKS LONDON 21D67380P-lZ ¦
wO 91/0.~191 PCT/GB90/0151~ ~
.
:; ' ' .
SD C fic Uses oS the ~ r.ven~Lon
~he liquid is not necessarily water, but Lt Wlll be SO
:- many cases ~he ~nven~lon can be parti~ularly usefu~ ¦
wnen remov~g unwante~ materlals Crom water whsch are ~n i
low concentration, for in~tance reducing concentra~ons
of nitrate, ~oron, strontiu~ or caesiu~ An advaneage
of the invention is that low prescur- diff-rentials can ¦
~e use~ for the ~ilter ng, say less than about 350, 2S0
or 200 kPa and down to abou~ 150, 100 or 50 kPa,
allowln~ large volumes to be ereated; say more than
a4Ou~ 10 or 20 m3/hour; ;h~s can be par:scularly
useful in the water industry
Oth-r uses envisaged include ¦
using or rogenerating powdered activated ca~bon
employed for purifying liqusds, e g eo remove
pesticides or other trace or~anic poll~tants such as
tsihalomethanes,
n
u~ing powdered activat-d carbon to re~ove e~u~s~ons
such a- paint from WatQr, or to removo organics suc~
as oil and butan- gas from a water/oLl/g~s e~uls~on
- nor~ally the car~on would noe be regen-r~ted
!
06 ~PR '9Z 16:02 M~RKS 8~ CLERKS LONDOI~ ~0673~ P.13
~1) 91/lW791 PCT/GB9h/nl!~
. . , ' 'I
. ~5. I .
us~n~ or regenerat~a ~agne;~e or oeher
-eaenerable, c_ :lon-rege~erable, coagu' a~ der.:s;
~, . ' i
using ~iolog~cally and o~her na~urally derlved
abQosbents in treat:ng process flui~s suc~ as
ra~ioacti~e wastes (here speclal f~lters such 8s
woven carbon or qlass fi~re, or sta~nless steel or
phosphor bronze, may De used);
con~rnuous lon e~change, :~ general - nor~ai:y ~he
~on exchPnged uould be r-generated
.' ' ~ ' ' '~
Tbc ~nvention w~ll be further de~cribed, by way of
~xample, with r~ferenc~ eo the acco~p~ny nq drau~nqs, ;~ ¦
~h~ch - i
I t~ ~ re schematic diagrams oS thr-~ di~f-r-ne¦
r c~r~ying out the meehod of th- ~nvent~on;
Figures 5a and 5b is a diagram of a pilo~ plant; and
Figure 6 i5 a vlew, par~ly n vert~cal sec~:on, of a
sock 'i~t~r ~n the ~lan~ Oc Fiqures 5a and Sb.
~'~
0~i92 16:02 M~RKS & CLERKS LONDON ~ P. l4 ;
. W0 91/0~791 2 0 6 7 3 8 PC~ `.BW)tl~ r
.
~hroughoue~ the ~ame refo -nce~ are us~d ~or compon-n~s ¦
c~rrying out s1mllar funceions
.. .. , . l
Fi~ure ;
.,,, ''', ,' ,,' .
~he contactin~ solid and the process 1:quld are ~xed :
~ tank ' ~nd ~re o~mpe~ out throu~h a ;arge d~meeer,
long fLexible hose 2 wound around a dr~m, g~ving
sub~t~ntial cont~ct time, the hose 2 acting a~ a contac~
.. cha~ber. The length of the hose ~ may be 1. 7S ~, g~v~n~
an ~pproxi~ee re~idence time of one m-nute at a flow
rate of ~O l/m Adequate ~ixinq ~s requ~ed so th~t
sufficient ~ontact occurs, and if desired, a stirr-r cao
be included in the mix~ng tank l, though the pu~p~ng
ac- ion will norm~lly giv~ good contact ~n the hose 2;
~oth i~ th- stirred mlxing eank I and in th~ hose 2 -h~
solid and the liqu~d are mo~ng ~n cocurrene The
subst~ntiaL residence t~me ~n the hose 2 ena~les the
t~nk 1 tO bo smaller and/or tho ~esidenc- e~o ~n :hc
r~l eo bo horter. Th- ~ixture then pas~-- to a
~ro~flow f~ltrat~on un~t 3 fro~ which the cle~n procel~ !
flu~a i~ uieh~rawn ae ~ I
At l--st two m thods of r-gener~eion ~re po-s~ bl~. :ni a
first method, th- reg-neran~ (regenerating agent~ ~ f~d
fro~ a fito~ago eank (no~ shown) onto the sol~d on ~h- l
.
06 f~PR '92 15: 44 MFIRKS ~ CLERKS LONDON 2 0 ~ 7 3 8 U PC~/~B 9 ~ I d 1 ~ 1
1 9 li I 9
17 19 Deco~u ~ 1991
filter ~o that the ~olid is regeneratea on th- filter
Ater regenoration, the ~olid i~ re~ov-d fro~ th-
filter, to pas6 along a recycle line S back to th-
mixing tank 1 In a second method, the solid is re~ov-d
fro~ th- filter and pa~ed to a conta¢t t8n~, the olid
then being regenerated, filtered, washea and rot~rned to
the mixlng tank 1 Th- ~ethod used dop-nds upon the
a-- of regeneration, though ~asically the ~lr~t method ¦
i8 faster ana easier than the ~econd
.' .
An ~lternativ~ proce~ure can b- used, particularly ~h-n
it i~ eh-aper to discharg~ the 60lid for lat-r
regenera~ion (wblch may be the cas- with e g powdor-d
activa~ed carbon) Wlthout rog-neration on the fllt-r
j, the solia i~ recircula~e~ along the lin~ S a- a
concentrat-d slurry or suspen~lon In this way, the
solid ¢an ~e re-clrculated for in6tance a m an 20 t~ m-J
~efo~e ~elng r-g-n-rat-d or discharged Th~
rec~rcu~atlon can occur during the normal c~os~flow
~lltratlon, or a cycl- of re~o~ing th- solid Pro~ th-
filt-r can b- incorporated so that the ~olia so removod
is l~m-diately r-clrculated
Standard componants ar- shown in a conventlon~l ~anner,
~ncluding lev-l gaug-s, one-way valve~, stop valv-~ an~
proc~ur- gaugo~ ~h~re i~ a flow ~eter 6 and an
._ . ~
01i P~PR '92 15:45 M~:lRKS ~ CLERKS LONDON 2 0 6 7 3 8 O P.25,
PCT/G~ 9 0 1 O 11 5 1 4
! 9 ~2 ¦ ~1
19 ~ ~ ;~z 1
18
elsctronic oon~rol 7 for a main ~ump 8 The filt-r 3
can be a~ di~olosed in US 4 765 gO6
Fiqure 2
A dead-ended crossflow filtration ~nit ~1 i9 u~ed, 1-. a .,
cro~flow filt~ation unit w~th a closed out~et valve A
contact cha~ber 18 not shown, but may be included if
aeqired Howovor, sufffcien~ contact ~ay occur in t~e
tank l and ln the plpework A recycle line 12 18 shown,
up~tream of the filter 6 The regeneration can be a~ !
above
,
The plant of ~igure 3 i5 simllar to that of ~i~ure 1 ~ ¦
ve~sQl 13 ls shown for the collect~on of treated water
withdrawn at 4, and a resin feed tank 14 ~ shown for
Qedin~ the ~ixing tank 1 There i5 a line lS for
r--d~ng unt~eatQd water However, a further c~o~Jflow
f~ter 16 i~ ~hown in a second recycle line 17 which
al~o includ-- eguip~ent 18 for regene~atlng the resin
and wa~hlng lt The filter 16, which aan be used ln tho ¦
croi-flow or d-ad-end ~ode, removes urther f~ult from
tho ~e~in be~ore Lt is passed to the e~u~p~-nt 18 ThQ
bul~c of the rcst n can ~e recyolea th2~ough the lin- S,
1 .
06 ~PR '92 15:40 M~RKS & CLERKS LONDON i P. 15
2067380 PC~/GB 9 0 l ~ li 5 1 4
28 lq 91
2 a Octo~er~
~u~ficlent being recycled through the line 17 to koep a
suita~le ~gencratlon level
Fiaure 4
~he con~acting ~tage of the plant of Figure 4 is ~ lar
~o that de-crib~d in relation to the alter~ativ-
proc-dure of F~gur~ 1 A prooe~s liquid i8 fed at 21
and a re~in suspenslon or slurry is fed ~t 22 into A
~eed tank 1 ~he su~penQiOn iA the feed tan~ 1 18 drawn
of~ at 2~ by ~ans of a fee~ ~ump 8 and pas-e~ through a~
cro~sflow filt-r 3 In the filter 3, the liquid i~
removed and a suspension or slurry of the solid with
reduced liquid content i~ returned at 5 to the feed tank !
1 whilst thc re~ove~ liquid exits ~t 4
.. . !
Tho r gen-ration procedure is count-rcurren~ I
re~ener~tion in a number o~ cocurrent steps Th-r- is a~
bl--d 24 whlch i~ pump-d by a variable-~trokc
di~placem-nt pump 25 into a thickening dovico 26 of any
~uitabl- type, illustrated a~ a ro~ary vacuum filt!r
~h- pu~p 2~ controls the ~olid concentration ana hence
the solid d-teAtLon ti~e in ths ~ystem The filtr~t~ i9 1
withdrawn at 27 and i~ returned to ~he feed tan~ 1 ~he
thickenod solid p~sses into a t~nk 28 cont~inin~ w-ak
-og-n-rant, wh-r- i~ form~ a quspens~on in the
. . . ~ SIJBSTITU~E SHE~T
i ~ al APS~i~cat~on , I
-- .--06 f~PR '9Z 16:04 ~1~RKS ~ CLERKS LONDON 206738~ P.18
~'o 91~n.1191 p~/~ tl~l~ r
' ' I 1
regenerant. The suspeAslor. ~s pump~ b~; a 2u~p -5
through a reverslble 50C~ f:~ ter '0 and the f~ a~e :3
returned to the t~nk 28 the solld be1ng held ~ac:~ :n
the fi~ter '0. After a suf~icient number of cy~l~s, ¦
valves 31 32 are closed and val~es 33 ~4 are opened.
There s a fu~ther tank 35 contAlnlng strong regenerant
which is then pumped by a pump 36 ln the reverse !
direction ~hrough the filter 30 backwashing the fllter
30 and picking up ~h~ solid reta~ned ~n he filee~ '
and formlng it lnto a ~uspenslon whLch 1S carr~ed .o d
he~d tank 37 (if requl-ed). The su~pension of sol~d ln ¦
srrong regene~ane is drawn off the head tank 37 at 38
~nd passed to a ~econd thickening device 39 o~ any
~ui~able ~ype ill~st~ated as a rotary vacuum filter.
T~e filtrate fro~ the device 39 ~s drawn off ~y a pump
40 ar.d is returned to the strong regenerant tank 'S.
optionally by way o' the head tank ~1. j
For rtnsin~ the thickened res~n from ehe ~h~cken~nq ¦ j
dov~co 39 is passed to a rinse tank ~2 to wh~c~ rln~n
l~qu~.is a~d-d; here it is mi~ed w~th a rlnsing 1~quld
to for~ a Suspens~on ~nd t~e su~pen~ion is pumped by al
pump 43 t~rough a sacond sock filter 44 and r~turned to¦
the rin~ t~nk 42. Aft~ a su~ta~le nu~ber of cyc`es. j
~alves 45 46 are closed and valves 4~ 48 are opened.
~here Ls a res~n so~ul~on ~ank 49 to which mak--up
- 0Ei I~IPR '9Z 1~:05 M~IRKS & CLERKS LONDON 2 o 6 7 3 8 ~ P. 19 I
~ ~ ,~0 ~I/n~ PC~r/~
: ~
Lqu~d ;s a~lded, and :~ILS ;_qu~.d :s pumoed by ~ pus~;: c,~,
~ e reverse d:--c' ~ on rhroug~ ;he sock ~'l.er ~
c~r-. a~a~ the sol:d heid back ln ;he sock ~ er ~ ' and
~orm a suspenslon ~n the ~ank 49 Fro~ the tank ~, a
~OSltlve d~splacemen~ pump Sl pumps the regenerae~d
i 30i~d :n suspenslon ~ack ;o the ~eed tank : Surplus
¦ -:nse llqu~d lS _e~oved '-om the eank 42 and spen;
¦ regenerant ~s removed f:om the tank 28.
~;.e S~er.~ soiu:~ o . :s ru~ o'~ cont:n~ousl{ and :n a
s~al' stream, and _oncentratlons around ehe system ~re
~u~scant ally constant. Thus ehere lS no re~ulrement
~or large ~alanclng tanks and blending.
Piaures Sa and 9~ ¦
~:,u~es ~a and -b shou'd be ,o_ned alon~ ~:nes:
-espect:vo r:sht and le~t marglns.
T~ ~ilo~ plan~ of r:gu~e- 5a and 5b L5 based _n ~he
plant of Figure ~.
~n e~e cont~ct stage ~FLgure Sa), a numbor of 'il:ers ' ¦
ar~ ~ed, divided ~n~o ;~re- banks sach se~Lced bv -s
owr. ~ump 3 - ~ho banks of f~leers 7 can be operaeed
~. 06 ~PR '9~16:05 MQRKS ~ CLERKS LONDON 2067380 P.Z0 1
'0 91/U.~791 " 1'C'I /(~B9/~ r
1 . 1
lndependently or ~o~e~he~ to ach eve the deslr~d
capac ty. The ~ er ~ are eursaLn ~od~ as ~ sc os~
~ gares '; 2 ~ aa and `8b o' us ~ 65 9G~ 5~c- ¦
w ~h a bacK-pressure 4aii valve 60 ~he f~ltes~ c-a: i
into a ~ray 61 whlc~ ln turn hos flap v~lved ou~7e~s so
.hat t can dra1n a; ~ ;nto a treated ~a~er tank 52 o-
.. ' ! .
can dr~r at 63 :nto ;he feed tank 1 ~ F the qual~ s
unacceptable These ls a cleanlng devlce for cleam ng
the filters 3 generally as described in US 4 ~65 906;
there is an arrangement for drawlng treae-d waeer from
the treated water tank 62 and pu~pinq it with a pu~p 64
through a hose r--l 65 to mov-able spray nozzles 66 ~or
cleaning the fi~ters 3 ehe spray nozzles 66 belng
car-~ed by ~ e-ansportin~ dev~ce 67 The fe-d ~nX ~5
equ ~ped wlth a ~et mlx pump 68 to ensure that ehe so ;~ i
and liquld form a good suspension There ~s a helicai
~-ter 69 n ~he .eed l:ne il ~ho treated wate~ ra~k 62
co~ains a V-notch ~e~r 70 form~ng a sep~rit- ¦
co~jart~ent 71 from wh~ch treate~ water LS pumped ~y a
puq~ 72 (contsolled by a level swltch 73) eo a serv~c- ¦
u~t-~ t~nk 74 of s~y 2 m3 capac~ty
In th- regenera~on stage (Figure 5b) each thickener
26 39 is assoc~ated ~lth a _~p-ceive suc~ion au~ ary
un~t 7S 76 T~e f 'trae- Crom the ~hickener 26 can ~e
pass~d alorg a l~ne '1a and pumped ~y a pump 77 :o ~~e
,
PR '9Z 16. 06 ~1~RKS & CLERKS LONDON 2 0 6 7 3 8 ~ P. 21 .l
I/(~79! P(~/~;B9~
. . . a~ I
~eed ~arX !, ~ ?~ss ~ o~g a ; ne '~ and ~- ?'~P~ !
bv a pum~ 78 tO the _e~ed ~-a~er tan~ 62, accord~ng :-
~uall~y The fi`~-~ee ~:om ~he th~ckener 39 c~n ~-
passed a_onc a l:ne 40a and retu-ned ;o the s~rong
-e~enera-~ cark '~ ~y a pu~p ~9, or ~an be passe~ alona
a l:ne 40b and pumped by a pump 80 to the feed ~ank 1 o-
vla a l;ae 81 to àny of the ~anks 2a, 35, 42 or 49 A
regenerant ~aturator 82 ~5 shown for feeding regeneran~
to :he strong re~enerant tank 3S There ~5 ~n o~erflow
feed 83 ~ro~ the stronq r~generane tank '5 to t~e ue~k
:eaenerars ~ank 28 ~he weak ~eaenerant ~ank 28 ~s
pro~ ed Ul_~ a s~ e_ 84 ~~e:e ~s an o~er~`ow i:ne
85 f so~ the weak regene:ant ~ank 28 to a wasee tank 86
wh~c~ overflows ln~o a bas~n ~7 pu~ped to w~ste by a
pu~p ~8
In th~ r~nsing stage, the rlnse tank 42 has a~ overflow
!:ne a9 ~e-ding to ehe uaste eank 86, and the eank 49
~as a safety overflow 90 leadinq ~o ehe wast- ~ank a6.
} Th~ t~nk 49 h~s ~ st~~rer I for form~ng ~ suspens~on o~
; th~ solid
1.
~ervlce uater l:n- 92 as prov~ded for stars up
- !
~n any o~ ~he Fiqures, tuO or more ~xing t~nks 1 c-n ~-
used :- parallel rn F:g~res ' to 4, two or more
~ srs or 'i or j -~n ~- used ~n parailel :~
, ' '' ' I .
06 ~PR '9Z 15: 41~ M~i~KS ~ CLERKS LOI`IDON 2 0 6 7 3 g J P. 16
P~16B ~ ~ / 01 $14
28 1~ 19~
2 4 2 8 ctobe4 1
~ead-end mode 1~ employed for the flltratlo~ unlts, thl~
enable~ A sem~-continuous proceduro to be oy-rat-d ~Y
sw~tchlng from flltsr 3, 11 or 16 to ~he other
F~aur- 6
F~gure 6 lllu~trates the sock filter 30 or 44 ~e
filter 30, 44 compsis-Y two cylindrlcal casing~ 101
bolted together at flange~ 102 The flanges 102
sandwieh between them suitab,le gaskets, flang-J 103 on
two stainles8 4teel conical cages 104 whlc~ are wlthin
the ca~ings, and the flange of a fllter cloth 10~ ~he
filter cloth 105 iS stltched to for~ a cone of the samo
slze aS the conical cages 104 wlth a flang~ on the open ¦
Qnd of the con- Tho çag~s 104 prevent the fllt-r cloth¦
lOS o~er-extending and bursting, ie 'they su~end and
re-train th- ~ilter cloth 105 ~he f~ltor cloth lOS can¦
be for~sd of poIyester and can ~e of a s~ngl- ply of t~-
~ame s~e¢i~cation as de~cribsd with reference to
F~gure~ 17 to 18a of US 4 765 906.
~ .
On a laboratory ~cale, the plant o Figu~o 1 was u~-d to
r-duce nit~to concentsatlon in wa~or from 93 to 1QSJ
than 13 mg-N0
.
U"~ ~.;o^.: O~f~ce c~ l ~ e TITI ITC C LI C C
P~ r~ A~ tion ~~ ccT
06 RPR '92 15: 45 Mf~RKS & CLERKS LONDON 2 0 ~ 7 3 8 ~) P. 26
PC~/G~ 9 0 /1 1151
1 9 12 9
. 25 1 ~ Dec~r: 0~3r 1091
U~ing "Duolite M~croi.onex AOH" lon-exchange re81n (a8
upplled by Roh~ & ~aa~) a~ a powde~ havlng partlcl-s 1~ ¦
th- range of 5 to 90 ~m, the contact tl~o was one
minute. Although a specific ion-exchange re~in ls
mentloned, a~y suitable powdered anionlc re-ln may be
used. Th~ concontration was.prererably gr~ter than
0.05%, 0.1% being effectlve and about 0.2% bo~ng
proferred - the~e seems to be no great advantage in
haYi~g concentratlons greater than 0.2~ at thls
~asticular i~it$al nitrate concentrat~on.
The ~llter 3 waQ a~ de~cribed with re~erence to Plgures
5 to 10 and 17 to 18b o~ US ~ 765 906. US 4 165 906
explains how the held-bacX solid can be r-moved fro~ the I
fllter 3. The ~ressure differential was lS0 kPa acros- i
the fllter 3, a #uitable range belng 100 to 200 kPa.
.1
Ex~ e 2
on ~ l-bor~tosy ~cale, th- plant of Figure 3 wa~ u~-d
~r ~e~ucing nitrate concentratlon ln water fro~ 100 to
~ NO3/1. Th- resln as ln Example l was ted i~ a~
a lur~y ln wster at O.1% w/w concen~sation, and wa~
~ilt-re~ by the f~lter 3 in cros~flow.~ode wlth.past of
the sl~rry r~cyeling via tho line S to ~he ~xing tan~
1. A bleed ~tsen~ wa~ ~-pasat-d by valvo~ to ~low lnto
--- 0~ RPR '92 16:07 11~RKS & CLERKS LONDOIY 2067380 P.24
~0 91/~ 91 " rC~ vl~
Z6
the f1lter ;6 whic~ waS oper~ced :- de~d-cnd mode. ~b.Q
p-od~c: wa~er thuS obca:ned was com~lncd wlth ~4a~ '-o~
~ne r- ~ ter 3 and col ' ec~ed ~. n ;.'1~ tank 13. Once
suf~ clenc ~esln had been col;ected :n the fi_.er 'i, a
alve was opened aliow~ng ~rlne solut~on (regen~ran~ J :O I
wash the resln into the ~onk l8 ~or regenerat:on. ~.e
~rine solution waS fol'owed by a small amount oC p:oduce
water to clean the filter 15 befo~e ~t was re-~ntroCuce~ ¦
~nto service as a dead-end ~ileer.
i
Other details were as 1 n ~xample l. I
' .
Ex~ol~ 3
On a p~lot plant scaLe, :he plar.e o~ ure 5 wa~ used
for reducing nitrate concentrat~or. .n ground water 'r~m ¦
~bou~ 60 to l9 mg-~O3~.. The t~.~oughpur was 11.9
m3,hour. She ground water contalned no detec~ble
~oli~J. Nin- filter~ 3 were used. each 8 ~ long.
.
; A ~Pusollt-~ AS20E ~on-oxchanqe res~n was used, ~s a
owder having p3rticles ~n a range of 50 eo ~00 ~
~h! re~ln ~-r dosed by the pump 51 ~nto ~he ~eed tank : j
~c such a r~te t~at ;he ~esln waS O. 2% w/w o~ ~.e .aw
water, thoug~ ~he dynamlcs of the sysce~ caused the
osLn conc-ntra~on :n :;~e ~eed eank 1 to be
'.
... ' I'
.,. - i
06 RPR '9Z 15:46 MRRKS & CLERKS LONDON 2 0 6 7 3 8 a PCT/G8 9PliZ7! ~ 1 5 1
- 1 9 12 91
27 19 ~ec~ ~ J~ 1~91
slgn~flcantly higher, namely about 1 25~ At ~teady
state, the tot~l load o re~in in the ~y-t-m wa~ a~out
11 kg The bloed pump 25 was pumplng at ~bout 1000 l~h, ¦
a~ountlng to 16% o~ the f~ed The pressure in the
filte~ 3 was about 175 kPa, or possibly up to 200 kPa
(higher pre~ure~ than thls could be used lf the raw
wator contalned ~olld m~tter whlch ~oul~d tho filters
3) T~e flltor~ 3 removed a~out 96~ o~ the water Y~om
the ~ucpenslon flowlng lnto t~e f~lter~ 3 T~- rosln on
average recycled about four ti~es ~o the feed tank
before belng r~generated
I
The thickener~ 26, 39 wero op~rated to discharge the
801id6 at 50% w~w concentration The f~lter 30 wa~
rever~e flow backwa8hed on each regeneration cycle aft-r ,
three minut-~ 10% w/w ~odiu~ chloride solution wa- i
u$ed a~ tne strong regeneran~ and 5% w/w sodiu~ chloride !
~olut~or a~ tbo we~k rogen-rant 1,
The desir-d nitrate concentra~ion was obtain~d ~n t'~e
tr-at-d wat-r, and chlorides were below 200 mg/l wator !
!
recovory wa~ about 84~ ' I
The ave,rag- r-tentlon t~me in the ~ced tank 1, p~p-work ¦
and f~lter~ 3 wa~ about 4 or 5 minutes
,
' ' I .
~06 RPR '9Z 16:08 MRRKS 8. CLERK5 LONDOl`i 2 0 6 7 3 8 ~ P.26 '
'' PC~/~,8~ 1CI~
~)91~0
~a
Th- ~ilters 3 were as dLsclosed ln Fig~res 11, 1^, li,
'8a and 18b of US ~ 7~5 ~06. However, as ~he~e were no
solfds ~resent Ln ~he raw waeer, r.o cle~nlng cycl~ waS
_e~ ed. Some of the res~-. set~led on ;he weave o' ~be
~ e~ support to form a membrane, bu~ ~h~ remainder o'
-h- re-ln did not ~u~ld ~p a s~gnifican~ layer.
',' ' . Il
~ 1 1
Example 3 was _~peaeed ~t~ a dif 'erent _aw wa~er.
ate conc~ntra~:on was reduced f~om 4~.3 ~o 16.5-18
mg-~03/1.
' i
Exam~le 5
Ex~mple 5 is as ~xample 3, w~th t~e follow~n~ para~e~ers¦ .
d,~f ferent: ¦
'
Resin dose: 0.8~ w~w of t~e raw water,
; Concen~ration ~n the 'eed tank: 5~ w/w;
'rotal load of resLn: ~4 kg;
Water secov-ry: 96~
.' 1,,
!
~e p~esenS in~en~on has been descr~ed a~o~- purel-; by
way ~ exa~ple, and modl-~ca~ons can be ~ad- w~ch~n ;~.e
5p~ 0~ th~ ven ion.
