close

Вход

Забыли?

вход по аккаунту

?

Патент USA US2411390

код для вставки
Nov. 19, 1946.
F. D. PRAGER
2,41 1,390
LIQUID TREATMENT
Filed April 3, k1944
fil
`
uw,
INVEN TOR.
ov.' 19, 1946.
2,411,390
F. D. PRAGER
LIQUID TREATMENT
Filed April :5, 1944
`
2 Sheets-Sheet 2
uw,
INVENTOR.
Patented Nov. 19, 1946
2,411,390' '
UNITED STATES PATENT OFFICE
LIQUID TREATMENT
Frank D. Prager, Chicago, Ill., assignor to Graver
Tank & Mfg. Co., Inc., a corporation of Dela
Ware
Application April 3, 1944, Serial N0. 529,333
13 Claims.
(Cl. 210-16)
l
2
This invention relates to liquid treatment and
particularly to the removal of` impurities from
of the tank.« The lower` part of the column is im
perforate but a number of steel pipes 28 commu
nicate with the lower part of the downfiow zone
liquids by precipitation, aided by sludge filtra
tion and recirculation.
It is an important object of this invention to
improve over previous devices for distributing
liquid> flows to be exposed to sludge filtration,
particularly in large tanks.
It is one Aparticular object hereof to transfer
- I8 within the hollow column and extend radially
below the grouted surface I5 toward the wall I2.
These radial steel pipes form how passage means,
as will be explained, and also serve to reinforce
the concrete bottom I I ; suitable reinforcing wires
2I being ' provided between these radial -pipes
liquid mixed with chemicals and sludge from the 10 `within` the concrete bottom: II, and having their
central to the peripheral part of a treatment tank
ends welded to the pipes.> In earlier construc
tions, somewhat similar flow passage means were
in a manner involving the least possible obstruc
tion to the necessary flows in the clarification and
sludgefiltration zone contained in the tank.
Another particular object is to transfer such
materials from-a central to a peripheral part in
installed in upper parts of the tank.> When so in-- ,
stalled they obstructed the upward flow in said
upper parts; they tended to interfere with cer
taindesirable types ‘of rotating scraper- assem-4
a manner which allows the use 'of an emcient
_ blies; and moreover their installation in such
and economicalÍ type of sludge scraping equip
upper parts involved expensive means and meth
ment»
ods of construction. ¿The absence of such pipes
Another object is to provide improved inlets 20 in the upper part of the tank is one of the advan
. or outlets in an annular channel zone surround
tages of the present invention.
ing a sludge filtration tank.Adjacent to the concrete column I1 and con
Still other objects will appear from the follow
centrically surrounding the same I provide a steel
ing description.
drum 22. forming an upñow zone 23 between this
In the drawings,
'
drum and the column. This upflow zone com
Fig. 1 is an elevation, partly in section, of one
municates with a lower, central part of the tank,
embodiment of this invention.
by means of the lower, open end 22-A of the
Fig. 2 is a plan view of the apparatus of Fig. 1.
drum 22. The two zones I8 and 23 may be re-`
Fig. 3 is a partial section, along- lines 3-3 in
ferred to as parts of a'central now collecting
Fig. 2; and
30 zone, in view of the operation to be described
Fig. 4 is a fragmentary, sectional elevation of
hereinafter. The two members I'I and 22, which
a modified embodiment.
.
are centrally located, annular wall means con-- Y
The tank I0 has a flat circular bottom I‘I of reinforced concrete. The side wall I2 ls cylindrical .
and made of steel.
A'lower portion I8 of the 3.5
wall is an inverted cone frustum vmade of -con
crete, upstandingrr from the periphery of the bot
tom II. The bottom II has a slight inward slope
to facilitate an occasional draining of the tank.
A thin layer of fine grout I6 forms the upper part 40
of this bottom; this grout being applied in a .
plastic condition when the „rough concrete work
has been completed. A proper, dat or smooth top
ñning said rspective zones, are similarly classifi
able as parts of a central flow collector means.
Thelower, open end 22-A of the drum 22 forms
the inlet of this flow collector means I'I, 22, or
more specifically, the inlet of the upñow- portion
thereof. Concentrically with the wall I2 and
adjacent this wall I provide a large steel drum,
baille, wall or‘,l partition 24. forming an annular
peripheral channel zone 25 between the wall I2
and the drum 24. The drums 22 and 24, or parts
integral therewith, extend downwardly, respec
surface I5 of the bottom, for the uniform accu- ' tively, to points‘28 and'2l at suitable elevations
mulation and quiescent scraping ofi’ of settled 45 above the surface I8. ak clarificationl zone or
sludge, is obtained by rotating the sludge scraper
assembly I8 over this grout before the grout has
chamber 28' is formed by and within the outer
drum 24, outside the inner drum 22. This clari
solidiñed. 'Thereafter the sludge scraperlmassem
bly is raised a fraction `of an inch.
iication zone has much greater area and volume
- b -
Concentrically. with the tank, a concrete co1
umn Il extends upwardly from the bottom II.
This column, and the central part of the bottom
5°,
ties, as will be explained hereinafter.
below it, are hollow, providing a cylindrical, -‘central downilow zone I8.„’Openings I9 are provided
in the top of the column, slightly below the top
than the peripheral channel 28, which in turn
is considerably larger than any of the other zones
of the tank, in orderl to insure proper flow veloci
55
,
The downfiow zone I8 receives raw liquid thru
the
II into
inleta pipe
‘ part29'ofwhich
this zone,
entersabove
thru the
the bottom
`
‘
2,411,390
3
4
thereof, centrally of the inner ends 2li-A of
the several steel pipes 2l).
Thus the flow from '
the inlet pipe` is uniformly distributed to the
several pipes 2B. These pipes 28 discharge into
.
l through the openings I9 down thru the central
downñow Zone I8 in the hollow column; then
' the peripheral channel 25 through discharge
outwardly thru the radial steel pipes 20, then
around the peripheral channel 25, with local 4up
and down currents,"then`inwardly and rotatingly
openings 30 which are uniformly distributed
along the channel and which are located above
-the lower limit 21 of the outer drum 24, but be
low the top of the tank, Adjacent each opening
` 30 the respective steel pipe 28 merges intoA a dis
y
and suction below the same. As a result, a stream
yof air and liquid rises in the upiiow zone 23;
air escapes at the top of that zone; liquid ñows
over the bottom of the clarification and sludge
10v
charge chamber 3| cored into the concrete of the
conical wall I3 and discharging into the periph
:ed zone, and finally back into the upiiow zone
3.
. The velocity of this >circulation is suitably reg
ulated by control means, not shown, in the sup
plyl line for compressed air leading to the airy
directions, about 45 degrees inclined from the
horizontal. As a result, the liquid is injected-into 15 lift device 38, y,in manner known from earlier
construction. The several parts of the tank are
the peripheral channel in a plurality of inclined
so
dimensioned that the circulating ilow is rela-'
jets, tending to produce a general horizontal r0
tively rapid in the up and downflow zones and in
` tation, and local up anddown agitation of the
the radial pipes, suitably slower in the peripheral
liquid in the peripheral channel.
>This jety action with up and down agitation is 20 channel, and still slower over the bottom of the
sludge bed zone.l In general, the aggregate or to
substantially confined to the peripheral channel,
tal iiow area of the several pipes 20 equals the
by virtue of the aforementionedouter drum 24
area of theK downiiow zone and this in turn equals
extending to _the level 21 below the discharge
v eral channel 25 in uniform upward and lateral
openings 30, but the general horizontal rotation
the area of the upflow zone, these areas being so
dimensioned that with proper amounts of liquid
recirculated, the liquid velocities thru these areas
amount to about 2 feet per second, with at least
enters this zone thru a long and wide slot 32,
50% variation plus or minus, depending on local
. between the surface I5 and the lower edge of the
conditions. The velocities in the peripheral chan
outer drum. Accordingly, the liquid tends to con
tinue its rotation in the bottom part of the clari 30 nel and over the bottom 0f the tank generally
range downward from '1 foot per second to only
, ' in the peripheral channel tends to continue in
,the clarification zone 28, .as the rotating liquidv
fication zone 28, but this continued'rotation can _
be prevented, or can be deñected into vertical
a few inches, or sometimes fractional inches per
second. In the upper parts of the peripheral
channel and clariñcation zone, the preferred ve
bailies 33 which are known from earlier construc-tions. Such deiiecting baffles can be located at 35 locities amount to only a few inches per minute,
`at most. However, a. somewhat higher velocity
and extend to any desired points outside or in
and agitation can be tolerated in the top of the
side of the large drum 24, depending on whether
channel, which serves for scum release, than in
the sludge formed in the process„and to be sus
the clarification zone, due to the relatively rapid
pended in the sludge bed. is relatively light or
rising rate of even minute air bubbles agglomer
40
heavy, requiring Vmore or less of saidvertical
ated with scum particles.
circulations in the clarification zone 28. A sus
Any chemical re-agents needed to precipitate
circulations, and ultimately stopped, by deiiecting
pended sludge bed 34 is provided and maintained
the sludge are added to the circulating liquid by
the pipe 33 terminating adjacent the top ofthe
the liquid percolates thru the sludge bed, in a
zone, Where rapid and complete mixing is
generally upward direction. Treated liquid _is 45 upflow
insured by vanes 40, deiiecting the rising stream
withdrawn above the sludge bed 34 by overñow
of air and liquid into a horizontal rotation, in the
inthe clarification zone in known mannen'and .
weirs 35 with effluent launders 36 of known con
top of the upflow zone. These vanes and the hor
g
izontal liquid rotation which they set up, serve
Once that the tank is ñlled the weirs 35 pre
also to dampen any surges of the air and liquid
vent the liquid level 31 from falling below said 50 stream, whereby they prevent any drops of liquid '
weirs. The liquid level 31 is prevented from
rising above the top of the tank by conventional - from being projected upwardly over the top of the
control means, not shown. 'I‘he inner drum 22
The circulating liquid, which' carries any re
extends above the liquid level 31, and the outer
drum or baille 24 _is integral with one wall 24-A 55 quired chemicals, spirals down the central zone
within thel hollow column, and meets the raw
of the outermost Alaunder 36, which wall also
liquid entering the inlet pipes to be mixed with
extends above the liquid level 31. By means of
-the same. _Mixing energy and turbulence is in
this arrangement, the peripheral channel 25 and
sured by the iiow velocity of the circulating liquid,
the central upflow zone 23 communicate with the
clarification zone 28 only in °the lower parts 60 and any continuing rotation thereof. Due to thisturbulence, the ’several constituents are inti
thereof. .This forces all of the ~rotating liquid
mately mixed in the bottom part of the downñow
' from the peripheral channel to enter the bottom
zore. Turbulence and agitation continue in the
of the clarification zone, and similarly, all liquid
vradial flow passages 20. Agitation'with suitably
withdrawn into the upiiow zone is removed from
lower velocity prevails in the peripheral channel
the bottom of the clarification zone.
65
and at the bottom of the sludge bed 34, and some
The rotary liquid ñow is augmented by a cireu
minute agitation continues in the sludge bed it
lation, which can also continue during any slow
self. The slowest liquid velocities are maintained
down or complete shutdown of the inñow thru
above this bed, in the large, unobstructed upper '
the pipe 23. _This circulation is established and
maintained in well-known manner, for instance 70 part of the clarification zone. Under conditions
of overload and the like, there may be a, tendency .
by an air lift device 38, mounted on the column
for certain sectors or constituents of the- sludge
I1 in the lower part of the upflow zone 23, and
bed to boil up toward the water level, but due to
releasing compressed air into that zone. The
the large and unobstructed construction and oth
release of air is conducive to the development- of
' relatively high pressure above the airA lift device 75 er features of this apparatus, suchtendencies are
struction.
2,411,390
emciently checked and the apparatus delivers
treated and clarifiect- liquid- at increased flow
rates. as compared with earlier devices operat
ing under comparableI conditions.
Generally I prefer to control the liquid veloci
sludge will rotate in the lower parts of the sludge
bed. As a result, the volume of the peripheral
channel- 25 can be made smaller, by reducing the
width and area' thereof, and adequate fioccula
tion is still provided. Desirably, the windows 52
ties in the clariñcation zone so as to allow and
force the largest `sludge particles to settle out on
are located between the discharge openings 30,l
and the solid lower skirts 5| in front of said dis
the dat surface I5. Frequently some sludge tends
to settle also in the peripheral channel, between
the discharge openings _30. In al1 other parts of
.the tank, liquid velocities are such as -to prevent
sedimentation of sludge. Any sludge sediment
charge openings, sothat the up-and-down flows
54, produced by the liquid jets 53'in the channel,
may not interfere with the necessary, relatively
quiescent conditions inside of the large baille 50.
Of course, the liquid iiows 55 entering this inner
from the peripheral channel slides down the in
clined wall i3 and collects on the flat -surface l5,
space may have any desired velocity, depending
on the size of the windows 52.
together with the sludge from the clarification
In order to prevent any settled sludge from col
zone 28. All this sludge is scraped from the ñat
lecting behind the ,baille skirts 5|, in the periph
surface l5 by the scraper assembly I6, which ro
eral channel, these skirts do not merge with the
tates slowly around the central column H, and
tank bottom, but allow the sludge to slide down
shifts the settled sludge into a sump M, formed
in the bottom il adjacent the central column. 20 the inclined wall i3 and into `the inner space, in
a flow shown at 56. .
'
From here the sludge is ultimately withdrawn
The modified embodiment includes also a sys
thru a pipe d2 with suitable, well known controls,
tem of auxiliary or alternative iìow passage means
not shown. The rotary velocity of the scraper
5l, extending from the central mixing -zone to
assembly l 5 is selected to prevent any undesirable
stirring up, or deñecting, of sludge and liquid - points above the liquid level 31 and discharging
currents in the clarification zone..
recirculated liquid
-
is supported by bearing'members 43;4 these bear
ing members in turn being supported by the hol
‘low column il. By means of this central, ele
vated bearing support, the weight lof the scraper
assembly, which may amount to- several tons,'is
emciently balanced and absorbed. _
into the peripheral channel, '
in directions tangential of the channel, through
outlet L fittings 58, whereby the recirculated liq
The scraper assembly i6 is fastened to the
lower part of the drum 22 which rotates slowly
together with the scraper assembly, and which
uid can be inspected and sampled.
30
It is often desirable rto provide at least one re
circulating pipe 2li with such a sampling arrange
ment, for close control over the condition of the
circulating fioc. Itis not quite suñcient, in many
instances, periodically to sample the lloc in the
channel 25, although this should be ‘done also.
The scraper assembly is preferably driven by a 35 It is inherent in the' rapid chemical mixing
stage, through which the circulating iioc must '
tion, adjacent the side wall l2. It will he noted
pass, that the i'loc is broken up to some extent.
traction drive assembly/.list of known construc
that with the aforementioned prior construction,
using distributing piœs in the top oi' the tank,
In the presence of proper chemical and pH con
ditions, the comminuted fioc is promptly built up
it was impossible to provide such desirable and 40 again, as soon as flow conditions of less turbu
eí‘ilcient traction drives, inasmuch as the distrib
uting pipes interfered with such a traction drive.
The general advantages of traction drives are
well known and will not be described. A special
advantage resides in the fact that such a drive
is most conveniently provided with- a scum re
moval blade «t5 depending from the outer parts
of the traction drive on top of the peripheral
lence are established; that is, upon discharge into
the peripheral channel.
In fact, more settleable ~
ultimate ?locs are formed in this manner than
without any breakup of fiocs.
With- the modiñed arrangement it is easy to
sample both the comminuted iioc discharged at
58 and the re-ñocculated particles in the top of
the channel 2d. Such sampling of the commi
nuted ?ioc is preferable over the prior method
channel 25 and suitably cooperating with a sta
tionary scum shelf and trough #6in the same 50 frequently used in plants of this general type,
channel (see Fig. 3); both blade and trough gen
wherein small sampling pipes, independent from
erally. being installed in substantially radial di
the main flow passages, are brought to the sev
rections across the top of the channel (see Fig.
eral ñowsto be sampled. >This earlier method
„ 2) and the trough being suitably emptied by a
furnishes inderiinite samples. due to the addi
pipe di. The chemical treatment, particularly 55 tional, indefinite comminution of ñocs in the sep
arate' sampling pipes. It is preferable to use~the
in connection with the air lift, promotes flotation
of relatively light particles, and such particles are
combined now passage and sampling pipe 5l, ei
readily released in the peripheral channel 25.
ther alone or suitably alternating with the pipes
2li.
'
Quiescent conditions are established in the top
of this channel, by means of- radial varies 48, 60 Of course, all this is possible only if the skim.-v
which may also support the large baille âfl and
ming device d5, d6 can be eliminated. In some
parts mounted thereon.
.
cases it is preferable -to have that skimming de
In the modification of Fig. 4, the large periph
vice, and in others, to provide the sampling iiow
passages.
"
eral baille does not have to extend downwardly
to points 2l below the discharge openings Sil, as 65 Various other modiñcations will occur to per
in the preferred embodiment. In this modiñca
sons skilled in the art.
I claim:
tion the large baille 50 has only spaced lower
portions 5l extending downwardly topoints be
low said openings, while large windows 52, of
l. In a liquid treatment tank, a bottom having
a substantially nat circular top surface for the
70
considerable height are provided between said
uniform accumulation of settled sludge; a side
spaced portions 5l. This may be desirable, above
all, in relatively deep tanks, and where a large
area is not so readily provided.
With this ar
rangement, a relatively deep layer of liquid and
wall upstanding from a peripheral part of said.
bottom; an annular baille downwardly extending
- in the tank to define a channel outside said baille
and a clarification chamber inside the same, said
baiiie being so located that said channel has con
anneau
.
d
Vsiderably less area than said chamber, and said
baffle terminating above said bottom so that the
lower part of said channel communicates with
the lower part of said chamber; flow collector
5. Apparatus according to claim 3, wherein said
means to circulate liquid is supported by said
column.V
g
6. In a liquid treatment tank, a bottom; a side
wall upstanding from a peripheral part of said
bottom; -a substantially cylindrical baiile concen
means in the tank, having an inlet in a lower,
central portion of said chamber and comprising
centrally located, annular wall means in the tank;
trically installed in the tank to define a channel
outside said baille 'and a clarification chamber
inside the same, said baiile being so located that
said channel has considerably less area than said
chamber, 'and said baffle terminating above said
bottom so that the lower part of said- channel
communicates with the lower'part of said cham
ber; flow collector means in the tank, having an
inlet in a lower, central portion of said chamber
, a set of ñow passages extending below said sur
face, communicating with and outwardly radiat
f ing from said now collector means, and also com
municating with said’ channel by means of dis
charge openings distributed along said channel,
the total flow areaof said flow passages being
considerably less' than that of said -channel;
means to circulate liquid from said clarification
chamber into said flow collector means, outwardly
and comprising centrally located, annular wall
means in the tank; a set of ñow passages extend
through said dow passages, through said channel,
ing through said bottom, communicating with
and outwardly radiating vfrom said flow collector
means, and also communicating with said chan->
nel by means of discharge openings distributed
Ainwardly over said surface, and back into said
flow collector means; means to deliver liquid to
be treated and. any chemical reagents required
into the circulating liquid; outlet means for
along said channel, the total flow area of said dow
passages being considerably less thanl that of said
channel; means to circulate liquid from said
sembly rotatably disposed over said surface to
clariñcation chamber into- said ilow collector
scrape sludge into said sump; and meansto rotate ' 25 means, outwardly through said iiow passages,
said assembly.
through said channel, inwardly-over said bottom,
2. Apparatus according to claim Ai., wherein said
and back into said now collector means; means
means to rotate said sludge scraper assembly
, to deliver liquid to be treated and any chemical
comprises a movable traction drive means se
cured to an outer part of said scraper assembly 30 reagents required into the circulating liquid; out
let means for treated liquid in the top of said
and having driving engagement with stationary
chamber; and sludge outlet means in a lower
means adjacent the top of the tank.
part
of said tank.
'
3. In a liquid treatment tank, a bottom having
'7. Apparatus according to claim 6 wherein said
a. substantially hat circular surface for the 4uni
‘formy accumulation of settled sludge; a side wall 35 discharge openings are located in said wall, op
treated liquid in the top of said chamber; a sludge
outlet sump in said bottom; a sludgescraper as
upstanding from a peripheral part of said bot
tom; an annular baño downwardly extending in
the tank to denne a channel outside said bañle
and a, clarification chamber inside the same, said
bañle terminating above said bottom so that the
lower part of said channel communicates with
` the lower partof said chamber; a column extend-A
posite said bañle.
'
\ '
.58. Apparatus according to claim 6 wherein said
discharge openings discharge in directions at
least comprising inward components.
9. Apparatus according to claim 6 wherein said
discharge openings discharge' in directions at
least comprising upward components.
10. Apparatus according to claim 6 wherein
said discharge openings discharge in directions
comprising at least components tangential of said
of the bottom below it being hollow; a drum con 45
centrically surrounding said column, extending
11. In a liquid treatment tank, a bottom; a side
from the top of the tank to above but relatively .
wall upstanding from a peripheral part of said
adjacent said bottom, and so arranged that the
bottom; an annular baffle downwardly extending
space within the drum communicates with the.
inside of said hollow column, whereby said drum 50 in the tank to define a channel outside said baille
a clarlñcation chamber inside thesame, said
and column provide a flow collector having an - and
baille being so arranged that said channel has an
inlet in a lower, central portion of said chamber;
open top, and said baille terminating above said ,
a set of flow passages extendingl through said
bottom so that the lower part of said channel
bottom, communicating with and outwardly
radiating from an inner, lower partof said flow 55 communicates with the lower part of said
ber; flow collector means in the tank, having an
collector, and also communicating with _ said
inlet in a lower, central portion of said chamber
channel by means of discharge openings dis
and comprising centrally located, annular wall
tributed along said channel, the total :dow-area
means in the tank; a set of ñow passages, com
of said flow passages being considerably less than
municating with and outwardly radiating from
that of said channel; means to deliver liquid to 60
said flow collector means,v and also communicat
_be treated and any chemical reagents required
ing with said channel by means of discharge
into said ilow collector; means to circulate liquid
openings distributed along said channel between
from said clar‘iñcation cha’mber into said flow
the top and bottom of the tank, the total flow area
collector, outwardly through said flow passages,
through said channel, inwardly 'over said surface, 65 of said flow passages being- considerably less than ,
that of said channel; means to circulate liquid
and lback into said ñow collector; outlet means
from said clarification chamber into said flow
for treated liquid in the top of said chamber; a
collector means, outwardly through lsaid now
sludge outlet sump in said bottom; a sludge
passages, through said channel, inwardly over
scraper assembly rotatably disposed ov'èr said
said flow collector
surface to scrape sludge into said sump; and 70 said bottom, and back- into
‘ means; means to deliver liquid to be treated and
means to rotate Isaid assembly.
any chemical reagents required into the -circu
4. Apparatus according Íto claim 3, wherein
lating liquid; outlet means for treated liquid in
said drum, concentrically surrounding said:l col
the top. of said chamber; sludge outlet means in
umn, is rotatably supported thereby, and forms
75 slower part of said chamber; a substantially sta
ing‘upwardly from said bottom in the center of
the tank, said column- and the central portion
baille.
part of said sludge scraper assembly.
~
'
'
‘ aaneen
tionary scum trough in the top o? said channel;
a movable scum blade associated with said
trough; power means .to move said blade along
the top of said channel; and an outlet for said
trough.
v
12. Apparatus according to claim 11 compris
ing a stationary scum shelf associated with said
trough, said shelfA and troughV spanning the top
i3. Apparatus according to claim il compris1 ~
ing battles extending between said side wail and
said annular baille, through a part of said chan'
nel above said discharge openings but below the
top of the tank, whereby the upper-part of said
channel forms a quiescent scum release zone.
while' the lower part of said channel» forms an
agitated ñoccniation zone.;
»
of said channel, and said power means being
adapted to move said blade along 'the top of said l0
_ FRANK D. PRAGER.
channel, up said shelf, and over said trough.
Документ
Категория
Без категории
Просмотров
0
Размер файла
882 Кб
Теги
1/--страниц
Пожаловаться на содержимое документа