Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
1~)4~8~(~
PROCEDURE ~OR TREATING NEWLY PLACED CoNCRETE W~L~EN CASTING CONCRETE
FLOORS AND T~E LIK~ AND EQUIPMENT l~R CARRYING OUT THE PP.OCEDURE
This ln~entlon relates to a procedure for treat1ng
newly placed concrete when castlrlg concrete ~loors and the like.
Su~plus ~ater ln the wet concrete is sucked vla a vacuum reser-
voir throu~h a llquid ring pump and lnto a water storage
conta1ner ln which atmospherlc pressure prevails and where the
~ater on attalnlng a certaln level in the container r10~8 out
through a ~elr o~errlo~ and the sealing water necessary for the
pump i8 sucked in ~rom the storage contalner through a ~pecial
inlet ln the pump and ls subsequently pumped out together with
the water Qucked up rrOm the concrete and back into the ~torage
¢ontainerO
A suctlon mat or suctlsn plate placed on top Or the
con¢rete sur~ace ls generally used ~or suck~ng up the surplus
~ater rrOm newly placed concrete. A hose ~rom the pump unlt ls
¢onne¢ted to the top o~ the mat or plate and a unlrorm ~acuum 18
~` obtalned over the sur~ace co~ered by the mat or plate by means
Or suction ductQ on the underslde o~ the mat or plate.
On prevlously kno~n vacuum units ror the purpose ln
questlon pumps are generally uced whlch do not allo~ the passage
of water through them. As a result, both va¢uum reservoir and
water ¢ontalner ~ill be under partlal vacuum. The water that ls
sucked up from the concrete and pumped lnto the water contsiner
can in consequence not be dralned e~¢ept when the pump 1s not in
operatlon. Purthermore, a larger water cont~lner l~ requlred to
avold the necesslty of dralning the ~ater container and con_e-
quently turnln~ the pump orf in the mlddle of a suction
operatlon.
The ln~entlon pro~ide~ an apparatus rOr compactlng
8~39(~
freshly placed concrete, comprl~3.ng ~uctlon mean~ adapted
~or sealable engagement wlth sald concrete ~urrace, a
vacuum tank havlng an ~nl~t and an outlet, whereln ~ald
outlet i~ at a lerel at or below th~t of sald lnlet and 18
above the level Or the bottom Or ~ald tank, a llquid ring
pump having a maln lnlet, a seallng llquid lnlet, and ~n
- outlet, a dohnstream recelving tank having an inlet, a
seallng llquld outlet, and a maln outlet whlch 1~ at a level
above that of sald sealing liquld outlet, means sealably
connectlng said suction means to sald vacuum tank lnlet~
: means sealably connecting $ald vacuum tank outlet to ~ald
llquid rlng pump main lnlet, means sealably connectlng sald
llquid rlng pump outlet to $aid down~tream recelvlng tank
lnlet, and means se~lably connectlng sald down~tream
receivlng tank seallng llquld outlet to said llquld rlng
pu~p ~eallng llquld inlet, ~ald llquid ring pump maln lnlet
thereby belng sealed rrOm sa~d liquid rlng pump outlet
- durln~ pumplng Or the water through the pump9 whereby water
may be drawn from sald concrete surrace lnto said vacuum
. 20 tank and contlnuously pumped from the ~acuum tank through
- said Yacuu~ tank outlet wlthout lmpairing the vacuum in
sald vacuum tank by preæsure leakage through the pump, and
~hereby solld partl~les carrled by the water ln~o sald
vacuum tank may be trapped in sald vacuum tank.
The ~nventlon also provldss a method rOr compactlng
rreshly plaoed concrete compriRlng placln~ suction means
into sealed engagement wlth the surrace Or said concrete,
sald means communlcatlng wlth a vacuum ~nk vla an inlet ln
sald vacuum tank, applylng ~uctlon to ~aid surface through
sald means wlth a llquid rlng pump downstream from sald
- 2 -
~ 34~89(~
vacuum tank and in communieation with an outlet in said
vaeuum tank, whereby water is drawn from said surfaee into
said vaeuum tank, and pumping the water from said vacuum
tank and through said liquid ring pump into a downstream
receiving tank which is open to the atmosphere, wherein
the sealing liquid from said liquid ring pump is drawn
into said pump from said downstream tank.
A sehematie diagram of a unit ~or carrying out
the procedure aeeording to this invention is shown on the
appended drawing in whieh Fig. 1 shows the unit viewed from
above and Fig. 2 show-s a vertieal eross-seetion of the same
through the line I-I in Fig. 1.
1 designates a liquid ring pump of eonventional
; design whieh is driven by an eleetrie motor 2 eoupled to
it. The pump has two inlets 3 and 4 and one outlet 5.
.,
Inlet 3 is conneeted to a reservoir 6 which is under
partial vaeuum when the pump is in operation. Inlet 4 is
connected to a container 7 which is separated from reservoir
6 and is of such dimensions that it holds at least the
volume of water required for satisfaetory operation of the
pump. The reservoir and eontainer may be entirely separate
but may also as shown on the drawing consist of two spaees
separated by a partition M in one and 'he same enelosure.
Pump outlet 5 is also connected to eontainer 7
whieh in such manner is supplied with water and the pump is
thereby assured of the neeessary minimum volume of water
for its operation. Inside vacuum reservoir 6 is a level
pipe 8 whieh is conneeted to the pump inlet 3. From inlet 3
it extends some way up in the container and is fitted at its
upper end with a strainer 9 which prevents large particles
1~48~9V
~rom entering the pump.
Before the pump 1s started the ~acuum re~ervolr
6 and the storage contalner 7 are rllled wlth ~ater up to
; a level whlch ln Fig. 2 is defined by the llne A-A,
i.e. level wlth the upper end Or plpe B.
Vacuum re~ervolr 6 ls ~itted wlth an inlet lO
to whlch the hose (not shown~ rrom the suctlon mat or
suctlon plate 18 connected~ When the pump 1 ls in operatlon
a part~al ~acuum arises ln reservolr 6 and water rrOm the
concrete 19 sucked ln through lnlet lO. The ~nter level
ln the reservolr wlll con~equently rise and water flow8
down through plpe 8 and lnto the pump 1, following whlch
it 18 pumped out through outlet 5 and Into ~torage contalner
7.
A certaln amount o~ cement slurry Orten accom-
panles the ~ater suck~d up ~rom the mat or plate. The
larger partlcles ln this slurry are prevented by stralner 9
on plpe 8 from being sucked lnto the pump. Instead they
settle to the bottom Or the vacuum reservoir whlch ln such
~anner acts as a partiole separator or sludge trap.
Extre~ely small partlcles are not stopped by the ~tralner,
however, but pa~s through the pump although slnce this is
Or llquld rlng type lt suffer~ no damage and the ~mall
partlcles can ~aslly pass out through outlet 5 and into the
storage contalner 7.
The ~ater that is pumped out lnto the storage
contalner conslst~ partly or water sucked ln ~rom the
~torage contalner throush lnlet opening 4 and partly Or
~ater rrom the vacuum reservolr. In order to divert the
surplu~ wRter ln ~torage container 7 the upper part Or lt
.
-- 4
1~34~t~90
ls fitted ~ith a welr overflow ll. As soon as the level
o~ the water reaches this overrlow the water flows out
through lt together with some of the partlcles still
remalning in the water sucked up from the concrete. The
remalnder o~ th0 partlcles of slurry 12 settle to the
bottom of the storage container whlch ln this ~anner like
the vacuum reservoir act~ as a sludge trap.
The slurry and ~he partlcles settllng on the
bottom of the vacuum reservoir and the storage conta~ner
mu~t be remored before the slurry set~ and form~ a hard
: slab. The reservoir and container must thererore be
cleaned and to fa¢llitate thls they are both provided
wlth a removable bottom. To facilitate cleanlng of the
stralner and the pump lnlet and outlet openlngs, the
oombined enclosure shown ln Flg. 1 ts also equipped wlth
a removable cover 13.
- 5 -
