Note: Descriptions are shown in the official language in which they were submitted.
~057703
This invention relates to a sand washer for removing
mud from sand for use, for example, as fine aggregate for
forming concrete.
Sand not so muddy can be washed as it is sieved
wit`h sprays of water under pressure. The aggregate covered
with much mud, however, cannot be cleaned without using a
washer specially designed therefor. The machines ~or clean-
in~ such muddy pebbles and sands include scrubbers and sand
washers, and the present invention falls under the domain of
the latter. Conventional sand washers comprise a rotating
drùm equipped with a trough at one end through which it is
charged with muddy sand, so that the charge is washed on
the bottom of the drum by water supplied from the outside
through the opposite end of the vessel. With the revolution
of the drum the sand cleared of mud is carried upward by a
number of scooping plates disposed on the inner surface of
the drum, and is then allowed to fall by gravity onto a belt
conveyor extended into the drum to convey the clean sand out
of the vessel.
Thus, for the washing of sand, the existing washers
depend on a single turn of the drum whereby the sand washed
on the bottom is scooped upward and then dropped onto the
belt conveyor. Consequently, the washing efficiency is
very low.
The present invention is directed to the provision
of a sand washer capable of thoroughly washing mud away from
sand by causing the muddy sand introduced into the drum to
go through a unique process therein.
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1~)57703
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According to the present invention there is provided a
sand washer for washing muddy sand comprising a drum mounted for
rotation on a plurality of rollers, means for charging said drum
with said muddy sand through an inlet means for supplying wash
water to said drum through an inlet, a plurality of annular
chambers formed in the drum, a plurality of scooping plates dis-
posed within each of said annular chambers, draining members
provided in said scooping plates, chutes secured to a base and
disposed between said annular chambers independently of drum
motion, a plurality of lengths of band steel helically coiled
along, and secured to, the inner wall surface of a section of said
drum close to said sand inlet, scooping plates located adjacent
terminating ends of said helical lengths of band steel, and a
chute secured to the base and associated with said scooping plates
and annular chambers within the drum, independently of the drum
motion, whereby washing of muddy sand with water and draining of
the washings are repeated a plurality of times.
The present invention will be further illustrated by
way of the accompanying drawings, wherein:
Fig. 1 is a front elevational view of a sand washer
embodying the invention;
Fig. 2 is a vertical sectional view of the washer;
Fig. 3 is a side view of the washer as viewed from the
right end of Fig. l;
Fig. 4 is a sectional view taken on the line A-A of
Fig. 2, and
Fig. S is a sectional view taken on the line B-B of
Fig. 2.
The drum body 1 of the sand washer according to this
invention, as better shown in Fig. 2, includes two circular plates
2, 3 at both ends having center openings, respectively. One of
the openings serves as an inlet 4 for charging muddy sand into
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the drum body, and the other opening as an outlet 5 for discharging
cleaned sand. The space inside the drum is roughly divided into
two sections. In the section on the left as viewed in Fig. 2, a
plurality of lengths of band steel 6 are helically coiled and
welded to the inner wall surface of the drum, thus forming grooves
7 therebetween. The band-and-groove structure is intended to
constitute a built-in screw conveyor, the bands serving as helical
blades. The muddy sand introduced into this section is conveyed
rightward while being washed with water. The lengths of band
steel 6 terminate at points of the inner surface of the drum
(in the center of the body as in Fig. 2)
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1057703
where a plurality of scooping plates 8 are extended axially
of the vessel and welded thereto adjacent the ends of the
grooves 7. The scooping plates 8, as shown .in Fig. 4, take
up the conveyed sand in succession and carry it upward until
the charge in the upper part of the drum will fall onto a
chute located below for transfer to the ne~t washing cycle.
. Although the SCOOpillg plates 8 are shown held apart from the
inner wall surface, with the gaps covered by drain nets 9,
this arrangement is not essential. Full-width scooping
plates may be employed to eliminate the nets. The numeral
10 designates a first chute. The other, right-hand section
of the drum body 1 has three circular partition plates 11,
12, 13 formed with circular center openings 14, lS, 16,
respectively. The diameters of these openings are gradually
increased in the flow direction of washing water, or leftward
as viewed in Fig. 2. The inner wall surface of the drum
body 1 combines with the circular plates 11, 12, 13 and the
right end plate 3 to form first, second, and third annular
chambers 17, 18, 19. As typically shown in Fig. 5, each of
the chambers 17, 18, 19 has a plurality of scooping plates
20, 21, or 22, welded to the inner wall surface of the drum
body. The circular plates 11, 12, 13 and scooping plates
20, 21, 22 are combined to divide the annular chambers 17,
18, 19 into groups~of sub-chambers 23, 24, 25, respectively.
In the same manner as with the scooping plates 8, the plates
20, 21, 22 are provided with drain nets 26, 27, 28.
The drum body 1 rests on pairs of rollers 32, 33
supported by bearings 30, 31, respectively, which in turn
~0$7703
are mounted on a base 29. Shafts 34, 35 of the rollers 32,
33 carry at both ends sprockets or pulleys 36, 37, and the
rollers are jointly driven by chains or V belts 38 extended
around these sprockets or pulleys. A motor 42 is drivingly
coupled to the rollers 33 through a pulley 39 on one end of
the roller shaft 34, a V belt 40, and a motor pulley 41.
On the l~ase 29 are held upright two pairs of posts
4~ and 44~ and two beams 45 are extended through the drum
body 1 and are supported at both ends by the posts. As shown
in Fig. 2~ the beams 45 provide a support for a trough 46 for
charging muddy sand into the drum body, and also for the
first chute 10, second chute 47, third chute 48, and fourth
chute 49 arranged within the drum body 1 to receive the sand
taken up by the scooping plates 8, 20, 21, 22 and caused to
fall gravitationally from the upper part of the drum, and to
carry the sand over to the next washing cycle. A belt con-
veyor 50 is located outside and below the outlet 5 of the
drum body so as to convey the washed sand to an open storage
yard. The numeral 51 indicates a pipe for pouring washing
20 water into the drum body 1, and 52 denotes a baffle plate.
The sand washer according to this invention operates
in the following way. In preparation for the operation,
the motor 42 is started ar.d its power is transmitted through
the pulley 41, v belt 40, and pulley 39 to rotate the rollers
25 33. ~t the same time, the turning force is transmitted
through the sprockets or pulleys 37, chains or V belts 38,
and sprockets or pulleys 36 to the rollers 32. This causes
the drum body 1 resting on the rollers 32, 33 to revolve,
~057 7()3
too. Then the belt conveyor 50 is started and washing water
is introduced through the pipe 51 into the drum body 1. The
sand washer is now ready for the washing operation, and
muddy sand is charged through the trough 46 into the drum
S body 1. The muddy sand introduced via the trough 46 first
falls into the first annular chamber 17 and the mud is washed
away by the water rlowing therethrough, and the sand is taken
up by the scooping plates 20 and is carried to the upper
part of the drum body while the washings are be;ng drained
off through the nets 26. Upon arrival at the highest point
within the drum body, the sand falls by gravity onto the
second chute 47. The sand then slides into the second annular
chamber 18 for the next washing cycle. In the second chamber
it is washed in the same manner and taken up by the scooping
plates 21 to the upper part of the drum body. Throughout
this period the sand is again drained of water by the nets
27 of the ~cooping plates 21. From the uppermost point
inside the drum body the sand falls onto the third chute 48.
(Refer to FIG. 5.) The sand then slides into the third
annular chamber 19, where it is again washed in the same way
as above described. Finally, the sand falls from the upper
part of the drum body 1 onto the fourth chute 49 and thence
onto the belt conveyor 50 for transport to an outdoor
storage yard. On the other hand, the portion of muddy sand
flown back by the force of the washing water flow to the
left-hand section of the drum body 1 as viewed in FIG 2
is conveyed rightward by the screw conveyor action o~ the
band steel 6, while being washed in that section. At the
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end of the section the sand is scooped by the scoopin~ plates
8 and is then dropped onto the first chute 10, as shown in
FIG. 4, for transfer to the second annular chamber 18.
As has been described hereinbefore, the sand washer
of the present invention achieves a very high washing effect
because of several washes and dra:ins repeated. The plurality
of cycles are accomplished by mere revolution of the drum
with a remarkable saving of labor.
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