STATE OF ART
[0001] The present invention relates to an apparatus for producing stabilizing mixture in
which a stabilizing mixture of uniform density used in excavation work can be produced
readily in volume.
BACKGROUND OF INVENTION
[0002] In order to smoothly carry out excavation work for well-digging, lower holes for
piles and the like, the excavation work is carried out while pouring into an excavated
hole a stabilizing mixture in slurry form produced by mixing stabilizing powder material
such as bentonite and water.
[0003] As the apparatus for producing stabilizing mixture of the type as described, stabilizing
mixture producing apparatuses B and C shown in Figs. 6 and 7 are known.
[0004] First, the stabilizing mixture producing apparatus B shown in Fig. 6 will be described.
The apparatus B is composed of a density regulating tank 60 interiorly provided with
a stirring pump 61 and a mud discharging pump 62, and a mud preparing tank 63 interiorly
provided with a mixer 64.
[0005] In this arrangement, first, bentonite 65 and water 66 are charged into the mud preparing
tank 63, which are stirred by the mixer 64 to produce stabilizing mixture or stabilizer
67.
[0006] The stabilizing mixture 67 is charged into the density regulating tank 60 and stirred
by the stirring pump 61, and the stabilizing mixture 67 formed into a uniform composition
by said stirring can be charged into an excavated hole not shown through a mud transferring
pipe 68.
[0007] The stabilizing mixture producing apparatus C shown in Fig. 7 will be described.
The apparatus C is composed of a stirring and mud preparing pump 69 which is larger
than the aforementioned stirring pump 61 and a mud discharging pump 62.
[0008] In this arrangement, bentonite 65 is charged into the density regulating tank 60
filled with water 66, which are stirred and prepared by the stirring and mud preparing
pump 69. The stabilizing mixture 67 produced into a uniform composition by said stirring
and mud preparation is charged into an excavated hole not shown through the mud transferring
pipe 68.
[0009] However, the above-mentioned stabilizing mixture producing apparatuses B and C still
have tasks to be solved as follows.
(1) In the stabilizing mixture producing apparatus B shown in Fig. 6, an expensive
mixer 64 is required, and therefore the apparatus B itself is costly. In addition,
two processes are employed in which after the mud has been prepared by the mud preparing
tank 63, the mud is regulated by the density regulating tank 60. Therefore, it takes
a considerable time to produce the stabilizing mixture 67 having a uniform composition
or no segregation.
(2) On the other hand, in the stabilizing mixture producing apparatus C shown in Fig.
7, the bentonite is directly charged into the density regulating tank 60 without using
the mud preparing tank 63 in advance, and thereafter, stirring and mud-preparation
take place by use of only one stirring and mud preparing pump 69. Therefore, the bentonite
65 becomes dissolved incompletely so that a large quantity of bentonite 65 remains
on the bottom of the density regulating tank 60, and particles of the bentonite 65
in the stabilizing mixture 67 become increased in size.
[0010] Accordingly, it is an object of the present invention to provide a stabilizing mixture
producing apparatus which can solve the above-described problems.
[0011] In summary, the present invention provides an apparatus for producing stabilizing
mixture comprising a stirring water tank containing water therein, an underwater pump
submerged in the water in the stirring water tank, the pump having a suction port
and at least one discharge port, the suction port and the discharge ports being opened
into the water in the stirring water tank, and a stabilizing material intake pipe
having one end connected to a supply source for stabilizing material and the other
end connected to the discharge port, whereby the stabilizing material can be sucked
into the discharge port due to the negative pressure generated in the discharge port
when the underwater pump is driven and vigorously mixed with water to produce a stabilizing
mixture of uniform concentration.
[0012] With the above-described construction, the present invention has the following effects:
(1) In the present invention, when the underwater pump is actuated, water is sucked
from the suction port and water is discharged from the discharge ports. Negative pressure
produced by said discharge of water is utilized, that is, by the ejector effect, powdery
stabilizing material is sucked into the discharge ports through an intake pipe for
bentonite or the like and mixed with the discharge water along with air, after which
the thus mixed liquid can be discharged out of the discharge ports.
In the above-described operation, the bentonite or the like is readily dissolved into
water when the former is mixed with the discharge water, and thereafter, it is discharged
from the discharge ports and stirred throughout.
Accordingly, a large quantity of stabilizing mixture having a uniform concentration
can be produced rapidly.
(2) Furthermore, since the stabilizing mixture discharged out of the discharge ports
has air mixed therein, a powerful stirring flow can be formed within the stirring
water tank, and the concentration of the stabilizing mixture can be made further uniform.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Fig. 1 is a front view in section of one embodiment of a stabilizing mixture producing
apparatus according to the present invention.
[0014] Fig. 2 is a plan view of the apparatus shown in fig. 2.
[0015] Figs. 3 and 4 are a front view in section and a plan view, respectively, of another
embodiment according to the invention.
[0016] Fig. 5 is a front view in section of a modification of the above embodiment shown
in fig. 3 and 4.
[0017] Figs. 6 and 7 are front views in section of a conventional stabilizing mixture producing
apparatus.
DETAILED DESCRIPTION OF THE DISCLOSURE
[0018] The structure of the stabilizing mixture producing apparatus A according to the present
invention will be specifically described by reference to the embodiments shown in
the drawings.
[0019] In Figs. 1 and 2, reference numeral 10 designates a stirring or agitating water tank,
which is interiorly filled with water W to a fixed height H.
[0020] An underwater pump 12 is stood upright within the stirring water tank 10 and above
the central portion of a bottom plate 11.
[0021] The underwater pump 12 comprises, as shown in Fig. 1, an impeller casing 13 which
encases an impeller 13a rotatably therein, and a motor casing 14 arranged adjacent
to said impeller casing 13 and housing therein a motor 14a connected to the impeller
13a to rotate the latter.
[0022] Rererence numeral 15 designates a support base on which the underwater pump 12 is
placed and supported.
[0023] With the above-described arrangement, the impeller casing 13 is provided in its front
central bottom portion with a suction port 16 and in its outer peripheral edge with
a plurality (three in this embodiment) of discharge ports 17a, 17b and 17c, as shown
in Figs. 1 and
[0024] Mounted on the discharge ports 17a, 17b and 17c are trumpet-like jet nozzles 18d,
18e and 18f, respectively, to bring discharge openings 18a, 18b and 18c to a position
away from the underwater pump 12.
[0025] As will be described hereinbelow, the discharge ports 17a, 17b and 17c are used to
discharge a stabilizing mixture which is a mixture of bentonite, air and water into
the stirring water tank 10.
[0026] In this embodiment, bentonite is used as a powdery stabilizing material.
[0027] The discharge direction of the discharge ports 17a, 17b and 17c extends in a tangential
direction of the outer peripheral edge of the impeller 13a to provide smooth discharge
and transfer of the stabilizing mixture.
[0028] That is, as shown in Figs. 1 and 2, bottom ends of a plurality of lower bentonite
intake pipes 19a, 19b and 19c are communicated with and connected to base ends of
the discharge ports 17a, 17b and 17c, and upper ends of the lower bentonite intake
pipes 19a, 19b and 19c are communicated with and connected to a distributing tube
20.
[0029] Communicated with and connected to the distributing tube 20 is one end of an upper
bentonite intake pipe 19d, which in turn has the other end thereof inserted through
a filter 23 into bentonite 22 within a bentonite container 21 as a supply source for
bentonite or the like provided externally of the stirring water tank 10.
[0030] The upper bentonite intake pipe 19d is provided in its midst with an opening and
closing valve 19e. The valve 19e is opened and closed to thereby assume a bentonite
mixing form suited to the conditions in the operation or construction site, that is,
supplying of bentonite 22 exclusively, supplying of air exclusively, or supplying
of neither bentonite 22 nor air.
[0031] As shown in Figs. 1 and 2, at one corner of the stirring water tank 10 is disposed
a mud transfer pump 40 provided at its lower portion with a suction port. One end
of a bendable mud transfer hose 42 is connected to a discharge port 41 provided at
an upper portion of the pump 40, the other end of the hose 42 being inserted or extended
into a desired excavation hole.
[0032] As shown in Fig. 1, an opening and closing valve 43 is provided on the hose 42.
[0033] Next, the manner of using the stabilizing mixture producing apparatus A having the
above-described structure will be described with reference to Figs. 1 and 2.
[0034] First, the valve 19e provided in the midst of the upper bentonite intake pipe 19d
is opened and the valve 43 provided on the hose 42 is closed. The underwater pump
12 and the mud transfer pump 40 are driven.
[0035] When the pumps 12 and 40 are driven, the impeller 13a within the impeller casing
13 rotates, whereby water is sucked from the suction port 16 into the impeller casing
13.
[0036] The water flown into the impeller casing 13 is discharged or jetted into the stirring
water tank 10 through the discharge ports 17a, 17b and 17c and the jet nozzles 18d,
18e and 18f from the casing 13.
[0037] In the discharging operation, negative pressure is generated within the discharge
openings 18a, 18b and 18c.
[0038] Due to this occurrence of negative pressure, that is, the ejector effect, powdery
bentonite 22 within the bentonite container 21 is jetted along with air into the discharge
ports 17a, 17b and 17c through the bentonite intake pipe 19d, the distributing tube
20 and the lower bentonite intake pipes 19a, 19b and 19c in said order and mixed with
discharging water flowing through the discharge ports 17a, 17b and 17c to produce
a mixed liquid.
[0039] Thereafter, the mixed liquid is powerfully jetted into the stirring water tank 10
from the jet nozzles 18d, 18e and 18f.
[0040] In the above-described operation, the bentonite 22 is instantly dissolved with the
discharging water and then is vigourously discharged from the jet nozzles 18d,18e
and 18f in all radial directions through the discharge ports 17a, 17b and 17c and
stirred throughout within the stirring water tank 10.
[0041] Accordingly, a large quantity of stabilizing mixture having a uniform concentration
without any segregation can be produced rapidly.
[0042] In the present invention, since the stabilizing mixture discharged out of the discharge
ports 17a, 17b and 17c is mixed with air, a powerful stirring flow can be formed within
the stirring water tank 10 to further promote making of concentration of the stabilizing
mixture uniform.
[0043] Thereafter, when the valve 43 provided in the mud transfer hose 42 is opened, the
stabilizing mixture produced in the above-described procedure is supplied rapidly
and positively to the desired excavated holes or the like through the hose 42 from
the discharge ports 41 of the pump 40.
[0044] Moreover, the above-described bentonite mixing and stirring action is continuously
carried out simultaneously with the aforesaid mud transferring action. Therefore,
the mud transferring action can be continuously carried out while uniformly maintaining
the concentration of the stabilizing mixture to enhance the efficiency of the excavation
work.
[0045] While in the above-described embodiment, the underwater pump 12 is merely provided
with the impeller 13a, it is to be noted that an output shaft of the motor 14a with
the impeller 13a may be extended downward, and a cutter may be mounted on said extended
portion.
[0046] In this case, mixing of the bentonite 22 and water can be further promoted, particles
of the bentonite 22 can be further made finer, and the stabilizing mixture can be
made further uniform.
[0047] Next, a further embodiment of the stabilizing mixture producing apparatus A of the
present invention will be described with reference to Figs. 3 and 4.
[0048] The present embodiment is substantially characterized by a structure which allows
the underwater pump 12 to have not only the stirring function but also the mud transferring
function. Parts of the same construction as those of the stabilizing mixture producing
apparatus A shown in Figs. 1 and 2 are indicated by the same reference numerals.
[0049] In the present embodiment, as shown in Figs. 3 and 4, a discharge port 17c of the
underwater pump 12 has its extreme end bended upwardly, to which is connected a lower
end of the mud transfer pipe 24. One end of a bendable mud transfer hose 25 is connected
to the upper end of the pipe 24, and the other end of the hose 25 is inserted into
the desired excavated hole.
[0050] As shown in Fig. 3 an opening and closing valve 26 is provided at the upper portion
of the mud transfer pipe 24.
[0051] Due to the above-described structure, the stabilizing mixture having a uniform concentration
can be produced by action, similar to the aforementioned embodiment. In addition,
the bentonite mixing and stirring action is carried out continuously simultaneously
with the mud transferring action. Namely, the mud transferring action can be continuously
carried out while maintaining the concentration of the stabilizing mixture uniform
to improve the efficiencey of excavating work.
[0052] Furthermore, in the present embodiment, since charging of bentonite 22, mud-preparation,
stirring and mud transferring can be carried out by use of a single underwater pump
12, the stabilizing mixture producing apparatus A can be manufactured inexpensively.
[0053] Next, a modification of the above described embodiment will be described with reference
to Fig. 5.
[0054] This modification is characterized in that a supply source for bentonite or the like
may be residual bentonite which floats in the upper part of an excavated hole, and
such floating residual bentonite can be transferred from an old excavated hole to
a new excavated hole.
[0055] That is, in Fig. 5, reference numerals 30 and 31 designate new and old excavated
holes, respectively, a foundation 33 of concrete is placed within the old excavated
hole 31, and the residual or excessive bentonite 22 floats thereabove.
[0056] On the other hand, no foundation is placed in the new excavated hole 30.
[0057] In the stabilizing mixture producing apparatus A according to the present embodiment,
one end of the lower bentonite intake pipe 19c is inserted into the bentonite 22 within
the old excavated hole 31, and one end of the mud transfer hose 25 is inserted into
the new excavated hole 30.
[0058] With the above-described structure, the negative pressure produced by the underwater
pump 12 can be utilized similarly to the aforementioned embodiments to suck the bentonite
22 from the old excavated hole 31 and the bentonite 22 can be mixed and stirred with
water efficiently and uniformly within the stirring water tank 10 to produce stabilizing
mixture.
[0059] The stabilizing mixture can be continuously supplied to the new excavated hole 30.
And, the thus obtained stabilizing mixture can be coated on the inner surfaces of
the new excavated hole 30 to thereby positively prevent the excavated walls from being
collapsed.
[0060] In Fig. 5, reference numeral 32 designates a concrete charging device.
[0061] While in the embodiments shown in Figs. 1 to 5, the bentonite 22 has been used as
a powdery stabilizing material to be mixed into water, it is to be noted that the
stabilizing mixture producing apparatus according to the present invention can use
other materials, for example, such as cement, which can be mixed with water to thereby
produce a slurry.