JPH0699425A - Water content reducing device for wet sand - Google Patents

Abstract

PURPOSE:To reduce the water content contained in wet sand continuously and efficiently by forming a helical guide passage along the inner peripheral face of a rotating drum, also forming open windows on which nets are stretched around on a drum peripheral wall in the middle of the guide passage and sucking the water content of wet sand passing through the guide passage through the windows. CONSTITUTION:A helical guide passage 6 is formed by fixing integrally a helical structural component 16 on the inner face of a peripheral wall 2x of a cylindrical drum 2, and wet sand fed from 2y side of one end of the drum 2 is guided toward the other end. A plurality of open windows are formed respectively on rotating racetracks A and B on the peripheral wall 2x of the drum 2, and nets 17a are stretched around over the windows. Suction tools are disposed on the rotation tracks A and B of the open windows. The continuous treatment of wet sand can be carried out simply by rotating the drum 2 by the above-said arrangement.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water content reducing apparatus for water-containing sand, and more particularly to a technology for efficiently reducing the water content of sand containing a large amount of water.

[0002]

2. Description of the Related Art In general, concrete for civil engineering and construction is mainly composed of cement, sand (fine aggregate) and water. However, in order to produce high quality concrete, water content in the whole concrete The ratio becomes extremely important. In this case, the amount of water in the entire concrete is the total amount of water added separately during kneading and the amount of water contained in the sand from the beginning.

The water content of the sand is an index showing the amount of water contained in the sand from the beginning, and the water content of the water permeates the internal structure of the sand. It is an added value of the rate (water absorption rate) and the rate of water adhering to the surface of the sand (surface water rate). Therefore, no matter how much water is added when kneading concrete, if the water content of sand is not appropriate, the water content in the whole concrete will not be appropriate, and high quality concrete will be obtained. It will not be possible.

On the other hand, in recent years, naturally existing mountain gravel, sea gravel, land gravel, or quarry excavated in a quarry is appropriately crushed or ground by using a sand crushing device to obtain high quality sand. Although it has been put into practical use, water is usually used in the crushed sand manufacturing process with this type of equipment, and therefore the final sand contains a large amount of water. Will be there. And, in general, sand with such a high water content (water-containing sand) is usually stored in a silo for a long time before use,
At the time of kneading concrete, a suitable amount of hydrated sand is taken out from under the silo, and the taken hydrated sand is kneaded with cement and water.

[0005]

By the way, since the hydrated sand produced using the crushed sand manufacturing apparatus as described above contains a large amount of water, it should be used immediately after the production for kneading concrete. If it is stored in a silo for a long time, the moisture content will be reduced only by natural drying, and the moisture content will fluctuate depending on the length of time the product is left standing. It becomes extremely difficult to take out sand with water content during actual kneading, and due to excess or deficiency of water content in the entire concrete,
There is a problem that high quality concrete cannot be obtained. Further, the water-containing sand produced by the above device, if you want to use for kneading of concrete within a short time, because the water content of the sand is too large, the water content is too large,
There is a problem that the amount of water to be separately charged at the time of kneading has to be made smaller than usual, and the correction for this becomes troublesome and complicated.

As a means for rapidly reducing the water content of sand, a method of stacking water-containing sand in a drying chamber or a method of centrifuging water from the water-containing sand using an apparatus utilizing centrifugal force is tried. However, the former method is disadvantageous in terms of cost because it requires large-scale equipment capable of temperature control, and the time reduction is not sufficient, and the latter method. According to this, an ultra-high speed rotation mechanism or the like is required to perform the centrifugal separation, and the apparatus becomes complicated. Furthermore, with any of the above methods, only batch processing can be performed and continuous processing cannot be performed, which causes a problem that work efficiency deteriorates.

[0007]

The water content reducing apparatus for water-containing sand according to the present invention is characterized in that it is configured as follows in order to solve the above-mentioned various problems. That is, the device according to the invention of claim 1 forms a spiral guide passage along which the water-containing sand passes along the inner surface of the peripheral wall of the rotating cylindrical drum, and the guide passage is formed on the peripheral wall of the cylindrical drum. An opening window is formed in the middle of which the mesh-like body is stretched, and moisture is sucked from the water-containing sand passing through the guide passage on the rotation track of the opening window outside the peripheral wall of the cylindrical drum. The suction means is provided.

According to a second aspect of the present invention, the spiral guide passage is formed between one end of the cylindrical drum and a predetermined position in the central axis direction, and the predetermined guide of the cylindrical drum is provided. In the internal space from the position to the other end, a screw conveyor that conveys the hydrated sand after passing through the guide passage to the other end side and a wind is fed to the hydrated sand conveyed by this screw conveyor. And a blowing means for controlling the air flow.

[0009]

According to the apparatus of the first aspect of the present invention, by rotating the cylindrical drum having the spiral guiding passage on the inner surface of the peripheral wall, the water-containing sand inside the cylindrical drum is transformed into the spiral guiding passage. It will move along, but during this movement, when the water-containing sand reaches the opening window in the middle of the guide passage, by the suction means existing outside through the mesh body,
The water content of the hydrated sand is sucked at once. In this case, since the opening window is also rotating in accordance with the rotation of the cylindrical drum, the suction of water by the suction means is possible only when the opening window passes through the location where the suction means is arranged. In order to avoid non-uniformity of the suction action due to such timing restrictions, it is preferable to dispose the opening window and the suction means at a plurality of locations.

According to the apparatus of the second aspect of the invention, the spiral guide passage is formed between the one end side of the cylindrical drum and a predetermined position in the central axis direction of the cylindrical drum as described above. The water-containing sand whose water has been sucked by moving along ends the movement along the guide passage when reaching the predetermined position, and thereafter, the inside of the cylindrical drum is moved to the other end side by the screw conveyor. It is transported toward. At the time of this transportation, since the air is sent from the blowing means to the hydrated sand, the hydrated sand is subjected to the forced drying action by the wind, whereby the moisture adhering to the surface of the hydrated sand is moderate. To dry. In this way, the forced drying action on the hydrated sand is achieved only by removing the water from the hydrated sand surface only by the suction action by the above-mentioned suction means,
This is because the surface becomes wet with water and the aforementioned surface water ratio cannot be significantly reduced. Therefore, by appropriately forcibly drying the surface in this way, the surface water content is greatly reduced, and the required water reduction effect can be obtained in an extremely short time by the synergistic action with the water reduction by the suction means. Will be possible.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a water content reducing device for hydrous sand according to the present invention will be described below with reference to the drawings. As shown in Figure 1,
The moisture reducing device 1 in this embodiment includes a cylindrical drum 2 and
The cylindrical drum 2 has a drive mechanism 3 for rotating the cylindrical drum 2 around its central axis, and a chute 4 for discharging the water-containing sand which has been subjected to a predetermined treatment inside the cylindrical drum 2.

The drive mechanism 3 has a total of four rollers 31 ... 31 supporting the lower part of the cylindrical drum 2, a motor 32 as a drive source, and a chain for transmitting the rotation of the motor 32 to the cylindrical drum 2. And a winding transmission member 33 such as the above. More specifically, the winding transmission member 33 is wound around the large diameter sprocket 2a fixed to the central portion of the cylindrical drum 2 in the central axis direction and the small diameter sprocket 32a fixed to the rotation shaft of the motor 32. The cylindrical drum 2 rolls above the rollers 31 ... 31 by driving the motor 32. A lateral shake preventing ring 34 is fixedly provided on the outer peripheral surface of the cylindrical drum 2 over the entire circumference, and the lateral shake preventing ring 34 has a concave peripheral surface. Is engaged with.

As shown in FIG. 2, in the inside of the cylindrical drum 2, a spiral guide passage 6 is formed on the inner surface of the peripheral wall 2x over approximately the left half of the inside thereof. A screw conveyor 7 and a blower pipe 8 are arranged in the right half portion.

The rotating shaft 7a of the screw conveyor 7 is
It penetrates through the inside of the cylindrical drum 2, and as shown in FIG. 1, it is rotatably held via two bearings 9 and 10 on both outer sides of the cylindrical drum 2. A sprocket 11 is fixed to the right end of the rotary shaft 7a of the screw conveyor 7, and the sprocket 11 and the auxiliary motor
The winding transmission member 14 is wound around the sprocket 13 fixed to the rotating shaft of 12, and the screw conveyor 7 is rotated by the driving of the auxiliary motor 12.

Further, as shown in FIG. 2, a large number of ejection holes 8a ... 8a are formed in the blower pipe 8, and by blowing air from the blower means 15 such as a blower to the blower pipe 8,
8a is a structure in which wind is jetted and supplied to the periphery of the screw conveyor 7 from the jet holes 8a. Further, the blower means 15 has a built-in flow rate control valve or flow rate control valve for performing control such as making the amount or speed of the air jetted and supplied from the blower pipe 8 constant, and the operation of these control valves. Thus, the wind is always jetted and supplied to the periphery of the screw conveyor 7 in an appropriate state. Further, if necessary, a temperature controller may be built in the blower means 15 and the temperature of the air blown from the blower pipe 8 may be appropriately controlled by the action of the temperature controller.

The spiral guide passage 6 is shown in FIGS.
As shown in, the spiral drum partition member 16 is integrally formed on the inner surface of the peripheral wall 2x of the cylindrical drum 2, and the water-containing sand introduced from the one end 2y side of the cylindrical drum 2 is The other end is guided toward the 2z side. The guide passage 6 may be a single spiral passage or two or more spiral passages.

Further, the peripheral wall 2x of the cylindrical drum 2 is formed with a plurality of opening windows 17 ... 17 on the two rotational paths A and B respectively, and the opening windows 17 ... 17 have a mesh-like body 17a. … 17a
Has been stretched over. In this embodiment, three opening windows 17 are formed at equal angular intervals for one rotary orbit, and a punching metal having a large number of circular holes is used as the mesh body 17a. Then, as shown in FIG. 4, on the inner surface of the peripheral wall 2x of the cylindrical drum 2, a protrusion 18 is fixed to the end portion of the opening window 17 on the side opposite to the rotation direction (the rotation direction is the direction a in the figure). . This projecting body 18 is the cylindrical drum 2
Is inclined by 60 degrees with respect to the tangential direction of the peripheral wall 2x.

In addition to the above construction, suction means 20 is installed outside the cylindrical drum 2 (see FIG. 4). The suction means 20 has a suction tool 22 that is rotatably held around a support shaft 21, and a negative pressure generator 24 that is connected to the suction tool 22 via a flexible hose 23. A water storage part is built in the negative pressure generating device 24. And the suction tool
The suction port 22a at the tip of 22 is arranged with a slight gap between the suction port 22a and the peripheral wall 2X of the cylindrical drum 2, and when the signal 25x from the control means 25 excites the electromagnet 26, The suction tool 22 rotates in the W direction against the biasing force of the spring 27. The suction tool 22 has two rotational trajectories A, which are the rotational trajectories of the opening windows 17 ... 17 in the cylindrical drum 2.
One is arranged on B.

Next, the operation of the above embodiment will be described. First, the drive device 3 is activated to rotate the cylindrical drum 2 in the direction a in FIG. 4, and under such a state, the hydrated sand is charged from the one end 2y side of the cylindrical drum 2. In this case, if the diameter of the cylindrical drum 2 is about 120 cm,
It is set to about 15 rpm. As a result, the hydrated sand moves along the guide passage 6 on the inner surface of the peripheral wall 2x of the cylindrical drum 2, but during this movement, the presence of the protrusions 18 collectively raises the hydrated sand to a predetermined height. During the lifting process, a large amount of hydrated sand S accumulates on the inner edge of the opening window 18 as shown in FIG. The accumulated hydrated sand S drops from a predetermined height position by further rotation of the cylindrical drum 2. The hydrated sand S that has fallen is the next protrusion 18 (one retard angle with respect to the rotation direction a). It is received by the side projection 18).

Then, when the opening window 17 reaches the position where the suction port 22a of the suction tool 22 is disposed with the rotation of the cylindrical drum 2 (when the state shown in FIG. 4 is reached), the control means. When 25 excites the electromagnet 26 and rotates the suction tool 22 in the W direction, the suction port 22a abuts or substantially abuts the mesh body 17a, and sucks moisture from the accumulated water-containing sand S at once. . After this suction, the control means 25 demagnetizes the electromagnet 26 to return the suction tool 22 to the initial position, and at the time when the next opening window 17 reaches the position where the suction port 22a is arranged, again in the same manner as above. Aspirate water. Such an operation is periodically performed at a predetermined timing. Note that the suction tool 22 may be always in the operating state, or may be controlled so that it is activated only when the suction tool 22 rotates in the W direction.

Next, the water-containing sand that has completed the movement along the guide passage 6 is conveyed toward the other end 2z side by the rotation of the screw conveyor 7 shown in FIG. The hydrated sand is appropriately dried by the wind blown from the jet holes 8a. The water-containing sand that has been subjected to this drying operation is dropped and collected from the other end 2z of the cylindrical drum 2 to the chute 4 as indicated by the arrow X, and then dropped and stored at a predetermined location.

The stored water-containing sand is subjected to a strong water suction action by the suction tool 22 and an appropriate drying action due to the wind from the blower pipe 8, and the water content is drastically reduced in a short time. The water content is such that the work is continuously performed, and the water content of the finally obtained sand does not vary. Furthermore, since the water content of the sand finally obtained is in a state of being sufficiently reduced, when this sand is piled up, the water content of the sand in the upper layer flows down and the water content of the sand in the lower layer is lowered. There is no variation in the water content between the upper and lower sides, such as the increase in water content.

A comparison between the water-reduced sand with reduced water content as described above and the conventional one with the water-containing sand stored in a silo and taken out from below after a long time has passed is as follows. The results shown were obtained. That is, when stored in a silo as in the conventional case, in the particle size constitution of FM 2.7, the surface water ratio is 5% to 6%, no change occurs between the upper layer portion and the lower layer portion, and those having a diameter of 1.2 mm or less are Surface water rate is 9%
And the surface water rate of 1.2 mm or more was 3%.
On the other hand, when water is positively sucked from the hydrated sand using the suction tool 22 as described above, the surface water ratio is 8% to 9% in the particle size configuration of FM 2.7. By blowing air in the state (8% to 9%), the surface water rate
It will be 5.5% to 6%. Since the degree of variation in the surface water ratio is extremely small, it is possible to always add sand having a constant surface water ratio or water content during concrete kneading.

[0024]

The water content reducing apparatus for hydrous sand according to the present invention comprises:
Since it is configured as described above, it has the following effects.

That is, according to the moisture reducing apparatus for water-containing sand of the first aspect of the present invention, the water-containing sand moves along the guide passage as the cylindrical drum having the spiral guide passage on the inner surface of the peripheral wall rotates. At the same time, during this movement, the water content of the hydrated sand is sucked all at once by the suction means through the mesh body of the opening window. As a result, the moisture reduction efficiency of the hydrated sand is significantly improved, and it is not necessary to use a centrifuge with a complicated structure that requires ultra-high speed rotation as in the past, and the cost can be reduced and the cylinder Since the hydrated sand moves in the central axis direction along the guide passage only by rotating the cylindrical drum, continuous treatment becomes possible, and various problems caused by the conventional batch treatment can be avoided.

Further, according to the moisture-reducing apparatus for hydrated sand of the second aspect of the invention, the moisture is reduced as described above from the one end side of the cylindrical drum to a predetermined position in the central axis direction of the cylindrical drum. The sucked water-containing sand is conveyed by the screw conveyor toward the other end inside the cylindrical drum, and at the time of this conveyance, it is subjected to the forced drying action by the air blown from the air blower. Water adhering to the surface of the sand dries properly. As a result, the surface water content of the hydrated sand is significantly reduced, and the required water reduction effect can be obtained in an extremely short time by the synergistic action with the water reduction by the suction means. Even when the sand is piled up, the water content in the upper layer and the lower layer is always constant.

[Brief description of drawings]

FIG. 1 is a schematic front view showing the overall configuration of an embodiment of a water content reducing device for hydrous sand according to the present invention.

FIG. 2 is an enlarged vertical sectional front view of an essential part showing the internal structure of a cylindrical drum which is a component of the above-described embodiment.

FIG. 3 is an enlarged schematic front view of a main part showing a structure of a guide passage which is a constituent element of the above embodiment.

FIG. 4 is a schematic configuration diagram showing an arrangement state of a cylindrical drum and a suction unit, which are components of the embodiment.

[Explanation of symbols]

 1 Water content reducing device for water-containing sand 2 Cylindrical drum 2x Circumferential wall 2y One end of cylindrical drum 2z Other end of cylindrical drum 6 Induction passage 7 Screw conveyor 8 Blower pipe (blower) 17 Open window 17a Net 22 Suction tool (Suction means) A Rotational orbit of opening window B Rotational orbit of opening window

Claims (2)

[Claims] 1. A spiral guide passage through which water-containing sand passes is formed along the inner surface of the peripheral wall of a rotating cylindrical drum, and the peripheral wall of this cylindrical drum is located in the middle of the guide passage and has a mesh shape. A body is formed with an open window, and suction means for sucking water from the water-containing sand passing through the guide passage is provided on the rotation path of the open window outside the peripheral wall of the cylindrical drum. A water content reducing device for hydrated sand. 2. A spiral guide passage is formed between one end of the cylindrical drum and a predetermined position in the central axis direction, and the spiral guiding passage is formed in an internal space from the predetermined position to the other end of the cylindrical drum. A screw conveyor that conveys the hydrated sand after passing through the guide passage to the other end side, and a blower that supplies air to the hydrated sand conveyed by the screw conveyor. The water content reducing device for hydrous sand according to claim 1.