JPH0738997B2 - Excavator and sand reformer - Google Patents

Description

TECHNICAL FIELD The present invention relates to an apparatus for mechanically and electrically efficiently modifying excavated sediment having a high water content.

[Conventional technology and problems]

As is well known, a large amount of excavated earth and sand with a high water content is discharged by the shield construction method and underground continuous wall construction method that use a slurry or stabilizer. Such excavated soil with high water content is regulated as industrial waste and cannot be used as it is for landfilling. For this reason, various attempts have been made to modify the excavated soil,
The efficiency of the treatment process is being improved.

Conventional methods for modifying excavated soil are roughly classified into mechanical methods such as compression drying, and chemical methods that use solidifying materials. Mechanical methods are advantageous in that they can be reformed without the use of a solidifying material, but on the other hand, there is a limit to reforming, and dehydration cannot be sufficiently achieved only by compression. The chemical method can surely improve the solidification material to some extent, but it has a problem that the cost increases due to the increase of pH and the cost of the solidification material and the amount of sediment treatment.

[Object of the Invention]

The present invention is to solve the above-mentioned problem of excavated sediment modification, and more specifically, it can be easily installed at the site of shield construction, wall construction, etc., and the moisture content of the discharged sediment can be adjusted. ， In terms of cost to the extent that it is not treated as industrial waste,
It is intended to develop an apparatus that can effectively dehydrate and reform while satisfying functionality, continuous operability, and labor saving.

[Structure of Invention]

The gist of the present invention, which is intended to achieve the above-mentioned object, is to connect a telescopic tube between gates with open / close shutters that are continuously provided at a predetermined interval, and connect the gate in the axial direction of the tube. A mechanism for reciprocating the movement is provided, and by a combination of the reciprocating movement of the gate in the axial direction and the opening / closing operation of the shutter, the earth and sand supplied to the inside of the tube are compressed between the gates while being unidirectionally moved from one to the other In this tube-type sediment transporting device, an anode is attached to one surface of the shutter of the gate, and a cathode is arranged on the other surface of the shutter through an insulating tank from the anode, and the tube compressed between the gates. Modification of excavated sediment, characterized in that a direct current is applied to the inner sediment through the electrode and a water passage for discharging water collected at the cathode out of the gate is provided. Apparatus resides in.

That is, the present invention uses an electro-osmotic principle in the process of transport compression when an expandable and contractible tube, for example, a bellows (bellows) tube is arranged between gates with shutters and moved in the tube while performing compression between the gates. By doing so, it is intended to provide a transfer compression energizing device that significantly reduces the water content of the excavated soil, and the dewatering of the device is also performed effectively at each gate.

Examples of the drawings will be described below.

〔Example〕

FIG. 1 shows the entire apparatus of the embodiment of the present invention. 1 is a telescopic bellows tube, and 2 is a gate.
In the illustrated example, five gates No. 1 to No. 5 are arranged on a straight track with their gate surfaces parallel to each other. The bellows tube 1 is connected between the gates 2, and the start end bellows tube connected to the No. 1 gate is connected to the sediment supply device 3. The earth and sand supply device 3 is a forced agitation and supply device in which a screw conveyor 4 is set in the hopper, and the excavated earth and sand charged therein is supplied into the start end bellows tube 1 by driving the screw conveyor 4. On the other hand, the No. 5 gate is connected to the end bellows tube, and the end of this end bellows tube is the earth and sand discharge port 5.
It is open as Each gate 2 is set so that it can be reciprocated in the axial direction of the bellow tube 1 by being guided by the guide rails 6 and 7 arranged in the axial direction of the bellow tube 1, and the reciprocating motion is fixed at an appropriate position. It is provided by connecting each gate 2 to a cylinder 8 and a piston rod 9 to which reciprocation is imparted.

As shown in the appearance of FIG. 2, the gate 2 has a circular opening 10 in its center, which has a circular opening 10 penetrating through the opening and the back.
A shutter member 12 for opening and closing 10 is inserted so as to be vertically movable. That is, a circular opening 10 that communicates with the bellows tube 1 described above is formed substantially at the center of the gate body 11, and a plate-shaped shutter member 12 having a shutter cross section sufficient to close the circular opening 10 is formed by the thickness of the gate body 11. It is slidably inserted from above. The entire gate with shutter is reciprocated in the axial direction of the bellow tube by the piston rod 9 while being guided by the guide rails 6, 7.

Figure 3 shows the cross section of this gate, and Figure 4 shows the shutter.
12 shows a cross section of twelve. As shown in FIG. 3, a dehydration channel 13 is provided at the bottom of the opening 10 within the thickness of the gate body 11. The dehydration passage 13 is connected to the hose 14 shown in FIG. The hose 14 is led to the dehydration tank 15 shown in FIG. The shutter 12 is plate-shaped as a whole, but has a laminated structure as shown in the cross section of FIG.
That is, a plate-shaped insulating material such as a resin plate 17 is used as a central core material, and an anode plate 18 is attached to one surface thereof, and the other surface is constituted as a cathode. In the illustrated example, this cathode is made up of a laminated body of a material 19 and a metal mesh 20, and the entire cathode laminated body is separated by a plurality of spacers 21 into a space 22 between it and the resin plate 17.
Is supported on the other surface of the resin plate 17 so that The void 22 behind the cathode stack is such that when the shutter is closed, the opening 10 in the gate body 11 is closed.
There is a positional relationship leading to the dehydration path 13 at the bottom of the. The anode plate 18 and the metal mesh 20 of the cathode stack are the terminals 2 on the top of the shutter.
The terminals 23 and 24 are electrically connected to the DC power source.

In the device of the present invention having the above configuration, the shutter 12
The excavated earth and sand supplied from the earth and sand supply device 3 to one end of the bellows tube 2 is conveyed toward the discharge port 5 at the other end by repeating the compression operation by appropriately opening and closing the door and reciprocating the gate 2. To be done. In addition to the compression dehydration by this compression, by applying one shutter of both gates performing the compression operation as a cathode and the other shutter as an anode to the sand between the shutters, the electroosmosis principle is used. Then, the water is forcibly collected on the cathode side, and is discharged to the outside of the system through the above-mentioned void 21 and dehydration path 13.
From the earth and sand discharge port 5, the cake is discharged as a highly dehydrated cake.

FIG. 5 schematically shows the reciprocating operation of the gate and the opening / closing operation of the shutter when the carrying, compression and application are performed. Assuming that the reciprocating distance of each gate from No. 1 to No. 5 is within the range shown in the upper part of Fig. 5, in step (a), the shutters of each gate are all open and the soil is supplied. When the tip is located close to the No. 2 gate, close the shutters of the No. 1 and No. 2 gates, move the No. 1 gate in the direction of No. 2 and compress the soil between both shutters. (Step (b)). As a result, compression dehydration and electroosmotic dehydration on the cathode shutter side of the No. 2 gate are performed. When this operation is completed, move the No. 2 gate to the No. 1 gate as close as possible with the shutter of the No. 2 gate open, and then close the shutter (step (c)). By moving the 2nd gate to the No. 3 gate, the earth and sand compressed by the closed shutter will be conveyed to the 3rd gate. Next, in step (d), the shutter of No. 1 gate is opened and moved toward the supply port, and the shutter of No. 3 gate is closed and moved toward No. 2 gate, and No. 2 and No. Sediment is recompressed between the three gates and applied simultaneously to perform compression dehydration and electroosmotic dehydration. Then, in the same operation as in step (c),
Move to No. 4 gate by No. 3 gate (step (e)). On the other hand, the No. 1 and No. 2 gates perform compression dehydration and electroosmosis dehydration on the newly supplied soil by performing the same operation as in the above step (b), and at the same time, No. 3 and No. Four
The gate performs the same operation as in the step (d) to perform compression dehydration and electroosmotic dehydration (step (f)). Stage (g)
Then, the No. 1 and No. 2 gates perform the same operation as in step (c), and the No. 3 and 4 gates perform the same operation as that of No. 2 and 4 gates in step (e) It is shown that, by repeating such an operation, the earth and sand supplied from one end is conveyed toward the discharge port at the other end while repeating compression dehydration and electroosmotic dehydration.

Thus, according to the device of the present invention, in the process of carrying out the sediment by the tube type conveyor, the sand is compressed, applied,
The function of dehydration is achieved at the same time. Then, the strength of compression and application can be easily adjusted, and therefore, the intended dehydrated cake can be modified according to the property of the target sand and sand, and mechanical dehydration (pressurized dehydration) can be performed. Dewatering of excavated soil beyond the limit is possible. In addition, since the device of the present invention can be installed at a construction site to improve the source of excavated sediment and can perform continuous (batch type) processing, the device of the present invention can be used in the process of transporting excavated sediment. By incorporating them, the work can be rationalized and modified at the same time, and the modified soil can be easily handled and reused.

According to the experiments conducted by the present inventors, when the sand + silt water content of 25% was pressed, the water content was 17% only by compression. However, under the same compression condition, the voltage was 100v and the current density was 0.3. ~
When a voltage (layer thickness of 00 mm) was applied for 6 to 12 minutes under 0.5 A / dcm ² , a dehydrated cake with a water content reduced to 7 to 8% was obtained. We also conducted an experiment when the voltage was raised to 200v.
There was not much difference from the case of 00v. In addition, the latter had a dehydrating effect more than double when applied without applying pressure and when applied with applying pressure. Further, when the conductive powder (iron powder) was mixed in the earth and sand and compressed, the dehydration effect was further improved.

Recently, a water-absorbent resin is sometimes used as a soil stabilizer, but the water-absorbent resin used for this has the property of expelling water when a direct current is applied. The device of the present invention can be advantageously applied to the above-mentioned soil.

[Brief description of drawings]

1 is a schematic sectional view showing an embodiment of the device of the present invention, FIG. 2 is an overall perspective view of each gate of FIG. 1, FIG. 3 is a schematic sectional view of the gate, FIG. 4 is a sectional view of a shutter, FIG. 5 is a diagram showing the sequence of carrying, compressing, and dehydrating earth and sand by the reciprocating operation of the gate and the opening / closing operation of the shutter of the device of the present invention. 1 …… Bello tube, 2 …… Gate, 3 …… Sand supply device, 5 …… Sand discharge port, 6,7 …… Gate guide rail, 8…
… Cylinder, 9 …… Piston rod, 10 …… Gate opening, 11 …… Gate body, 12 …… Shutter, 13 …… Dehydration path,
14 …… dehydration hose, 15 …… dehydration tank, 17 …… insulating resin plate, 18
…… Anode plate, 19 …… Material, 20 …… Metal mesh (cathode), 2
2 …… The void behind the cathode.

Claims (1)

[Claims] 1. A mechanism in which an expandable tube is connected between gates with open / close shutters that are continuously provided at a predetermined interval, and a mechanism that reciprocates the gate in the axial direction of the tube is provided.
In a tube-type earth-and-sand conveying device configured to move unidirectionally from one side to the other while compressing the earth-and-sand supplied in the tube between the gates by a combination of reciprocating movement of the gate in the axial direction and opening / closing operation of a shutter. , An anode is attached to one surface of the shutter of the gate, and a cathode is arranged on the other surface of the shutter through an insulating layer with this anode, and a direct current is passed through the electrode to the sand in the tube compressed between the gates. An apparatus for reforming excavated earth and sand, characterized in that a water passage for discharging the water collected by the cathode to the outside of the gate is provided while being configured to energize.