JPH0299182A - Continuous mud solidification apparatus - Google Patents

Abstract

PURPOSE:To effect a continuous mud solidification by blending a solidifying material with mud by means of a continuous kneading machine which produces such a strong shearing force that effects discontinuous volume changes in the mud, imparting compressive and expansive action to the mud continuously. CONSTITUTION:The apparatus consists of a solidifying material supply system A, a mud supply system B and a solidifying material-mud continuous kneading device C, wherein said kneading device C is a continuous kneading machine 11 (e.g., screw extruding kneader) which produces such a strong shearing force that effects discontinuous volume changes in mud, imparting compressive and expansive (elongation) action continuously to the mud. By the use of this continuous kneading machine, the solidifying materials can be uniformly blended with the mud, so that treated mud 14 having desirable strength can be produced using an appropriate quantity of solidifying materials, avoiding thereby an excessive use of solidifying materials, and at the same time a large amount of mud can be treated continuously in a narrow place, employing a few number of operator.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a continuous mud solidification device, and more specifically, a continuous mud solidification device that can economically and continuously solidify a large amount of mud in a narrow space. Regarding.

(Conventional technology) Traditionally, civil engineering work generates a large amount of excavated mud, a large amount of sludge is also generated from wastewater treatment equipment, etc., and dredging work for irrigation ponds etc. generates a large amount of sludge (bottom sediment). ) is occurring.

Since these muds contain a large amount of water and are fluid, they are treated as "sludge" of industrial waste, and a large amount of processing cost is required to dry and solidify this for disposal.

Therefore, methods have become widely used to economically solidify these muds without drying them and to facilitate their disposal.

Methods for solidifying mud include using cement-based, lime-based, or polymer-based solidifying agents that absorb water in the mud to lower its moisture content, or react with the water in the mud to solidify the entire mud. is commonly practiced.

(Problem to be Solved by the Invention) The conventional methods of solidifying mud using the solidifying agent described above include methods in which the solidifying agent is sprinkled on the mud on the ground or in a pool and mixed mechanically, and mud is mixed in a stirring tank. However, in any case, the moisture content of the mud varies widely even if the source is the same, and in order to achieve sufficient solidification, a large excess amount of solidification agent must be added. I have no choice but to do it. Therefore, there is a problem that the cost of the solidifying material increases. Furthermore, in order to sufficiently mix the solidifying material, excessive mixing operations are similarly required, resulting in high energy costs. Furthermore, processing a large amount of mud requires a large area, and processing is difficult in mountainous areas such as tunnel construction or urban areas such as subways. Therefore, this places a heavy burden on the transportation of mud, which is difficult to handle.

Therefore, an object of the present invention is to provide a continuous mud solidification device that significantly improves the human cost, solidification material cost, and processing area cost, and that can turn mud with any water content into treated mud with a desired unconfined compressive strength. It is to provide.

(Means for solving problems) The above objects are achieved by the present invention as described below.

That is, the present invention consists of a solidification material supply section, a mud supply section, and a solidification material-mud continuous kneading section, and the kneading section continuously applies compression and expansion (stretching) actions to the mud to create a discontinuous state in the mud. This continuous mud solidification device is characterized by being a continuous kneader that has a strong shearing force that causes volume changes.

(Function) The solidification material and mud are mixed using a continuous kneader that has a strong shearing force that continuously compresses and expands (stretches) the mud, causing discontinuous volume changes in the mud. By doing so, the solidification of mud can be made continuous, and the cost of solidifying material, human cost, and processing area cost are reduced.

(Preferred Embodiments) Next, the present invention will be described in more detail by citing preferred embodiments.

FIG. 1 is a diagram for explaining the apparatus of the present invention as a whole. As shown in the first figure, the continuous mud solidification apparatus of the present invention includes a solidification material supply section A, a mud supply section B, and a solidification material-mud soil solidification system. It consists of a kneading section C. The solidified material supply section consists of a solidified material silo 1 and a solidified material receiving hopper 2, and the solidified material 3 is transported by, for example, a lorry and stored in the silo 1, and the required amount is supplied to the rotary pulp 4 of the silo 1 and the flow conveyor 5. It is then sent to hopper 2. At the bottom of this hopper 2, a powder feeding device 6 is provided that can control the amount of solidified material discharged. The solidified material supplied from the feeder 6 is sent to the hopper 11 by the injection screw conveyor 7.

The mud supply section B includes a piston pump (not shown) connected to a mud source, a pressure feed pipe 8, and a hopper 9.

The mud and solidifying material supplied as described above are sent to the hopper 10 of the kneading section C, kneaded by the extrusion kneader 11, and discharged. The thus discharged mud solidifies while being sent to the sand bit 13 on the discharge conveyor 12, loses fluidity and stickiness, and becomes a block-shaped treated mud 14 having a desired unconfined compressive strength.

The main feature of the present invention is that the solidification material and mud are mixed continuously. In other words, in the conventional technology, mixing of the solidification material and mud is mostly done batchwise even when mechanical stirring is used.
Because it relied on stirring bodies such as wheels and plates, and scrapers, it was impossible to uniformly disperse the solidifying agent, and therefore a large excess of assimilating agent was required in order to obtain treated mud with unconfined compressive strength above a certain level. .

On the other hand, in the present invention, an extrusion continuous mixing machine with a strong shearing force that continuously compresses and expands (stretches) the material to be mixed is used to mix the solidification material and mud. As such a continuous mixer, a screw extrusion kneader, for example, a twin-screw kneader KRC kneader (manufactured by Kurimoto Iron Works) can be advantageously used.

By using such a continuous mixer, the solidification material and mud are mixed uniformly, and the treated mud can be made to the desired strength with the appropriate amount of solidification material. There is no need to use it anymore. Furthermore, a large amount of mud can be continuously processed at the same time even in a narrow space by a small number of people.

When actually operating the above-mentioned apparatus of the present invention, it is preferable to measure the flow rate, moisture content, and density of the supplied mud, and change the supply of the solidification material (2) according to these measured values.

In the present invention, it is preferable to use Model FT-102 manufactured by Field Chick as a device for measuring the water content and density of mud. This device has the advantage of being a measuring device that uses radioisotopes, and can simultaneously measure the density of mud using gamma rays and the water content in the mud using neutrons.

This measuring device has conventionally been used as a device for managing the compaction of embankment, but according to the present inventor, it is very effective for the purpose of the present invention, that is, as a density meter and moisture meter for mud.

In addition, in the present invention, it is preferable to measure the flow rate of the supplied mud in addition to measuring the water content and density of the mud, and as this flow meter, an electromagnetic flow detector (manufactured by Yokogawa Electric) such as YMloo, 200.300 type, etc. is used. is preferable.

The following three methods are mainly possible for controlling the device of the present invention using the measuring equipment as described above.
By measuring t/rn') and multiplying these values, the weight fi (t/Hr) of the mud supplied per unit time can be obtained.If the water content of this mud is approximately constant, Since the amount of water supplied per unit time is required, it is possible to always mix a fixed ratio of solidification agent into the mud.

(2) The amount of water in the mud supplied per unit time is determined by comparing the mud flow ffi (Q: ♂/hr) and its water content.
The setting is adjusted so that a fixed ratio of the solidifying material is supplied to this amount of water.

By adjusting as described above, the solidifying agent can always be mixed in a constant proportion to the water content in the mud, and treated mud with a constant unconfined compressive strength can be obtained.

(3) What is the water content ratio and unit volume weight N (wet density) of mud?
If the specific gravity of soil particles and the air gap ratio of soil particles are constant,
There is a relationship shown in FIGS. 2 and 3, and the water content ratio of mud can be predicted by measuring the wet density of mud. On the other hand, the relationship between the water content ratio and the unconfined compressive strength of the treated mud is as shown in Figure 4, and once the target strength of the solidified mud is determined, the water content ratio is determined. Further, as shown in Figure 5, the addition rate of the solidifying agent is determined by determining the target strength based on the relationship between the solidifying agent addition rate and the unconfined compressive strength. From FIGS. 4 and 5, if the unconfined compressive strength of the treated mud is 9u, the water content of the mud to be treated is W, and the amount of solidification agent added is a, the following relational expressions hold true for each of them.

(K, m, and n are constants determined by each muddy soil) By taking the logarithm of both sides of equation 1, it is transformed as shown in equation 11.

1ogqu = m Ioga−n logw+
logk·11 Therefore, the target unconfined compressive strength of the treated mud is determined, and if the water content ratio of the mud can be measured, the amount of solidification agent added can be determined. The relationship between the amount of solidifying agent added and the unconfined compressive strength when the water content ratio of each mud is kept constant is as shown in FIGS. 6 and 7.

On the other hand, the flow rate (Q) of the supplied mud is measured by an electromagnetic flow meter, and the supplied mud ff1 (QXb) can be found by multiplying it by the density (d) measured together with the water content ratio. By calculating and controlling so that a predetermined amount of solidifying agent is added to this amount, treated mud having the target unconfined compressive strength can be stably obtained regardless of changes in the properties of the supplied mud.

The above is the main part of the present invention, and other solidifying materials used are not particularly limited, and may be conventionally known such as cement, slag, or polymer. Moreover, the silo, hopper, feeder, conveyor, etc. for the solidifying material are not special, and any conventionally known suitable ones may be used and combined.

(Example) The apparatus of the present invention shown in Figure 1 was used to solidify excavated material (water content 50%, specific gravity 1.48) generated during tunnel construction. When adding the solidification agent, the manager measured the water content, density, and flow rate of the mud on site, and changed the addition rate of the solidification agent according to the measured values. The details of the main equipment are as follows.

Solidification material silo: 2 units, 30 go, conveyance equipment with bag filter = 1 unit, flow conveyor powder feeding equipment = 1 unit, 2♂ hopper, powder feeder, powder feeder with injection screw conveyor: 100IL to 3,500J2/ H "Mud receiving potspar: 1 unit, 3m', mixed line machine with air quad gate: 1 unit, capacity 60rr + 3/day, S-18K
RC kneader (two-shaft kneader) Discharge conhair: 1 unit, capacity 100rn'/day, 900w
x GlIIL, flow rate meter with belt scale: YM300 type electromagnetic flow detector (manufactured by Yokogawa Electric) Water density meter, RI water density meter (model FT102 type, ■
(Manufactured by Field Chick) Treatment i: 900 rn''/day Target - Axial compressive strength: 0.5 Kg/cm'' (2 hours after kneading) γ7 1 -- Tomo Kibata Rescue worker (person) 22 Monitoring time ( 1) 416 Amount of solidifying agent used (%) 1.7~2.0 2.5~
4-axis compressive strength 18-2.0 15-22 Kneading machine power (W) 90 150 Processing capacity (rn'/fir) 80 6
0 The comparative example is a case where a batch type wheel type stirring type mixing tank was used.

From the above results, it is clear that in the present invention, compared to the conventional method, the number of workers, labor, and amount of solidifying agent used are significantly improved, and the strength of the treated mud is uniform.

[Brief explanation of drawings]

FIG. 1 is a diagram schematically showing the apparatus of the present invention, and FIGS. 2 to 7 are diagrams explaining the properties of mud. A: Solidification material supply section B: Mud supply section C: Solidification material-mud kneading section 1: Solidification material silo 2: Solidification material receiving hopper 3: Solidification material 3 4: Rotary valve 5: Flow conveyor 6: Powder feeding device 7: Conveyor 8: Pressure feed pipe 9, hopper 102 Hopper 11: Kneading machine 12: Conveyor 13: Earth and sand bit 14: Applicant for processing mud To Kankyo Engineering Co., Ltd.? 1 BiS Water content ratio (%) To water content ratio) Figure 4 Figure 5 Solidification agent addition rate (%)

Claims (2)

[Claims] (1) Consisting of a solidification material supply section, a mud supply section, and a solidification material-mud continuous kneading section, the kneading section continuously applies compression and expansion (stretching) effects to the mud to cause discontinuous volume changes in the mud. A continuous mud solidification device characterized by being a continuous kneading machine that has a strong shearing force. (2) The continuous mud solidification apparatus according to claim 1, wherein the kneader is an extrusion kneader.