JPH01293199A - Drying treatment of muddy material - Google Patents

Abstract

PURPOSE:To increase the contact area with the outdoor air in an initial period of drying by adding a prescribed amt. of a solidifying agent to a muddy material, agitating the material, drying the material for a prescribed period of time, forming grooves or ruggedness on the surface of the muddy material and drying and curing the material. CONSTITUTION:The muddy material 9 is dried in a recessed natural drying field 8 provided adjacently to an outdoor mud storage tank 7. The muddy material 9 carried by a cart 10, etc., is pumped 11 to a mixer 12 where the solidifying agent such as cement is added at a slight ratio to the material and the material is agitated. This material 9 is then transferred by a hose 13, etc., to the natural drying field 8. The material 9 is dried for several days in the drying field 9 and thereafter, the ruggedness is formed on the surface of the material 9 by using a cultivator, etc. After this material 9 is dried to attain the prescribed strength, the fresh material 9 is transferred from the storage tank 7 onto the treated material 9 and the above-mentioned drying treatment is repeated.

Description

Detailed Description of the Invention "Field of Industrial Application" This invention is applicable to the drying treatment of muddy materials discarded in civil engineering works such as construction foundation work, dredging, and reclamation, or in various industries. This relates to a drying method.

"Conventional technology" Conventionally, methods for treating muddy substances include mechanical dehydration treatment such as pressure dehydration, vacuum dehydration, and centrifugal dehydration, solidification treatment that solidifies by adding a solidifying agent, and drying treatment such as sun drying. and so on.

``Problems to be Solved by the Invention'' However, while the above-mentioned mechanical dehydration treatment and solidification treatment have high treatment efficiency, they require mechanical equipment, chemicals, etc., resulting in high costs; Although the processing method is low in cost, there is a problem in that the processing efficiency is low.

For this reason, in recent years, it has been desired to treat muddy substances at low cost and with high efficiency, and an example of this is the solar drying treatment method for waste sludge disclosed in Japanese Patent Application No. 172198/1983. there were.

This method is basically a drying method in which muddy materials are dried in the sun, but by adding a small amount of solidifying agent to the muddy materials being dried, a weak support structure is created. It restricts the shrinkage of the solid content that accompanies drying and facilitates the movement of moisture, allowing the moisture to easily evaporate during drying. Additionally, since this drying method has a weak support structure as described above, cracks are likely to occur as the drying progresses, and when cracks occur, the contact area with the outside air increases and moisture is absorbed. Evaporation will be further promoted.

This invention is a further development of the drying method described above, and by forming grooves or irregularities on the surface of the muddy material, the contact area with outside air is increased in the early stage of drying, and cracks that occur as the drying progresses are prevented. The purpose is to dramatically increase drying efficiency by forming fine particles.

``Means for Solving the Problems'' The method for drying muddy materials of the present invention provides a method for drying muddy materials with 0.
1 to 5% by weight of a solidifying agent is added and stirred, and then this muddy material is dried for a predetermined period of time to reduce the fluidity of the surface of the muddy material. This method forms grooves or irregularities, and then dries and hardens this muddy material.

"Function" In the slurry material drying treatment method of the present invention, a weak supporting structure is provided by adding 0.1 to 5% by weight of a solidifying agent to the mud material, thereby causing the solid content to shrink as it dries. to make it easier for moisture to move and promote evaporation of moisture during drying. At that time, after drying this muddy material for a predetermined period of time to reduce the fluidity of the surface of the muddy material so that the surface can be formed into a predetermined shape,
A plurality of grooves or irregularities are formed on the surface of this slurry material, thereby increasing the external contact area from the initial stage of drying and making it easier for water to evaporate. After doing this, when this muddy substance is further dried, cracks occur as the drying progresses, but these cracks are formed finely along the grooves or irregularities, so that the evaporation of water is further prevented. The drying efficiency is dramatically increased.

(Experimental example) In order to investigate the effect of the drying method for muddy materials of the present invention, two types of muddy materials shown in Table 1 were tested in a room maintained at a constant temperature and humidity of 20°C and 60% humidity. A drying experiment was conducted.

Table 1 In this experiment, two types of surface treatment were performed on each of the muddy substances (1) and (2): surface treatment method A shown in FIG. 1 and surface treatment method B shown in FIG. 2. The above-mentioned surface treatment method A involves adding 0.5% by weight of cement to each muddy substance, and 6 hours later, forming grooves 1 with a depth of 2 cm in a lattice shape at intervals of LO cm vertically and horizontally. Method B involves adding 0.5% by weight of cement to each slurry, and after 6 hours, 2 cm
il with a depth of 2CIR at intervals! ! 2. Then, each of the muddy materials 1 and (2) subjected to each of these surface treatment methods ASB and the untreated muddy materials I and (2) were dried using a drying apparatus shown in FIG. 3. This drying device is used for each muddy substance 1. A styrofoam container 3 containing II is placed on an electronic balance 4 connected to a microcomputer, and a wind tunnel 6 equipped with an air blower 5 for drying each muddy substance (1) and (2) is arranged above the polystyrene foam container 3. It is.

FIGS. 4 and 5 show the drying characteristics of each muddy substance obtained in this experiment. However, FIG. 4 is a graph showing the relationship between the amount of water evaporation of muddy material I and the number of days that have passed, and FIG. 6 is a graph showing the relationship between the amount of water evaporation of muddy material H and the number of days that have passed.

As a result of this experiment, muddy materials treated with surface treatment method A or surface treatment method B with the addition of 0.5% cement as a solidifying agent showed a higher water evaporation rate from the initial stage of drying compared to untreated muddy materials. It was confirmed that the drying temperature increased by 1.2 to 2 times and that drying was completed early.

"Example" Hereinafter, a first example to which the method for drying muddy substances of the present invention is applied will be described with reference to FIG. 6.

In this embodiment, a muddy substance 9 is dried in a natural drying area 8 in the form of a depression provided adjacent to an outdoor mud storage tank 7.

When drying the muddy material 9 in such a natural drying field 8, first, the muddy material 9, which has been transported by a transport vehicle 10 and stored in the mud storage tank 7, is transferred to the mixer 12 using a pump 11. Slightly lift the solidifying material such as cement here.
After stirring and stirring, the muddy substance 9 is transferred to a natural drying place 8 using a hose 13 or the like. After drying the muddy material 9 for several days in the natural drying field 8, irregularities are formed on the surface of the muddy material 9 using a tiller or the like. After doing this, the slurry material 9 is dried until it reaches a predetermined strength.

In this drying method, after the drying process of the muddy substance 9 is completed as described above, a new muddy substance 9 is transferred from the mud storage tank 7 onto the treated muddy substance 9. However, by repeating the above drying treatment operation, a reclaimed ground may be finally formed on top of the drying treatment plant 8.

Next, a second embodiment to which the method for drying muddy substances of the present invention is applied will be described with reference to FIGS. 7 to 10.

In this embodiment, as shown in FIGS. 7 and 8, an air vibrator 15 is arranged above a flat drying bed 14 with a rectangular recessed bottom. Air is blown onto the slurry material 9 placed in the drying bed 14 through the holes provided in the drying bed 14 to perform drying treatment. Rails 16.16 are laid on both sides along the long sides of the drying bed 14, and on each rail 16 a traveling machine 17.17 that self-propels along each rail 16 is mounted. These traveling machines 17, 17 are connected by a bar 18, and the air pipe 15 is removably supported at the lower part of the bar 18 and extends along the short side of the drying bed 14.

When drying a muddy substance in such a drying bed 14, first, the muddy substance 9 carried by a transport vehicle 10 or the like is put into a hopper 19 and sent from this hopper 19 to the mixer 12. A small amount of solidifying material such as cement is added using the mixer 12 and the mixture is charged into the drying bed 14 while being stirred. After doing this, air is blown from the air pipe 15 and the traveling machine! 7 to avoid moving the air pipe 15 in the longitudinal direction of the drying bed 14, thereby drying the muddy material 9 for several days while blowing air evenly over the surface of the muddy material 9.

After drying the surface of the muddy substance 9 to some extent in this way to reduce the fluidity of the surface, the traveling machine 17 is stopped, and then the air pipe 15 is removed from the bar 18, and the air pipe 15 is removed from the bar 18. 15, a surface treatment jig 20 shown in FIG. 9 or a surface treatment jig 2 shown in FIG.
Attach 1.

The surface treatment jig 20 has a plurality of blades 22 on the side...
By rotating the rotary shaft 23 to which is attached a motor 24 attached to the end of the rotary shaft 23, the blades 22 disturb the surface of the muddy substance 9 and cause the surface to be coated. It is configured to form unevenness. Further, the surface treatment jig 21 is formed by forming a plurality of protrusions 25 in a comb shape, and these protrusions 25 form a plurality of parallel grooves on the surface of the muddy substance 9. This is how it was done. After forming grooves or irregularities on the surface of the muddy substance 9 using the surface treatment jig as described above, the surface treatment jig is attached to the bar 18.
and then attach the air vibrator 15 to the bar 18 again. After doing this, the air pipe 15 is used to further dry the muddy material 9, and when the muddy material 9 reaches a predetermined strength, the air blowing is stopped and the traveling machine
Stop 7. After the drying process of the muddy substance 9 is completed in this way, the treated muddy substance 9 is transferred to the drying bed 1.
4, and then repeating the drying process described above to dry a new muddy substance 9.

"Effects of the Invention" According to the method for drying muddy substances of the present invention, since 0.1 to 5% by weight of a solidifying agent is added to the muddy substances and stirred,
By providing a weak support structure to the slurry material, it is possible to restrain the shrinkage of the solid content due to drying, thereby facilitating the movement of water and promoting the evaporation of water. Furthermore, after drying this muddy material for a predetermined period of time to reduce the fluidity of the surface of the muddy material, a plurality of grooves or irregularities are formed on the surface of this muddy material, and further this muddy material is Because it dries and hardens, it increases the external contact area from the beginning of drying, making it easier to evaporate water, and as drying progresses, fine cracks are formed, further promoting evaporation of water. This allows the drying efficiency to be dramatically increased.

[Brief explanation of the drawing]

FIGS. 1 and 2 are diagrams showing grooves formed on the surface of a muddy substance in the present invention. FIG. 1 is a plan view of the groove, and FIG. 2 is a sectional view of another groove. FIG. 3 is a schematic diagram of the drying apparatus used in the indoor drying experiment. FIG. 4 is a graph showing the drying characteristics of muddy material I, and FIG. 5 is a graph showing the drying characteristics of muddy material H. FIG. 6 is an explanatory diagram illustrating the method for drying muddy substances according to the first embodiment of the present invention. 7 to 10 are diagrams for explaining a method for drying muddy substances according to a second embodiment of the present invention, in which FIG. 7 is a sectional view of the drying bed, and FIG. 8 is a plane view of the drying bed. FIG. 9 is a schematic diagram of a surface treatment jig, and FIG. 1O is a schematic diagram of another surface treatment jig. 1.2... groove, 9... muddy material.

Claims (1)

[Claims] A solidifying agent of 0.1 to 5% by weight is added to a muddy substance and stirred, and then this muddy substance is dried for a predetermined period of time to reduce the fluidity of the surface of the muddy substance. A method for drying a muddy substance, which comprises forming a plurality of grooves or irregularities on the surface of the substance, and further drying and hardening the muddy substance.