JPH0729008B2 - Drum type classifier - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a drum type classifier that performs solid-liquid separation using a rotating drum.

(Prior Art) Muddy water was introduced into a rotating drum, solids in the muddy water were allowed to settle, and a spiral plate provided on the inner surface of the settling drum brought the solids to one end of the settling drum to take them out to remove the solids. Drum type classifiers for performing solid-liquid separation by overflowing the latter liquid from the other end of the sedimentation drum are known.

This drum type classifier draws large particles that have settled faster due to the difference in settling speed due to the difference in specific gravity between large particles and small particles such as mud particles by a spiral blade and takes them out from the discharge hole, while discharging small particles. It also has a washing function that discharges with the liquid overflowing from the holes.

(Problems to be Solved by the Invention) However, the known drum type classifier has the following problems.

First, the raw material put into the sedimentation drum vigorously agitates the liquid in the sedimentation drum, which hinders the sedimentation of solids and causes the solids to overflow with the liquid to the outside of the sedimentation drum. There was a problem of reduction.

Also, because the size of the sedimentation drum is practically limited,
A large amount of small particles attached to the large particles were discharged from the discharge hole, and the washing function was unsatisfactory.

The object of the present invention is to improve the washing function by promoting the sedimentation by improving the solid-liquid separation function by promoting the sedimentation by preventing the stirring of the liquid in the sedimentation drum as much as possible, and improving the washing function by promoting the separation of large-diameter particles and small-diameter particles. To provide a classifier.

(Means for Solving the Problems) In order to achieve the above object, the present invention is arranged on the axis of the raw material introducing pipe inserted into the sedimentation drum from the drainage hole and the axis of the discharge port of the raw material introducing pipe. And a small drum that surrounds the collision body and is provided so as to rotate integrally with the sedimentation drum, and an opening formed by opening the end of the small drum on the discharge hole side. And a stirring plate provided on the inner surface of the drum.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings.

In this embodiment, a drum type classifier used for the purpose of removing excavated soil from muddy water in a muddy water treatment system of the shield construction method is exemplified. However, the use of the drum type classifier of the present invention is not limited to this.

First, an outline of the muddy water treatment system of the shield construction method will be described with reference to FIG.

In the shield construction method, muddy water mixed with bentonite is sprayed on the face of the excavator to prevent the face from collapsing. The muddy water treatment system removes excavated soil from the muddy water carried out from the excavator and adjusts the specific gravity of the muddy water for reuse.

Muddy water (raw material) mixed with excavated soil is carried out from the excavator 1 and put into the drum type classifier 2. Drum type classifier 2
In, the soil and the muddy water are separated, and the muddy water is sent to the dewatering conveyor 3 which also serves as a washing machine, and the muddy water is sent to the settling tank 4.

The earth and sand conveyed on the dewatering conveyor 3 are compacted and dewatered by the washing shower 5 to remove fine sand having a small particle size, and are shaken by the shaker 6 to be dehydrated and taken out. Sediment with large particle size (large particle) excluding fine sand (small particle) is collected as aggregate for concrete.
Hereinafter, the sediment excluding this fine sand will be referred to as aggregate sediment.

On the other hand, the fine sand flows into the settling tank 4 together with the wash water flowing down along the inclination of the dehydration conveyor 3.

Muddy water from drum type classifier 2 and dewatering conveyor 3 settles in tank 4
Into which the fine sand settles. The supernatant water of the precipitation tank 4 flows into the specific gravity adjusting tank 7. The specific gravity adjusting tank 7 adjusts the specific gravity of the muddy water by adding the muddy water created in the mud making tank 8. The muddy water after the specific gravity adjustment is fed to the excavator 1 by the circulation pump 9 and reused.

The fine sand settled in the settling tank 4 is mixed with earth and sand having a large particle size. Therefore, as described below, the sediment is re-separated from the fine sand to improve the collection rate of the aggregate sand.

The excavator 1 repeats excavation and stop such that it stops after excavation to some extent and prepares for the next. When the excavator 1 is stopped, muddy water containing excavated soil is not fed to the drum type classifier 2. Therefore, when the excavator 1 is stopped, the fine sand that has settled in the settling tank 4 is re-introduced into the drum classifier 2 to reseparate the aggregate sand and the fine sand, and the fine sand bones in the settling tank 4 Reduce the mixing rate of lumber for timber. The fine sand after the re-separation process is sucked by the sand pump 11 suspended by the traveling crane 10 and fed to the dehydrator 12, and is taken out after the dehydration process. The changeover valves 13 and 14 are used to select the destination of whether the fine sand in the settling tank 4 is sent to the drum type classifier 2 for re-separation or the re-separated fine sand is sent to the dehydrator 12 for dehydration. Can be switched.

Next, the structure of the drum classifier will be described with reference to FIGS. 1 and 2.

The drum type classifier 2 of this embodiment is installed on a frame 15 arranged in the settling tank 4. In the frame 15, the traveling crane 10
Rails 16 are provided. The traveling crane 10
The sand pump 11 is suspended as described above.

A support roller 17 is rotatably mounted on the frame 15, and a sedimentation drum 18 is rotatably mounted on the support roller 17. A belt 19 is wound around the sedimentation drum 18, and is rotated via the belt 19 by a prime mover (not shown).

A drainage hole 20 for introducing the raw material is provided on one end surface of the settling drum 18, and a discharge hole 21 is provided on the other end surface. The drain hole 21 is formed to have a smaller diameter than the drain hole 20.

The inner surface of the settling drum 18 is provided with a spiral blade 22 formed in the transfer direction from the drainage hole 20 side to the discharge hole 21 side, and a plurality of lifting plates 23 are provided at the end of the discharge hole 21 side. Are provided radially. A conical chute 24 is disposed in the discharge hole 21 with its tip facing outward, and the conical chute 24 has a partition plate 24.
a is provided radially.

A raw material introducing pipe 25 is inserted into the sedimentation drum 18 from the drainage hole 20. Then, the tip of the raw material introducing pipe 25 is settling drum 18
Is supported by a first arm 27 extending from the inner wall of the bearing via a bearing 28. A plate-shaped collision body 29 is attached to the first arm 27 via a bracket 28. This collider
29 is arranged on the axis of the discharge port 30 of the raw material introducing pipe 25.

The second arm is located closer to the discharge hole 21 than the first arm 26.
31 extends from the inner wall of the settling drum 18 and the first arm
A small drum 32 is attached between 26 and the second arm 31. The small drum 32 is provided so as to surround the collision body 29, and an opening 33 is formed by opening the end on the side of the discharge hole 21. A stirring plate 34 is provided radially on the inner surface of the small drum 32.

The drum type classifier configured as described above operates as follows.

Muddy water (raw material) containing excavated soil sent from the excavator 1
It is introduced into the drum type classifier 2 through the raw material introducing pipe 25. The raw material discharged from the discharge port 30 of the raw water introducing pipe 25 collides with the collision body 32 and then drops into the small drum 32. The small drum 32 rotates integrally with the sedimentation drum 18, and the earth and sand and the muddy water are agitated by the agitating plate 34, so that the earth and sand for the aggregate and the fine sand are well separated. After that, it falls into the muddy water of the sedimentation drum 18 through the opening 33.

The raw material is reduced in momentum from the raw material introduction pipe 25 through the small drum 32, and then drops into the muddy water in the sedimentation drum 18. Therefore, the agitation of the muddy water in the sedimentation drum 18 is reduced, the sedimentation of the muddy water is promoted, the amount of the muddy water overflowing from the drain hole 20 is reduced, and the sediment recovery rate is improved.

Further, since the raw material collides with the colliding body 29 and is dispersed, and is further stirred by the stirring plate 34 of the small drum 32 to largely separate the large-diameter particles and the small-diameter particles, and then drops them into the muddy water in the sedimentation drum 18, Washing is promoted.

(Effects of the Invention) According to the present invention, since the raw material is reduced in its momentum from the raw material introduction pipe through the small drum and then drops into the muddy water in the sedimentation drum, stirring of the muddy water in the sedimentation drum is prevented. As a result, sedimentation is promoted, and the recovery rate of solids is improved.

In addition, the raw material collides with the colliding body and disperses, and is further stirred by the stirring plate of the small drum to separate large particles and small particles considerably and then drop them into the muddy water in the sedimentation drum, which facilitates washing. It

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an embodiment of the present invention. FIG. 2 is a front view thereof. FIG. 3 is a sectional view taken along the line AA of FIG. FIG. 4 is a schematic diagram of a system in which the embodiment of FIG. 1 is installed. 2: Drum type classifier, 4: Settling tank 10: Traveling crane, 11: Sand pump 18: Settling drum, 20: Drainage hole, 21: Discharge hole 22: Spiral blade, 23: Lifting plate 24: Conical chute , 25: Raw material introduction pipe 26: First arm, 27: Bearing 28: Bracket, 29: Collision body, 30: Discharge port 31: Second arm, 32: Small drum 33: Opening part, 34: Stirrer plate

Claims (1)

[Claims] 1. A settling drum rotatably provided, a drainage hole provided at one end surface of the settling drum for introducing a raw material, and a discharge hole provided at the other end surface of the settling drum. A spiral blade provided on the inner surface of the drum so as to have a transfer direction from the drain hole side to the drain hole side, a lifting plate provided at the drain hole side end of the inner surface of the sedimentation drum, and a drain hole In a drum type classifier consisting of a conical chute arranged, a raw material introducing pipe inserted from the drainage hole into the sedimentation drum, and a collision body arranged on the axis of the discharge port of the raw material introducing pipe, A small drum that surrounds the collision body and is provided so as to rotate integrally with the sedimentation drum, an opening formed by opening the end of the small drum on the side of the discharge hole, and an inner surface of the small drum. A drum type classifier comprising a stirring plate.