JPS62214898A - Screen residue dehydrator - Google Patents

Abstract

PURPOSE:To make a continuous dehydration with high dehydration efficiency by press-feeding screen residues by a conveying screw into a conveying press pipe, then compressing and dehydrating the same. CONSTITUTION:The screen residues are thrown from a supply port 7 into an outside cylinder 5 and are gradually conveyed from a hermetic end 5a side to an open end 5b side and are further fed by the conveying pressure of the screw 6 into the conveying press pipe 25. The screen residues are then pushed out of a hopper part 29 at the top end of the conveying press pipe 25. The screen residues are gradually compressed and dehydrated in this process. The dehydration is executed in the stage when the screen residues are not compressed in the primary water draining hole in the lower part of the supply port 7 and thereafter, the dehydration of the highest efficiency is executed on the upper side of a water draining plate. The dehydrated water is discharged from the water draining hole into a receiving tray 22. The screen residues are further dehydrated in the conveying press pipe 25 and the water thereof arrives at the outside cylinder 5 by flowing in the pipe 25 and is discharged from the water draining hole.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a screen sludge dewatering device suitable as a device for dehydrating screen scum collected in a sewage treatment plant or the like.

[B, +i:s French tkrim] At sewage treatment plants, in order to remove relatively coarse suspended matter in the sewage, sewage flows into a screen, which removes floating matter larger than the screen. I try to leave it on the screen and then remove it.

This removed floating material (hereinafter referred to as screen scum) is dehydrated and then carried out and disposed of by incineration or landfill, but a screw press is used as a device to perform this type of dehydration treatment. There is. This supplies screen scraps from one end of a horizontally suspended fixed outer cylinder.
A screw that rotates while maintaining a certain gap with the outer cylinder presses and compresses the screen scraps, while draining the impregnated water from the water outlet in the outer cylinder, dewatering it, and discharging it from the outlet at the other end. be. By the way, in such a device, it is necessary to compress the screen scum, so the diameter of the flow path is gradually reduced, or a material is provided along the way to provide resistance to the flow of the screen scum. .

[Problems to be Solved by the Invention] However, in such conventional techniques, the diameter of the screen scum flow path is reduced and a resistance member is provided, so the structure of the outer cylinder and screw is complicated. As a result, there were problems such as increased manufacturing costs, easy clogging with screen scum, and difficulty in cleaning and maintenance of the clogging.

When the diameter was reduced or no resistance member was provided, the dewatering efficiency was poor. In addition, the supply port for the screen waste is located at the top, and the outlet for the dehydrated waste is located at the bottom, so when loading the waste from the outer cylinder onto a truck, etc. This required measures such as installing the outer cylinder higher in advance, which caused problems such as the need to make the building higher.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides a water drainage hole formed in the lower surface of the outer cylinder, which is installed inside the outer cylinder installed almost horizontally. A conveying screw is provided to convey the screen scraps from the closed end to the open end, and the lower end of a conveying press tube having an open upper end is connected to the open end.

[Function] In such a dewatering device, the screen scum is forced into the conveying press pipe by the conveying screw, and the pressure caused by its own weight, the pumping resistance with the conveying press pipe, the extrusion pressure of the conveying screw, etc. is absorbed in the outer cylinder and the conveying press pipe. Receive, compress and dehydrate. The dewatered screen is discharged from the upper open end of the transport press tube.

[Example] An embodiment of the present invention will be described below with reference to the drawings.

1 to 6 show a first embodiment of the present invention, and in these figures, ▪ is a pressure-feeding dewatering section, and 2 is a conveying section.

This pressure-feeding dewatering section l consists of an outer cylinder 5 installed almost horizontally on a base 3 via a frame 4.4, a conveying screw 6 rotatably provided inside this outer cylinder 5, and It consists of a supply lower opening at the upper surface of the closed end 5a of the cylinder 5. The rotating shaft S of the screw 6 is supported by a pair of external bearings 9.9, and the closed end 5a of the outer cylinder 5 is mounted inside the outer cylinder 5.
It is inserted from the side. The rotating shaft 8 is connected to a sprocket I on an output shaft 11 of a drive device IO installed beside the outer cylinder 5.
2. It is connected via a chain 13 and a sprocket I4 and is driven to rotate.

As shown in FIG. 3, the outer cylinder 5 has two types of drain holes 15, 16, and the like having different diameters formed on its lower peripheral surface. That is, in the closed end 5a side portion corresponding to the lower side of the supply lower, a row of relatively large drainage holes 15 are formed at the lowest part of the outer cylinder 5 along the axial direction of the outer cylinder 5.
On the other hand, the lower circumferential surface of the outer cylinder 5 on the side of the open end 5b is opened in an arcuate shape, and this opening 17 can be freely attached and detached by a water drain plate 18 in which small diameter water drain holes 16 are evenly distributed. covered in. These drainage holes 15 and 16 are formed in equal diameter parts 15a and 16a on the inside of the outer cylinder 5 and enlarged diameter parts 15b and I6 on the outside, respectively.
b, which prevents clogging from occurring. The portion of the outer cylinder 5 corresponding to the upper side of the water drain plate I8 is
An opening 19 is provided for convenient cleaning or replacement of the water drainage plate 18, and is removably covered by shoes 20. A substantially semi-cylindrical water tray 22 having a drainage hole 21 is attached to the lower side of the outer cylinder 5.

The li/J distal end 5b of the outer cylinder 5 has a flange 23.2.
A conveyance press pipe 25 is attached via 4. The conveying press pipe 25 has a circular cross section, a central axis extending upward from the open end 5b, and a flange 26.2 at the other end.
An elbow portion 28 is attached via 7. This elbow portion 28 gradually expands in diameter and changes the flow direction of the screen scum slightly downward, and a hopper portion 29 is attached to the tip of the elbow portion 28, the diameter of which decreases downward again.

These conveyance press pipe 25, elbow section 28, and hopper section 29 constitute the conveyance section 2.

In this example, the diameter of the conveying press tube 25 is formed uniformly, but the diameter may be reduced as the pipe rises, or conversely, the diameter may be enlarged. The cross section is not limited to a circle, but may be an ellipse or a rectangle. Although the conveyance press pipe 25 is integrally formed in this example,
For example, the pieces may be divided along a vertical plane including the center line and then joined by Franz. Further, a groove may be formed on the inner surface of the conveying press pipe 25 to guide the water dehydrated in this portion to the pressure-feeding dewatering section l, or a drainage hole may be formed. Furthermore, in this example, the conveying press pipe 25
Although the center line is in the shape of a circular arc, the center line is not limited to this, and may be a curved line with an appropriate curvature without a bent part. Alternatively, a straight line portion of arbitrary length may be added to this curved portion.

Next, the operation of the dewatering device configured as described above will be described.

The screen scraps collected during the screening process are put into the upper outer cylinder 5 of the supply lower, and the screw 6
The press pipe 2 is gradually conveyed from the closed end 5a side to the open end 5b side by the conveying pressure of the screw 6.
5 into the hopper section 29 at the upper end of the conveyance press pipe 25.
being pushed out. During this process, the screen waste is gradually compressed and dehydrated. This dewatering is first carried out at the stage where the screen scum is not compressed in the lower rl< of the supply lower outlet water hole 15... (-next dehydration)
Next, dewatering with the highest efficiency is performed above the water drain 18 (secondary dewatering). The water dehydrated here is discharged into the water tray 22 through the drainage holes 15,16. Further, the screen residue is dehydrated inside the conveying press pipe 25 (tertiary dehydration), and the water passes through the inside of the conveying press pipe 25, reaches the outer cylinder 5, and is discharged from the drainage holes 15.16.

As seen in this process, the provision of the conveying press pipe 25 in this dewatering apparatus achieves two effects. Specifically, one reason is that the weight of the screen scum in the conveying press pipe 25 acts on the open end 5b side of the outer cylinder 5. The second purpose is to strengthen the compression dewatering effect, and the second is to increase the discharge position of screen waste to facilitate transportation to the next process. By the way, in order to increase the dewatering efficiency of the above-mentioned apparatus, the length of the conveyor press 125 can be increased, but in that case, the apparatus itself becomes larger and the cost increases, or the load on the drive device 10 increases. This will reduce the processing capacity and increase the required energy, so the transfer press pipe 2 should be adjusted depending on the properties of the screen residue and the diameter of the outer cylinder 5.
It is desirable to select the length and shape of 5.

FIG. 7 shows the results of experiments actually conducted on the first embodiment and other embodiments in which the conveying press tube 25 was changed into various shapes. That is, in the first embodiment, the conveying press pipe 25 has an arc shape with a center angle of 90 degrees, whereas in the second embodiment, the conveying press pipe 25a has an arc shape with a center angle of 1T.
The conveying press tube 25b of the third embodiment has a configuration in which an arcuate tube with a center angle of 45 degrees is attached in the opposite direction to the conveying press tube of the first embodiment (in the figure, (Elbow part and hopper part are omitted).

The screen waste used in this experiment has a moisture content of approximately 85%.
Its composition is 94.5% paper and 3.4% kitchen waste.
, cloth 0.1%, plastics l.

4%, hair 1iJio 4%, and other 0.2%.

In this apparatus, the processing 1 is approximately proportional to the rotation speed of the conveying screw 6, and in six cases in the experiment, the rotation speed was made equal and the throughput was almost the same. The moisture content is calculated using the following formula.

It = too(W, -W,)/w, (%
) where Wl is the dry moeju nail and W2 is the weight after drying.

According to this result, the moisture content after dehydration is 70% or less, which is the upper limit of the moisture content at which no HLT auxiliary fuel is required when incinerating this screen waste, compared to the zero deviation example. . Comparing these four examples, it is considered that the first example is preferable in terms of equipment cost, operating cost, and effectiveness.

[Effects of the Invention] As described in detail below, the present invention has a water drain hole formed in the lower surface and a screen installed inside an almost horizontally installed outer cylinder from the closed end to the open end. A conveying screw is provided to convey the force, and the lower end of the conveying press pipe with one end open is connected to the two open ends, so the weight of the screen scum in the conveying press pipe can be reduced. This compresses the waste, dehydrates it, and transports the waste to a high discharge location. This makes it possible to perform continuous dewatering with less clogging and high dewatering efficiency, and the structure of the equipment is simple and the building is low, so construction costs are low and maintenance is easy. It has excellent effects such as:

[Brief explanation of drawings]

1m is a front view of the first embodiment of the present invention, FIG. 2 is a plan view thereof, FIG. 3 is an enlarged view of its main parts, FIG. 4 is a view taken along the line IV-IV in FIG. 3, and FIG. 6 is a view taken along the V [-■ arrow, and FIG. 7 is a diagram showing the experimental results of the first to third embodiments. 5... Outer cylinder, 5a... Sealed end, 5b.
...Open end, 6...Transportation screw, 1
5.16... Water drain hole, 25... Transfer press pipe.

Claims (2)

[Claims] (1) A conveying screw is provided inside the outer cylinder, which has a drainage hole formed on the lower surface and is installed almost horizontally, to transport the screen scum from the closed end of the outer cylinder to the open end. is a screen dregs dewatering device characterized in that the lower end of a conveying press pipe whose upper end is open is connected to the lower end. (2) The screen dregs dewatering apparatus according to claim 1, wherein at least a part of the central axis of the conveying press pipe is curved upward.