JPH0829434B2 - Screen residue dehydrator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is to remove a residue (screen residue), which has been scraped off from a water channel of a sewage treatment plant, a pump station, etc., to a predetermined position while dehydrating it in a duct. The present invention relates to a screen residue dehydrator to be transported.

[Conventional technology]

Conventionally, the waste water collected from a sewage treatment plant or the like has a high water content, and it is troublesome for subsequent treatment to put it in a hopper or put it in an incinerator in a collected state.

Therefore, it is necessary to dehydrate the collected residue until the water content falls below a predetermined water content.

Conventionally, this residue is dehydrated by a dehydrator, and the residue after dehydration is conveyed to a hopper or incinerator by an unloader.

In addition, the method of pumping the inside of the sealed cylinder (duct) is
It is disclosed in Japanese Patent Publication No. 46-26285.

[Problems to be Solved by the Invention]

By the way, in the conventional method of dehydrating the residue with a dehydrator and then transporting it to a predetermined position with a transporter, the space for installing the device becomes large and it is a maintenance and inspection that the device is sealed. It is difficult and because it is an open type, it causes a bad working environment such as odor scattering.

On the other hand, in the method of pressure-feeding in the closed cylinder, a large resistance is generated between the inner surface of the duct and the residue in all the steps of conveyance except for dehydration, and a strong pressure-feeding force is required for conveying the residue, which results in the apparatus. In particular, there are drawbacks that the pressure feeding device becomes large and the running cost becomes high.

It is an object of the present invention to provide a residue dehydrator capable of obtaining internal pressure necessary for dehydration in the dehydration step and enabling low head and high lift transfer in the transfer step.

[Means for solving the problem]

In order to achieve the above-mentioned object, the residue removal machine of the present invention comprises a conveying means having a dehydrated residue discharge port at the upper end, and a required lift with a pressure supplying means at the lower end of the conveyor. In a residue dehydrator, pressure dewatering means is locally provided near the forward end of the pressure supply means so that the inner diameter is smaller than the inner diameter of the conveying means, and a dehydration hole is formed on the outer peripheral surface. Raise the residue supply pressure to the value required for dehydration,
Further, it is characterized in that the flow resistance of the residue after passing through the pressure dehydration means in the transportation means is reduced.

〔Example〕

The screen residue dehydrator of the present invention will be described below based on the illustrated embodiment.

In the figure, reference numeral 1 denotes a conveyer such as a conveyor for continuously or intermittently conveying the residue collected from a sewage treatment plant, a pumping station, etc., and a hopper 2 for supplying the residue is provided at a position below the end of the carrier 1. Arrange.

The hopper 2 is provided so as to project from the upper portion of the screen residue pressurizing and supplying means 3, and the pressurizing and supplying means 3 includes a cylindrical main body 31 whose one end is bent at a required upward angle, and The discharging means 32 is housed in the horizontal portion of the main body 31, and the discharging cylinder 32 can be a hydraulic cylinder 32a or a screw conveyor 33.

The cylinder 32a is provided with a piston 32b.
The hopper 2 is disposed above the front position with respect to the rear position where the b is buried.

The outlet of the lower part of the hopper 2 is made slightly shorter than the stroke of the piston 32b, and the pressure dehydration means 4 is provided at a position slightly forward of the position where the piston 32b projects.

Then, the main body 31 has a dehydration hole extending from the lower position of the hopper 2 to a position past the pressure dehydration position of the pressure dehydration means 4.
3H is perforated, and after the water contained in the residue is supplied from the inside of the hopper to the inside of the main body, it is dehydrated by applying the pressure dehydration means 4 and then drained to the outside of the main body 31.

The pressurizing and dehydrating means 4 squeezes the residue with the pressurizing and supplying means 3 and raises the pressurizing force to a value necessary for dehydration, and even when the pressurizing and supplying means 3 is retracted, it is kept for a predetermined time. The pressurized state is maintained, and an example thereof is shown in FIGS. 3 to 6.

The pressurizing / dehydrating means 4 is interposed between the main body 31a on the horizontal supply side and the main body 31b on the bent discharge side of the pressurizing / supplying means 3. In the embodiment shown in FIG. The flanges 41 and 42 connected to
In addition, a large number of taper plates 43 are arranged in an annular shape at a predetermined pitch between 1, 42, and the inner surface of the flange and the front surface of the taper plate are butted against each other and integrated by welding or the like.

When the taper plate 43 is installed between the flanges 41 and 42, the taper surface 43t is formed on the inner peripheral side at both ends. The taper plate 43 is formed by cutting a flat bar having a required plate thickness and width to a certain size, and forming both end portions of the inner peripheral surface side thereof so as to have a required inclination angle θ that lowers the tip side, As shown in FIG. 3 (B), a large number are arranged in an annular shape, a slit-shaped gap 4H is formed between the adjacent tapered plates 43, 43, and this gap is used as a dehydration hole.
Further, the length L of the flat portion of the inner peripheral surface of the tapered plate 43 is
It is assumed to have a length substantially equal to the length in which the residue supplied by one stroke of the piston 32b can be stored.

The pressurizing / dehydrating means 4 is constructed in this manner, and is interposed between the opposed main bodies 31 and 31, and the flanges 41 and 42 are fixed by bolts or the like.

As a result, the residue supplied to the hopper 2 by the pressure supply means 3 is moved into the discharge side body 31 by the piston 32b that advances from the horizontal supply side body for each stroke of the piston of the pressure supply means 3. Pushed out.

At this time, the residue that is pushed out by the advancing piston is pushed out into the pressurized dehydration means 4 only for one stroke. At this time, the required squeezing is performed to dehydrate the taper plate.
It is drained from the slit-shaped gap 4H formed between 43.

Even if the piston 32b retreats, the residue that has been pushed into the pressure dehydration means 4 is the time until the piston 32b moves forward and the next stroke of residue is pushed out into this pressure dehydration means. It is stopped and the pressed state is maintained and dehydrated.

Then, when the piston 32b is retracted, the next residue is supplied from the hopper 2 to the position in front of the piston 32b, so that the residue for each stroke of the piston 32b is supplied to the pressurizing / dehydrating means 4, and intermittently. The residue is dehydrated.

The dehydrated residue is pushed out by the pressure dehydration means 4 into the discharge side main body 31b in a light manner.

This is the discharge side main body 31b with respect to the sectional area of the pressure dehydration means 4.
Since the cross-sectional area of the cylindrical conveying means (duct) 5 connected to it and the duct means 5 is large, the residue after the pressurization dehydration has a frictional resistance value with the main body 31 (flow resistance). ) Is smaller and the residue transfer is lighter.

In this case, the conveying means 5 connected to the tip of the discharge-side main body 31b is formed in substantially the same cross-sectional area as the discharge-side main body 31b, and has a substantially vertical direction so as to have a required lift H from the pressure dehydration means 4. Alternatively, it is arranged at a required inclination angle, and the upper end of the conveying means 5 is used as a discharge port so as to be dehydrated and discharged into the residue storage hopper 6.

An opening / closing gate is provided at the lower end of the dehydrated residue storage hopper 6, and a truck or the like enters the lower portion of the dehydrated residue storage hopper 6. The hopper 6 is placed at a predetermined height on a stand 7.

Since the pressurization and supply means 3 for supplying the residue to the pressure dehydration means 4 is the hydraulic cylinder 32a in the embodiment shown in FIG. 1, the residue is supplied to the pressure dehydration means 4 by the piston 1.
The stroke is intermittent, while the screw conveyor is used in the embodiment shown in FIG. 2, so that the residue can be continuously supplied to the pressure dehydration means 4. The pressurized and compressed state is maintained for the time during which the length of the flat portion L of 43 is advanced, and the dehydration is continuously performed.

The pressure dehydration means 4 shown in FIG. 4 is a pipe-shaped main body portion.
45, a large number of dehydration holes 4H are formed in the outer peripheral portion, the central portion is made small in diameter, and both ends are tapered to be large diameter.
Are provided with mounting flanges 41 and 42, and the angle θ of the tapered surface 43t, the length L of the flat portion, etc. are the same as those in the embodiment of FIG.

The pressurizing and dehydrating means 4 shown in FIG. 5 is a modification of that shown in FIG. 4, in which flanges 41 and 42 are provided at both ends so that the pipe-shaped main body portion 46 has a large diameter on the supply side and a small diameter on the discharge side. With a taper shape and a large number of dehydration holes 4H formed on the outer peripheral surface, the residue that is pressurized and supplied to this pressure dehydration means is dehydrated when it moves to the discharge side, and is removed from the discharge port toward the main body side. When it goes out, the pressed and pressed state of the residue is alleviated by the difference in cross-sectional area, and the flow resistance is reduced.

The pressurizing / dehydrating means 4 shown in FIG. 6 has a taper pipe 47 protruding from the inner peripheral surface of the supply side flange along the tip side taper surface of the taper plate 43 shown in FIG. The operation is similar to that shown in FIGS.

In the screen residue dehydrator configured as described above, the transfer resistance (pushing force) R of the screen residue is related to the pressure of the screen residue and is represented by the following equation.

Where R: axial resistance when the residue moves P: internal pressure μ: coefficient of friction between residue and body wall π: circumference ratio D: diameter of the body The pressure distribution in the pipe is shown in Fig. 11. Therefore, the resistance (pressing force) R has a value corresponding to the area surrounded by a, a ', c in FIG. In this method, the value is equivalent to the area surrounded by a, a ', b ", b', and c, and the resistance is small by the amount shown by hatching, so it can be pushed with a small force.

FIG. 7 shows the relationship between the ratio d / D of the inner diameter d of the small diameter portion of the pressure dehydration means to the inner diameter D of the large diameter portion and the resistivity.
Fig. 8 shows the relationship between the resistance and the resistance, Fig. 9 shows the relationship between the length L of the flat portion and the resistance, and Fig. 10 shows the relationship between the internal pressure of the residue and the water content of the dehydrated residue.

Therefore, if the time during which the piston 32b is pressurized (pressure holding time) is long, it is possible to perform good dehydration even with low pressure. Therefore, the piston 32b stays in the high pressure section until the residue is pushed out, so the piston should be immediately retracted. The processing capacity can be improved. Furthermore, the pressure dehydration unit 4 separates well from water, and efficient dehydration can be performed.

〔The invention's effect〕

According to the present invention, the inner diameter is locally reduced in the vicinity of the forward end of the pressure supply means so as to be smaller than the inner diameter of the transport means,
Equipped with a pressure dehydration means with dehydration holes formed on the outer peripheral surface, the residue supply pressure during pressing is increased to the value required for dehydration, and the flow resistance in the residue transfer means after passing through the pressure dehydration means is reduced. Therefore, it is possible to efficiently pressurize and dehydrate the residue, and it is possible to significantly reduce the flow resistance, thereby reducing energy loss and efficiently performing residue dehydration. You can

[Brief description of drawings]

FIG. 1 shows the first embodiment of the residue dehydrator of the present invention, and the second embodiment
The drawing shows the second embodiment, and FIGS. 3, 4, 5, and 6 are explanatory views of different embodiments of the pressure dehydration means, FIG. 7, and FIG.
FIG. 8 and FIG. 9 are graphs showing changes in the resistance to circulation of residue on the screen,
FIG. 10 is a graph showing the relationship between the length of the pressure dewatering means and residue pressure, and FIG. 11 is a graph showing the pressure distribution in the pipe. 2 is a hopper, 3 is a pressure supply means, 4 is a pressure dewatering means,
5 is a transportation means.

Claims (1)

[Claims] Claims: 1. A pressurizing and dewatering machine having a required head, comprising a conveying means having a dehydrated residue discharge port at the upper end, and a pressurizing and supplying means at the lower end of the conveying means. The pressure dewatering means that locally narrows the inner diameter of the advancing end to be smaller than the inner diameter of the conveying means and has a dehydration hole on the outer peripheral surface is provided, and the residue supply pressure during pressing is the value required for dewatering. And a flow resistance of the residue in the conveying means after passing through the pressurized dehydration means are reduced.