JPH0468039B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention concentrates sludge produced during the treatment of urban sewage and various industrial wastewater in a closed container equipped with a rotating screw, and converts it into a concentrated liquid. The present invention relates to a sludge thickening device that separates the sludge into a supernatant liquid and a supernatant liquid.

[Conventional technology]

Conventionally, as shown in Japanese Patent Publication No. 60-5323, for example, the screw blades of the screw conveyor installed in the screw tube have been given the function of an inclined plate, and the sludge flows into the screw tube from the inlet. While the sludge is being concentrated and transferred to the concentrate discharge port by the screw conveyor, the supernatant liquid separated from the concentrate is discharged to the supernatant discharge port by the function of the screw blade as an inclined plate. There is something like this.

[Problem that the invention seeks to solve]

However, since this apparatus does not have any means for adjusting the discharge amounts of the supernatant liquid and the concentrated liquid, it has not been possible to obtain a concentrated liquid of a constant concentration.

That is, when concentrating sludge, it is important to adjust the degree of concentration in order to obtain a concentrated liquid with a constant concentration. However, if you try to directly adjust the flow rate of the thickened sludge at this time, there are problems such as the thickened sludge tends to clog, the flowability tends to deteriorate due to insufficient water volume, and it becomes difficult to control. Ta.

This invention was made to solve the above-mentioned problems, and it is possible to completely eliminate odor, control on the sludge inflow side, and provide a function to promote sedimentation of inflow sludge. Furthermore, by being able to adjust the degree of sludge concentration, it is possible to obtain a concentrated liquid of a constant concentration without being affected by clogging or viscosity of the thickened sludge, thereby providing a sludge thickening device that is extremely easy to manage the thickened sludge. The purpose is to

[Means for solving problems]

The sludge thickening device according to the present invention has a sludge inlet at one end, a concentrated liquid outlet at the lower part of the other end, and
A rotary screw is housed in the inner bottom of a closed container having a supernatant liquid outlet at the top of the other end, and above the rotary screw in the closed container, the outer circumference of the screw blade of the rotary screw A plurality of inclined plates are housed and arranged, the lower ends of which are close to each other and are inclined diagonally upward in a parallel manner, and which form a flow path with the upper wall of the closed container,
Further, a flow rate adjusting means is provided in the system of the supernatant liquid discharge port, and a sludge injection means is provided for press-feeding raw sludge into the closed container from the sludge inlet.

[Effect]

The sludge thickening device according to the present invention houses a rotating screw and a plurality of inclined plates, and the container into which the sludge is press-fitted is a closed container, so the sludge thickening device has less odor than this type of open container. All measures will be taken.

Further, by providing the sludge injection means on the sludge inlet side of the closed container as described above, control on the sludge inflow side becomes possible.

The inflow sludge press-fitted into the closed container is promoted to settle over substantially its entire length toward the rotating screw by each of the plurality of inclined plates.

The sludge thus precipitated is transported toward the concentrate outlet while being concentrated by the rotating screw. In this case, since the lower ends of each of the inclined plates are close to the outer periphery of the screw blade of the rotating screw, these inclined plates improve the sludge concentration efficiency and the sludge concentrate transfer efficiency of the rotating screw. will improve.

In addition, the separated liquid separated from the sludge concentrate is discharged from the supernatant liquid outlet of the sealed container. The degree of concentration can be adjusted appropriately. This makes it possible to obtain a concentrated liquid of a constant concentration without being affected by the clogging or viscosity of the thickened sludge, making the management of the thickened sludge extremely easy.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. The airtight container 1 is horizontally long, with an upper side having a rectangular shape and a lower side having a semi-cylindrical shape. A rotary screw 2 is housed horizontally in the lower part of the airtight container 1, and the rotary screw 2 has screw blades 4 of a multi-screw structure with a relatively large lead pitch attached to the outer periphery of a horizontal screw shaft 3. It is. One end of the screw shaft 3 is supported by a bearing 5, and the other end of the screw shaft 3 is connected via a coupling 8 to a motor shaft 7 of a motor 6 provided outside the closed container 1.

In addition, a plurality of inclined plates 1 are provided at the upper part of the airtight container 1.
0 is provided inclined at a predetermined angle.

Note that a flow path 11 is formed between the upper ends of these inclined plates 10 and the upper wall 1a of the closed container 1, and a circular arc is formed at the lower end of these inclined plates 10 close to the outer periphery of the screw blade 4. A surface 12 is formed. Further, the lower wall 1b of the closed container 1 is close to the outer periphery of the screw blade 4 and is formed in a cylindrical shape.

A sludge inlet 16 is opened in one side wall 1c of the closed container 1 at one end 14 side of the horizontally long closed container 1, and a sludge inlet pipe 17 is connected to the sludge inlet 16. There is. In addition, the airtight container 1 is placed on the other end 15 side of this horizontally long airtight container
A concentrated liquid outlet 18 is opened in the lower wall 1b, and a supernatant liquid outlet 19 is opened in the upper wall 1a.
A concentrated liquid discharge pipe 20 and a supernatant liquid discharge pipe 21 are connected to the concentrated liquid discharge port 18 and the supernatant liquid discharge port 19, respectively. The concentrated liquid discharge pipe 20 is raised such that its tip extends above the closed container 1, or is provided with a valve or the like.

Furthermore, the raw sludge is transferred to the sludge inflow pipe 17 from the pump 2.
3, it is configured to be press-fitted. Further, the supernatant liquid discharge pipe 21 is provided with a flow rate adjustment valve 25 that constitutes a flow rate adjustment means 24 .

In addition, one side wall surface 1 on the other end 15 side of the airtight container 1
A concave groove 27 is formed in the vertical direction inside c, and a sludge interface meter 28 is provided within this concave groove 27.

Next, the operation of the sludge thickening device of the present invention will be explained. While the rotary screw 2 is driven to rotate slowly by the motor 6, the raw sludge is pressurized by the pump 23 and passed through the sludge inlet pipe 17 at a constant inflow rate from the sludge inlet 16 to the one end side 14 of the closed container 1.
flow into the interior of the This raw sludge that has flowed in is precipitated and concentrated between the screw blades 4 of the rotating screw 2. Here, effective concentration is achieved by the function of the screw blade 4 as an inclined plate and the more effective precipitation promoting function by the plurality of inclined plates 10. Then, the concentrated liquid that has settled and separated in the lower part of the closed container 1 is moved by the screw blade 4 to the arrow a
direction, the concentrated liquid is scraped up to the side of the concentrated liquid outlet 18, and the concentrated liquid is drawn from the concentrated liquid outlet 18 to the concentrated liquid outlet pipe 2.
Exhausted through 0. Further, the supernatant liquid separated from the concentrated liquid is passed between the plurality of inclined plates 10 into a sealed container 1.
It rises diagonally towards the upper side of the interior as shown in the direction of arrow b. Then, this raised supernatant liquid flows through the upper channel 11 in the closed container 1 to the supernatant liquid outlet 1.
9 in the direction of arrow c, and is discharged from the supernatant liquid discharge port 19 through the supernatant liquid discharge pipe 21.

At this time, by adjusting the flow rate regulating valve 25, the discharge amount of the concentrated liquid can be controlled by adjusting the discharge amount of the supernatant liquid. The flow rate adjustment valve 25 is normally adjusted automatically (the difference with the inflow amount is the concentrated liquid amount), but the flow rate adjustment valve 25 may be adjusted manually, or by adjusting the pump 23. It may be linked to flow rate control.

At this time, in order to prevent the sludge interface meter 28 provided in the closed container 1 from deviating from a predetermined range,
It is preferable to adjust the inflow amount of raw sludge and the discharge amount of concentrated liquid by the pump 23.

Therefore, in a state where the inflow amount of raw sludge that is pressurized by the pump 23 is constant, the flow rate regulating valve 25
By controlling the discharge amount of the concentrated liquid, the concentration ratio of the concentrated liquid can be freely adjusted, and a concentrated liquid having a constant concentration can be obtained. Moreover, at this time, since the discharge amount of the concentrated liquid is adjusted by adjusting the flow rate adjustment valve 25 provided in the supernatant liquid discharge pipe 21, the flow rate adjustment valve 25 may become clogged with concentrated sludge. It is completely unaffected by viscosity and can be easily and accurately adjusted by the flow rate adjustment valve 25.

Further, the discharge amount of the concentrated liquid is controlled by the flow rate adjusting means 24 provided on the supernatant liquid outlet side, but when the flow rate adjusting valve 25 is released, almost the entire amount is discharged from the supernatant liquid outlet 19. Concentrate discharge pipe 20
Measures have been taken such as launching a.

By the way, when a flocculant (particularly an organic polymer flocculant) is added to the raw sludge flowing into the closed container 1, the sludge forms a dense block, so that very effective concentration can be achieved. That is, if a flocculant is added to the raw sludge, when the concentrated liquid that has been sedimented and separated in the closed container 1 is moved to the concentrated liquid outlet 18 side, it is moved by the screw blade 4, so that the above-mentioned The sludge blocks of the concentrate are combined into a harder state and granulated. The granulated sludge can be very effectively dehydrated in the next step.

In the above-mentioned embodiment, since the inclined plate 10 which performs the function of promoting precipitation is provided in the closed container 1, the apparatus itself can be made vertical, and the site area can be saved.

As described above, one embodiment of the present invention has been described, but the present invention is not limited to this in any way, and various effective changes can be made based on the technical idea of the present invention. For example, the means for pressurizing raw sludge may be other than a pump, such as an elevated sludge tank, as long as it can pressurize a certain amount of sludge. Further, the flow rate adjustment means may be other than the flow rate adjustment valve 25 as long as it can adjust the flow rate.

Also, in this embodiment, the screw blade of the rotary screw is shown as a double screw, but it may be a single screw or a triple screw.Generally speaking, the larger the helical angle, the better. is preferred.

Further, in the embodiment, the screw blade is shown as a continuous blade, but a cut screw blade may be used in which the screw blade is provided with cutout portions at predetermined intervals. This can prevent the supernatant liquid from throwing up the settled sludge. However, at this time, it is preferable that the cutout parts are not in a straight line with each other in the axial direction to prevent a short circuit from occurring.

〔Effect of the invention〕

As described above, according to the present invention, since the container housing the rotating screw and the plurality of inclined plates is a closed container, odor control is more thorough than in the case of this type of open container. Further, by providing the sludge injection means on the sludge inflow side of the closed container, control on the sludge inflow side becomes possible.

Moreover, since the lower ends of each of the inclined plates are close to the outer periphery of the screw blades of the rotating screw, the inflow sludge press-fitted into the closed container is
Each of the inclined plates allows efficient precipitation over substantially the entire length on the rotating screw side.

Further, the settled sludge is transferred toward the concentrated solution outlet while being concentrated by the rotating screw, but even in this case, as described above, the lower end of the rotating screw is close to the outer periphery of the screw blade of the rotating screw. Each of the inclined plates improves the sludge concentration efficiency and the sludge concentrate transfer efficiency by the rotating screw.

Further, the separated liquid separated from the sludge concentrate is discharged from the supernatant liquid outlet of the closed container, and at this time, the amount of supernatant liquid discharged is adjusted by the flow rate adjusting means to concentrate the sludge. The concentration can be adjusted appropriately, and in the end, a concentrated liquid with a constant concentration can be obtained without being affected by the clogging or viscosity of the thickened sludge, and the management of the thickened sludge becomes extremely easy. be.

[Brief explanation of the drawing]

FIG. 1 is a vertical longitudinal sectional view of an embodiment of the present invention;
FIG. 2 is a vertical cross-sectional view of the same. 1 is a sealed container, 1a is a lower wall of the sealed container, 2 is a rotating screw, 14 is one end of the sealed container, 15 is the other end of the sealed container, 16 is a sludge inlet, 18 is a concentrated liquid outlet, and 19 is a supernatant. 21 is a supernatant liquid discharge pipe, 24 is a flow rate adjustment means, and 25 is a flow rate adjustment valve.

Claims (1)

[Claims] 1. A closed container having a sludge inlet at one end, a concentrated liquid outlet at the lower end of the other end, and a supernatant liquid outlet at the upper end of the other end, and a sealed container which is housed in the inner bottom of the closed container. a rotating screw that is housed above the rotating screw in the sealed container, a lower end of which is close to the outer periphery of the screw blade of the rotating screw, and inclined diagonally upward in a parallel spaced state; A plurality of inclined plates forming a flow path with the upper wall, a flow rate adjusting means provided in the system of the supernatant liquid outlet, and raw sludge being press-injected into the closed container from the sludge inlet. A sludge thickening device comprising: sludge injection means.