JPH04294898A - Method for washing and dehydrating screen scum - Google Patents

Abstract

PURPOSE:To effectively execute the dehydration of the screen scum by carrying the screen scum of high water content to the dehydration process with the flowing water through, forcibly washing it just before the dehydrating process, then carrying it to the dehydrating machine. CONSTITUTION:The screen scum is pressurized and dehydrated by moving with reciprocating the plunger 6 in the tubular screen 5, and the dehydrated water is discharged. The screen scum dehydrating machine which carrys it in the duct 7 connected to the tubular screen is connected to the flowing water through 1. The screen scum raked up with the dust removing machine G is made to flow down through the flowing water through 1 and carried to the dehydrating machine. The water receiving tank 2 is set at the finish end part of this flowing water through, the screen scum is received in this water receiving tank, the screen scum is washed forcibly, then dehydrated.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention involves transporting screen sludge with a high moisture content scraped and collected from a sewage treatment plant, etc. to a dewatering process in a running water trough, forcibly washing it just before the dewatering process, and then transferring it to a dehydrator. The present invention relates to a method for more efficiently dewatering screen residue.

0002

BACKGROUND OF THE INVENTION Conventionally, screen sludge collected from sewage treatment plants has a high moisture content, and it is troublesome for subsequent treatment to put it into a hopper or an incinerator in the collected state. For this reason, it is necessary to dehydrate the collected screen residue until the moisture content is below a predetermined level. Conventionally, this screen residue is dehydrated using a dehydrator, and the screen residue after dewatering is transported to a hopper or an incinerator using a carry-out machine. The method of dewatering the screen residue using a dehydrator and then transporting it to a predetermined location using a conveyor requires a large amount of equipment installation space, and it is difficult to seal the equipment for maintenance and inspection purposes. is an open type. This causes a deterioration of the working environment, such as the scattering of bad odors. In addition, a method of supplying screen residue into a sealed duct, dehydrating it under pressure, and then pumping it was introduced in Japanese Patent Publication No. 46-262.
It is disclosed in Publication No. 85.

0003

[Problem to be solved by the invention] Screen residue collected from sewage treatment plants also contains undissolved filth such as human excrement, and if this is dehydrated as it is, this filth will remain in the dehydrated screen residue, which will require post-treatment. cause difficulties. Particularly in small-scale sewage treatment plants, the pipes that send the scraped screen residue to the dehydrator are short, and the amount of waste is large.

[0004] The object of the present invention is to send the scraped up screen residue to a dehydrator using a running water trough, and to wash the screen residue in a water tank provided at the end of the running water trough and then dewater it.

[0005]

[Means for Solving the Problems] The present invention has been made to achieve the above object, and includes reciprocating a plunger within a cylindrical screen to dehydrate the screen residue under pressure and draining the desorbed water. A screen sludge dehydrator that is conveyed in a duct is connected to a running water trough, and the screen sludge scraped up from the dust remover is sent down through the running water trough to the dehydrator, and the terminal end of this running water trough is connected to a running water trough. The gist is that a water tank is installed in the tank, the screen residue is received in the tank, and after the screen residue is forcibly washed, it is dehydrated.

[0006]

[Operation] When the screen sludge scraped up by the dust remover is supplied into the running water trough, it is also washed as it flows down the trough. Since a water tank is provided at the end of the trough and holds water up to a certain level, the screen residue flowing down the trough is temporarily supplied to this water tank. The screen residue is forcibly washed by the agitation device in the water receiving tank, undissolved dirt is dissolved, and then fed to a dehydrator for dewatering. Therefore, the screen residue can be dehydrated more efficiently without dirt being mixed in the dewatering screen residue. Furthermore, since the desorbed water is returned to the running water trough, it can be applied to equipment with a small amount of water.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained below based on the illustrated embodiments. As shown in FIG. 1, the screen residue is scraped up by one or more dust removers G, G installed in the waterway S, and then transferred to a running water trough 1 installed in a direction intersecting with the dust removers G.
It is thrown inside. Water is poured into the running water trough 1 from one end thereof, and a water receiving tank 2 is provided at the other lower end. Therefore, the screen residue thrown into the running water trough 1 flows down the inside of the trough together with running water and is supplied into the water receiving tank 2.

[0008] Water is always stored in the water receiving tank 2 up to a certain level, and a high-pressure nozzle N or stirring screw K is provided for spraying cleaning water at high pressure, so that the screen residue supplied into this tank is It will be forcibly washed along with the washing water that flows down. Therefore, even if undissolved dirt such as human excrement is mixed in this screen residue, it will be dissolved and cleaned in this water receiving tank.

The water receiving tank 2 has a required volume and its lower part is sloped so that the screen residue put into the tank can be reliably discharged from the discharge port 3 at the lower part after cleaning. This water tank 2 doubles as the hopper and chute of the dehydrator, and if necessary, a coarse bar screen 9 is placed on the top of the water tank.
This will remove coarse particles that cannot be dewatered by the dehydrator from the screen residue that flows into the water tank from the running water trough.

A dehydrator 4 for pressurizing and dewatering the screen residue is disposed below the water receiving tank 2, and a cylindrical screen 5 of this dehydrator is connected to a discharge port 3. The residue flows through the outlet 3 into the cylindrical screen 5. This pressurized dehydrator 4 is provided with a plunger 6 at the base end of a cylindrical screen 5 and a cylindrical conveyance duct 7 at the other end.
moves along the length of the cylindrical screen,
The diameter of the plunger and the diameter of the cylindrical screen are determined so that when the plunger is projected, the discharge port 3 connected to the top surface of the cylindrical screen can be closed.

The plunger 6 is equipped with a hydraulic cylinder and other pressurizing device 61, and the plunger 6 is driven by the hydraulic cylinder 61 so as to reciprocate from the proximal end to the distal end of the cylindrical screen 5. Eggplant. The dehydrated water that has been dehydrated and separated by this cylindrical screen is led to a storage tank T, where it is further supplied with water if necessary, and from this storage tank T is returned to the base end of the water trough by a pump P, and then again. It is used as running water in the running water trough.

The conveying duct 7 has a required diameter, length, and height, and a back pressure device 8 is provided in a part of the duct 7, and a plunger 6 applies a lower pressure to the screen residue pushed into the duct. is applied to perform pressurized dehydration, and during transportation, the back pressure device 8 lowers the pressure inside the duct, that is, the back pressure device 8 repeatedly pressurizes and depressurizes the inside of the duct.
The screen fed into the duct is dehydrated by the plunger 5 and transported one by one. A hopper or bag B is provided at the tip of the conveying duct 7 to receive the screen residue after dewatering. If bag B is attached to the tip of the duct, the screen residue after dehydration can be directly packed into a bag and discharged.

[0013] In the dust remover/dehydrator configured as described above, the screen residue scraped up and collected by each dust remover G from a sewage treatment plant, etc. is fed into a running water trough, and is made to flow down with water supplied from the end of the trough. . The screen residue is washed while being transported in the running water trough, but it is transferred from the running water trough to the water receiving tank, where the screen residue is forcibly stirred in the water stored there and is washed again. Undissolved dirt such as human excrement is dissolved here and cleaned more reliably. In this way, the screen residue is sequentially fed into the water tank until a predetermined amount is reached.

In this case, the plunger 6 is in a protruding state and the discharge port 3 is closed. After the screen residues that are successively introduced are washed in the water tank, the plunger 6 is moved back. As a result, the discharge port 3 at the bottom of the water receiving tank is opened, and the screen residue in the water receiving tank flows into the cylindrical screen together with water all at once. At this time, coarse screen residue that cannot be dehydrated by the dehydrator is previously removed and discharged using a coarse bar screen. Next, the plunger 6 moves forward by driving the cylinder 61, pressurizes the screen residue that has flowed into the cylindrical screen, and dehydrates it. The plunger 6 maintains the protruding state, that is, the state in which the discharge port 3 is closed, and stores the next screen residue in the water receiving tank.

After dewatering the screen residue by protruding the plunger for a predetermined period of time, the plunger is moved back and stopped, the discharge port 3 opens, and the screen residue in the water receiving tank flows into the cylindrical screen and is dehydrated. In this way, the screen residue is dehydrated intermittently by repeating the operations one after another.

[0016]

[Effects of the Invention] According to the present invention, the screen residue scraped up by the dust remover is supplied through a running water trough to a water receiving tank provided at the end of the trough, where it is forcibly stirred. After undissolved human waste and other filth is dissolved, it becomes dehydrated. Therefore, the screen residue can be reliably and efficiently dehydrated without dirt being mixed in the dewatering screen residue, and coarse screen residue that cannot be dewatered by the dehydrator is removed immediately before being fed to the dehydrator. It does not clog or damage the dehydrator, and furthermore, since the dewatered water is reused as flowing water in the running water trough, it has the advantage of reducing the amount of water used.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing an embodiment of the present invention.

FIG. 2 is an embodiment diagram with a high-pressure nozzle.

FIG. 3 is an embodiment diagram with a stirring screw.

FIG. 4 is a diagram showing an example of recycling and utilizing desorbed water.

FIG. 5 is an explanatory diagram of an embodiment in which a coarse bar screen is provided in a water tank.

[Explanation of symbols]

1　Flowing water trough 2 Water tank 3. Discharge port 4　Dehydrator 5 Cylindrical screen 6 Plunger 7 Conveyance duct 8 Back pressure device 9 Coarse bar screen S Dust remover N High pressure nozzle T Storage tank P Pump B Bag K Stirring screw

Claims (5)

[Claims] Claim 1: A screen residue dehydrator is connected to a running water trough, in which a plunger is moved back and forth within a cylindrical screen to pressurize and dehydrate the screen residue, and the desorbed water is drained and conveyed through a duct. Then, the screen residue scraped up from the dust remover is sent down through a running water trough and sent to the dehydrator, and a water receiving tank is installed at the end of this running water trough, and the screen residue is received in this water tank. A method for cleaning and dewatering screen residue, characterized in that the screen residue is dehydrated after forced cleaning. [Claim 2] After the screen residue supplied into the water receiving tank from the running water trough is forcibly washed by stirring the water stored in the water receiving tank to improve the cleaning effect of the screen residue,
The method for washing and dewatering screen residue according to claim 1, wherein the screen residue is dehydrated under pressure in a dehydrator. [Claim 3] The screen residue is dehydrated using a cylindrical screen for dewatering, and the separated desorbed water is stored directly or temporarily, and is returned to the base end of the water trough and allowed to flow down the inside of the trough again. The method for washing and dehydrating screen residue according to claim 1. [Claim 4] A coarse bar screen is installed above the water receiving tank located at the end of the flowing water trough, and coarse particles are removed from the screen residue supplied from the flowing water trough to the water receiving tank with water. 2. The method for washing and dewatering screen residue according to claim 1, wherein the screen residue is then dehydrated. 5. Screen residue cleaning according to claim 1, wherein a garbage bag is detachably provided at the tip of the conveying duct, and the screen residue being dehydrated and conveyed through the duct is stuffed into the bag and discharged from the dehydrator. Dehydration method.