JP4797061B2 - Belt type concentrator and belt type concentrator operation method - Google Patents

Description

  The present invention relates to a water-saving belt-type concentrator having an endless filter cloth and capable of reusing a separation liquid and a washing waste liquid as a washing liquid, and using a plurality of washing means having a self-cleaning function. The present invention relates to a belt type concentrator that alternately performs belt cleaning and self-cleaning of the cleaning means.

A belt type concentrator is known as one of apparatuses for separating sludge solids (SS) from moisture and concentrating sludge slurry when processing an object to be treated such as sludge. A similar belt type concentrator is disclosed in Patent Document 1. The belt type concentrator disclosed in Patent Document 1 is a storage tank for receiving a separation liquid obtained by permeating an endless belt from a slurry placed on a filter-like endless belt; In order to prevent clogging, a storage tank is provided for receiving the cleaning drainage liquid after cleaning the endless belt with the cleaning liquid ejected from the cleaning nozzle. The stored liquid in these two tanks is mixed in the same line, a part is reused as a cleaning liquid, and the rest is discharged outside the apparatus.
According to the present invention, the separation liquid and the cleaning waste liquid can be reused as the cleaning liquid. However, a slight amount of SS remains in the cleaning waste liquid. There is.
In order to solve the problem shown in Patent Document 2, the patent document 2 divides the separation liquid and the cleaning waste liquid and collects them, and then the former is reused as a cleaning liquid without mixing or discharged outside the apparatus. The latter discloses a belt-type concentrator that is mixed in the sludge slurry before treatment and performs the concentration treatment again.
If the cleaning nozzle becomes clogged, an uncleaned area is generated on the belt, which reduces the dewatering performance. As with the self-cleaning nozzle disclosed in Patent Document 3, when the nozzle itself is clogged with foreign matter, a nozzle having a function of eliminating the clogging by washing out the foreign matter by pressure adjustment is known. Even if the blockage occurs, the blockage is solved in the process of once stopping the supply of the cleaning liquid and supplying the cleaning water again.
JP-A-55-27047 JP 2008-73670 A Japanese Utility Model Publication No. 53-156917

In the prior art described in Patent Document 2, the stored separation liquid is reused as a cleaning liquid, but there is no means for preventing the scum from mixing into the separation liquid and no means for removing the scum, and this is reused as the cleaning liquid. As a result, the cleaning nozzle may be frequently blocked. In addition, since the separation liquid and the washing drainage are stored in a storage tank outside the apparatus, the storage tank needs a large space.
Further, even if a self-cleaning nozzle as disclosed in Patent Document 3 is used, it is necessary to switch the manual valve in order to eliminate the blockage after confirming the blockage by visual observation such as poor cleaning of the belt. The belt cleaning must be stopped or the operation of the belt concentrator itself must be stopped, which reduces work efficiency. Furthermore, when the cleaning nozzle is blocked, if the above operation is not performed for a long time, the foreign material under the blocking will stick, and the operation must be stopped once and the cleaning work must be performed after removing the nozzle. There was also a problem.
As described above, in the belt concentrator, when the separation liquid is reused as the cleaning liquid, the clogging of the cleaning nozzle due to the mixing of residual SS and scum, and the operation interruption for removing the clogging are the operation of the belt type concentrator. It was a factor that reduced efficiency. An object of the present invention is to provide a belt type concentrator capable of continuously operating while reducing the mixing of SS and scum into a cleaning liquid reused as a separation liquid and cleaning the inside of the cleaning nozzle. is there.

<Invention of Claim 1>
The invention according to claim 1 includes a water-permeable endless belt that is wound around a plurality of rollers and travels along the rotation direction of the rollers.
A belt type concentrator that concentrates sludge by supplying the sludge to the start end side of the conveying surface of the endless belt and allowing the water in the sludge to pass through the endless belt as a separation liquid while being transferred to the end side,
Separation liquid storage means for storing the separation liquid;
A plurality of cleaning means for cleaning the endless belt returning from the end side to the start side with a cleaning liquid;
Cleaning liquid supply means for supplying the stored separation liquid to the cleaning means as the cleaning liquid;
The cleaning means is a self-cleaning spray nozzle , and a cleaning switching means for switching a cleaning liquid supplied to each cleaning means is installed,
Provided is a belt type concentrator wherein the cleaning switching means is configured to switch to the other cleaning means when the pressure of the cleaning liquid exceeds a predetermined value .

(The invention's effect)
The belt type concentrator includes a storage unit for storing the separation liquid in order to reuse the separation liquid as a cleaning liquid.
Since the cleaning liquid is a separation liquid obtained from the object to be processed, there is a high possibility that the cleaning means is blocked by SS, scum, etc., compared to a clean cleaning liquid supplied from outside the apparatus. Therefore, by arranging a plurality of cleaning means and operating them alternately, even if one of them becomes clogged, other use is possible and continuous operation is possible.
In addition, a plurality of self-cleaning spray nozzles (illustrated in FIG. 2) are used as the cleaning means. By switching between these, the belt cleaning and the cleaning of the inside of the nozzle are performed alternately, and continuous operation is performed. Is possible.
When the cleaning means is clogged, the pressure of the cleaning liquid supply means (cleaning pipe) increases. By detecting this pressure increase and closing the automatic control valve of the cleaning pipe whose pressure has increased and opening the automatic control valve of the other cleaning pipe, it is possible to switch the cleaning liquid piping. Can be prevented.

<Invention of Claim 2 >
According to a second aspect of the present invention, there is provided the belt type concentrator according to the first aspect , wherein the cleaning switching means switches to the other cleaning means when a predetermined time elapses without being switched.

(The invention's effect)
In the plurality of cleaning means, the cleaning nozzle can be prevented from being blocked by performing self-cleaning of the cleaning nozzle alternately for a certain time, preferably every 60 to 120 minutes.

<Invention of Claim 3 >
According to a third aspect of the present invention, the cleaning switching means switches to the other cleaning means when the pressure of the cleaning liquid exceeds a predetermined value, and outputs an abnormal signal when the time until the next switching falls below a predetermined time. The belt type concentrator according to claim 1 or 2, wherein the belt type concentrator outputs.

(The invention's effect)
According to the first aspect of the present invention, it is possible to continuously operate the belt type concentrator even if the cleaning nozzle is blocked. However, the cleaning liquid piping should be switched frequently in a short time, such as when a large amount of SS enters the separation liquid due to some abnormality of the equipment body, or when the clogging is not resolved due to foreign matter adhering to the cleaning nozzle. It becomes. In this case, there is a high possibility that it is necessary to stop the operation and perform inspection and treatment. Therefore, in the present invention, when the pressure increase of the cleaning pipe due to the blocking of the cleaning nozzle occurs in the belt type concentrator for an extremely short time, preferably within 3 to 5 minutes after the pipe switching, an abnormal signal is output. A function to call attention to the user is added.

<Invention of Claim 4 >
According to a fourth aspect of the present invention, a trough that receives the separation liquid and the washing drainage liquid after washing the endless belt is divided into a start end trough and a termination end trough below the endless belt. The separation liquid storage means is a starting end side trough, and provides a belt type concentrator according to any one of claims 1 to 3 .

(The invention's effect)
Instead of using a storage tank that was previously required, the trough located at the bottom bottom of the workpiece transfer surface of the main body is divided into the start and end sides and used as an alternative to the storage tank. . The cleaning drainage liquid containing a small amount of SS is discharged only to the end side trough, and the cleaning drainage liquid is prevented from being mixed into the separation liquid stored in the starting end side trough.

<Invention of Claim 5 >
The invention according to claim 5 includes a water-permeable endless belt that is wound around a plurality of rollers and travels along the rotation direction of the rollers.
This is an operation method of a belt type concentrator that supplies sludge to the start end side of the conveying surface of the endless belt and concentrates the sludge by allowing the water in the sludge to pass through the endless belt as a separation liquid while being transferred to the end side. And
Using a belt-type concentrator that uses a self-cleaning spray nozzle as a plurality of cleaning means for cleaning the endless belt returning from the end side to the start side with a cleaning liquid,
Storing the separation liquid, and supplying the stored separation liquid to the cleaning means as the cleaning liquid;
By the cleaning switching means for switching the cleaning liquid supplied to each cleaning means ,
Provided is a belt type concentrator operating method, characterized in that when the pressure of the cleaning liquid exceeds a predetermined value, switching to the other cleaning means is performed .

  According to the present invention, while maintaining the water saving effect by reusing the separation liquid as the cleaning liquid, a plurality of cleaning means having a self-cleaning function are arranged in the belt cleaning, and the belt cleaning and the cleaning inside the nozzle are alternately performed by switching these. By implementing the above, it is possible to provide a belt-type cleaning machine capable of discharging foreign matter in the cleaning means while continuously operating.

  Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a flow sheet including a schematic side view of an example of the belt type concentrator of the present invention. In FIG. 1, the cylindrical drive roll 15 and tension roll 16 of the belt type concentrator body 1 are installed so that the cross section faces the front and rear surfaces, and the endless belt 13 is wound around the rolls 15 and 16. It has been. The drive roll 15 is connected to the belt travel speed reducer 4 and enables belt travel and travel speed control in the direction of the arrow shown in FIG.

  As the belt 13, a belt normally used in a belt type concentrator such as a metal belt made of resin (polyester or the like) or a mesh structure made of a metal wire can be used.

  The sludge slurry containing the solid content obtained from the sedimentation basin or the like in the sewage treatment process is added with a flocculant and sent to the flocculation mixing tank 2. The sludge slurry mixed with the flocculant by the stirring device 3 is supplied from the inflow chute 14 near the start end of the running belt 13. The sludge slurry is concentrated on the belt 13 by allowing moisture contained therein to permeate to the back side of the belt 13 as a separation liquid by gravity, and is transported to the other end (end) side and discharged to the discharge chute 17. Is done. In order to promote the concentration effect and improve the recovery rate of SS, the sludge slurry is turned over and the filtration surface is updated above the belt 13, and a chicane for promoting the concentration, and sludge slurry near the end of the belt. It is preferable to install a press strip for pressing lightly against the belt to further increase the concentration effect, and a scraper for scraping the residual sludge on the belt in the vicinity of the drive roll 15 disposed at the end (not shown).

  At the bottom of the belt-type concentrator main body 1 below the belt, a trough is divided into a start-side trough 6 and a termination-side trough 7. The separation liquid that has passed through the belt flows down to the start-end side trough 6 and the end-side trough 7. The width and length of the bottom of the main body including the start-side trough 6 and the end-side trough 7 are larger than the belt width and belt length (in a state of being wound around a roll), and receive all of the separation liquid and the cleaning waste liquid described later. It is possible.

  The separation liquid stored in the start end trough 6 is extracted from the lower part of the start end trough, passes through the automatic operation three-way ball valve 18 and the double strainer 23 by the cleaning liquid pump 5, and is installed above the end end trough 7. The cleaning nozzles 9 and 10 supply the cleaning liquid for the belt 13. The cleaning nozzles 9 and 10 are arranged in two systems above the terminal trough so as to sandwich the lower belt folded back at the terminal end of the belt 13 in the vertical direction. The cleaning nozzle 9 is disposed on the front side (lower side) of the belt and ejects cleaning liquid upward, and the cleaning nozzle 10 is disposed on the back side of the belt (air gap in the belt) and ejects cleaning liquid downward. By removing a small amount of residual SS that has entered the gap of the mesh structure of the belt 13 with the jetted cleaning liquid, the clogging of the belt 13 is eliminated and continuous use is possible. In this embodiment, the cleaning nozzles 9 and 10 are arranged on both the front and back sides of the belt, but both of the cleaning nozzles 9 and 10 may be arranged side by side in the running direction of the belt on only one of them. In this embodiment, the cleaning nozzles use two systems of 9, 10, but three or more systems may be used.

  As the cleaning nozzle, a self-cleaning spray nozzle is used. A known self-cleaning spray nozzle can be used. An example is shown in FIG. The self-cleaning type spray nozzle has a narrow outlet when a pressure higher than a predetermined level is applied, and as a result, liquid can be ejected at high pressure. The foreign matter is discharged by the liquid to be cleaned, thereby cleaning the inside of the nozzle and removing the blockage.

  The cleaning liquid supply paths to the cleaning nozzles 9 and 10 are controlled by automatic operation ball valves 11 and 12, respectively. One valve 11 is opened and the other valve 12 is closed while the cleaning liquid is sprayed onto the belt. Conversely, while the valve 12 is opened, the valve 11 is closed. When switching between opening and closing of the two valves, the pressure of the cleaning nozzle is reduced in the cleaning nozzle on the side where the valve is closed, and self-cleaning inside the nozzle is performed accordingly, so when the valve is opened next time In this state, the belt cleaning is started immediately without the SS being blocked or stuck. Accordingly, the inside of the cleaning nozzle can be cleaned at the same time without interrupting belt cleaning, and the main body can be continuously operated without causing belt cleaning failure. The switching of the washing nozzle is performed at regular intervals, preferably every 60 to 120 minutes, when there is no pressure increase described later.

  When the cleaning nozzle is clogged, the pressure of the cleaning pipe increases. When the pressure in the cleaning pipe is increased, the open automatic operation ball valve 11 (or 12) is closed by the signal from the pressure switch 20, and the other valve 12 (or 11) is closed. Is opened and belt cleaning is continued. Usually, the pressure of the cleaning pipe is 0.3 to 0.8 MPa, but when the pressure is preferably 2.0 MPa or more, it is desirable to switch the cleaning liquid pipe.

  In order to detect abnormalities in the operating state such as the mixing of SS into the cleaning liquid supply path, the time from when the cleaning liquid pipe is switched until the pressure of the cleaning pipe exceeds a predetermined value (eg, 2.0 MPa) is monitored by a timer or the like. If it is shorter than the predetermined time, an abnormal signal is output. As the output signal, a commonly used signal such as a warning lamp or a warning sound can be used (not shown). The predetermined time is more preferably set within 3 minutes to 5 minutes. If the cleaning liquid piping is switched in a time shorter than the predetermined time, there may be some abnormality in the equipment body such as a large amount of SS or scum entering the separation liquid. Take action.

  The separated liquid flowing down to the start end side trough 6 is stored by closing the discharge pipe of the start end side trough 6 during operation, and if it exceeds a predetermined storage amount, it flows out to the adjacent end side trough 7 due to overflow. The separation liquid flowing down to the end side trough 7 is discharged out of the apparatus together with the separation liquid flowing out from the start end side trough 6 due to overflow from a discharge nozzle provided at the bottom of the end side trough 7.

  Of the separation liquid stored in the start end side trough 6, the remaining separation liquid supplied to the cleaning means flows out by overflowing from the entire surface in the trough width direction to the end side trough 7, and is drained from the end side trough 7 together with drainage of the belt cleaning. It is discharged out of the machine from the discharge nozzle. The separation liquid stored in the start-end side trough 6 has scum in some cases. However, the scum has floating characteristics, and most of the scum flows out to the end-side trough 7 and is discharged due to the overflow. The belt cleaning liquid is ejected at a high water pressure in order to reliably remove the SS that has entered the gap between the belts. For this reason, the cleaning waste liquid contains SS and spreads over a wide range on the bottom surface and wall surface of the termination side trough, causing the SS to adhere to the bottom surface and wall surface. Since it is always washed away, it is possible to prevent SS from being deposited on the bottom surface and the wall surface of the terminal trough 7.

  In addition to the cleaning liquid supply path from the start end side trough 6, a cleaning liquid supply path from outside the apparatus (for example, treated water) is also provided. A liquid level switch 21 is disposed in the vicinity of the bottom of the starting end side trough 6, and the automatic operation three-way ball valve 18 is switched based on a detection signal of the remaining amount of separation liquid in the starting end side trough 6, and the two systems of cleaning liquid supply paths The cleaning liquid is stably supplied by selecting and changing the timely. That is, if the amount of the separation liquid in the start end trough 6 is sufficient, the cleaning liquid is supplied from the start end trough through the cleaning liquid supply path. If the amount is insufficient, the cleaning liquid is supplied from the outside of the apparatus through the cleaning liquid supply path. Can be continuously washed. Furthermore, it is possible to prevent the scum from flowing out to the cleaning liquid side due to a decrease in the amount of the separated liquid stored, and it is possible to prevent the cleaning nozzle from being blocked. Depending on the setting of the liquid level switch 21 and the valve 18, it is possible to switch to the supply of the cleaning liquid from outside the apparatus for a certain period of time due to the above-described cleaning process of the end side trough due to the separation liquid overflow.

  In actual operation, about 10% of the separation liquid stored in the start side trough is reused as cleaning liquid, and most of the separation liquid overflows to the end side trough. To be discharged. Therefore, the cleaning liquid supply path from the outside of the machine is used only in the case of the belt cleaning operation in the state where the sludge supply is stopped, such as at the start or end of operation, or the situation where normal operation is difficult. It is assumed.

  The present invention provides a concentrator that has lower manufacturing costs and lower operating costs and saves space while maintaining conventional functions in fields that require solid-liquid separation of a large amount of slurry-like substances, such as sewage sludge treatment. To do.

It is a belt type concentrator and a piping flow sheet concerning the present invention. It is sectional drawing of an example of a self-cleaning type spray nozzle. (A) During normal cleaning (pressure increase) (B) During foreign matter cleaning.

DESCRIPTION OF SYMBOLS 1 ... Belt concentrator main body 2 ... Coagulation mixing tank 3 ... Stirrer 4 ... Belt travel speed reducer 5 ... Belt washing liquid pump 6 ... Start end side trough 7 ... End side trough 8 ... Separation liquid 9, 10 ... Washing nozzles 11, 12 ... Automatic operation ball valve 13 ... belt 14 ... inflow chute 15 ... drive roll 16 ... tension roll 17 ... discharge chute 18 ... automatic operation three-way ball valve 19 ... pressure gauge 20 ... pressure switch 21 ... level switch 22 ... flow meter 23 ... double strainer 24 ... Cleaning solution 25 ... Spring

Claims (5)

Comprising a water-permeable endless belt that is wound around a plurality of rollers and travels along the rotation direction of the rollers;
A belt type concentrator that concentrates sludge by supplying the sludge to the start end side of the conveying surface of the endless belt and allowing the water in the sludge to pass through the endless belt as a separation liquid while being transferred to the end side,
Separation liquid storage means for storing the separation liquid;
A plurality of cleaning means for cleaning the endless belt returning from the end side to the start side with a cleaning liquid;
Cleaning liquid supply means for supplying the stored separation liquid to the cleaning means as the cleaning liquid;
The cleaning means is a self-cleaning spray nozzle , and a cleaning switching means for switching a cleaning liquid supplied to each cleaning means is installed,
The belt-type concentrator , wherein the cleaning switching means is configured to switch to the other cleaning means when the pressure of the cleaning liquid exceeds a predetermined value . The belt-type concentrator according to claim 1 , wherein the cleaning switching unit switches to the other cleaning unit when a predetermined time elapses without switching the cleaning unit. 3. The cleaning switching unit according to claim 1 or 2, wherein when the pressure of the cleaning liquid exceeds a predetermined value, the cleaning switching unit switches to the other cleaning unit and outputs an abnormal signal when the time until the next switching is less than a predetermined time. The belt-type concentrator as described. The trough that receives the separation liquid and the cleaning drainage liquid after washing the endless belt is provided on the lower side of the endless belt, and is divided into a start end trough and a termination end trough, The belt type concentrator according to any one of claims 1 to 3 , wherein the belt type concentrator is a start end side trough. Comprising a water-permeable endless belt that is wound around a plurality of rollers and travels along the rotation direction of the rollers;
This is an operation method of a belt type concentrator that supplies sludge to the start end side of the conveying surface of the endless belt and concentrates the sludge by allowing the water in the sludge to pass through the endless belt as a separation liquid while being transferred to the end side. And
Using a belt-type concentrator that uses a self-cleaning spray nozzle as a plurality of cleaning means for cleaning the endless belt returning from the end side to the start side with a cleaning liquid,
Storing the separation liquid, and supplying the stored separation liquid to the cleaning means as the cleaning liquid;
By the cleaning switching means for switching the cleaning liquid supplied to each cleaning means ,
A method of operating a belt-type concentrator, characterized in that when the pressure of the cleaning liquid exceeds a predetermined value, switching to the other cleaning means is performed .

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