JPS59133996A - Belt press type dehydrator - Google Patents

Abstract

PURPOSE:To provide a titled device which maintains an optimum condition according to the fluctuation in the characteristic of sludge and permits automatic operation by the constitution wherein the feed rate of a raw liquid, the feed rate of a flocculating agent and the speed of filter cloth belts are controlled by the output signal from a liquid level detecting means provided in a gravity dehydrating part. CONSTITUTION:A liquid level controller 13 is provided to a sludge receiving tank 8 in a gravity dehydrating part 4' to detect continuously the liquid height of sludge in a belt press type dehydrator which extends and runs endless filter cloth belts 5, 6 between a low pressure roll 9 and a press roll 10, introduces a raw liquid A mixed with a flocculating agent B through a flocculating and mixing tank 3 into the part 4' and a pressure dehydrating part 4'' and separates the liquid to dehydrated cake C and filtrate D. The controller outputs a control signal according to the detected value to control a flocculating agent feeder 2 via a control circuit 15 thereby adjusting the feed rate of the flocculating agent. A driving device 7 for the filter cloth belts is also controlled via a control circuit 16 for rotating speed. A raw liquid feeder 1 is further controlled via a control circuit 14 according to need to adjust the feed rate of the raw liquid.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a belt press type dewatering apparatus for dewatering sludge generated in the treatment of water such as tap water, sewage, and industrial wastewater.

In a belt press type dewatering device, sludge and a polymer flocculant are uniformly mixed and weighed, and a flocculation section that creates flocculated sludge is the first stage. The gravity IR wood section that carries IR water, the sludge obtained in the gravity dewatering section, is separated by two sheets: an endless furnace cloth belt that runs on the front side, and an endless furnace cloth belt that runs parallel to the top and runs parallel to the belt. This belt press type dewatering device (which runs between multiple rolls) is equipped with a pressurized N water release section that removes water by compression and shear force. It has become popular in recent years because it is simple and easy to maintain, uses a small amount of flocculant, has a solid content collection vehicle height, and has high deicing water effect.

If the supplied sludge is not completely treated in the gravity dewatering section of the device, ζ build-up due to belt side force etc. will occur, making it impossible to fully demonstrate the performance. The supply amount of flocculation 1i1J is determined based on the processing amount, and the flocculant is automatically supplied in a fixed amount to form an optimal flocculation floc.

However, if the properties of the sludge change, the amount of coagulant may be too much or too little, resulting in incomplete coagulation, resulting in sludge protruding from the belt side, clouding of the filtrate, etc., and the solids recovery rate is also poor. For this reason, there is a drawback that automatic operation is difficult when there are many variations in sludge properties. The present invention has been made in view of the above-mentioned circumstances, and provides a device that eliminates the above-mentioned drawbacks, maintains optimal operating conditions, and makes automatic driving possible. In a belt press type dewatering device in which a Shito cloth belt is stretched so as to run between a plurality of rolls and is provided with a gravity dewatering section and a pressure dehydrating section, the gravity dewatering section (4I has a liquid level detection means (13)).
A control circuit (15) of the flocculant supply device (2) which is operated by the output signal of the detection means (13), a control circuit (14) of the stock solution supply device (1), and an endless belt feeding drive device M (7). ) A control circuit (16) is provided.

An embodiment of the present invention will be described based on the drawings.

FIG. 1 is a system diagram of an embodiment according to the present invention.

fil is a stock solution supply device that supplies a fixed amount of stock solution A such as sewage sludge, (2) is a flocculant supply device that supplies a fixed amount of flocculant B such as a polymer flocculant, and (3) is the device (1) and (2). ) A coagulation mixing tank that uniformly mixes the sludge and flocculant supplied from the sludge with an agitator attached to the top and measures the flocculation of the sludge. is a belt press type dewatering device that dehydrates sludge (4 is a gravity-fed dewatering device that dewaters flocculated sludge introduced from the flocculation mixing tank (3) on a single endless belt (5) that runs on it by gravity) The dewatering section (4) is an upper running endless cloth belt (6) provided parallel to and opposite to the endless cloth belt (5) for removing dehydrated sludge.
A pressurized dewatering section (5
) and (6) are cloth belts with a constant width woven from synthetic WA fibers such as nylon or polyester, which are stretched endlessly between rolls and are constantly driven in the direction of the arrow by a driving device W (7). Run at speed. (7) Beam furnace cloth belt (5), (6)
(8) is a sludge receiving tank that receives and retains flocculated sludge with the furnace cloth belt (5) of the gravity dewatering section (4) as the bottom surface, (9) beam furnace cloth belt (5) ,(5
It consists of a large-diameter low-pressure roll that gradually compresses the 1g of sludge that has been conveyed under low pressure, and a plurality of small-diameter press rolls that are installed to apply even higher pressure to the furnace fabric. By running between the rolls, belts (5) and (6) apply pressure accompanied by shearing force to the cake.

(11) and (11') are drive rolls for the cloth belts (5) and (6), and the scraper (17) reverses the furnace cloth.
The dehydrated sludge is peeled off and discharged as dehydrated cake C to the outside of the system. (12) is a liquid collector that collects the filtered liquid. The collected liquid is extracted and discharged outside the system. A liquid level control meter (13) equipped with a signal transmission circuit is installed as a liquid level detection means in the sludge receiving tank (8) provided in the gravity dewatering section (41) of such a known belt press type dewatering device, and the sludge The liquid level height is continuously detected and signals are sent to each control circuit (14), (15), and (16) to ensure optimum operation at all times. Sludge receiving tank (8
) describes the case where the sludge liquid level in the sludge exceeds a certain height set when the amount of flocculant added is insufficient.
A signal is output from the liquid level controller (13) to the supply amount control circuit (15) of the flocculant supply amount Mf21 to increase the rotation speed of the supply device (2), thereby proportionally increasing the supply amount;
If the liquid level does not drop even after a certain period of time has elapsed, a signal is output to the rotation speed control circuit (16) of the endless belt running drive device (7) and the rotation speed of the drive device (7) is increased. increasing the running speed of the belts (5) and (6);
Furthermore, if no improvement is seen even after a certain period of time has passed, the stock solution supply device I (B outputs a signal to the supply amount control circuit (14) of 11 and reduces the rotation speed of the supply device (1)). Decrease the supply amount.If necessary, an alarm may be installed to issue an alarm.If the above operation does not resolve the problem, stop supplying the stock solution and flocculant, and after a certain period of time, remove the attached Stop the entire system including related machines.

In addition, the above continuously detects the liquid level of sludge in the sludge receiving tank (8) and outputs a signal, and each control circuit (14), (15)
, (16) are being switched continuously, but if the flocculant supply rate is increased and the liquid level does not drop after a certain period of time, the flocculant supply rate is further increased, and if no improvement is seen, further flocculation is performed. Each control circuit (14), (15) increases the amount of agent supplied by a signal from the liquid level controller (13).
), (16) may be switched in stages, or in other embodiments, contrary to the above, when the liquid level of sludge in the sludge receiving tank (8) falls below a predetermined height, It is also possible to reduce the amount of flocculant supplied proportionally and operate with the optimum amount of flocculant.

When dewatering sludge generated in the water treatment of tap water, sewage, industrial wastewater, etc., if a belt press type dehydrator equipped with the control mechanism of the present invention configured as described above is used, changes in the properties of the sludge can be prevented. Even if the sludge does not coagulate, the amount of flocculant supplied will be insufficient and the sludge will not flocculate incompletely, causing sludge to protrude from the belt side or turbidity of the door liquid.In addition, the equipment can be fully automated and can be operated unmanned. -It is an extremely effective device in industry because it can cause problems.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of an embodiment according to the present invention. 11+・Stock solution supply device, (2): Coagulant supply device, (3
): Coagulation mixing tank, (a): Belt press type dehydrator, +4
i: gravity dehydration section, (j'r: pressure dehydration section, (6),
(6) Niji Tofu Pel h, (71:5 Tofu belt drive device, (8): Sludge receiving tank, (9): Low pressure roll, QOI:
Press roll, (11), +111: Drive roll,
+12): Liquid collector, +131: Liquid level controller, +14):
Stock solution supply amount control circuit, (15) = Coagulant supply amount control circuit, +16); Rotation speed control circuit, +17); Scraper A: Stock solution, B: Coagulant, C: Dehydrated cake, D: Noodle liquid patent application Person: Mitsubishi Kakoki Co., Ltd.

Claims (1)

[Claims] In a belt press type dewatering device in which an endless f-cloth belt is stretched to run between a plurality of rolls and is provided with a gravity dewatering section and a pressure dehydrating section, a liquid level detection means (13) is provided in the gravity dewatering section (4). ), a control circuit (15) for the flocculant supply device (2), a control circuit (14) for the stock solution supply device (1), and an endless belt conveyance drive device (7) operated by the output signal of the detection means (13). ) A control circuit (16) is provided.