JPS6016879B2 - Sludge treatment equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a belt press type sludge treatment apparatus for dewatering sludge.

Conventionally, it has been proposed to control the flow rate of a belt press type dehydrator depending on the sludge concentration supplied to the dehydrator to keep the amount of solids supplied constant.

This belt press type sludge treatment apparatus is shown in FIG. The sludge 1 is supplied to a feed box 3 with its flow rate and concentration controlled by a supply pump 2 so that the amount of solids remains constant.

The supplied sludge is drained by the gravity dehydration mechanism 4 of the belt press type dewatering device 40, then compressed and dehydrated by the low pressure compression dehydration mechanism 5, and the sludge 1 is compressed and dehydrated by the high pressure dehydration mechanism 6 at a high pressure of approximately 11k9/carp. The cake is dehydrated under pressure and then discharged as a dehydrated cake 7 from a high-pressure belt press. In this case sludge 1
If the supply amount and concentration of V are constant, the flow rate and thickness will be approximately constant, and stable dehydration and processing amount can be ensured.

However, when changing the flow rate using the supply pump 2, the flow rate is not proportional to the rotational speed, so it is more complicated than changing simply by controlling the rotational speed.

Also, the relationship between the time required for dehydration and the concentration of the dehydrated cake is the second
As shown in the figure, the higher the initial concentration, the faster the predetermined concentration is reached. Therefore, if the amount of solids is controlled to be constant, if the concentration is high, the sludge will be dehydrated more than necessary, and if the concentration is low, if the amount of supplied sludge is too large, it will overflow from both sides of the endless belt. Become. In addition, if the sludge supply per area of the endless belt is not controlled, if the sludge is concentrated, the thickness of the dehydrated cake will increase, causing a difference in the running distance of the two inorganic belts, making normal operation difficult. was.

This invention eliminates the above-mentioned drawbacks and provides a belt speed control device and sludge supply control device that control the running speed of an endless belt to keep the amount of solids fed per belt area constant in order to efficiently operate a belt press type dewatering device. , an object of the present invention is to provide a sludge processing bag hawk including a flocculant addition device. Embodiments of the present invention will be described below with reference to FIG. 3 of the drawings.

The flow rate and concentration of sludge 1 are determined by flow rate detector IA and concentration detector IB.
A supply pump 2 is provided whose flow rate is controlled to be substantially constant by a signal from a flow rate detector IA. Further, the flow rate and concentration signals are sent to the calculator 8, where they are multiplied to calculate the amount of solid matter. A flocculant is added to the sludge from the supply pump 2 in the mixer 13 to form a floc, and then the sludge is sent to the dewatering device 40 for cleaning. The flocculant is supplied from the flocculant tank 10 to the mixer 13 by the addition pump 12. Based on the signal of the amount of solids from the calculator 8, the adjuster 12 is adjusted so that the amount of flocculant added per amount of solids is constant. controlled by Dehydration bag demon 40 is gravity dehydration part 4,
It consists of a low pressure compression dehydration section 5 and a high pressure dehydration section 6.

The sludge is poured onto the lower endless belt by the feed box 3 in a predetermined width. The sludge on the lower endless belt moves together with the inorganic belt, and is drained by gravity in the gravity dewatering section. If the sludge on the belt is raked or leveled at this point, the effect of gravity dewatering will increase. The sludge is then sandwiched between the upper inorganic belt and the lower inorganic belt, and is dehydrated under pressure by a plurality of rollers in the low-pressure compression dewatering section 5.
After the treatment, it is dehydrated in a high-pressure dehydration section 6 that is also pressed from the outside by a high-pressure belt and discharged as a dehydrated cake 7.Next, it is sandwiched between an upper inorganic belt and pressed by multiple rollers. Low pressure compression dehydration 5, high pressure dehydration 6
The water flows into the dehydrator 40 consisting of a dehydrated cake T.
Sent as .

' The above-mentioned dehydrator 40 has solid objects per belt area,
A belt control device 8 is provided to control the running speed to be constant.

This is done by controlling the rotational speed of the roller drive motor M with the control device 9 in accordance with the solid matter amount signal from the computing unit 8. - Therefore, when it is notified by the signal from the computing unit 8 that the amount of solid material being fed to the wheel will increase, the motor rotation speed is increased by the motor rotation control unit 9, and the belt running speed is controlled to increase. be done.

When the amount of solids supplied decreases, the running speed of the belt is conversely controlled to decrease by 4 mm, so that a constant amount of solids is always supplied onto the belt. With the above structure, the sludge into which the flocculant is injected at a constant rate is dehydrated for a shorter period of time as the initial concentration is higher, so that the sludge can be efficiently dehydrated to a predetermined concentration.

Control of the constant supply of solids per belt (furnace cloth) area can be accurately achieved by controlling the rotation speed of the motor.

In addition, when the amount of solids is large, it is possible to prevent sludge from protruding from the side of the belt, increasing the side effects of sludge caught between the belts, and causing a difference in the running distance of the two belts, thereby preventing uneven driving of the belts. According to this invention, the flow rate of sludge is detected and controlled to be constant, the concentration of sludge is further detected, and the amount of solids is calculated by multiplying it by the flow rate, so that the amount of solids supplied per area of the endless belt is constant. The running speed is controlled by a belt speed control device so that the running speed is controlled, and the flocculant is added at a fixed ratio to the amount of solids in the sludge to floc the sludge, resulting in efficient operation of the dewatering equipment. This makes it possible to obtain a dehydrated cake with a nearly constant water rate and to improve the dewatering capacity.

In particular, in belt presses with high-pressure dewatering sections, it is very important that the sludge is spread evenly on the belt and that its thickness is constant, so that the pressure of the pressure belt is spread over the entire surface of the furnace cloth. The effect is that the pressure belt acts uniformly and runs smoothly.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a conventional sludge processing bag counterfeit, FIG. 2 is a graph showing the relationship between sludge concentration and dewatering time, and FIG. 3 is a block diagram showing an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1...Sludge, 2...Sink stand pump, 40...Dewatering device, 8...Calculator, 9...Belt speed control diamond counterfeit,
10... Coagulant tank, 11... Coagulant addition pump, 13... Mixer. A'Multiple 2nd and 3rd figures

Claims (1)

[Claims] 1. A concentration meter that detects the concentration of sludge to be supplied, a sludge supply control device that controls the flow rate to a constant level, a flocculant addition device that adds a predetermined amount of flocculant to the amount of solids in the sludge, and a flocculant addition device that controls the flow rate to a constant level. A dewatering device consisting of a low-pressure compression dewatering section that presses and dewaters the remaining sludge while moving it between two endless belts, and a high-pressure dewatering section that presses both of the endless belts with a pressure belt; A sludge treatment device comprising a motor rotation control device that controls the running speed of an endless belt so that the amount of solids supplied per area of the endless belt is constant.