JPS61222700A - Automatic control device of belt press dehydrator - Google Patents

Abstract

PURPOSE:To prevent the generation of the over-load phenomenon, etc. of sludge dehydrator and to make it effectual by setting up a sludge densitometer on the upstream side of the dehydrator and by controlling the flow discharges of the sludge feeding pump and chemicals feed pump based on the detected sludge density. CONSTITUTION:The flow quantity control is performed by making a sludge feed pump 1 variable in order to measure the density of the sludge to be fed to a dehydrator 15 by sludge densitometer 13 and to make the solid substance quantity to be fed to the dehydrator 15 constant and the sludge feed quantity is measured by flow meter 2. THe chemicals feed factor for the sludge density is set by ratio setter 11 at the same time and the flow discharge of chemicals feed pump 4 is controlled. The internal operation is performed by inputting into microcontroller 9 the level position by gravity filter level detector 6 and the signal by side leakage detector 7 and the motor 5 for filter cloth speed control is stepwisely made variable and controlled continuously. The reference speed of the filter cloth is determined and made variable with the manual setter 10 of the external part.

Description

[Detailed Description of the Invention] (Industrial Application Field) (Prior art) - The instrumentation flow shown in Figure 3' is based on a belt press dehydrator used for dewatering sewage sludge, human waste sludge, industrial wastewater sludge, etc.' This is the conventional processing flow.

The device shown in FIG. 3 is operated manually or in conjunction with operation. In other words, when the interlocking person operates the switch 01iK, the sludge dewatering machine 06 → mixing tank agitator 05 → chemical injection of polymer flocculant from the conveyor 07 on the downstream side. Pump 04 -> sludge supply pump 03 are started upstream in this order.・Also, furnace cloth meandering detector t11,
If the side leak detector (i2 is activated, the i1 alarm is issued and the sludge supply pump 0 is stopped. In Fig. 3, 08 indicates the sludge storage tank, 09 indicates the mixing tank, and 010 indicates the separated liquid tank. .

In this way, the conventional sludge dewatering process only requires manual operation or interlocking operations, and the sludge dewatering machine
6 "Automatic control, - chemical injection control and mud supply amount control are not performed,
The installation of a meandering pole extractor 01 and a side leak detector 020 was limited to simply protecting the operation of the sludge dewatering machine 06, and the operation was only halted by alarm display and interlock in the event of an abnormality. Due to this, changes in the amount of sludge supplied (moisture content) often caused an overload phenomenon in the sludge dewatering machine 06, resulting in a stoppage of the treatment process or an increase in the water content of the dewatered cake.

Therefore, it has been desired to develop a continuous and efficient automatic control system that prevents overload phenomena and increases in water content.

(Problems to be Solved by the Invention) An object of the present invention is to prevent the occurrence of overload phenomena in a sludge dehydrator, establish a continuous and efficient automatic control system without stopping the treatment process, and The purpose of this invention is to provide an automatic control device for a belt press dewatering machine that integrates the functions of the instruments used and integrates electronics.

(Means for Solving the Problems) The present invention provides a belt press dehydrator that performs sludge dewatering treatment, in which a sludge concentration meter is installed on the upstream side of the dehydrator, and this detects the sludge concentration. Based on the detected sludge concentration, the amount of solid material supplied to the sludge storage tank and dewatering machine is controlled by variable control of the sludge supply pump, and at the same time, the chemical injection rate of the polymer flocculant is controlled by a ratio setting device based on the detected sludge concentration. On the other hand, the dehydrator is equipped with a gravity filtration level detector and a side leak detector, and the signals from each detector are input to the microcontroller and calculated. The present invention relates to an automatic control device for a belt press dewatering machine, characterized in that the speed is controlled.

That is, the present invention has the following features.

(1) Control of sludge supply amount and chemical injection amount with respect to sludge concentration.

(2) Dehydrator cloth speed control.

(3) Electronics using microcontrollers (sequencers, etc.).

(4) By detecting gravity overlevel and side leak, the furnace cloth speed can be controlled continuously in stages, minimizing the number of stoppages in the treatment process.

(effect) The present invention will be explained below based on the drawings.

FIG. 1 shows the flow of an automatic control device according to the present invention.

In the figure, 1 is a sludge supply pump (variable speed motor), 2 is a supply sludge flow meter, 3 is a sludge concentration meter, 4 is a polymer flocculant chemical injection pump (flow rate adjustment motor), and 5 is a furnace cloth speed control electric motor (variable speed motor), 6 is gravity filtration level detector,
7 is a side leak detector, 8 is a furnace cloth meandering detector, 9 is a microcontroller, 10 is a manual setting device, 11 is a collection rate ratio setting device, 12 is a furnace cloth spade controller, 14 is a sludge storage tank, 15 16 is a dehydrator, 16 is a conveyor, 17 is a mixing tank, 18, 19, 20 is a control unit, 21 is a separated liquid tank, 22 is a detection unit, 23 is a calculation unit, and 24 is a sequencer. Further, IM means a main motor that drives the furnace cloth of the dehydrator 15, and OM means a pilot motor that changes the rotational speed of the main motor 111M and the stroke speed of the pump.

First, the concentration of sludge supplied to the dehydrator 15 is measured using the sludge concentration meter 3.
In order to keep the amount of solid matter entering the dehydrator 15 constant, the sludge supply pump 1 is controlled to vary the flow rate.
The amount of mud supplied is measured with flow meter 2. At the same time, the ratio setting device 11 sets the chemical injection rate for the sludge concentration, and the discharge flow rate of the chemical injection pump 4 is controlled. The level positions determined by the gravity filtration level detector 6, 'L (lower limit position), H (upper limit position), TIH (
jJ4 Normal height Permanent position The signal W from the side leak detector (photoelectric switch) 7 (detection position of sludge leak from the furnace cloth side) is input to the microcontroller 9, which performs internal calculations to control the furnace cloth speed. The electric motor 5 is varied stepwise and controlled continuously. In addition, determine the standard speed of the furnace cloth, and set this standard speed using the external manual setting device 1.
It is variable with 0.

In the automatic control of the furnace cloth speed, first, when the gravity filtration level is L or less and the dewatered sludge width is W or less, the furnace cloth speed is decreased. If the gravity filtration level is between L and ■ and the dewatered sludge width is W or less, maintain the current status. Nine, if the gravity filtration level is between H and 11H and the dehydrated sludge is below W,
Increases furnace cloth speed. Furthermore, if the 1 gravity filtration level is 111H or higher and the content of the dehydrated sludge is W or lower, it is regarded as an overload phenomenon and the dewatering process is stopped.

Next, if the 1 gravity filtration level is below L and the dewatered sludge is above 7 (side leak), it is regarded as an overload phenomenon and the dewatering process is stopped. Further, when the gravity filtration level is between L and H and the dewatered sludge is 7 or higher, the furnace cloth speed is increased. Also, the gravity filtration level is from ■ to H.
If the content in the dehydrated sludge is 7 or more during TI, the furnace cloth speed is increased, and if the gravity filtration level becomes HH or more with side leakage, the dewatering process is stopped.

FIG. 2 shows a furnace cloth speed control system, and the control method of the present invention will be further explained based on this.

The oven cloth speed controller 12 receives the oven cloth speed setting signal from the microcontroller 9 and compares the feedback signal from the speed detector 13 with the current signal converted by the detection unit 22 . Here, if there is a difference between the setting signal and the feedback signal, a contact signal is output, the pilot motor CM is rotated forward or backward, and the furnace cloth speed is increased or decreased.

As mentioned above, the speed of the furnace cloth is controlled by signals from the gravity filtration level and the dehydrated sludge, and the step change in speed is performed with a time limit.

Table 1 shows such a furnace cloth speed control pattern.

Table 1 Tatami: Carryover status Shaft: Side leak status In Table 1, the furnace cloth speed steps are performed in the following manner. That is, the standard speed control is changed by, for example, front and rear alV steps. This standard speed Vhs can be varied using an external setting device. or,
The step change shall be performed with a time limit of about 10 to 20 degrees. If the furnace cloth speed exceeds the step range of α77 and t37, a time limit is set and a 1% F alarm is issued at the center. It should be noted that the signal to stop the processing process is detected after waiting for 2 to 20 minutes and then detects the next situation, in case the condition continues.

(Effects of the Invention) Since the speed of the furnace cloth is automatically and continuously controlled, overloading of the dehydrator is suppressed, and continuous and efficient operation is possible at all times.

[Brief explanation of the drawing]

FIG. 1 shows the flow of an automatic control system for a belt press dewatering machine according to the present invention, and FIG. 2 shows a furnace cloth speed control system in the system according to the present invention. FIG. 3 shows the instrumentation flow of a conventional belt press dewatering machine operated manually or in conjunction with each other. Sub-agents 1) Meifuku agent Ryo Hagiwara - Figure 2

Claims (1)

[Claims] In a belt press dehydrator that performs sludge dewatering processing, a sludge concentration meter is installed upstream of the dehydrator to detect the sludge concentration, and based on the detected signal, the sludge is supplied from the sludge storage tank to the dehydrator. At the same time, based on the detected sludge concentration, the chemical injection rate of the polymer flocculant is set using a ratio setting device, and the discharge flow rate of the chemical injection pump is controlled. , a belt press dehydrator characterized in that the dehydrator is equipped with a gravity filtration level detector and a side leak detector, and the signals from each detector are input to a microcontroller and calculated to control the filter cloth speed. Machine automatic control device.