JPS6116954Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention improves the dewatering effect and processing capacity by always keeping the wedge effect length constant in the wedge effect dewatering zone in a belt press type dehydrator that dewaters sludge, etc. It relates to a device that performs.

Belt press type dehydrators, which are used for dewatering sewage sludge, human waste sludge, industrial water sludge, etc., are becoming more and more popular due to recent advances in polymer flocculants and growing interest in energy conservation.
Recently, the number of vacuum dehydrators has been increasing in place of conventional vacuum dehydrators, filter presses, centrifugal dehydrators, etc. The structure of this belt press type dehydrator is that a press roll, drive roll, tension roll, etc. are assembled in a copper frame, and this includes two endless filter cloths (upper and lower), a filter cloth cleaning device, and a meandering filter cloth. A correction device, filter cloth tension adjustment device, etc. are installed.

Further, the dewatering process of this belt press type dehydrator is composed of three dewatering zones. Firstly, the sludge passes through a gravity over-dehydration zone where the retention force between the flocs is dehydrated due to the action of gravity, and secondly between the wedges formed by two running upper and lower endless filter cloths and a group of small rolls that support them. There is a wedge-effect dehydration zone where the liquid pressure generated during the process forms a dehydrated cake, and thirdly, when the filter cloth passes between a group of rolls arranged in an S-shape, the sludge is removed by the tension of the filter cloth. This is a pressurized belt compression dewatering zone. Through the three dewatering processes described above, the system is designed to reduce the volume of sludge. On the other hand, regarding the dewatered cake water content and processing capacity that affect the performance of the belt press type dehydrator, we have established a system that can accurately sense fluctuations in sludge supply amount and changes in sludge properties and can always operate in a constant state. is necessary.

However, the sludge properties on the filter cloth change due to fluctuations in the sludge supply amount, and for this reason, it is not possible to obtain sufficient wedge effect dewatering time with a semi-fixed wedge effect dewatering zone mechanism like the conventional belt press. Ta.

The present invention was proposed with the aim of always maintaining a constant wedge effect length in the wedge effect dewatering zone to improve the dewatering efficiency here and eliminate the drawbacks of the conventional devices described above. In a belt press type dehydrator that sandwiches a workpiece between two pieces of cloth and dehydrates it through a gravity dehydration zone, a wedge effect dehydration zone, and a cloth compression dehydration zone, the workpiece liquid on the cloth is removed in the gravity filtration dehydration zone. To provide a belt press type dewatering machine, which is equipped with a detector for detecting the position, and is configured to automatically adjust the wedge height according to the detected value to always maintain a constant wedge effect length.

In the device of the present invention, the wedge height in the wedge effect dewatering zone is automatically adjusted according to fluctuations in the amount of sludge supplied, and a constant wedge effect length is always maintained. As a result, wedge effect dehydration can be achieved for a long time, reducing the water content of the dehydrated cake and improving processing capacity.

Next, one embodiment of the device of the present invention will be described based on the drawings.

FIG. 1 shows the gravity filtration dehydration zone and the wedge effect dehydration zone of this embodiment, and in the figure, 1 is the level transmitter provided in the gravity filtration dehydration zone, 2 is the level meter electrode, and 3 is the wedge effect dehydration zone. It is a cylinder with a potentiometer that moves the wedge arm 4 up and down to position it, and is attached to the support frame 5. 6 is a group of small rolls that support the upper filter cloth 7 and is rotatably attached to the wedge arm 5; 8 is a group of small rolls that support the lower filter cloth 9 and is rotatably attached to the support frame 10. 11 is a mud supply hopper, 1
2 is a reversing roll for reversing the upper filter cloth 7, and 13 is a pressing roll for compressing the upper filter cloth 7 and the lower filter cloth 9.

In this device, an increase or decrease in the sludge liquid level is detected by a level meter electrode 2 and a level transmitter 1 provided in a sludge supply hopper 11 in a gravity filtration dewatering zone,
Convert to DC signal, etc.

This signal synchronizes the cylinder 3 with a positioner that supports the wedge arm 4 and the upper small roll group 6 to control the stroke amount. As a result, the starting point of wedge effect dewatering in the wedge effect dewatering zone can always be effectively taken from point A in the figure, regardless of increases or decreases in the sludge liquid level.

Therefore, sufficient wedge-effect dewatering time can be taken even when the sludge supply amount fluctuates. Therefore, it is possible to reduce the moisture content of the dehydrated cake and improve processing capacity.

Next, a second embodiment of the device of the present invention will be explained based on FIG.

In this embodiment, a level signal converter 101 and a float type level meter 102 are installed in the gravity filtration dehydration zone.
and other structures, namely, a cylinder with a potentiometer 103, a wedge arm 104, and a support frame 10.
5, 110, small roll group 106, 108, upper filter cloth 107, lower filter cloth 109, mud supply hopper 111,
The reversing roll 112, pressing roll 113, etc. have the same structure as the apparatus shown in FIG.

This device is a float type level meter 102 installed in a slurry supply hopper 111 in a gravity filtration dewatering zone.
The level signal converter 101 converts the increase or decrease in the sludge level into a DC signal or the like. Based on this signal, the wedge arm 104 and the cylinder 103 with a positioner supporting the small roll group 106 are synchronized to control the stroke amount.

This allows the wedge effect dewatering starting point of the wedge effect dewatering zone to always be at A in FIG. 2 regardless of the increase or decrease in the sludge liquid level.
From these points, it is possible to effectively reduce the moisture content of the dehydrated cake and improve the processing capacity in the same manner as in the previous embodiment.

FIG. 3 shows a third embodiment of the device of the present invention, which includes an electropneumatic converter 20 in the gravity filtration dehydration zone.
1. A level meter electrode 202 is provided, and a wedge arm 20 is installed.
4, a torque actuator with a positioner 214 and its output shaft gear 215 are used as means for vertically moving the
A rack 217 is provided, and the output shaft gear 215 is fixed to the wedge arm 204 via a pinion 216.
It meshes with the Other structure, i.e. support frame 20
5,210, small roll group 206,208, upper filter cloth 207, lower filter cloth 209, mud supply hopper 211,
The reversing roll 212, pressing roll 213, etc. have the same structure as the apparatus shown in FIGS. 1 and 2.

This device detects increases and decreases in the sludge level using a level meter electrode 202 provided in the sludge supply hopper 211 in the gravity filtration dewatering zone, and outputs it as a current signal. Further, an electropneumatic converter 201 converts the current signal into a pneumatic signal.

The rotation angle of the torque actuator with positioner 214 is controlled by this air pressure signal. The rotational force of this torque actuator with positioner 214 uses a high pneumatic signal in addition to the control pneumatic signal.

The rotational force of the torque actuator with positioner 214 moves the wedge arm 204 and the small roll group 206 up and down by a combination of an output shaft gear 215, a pinion 216, and a rack 216.

Therefore, the starting point of wedge effect dewatering in the wedge effect dewatering zone can always be effectively set from point A in Figure 3 regardless of the increase or decrease in the sludge liquid level, and the water content of the dehydrated cake can be reduced and the processing capacity can be reduced as in the embodiment shown in Figure 1. can achieve improvements in

[Brief explanation of the drawing]

1, 2 and 3 are elevational views showing first, second and third embodiments of the device of the present invention, respectively. 1...Level transmitter, 2,202...Level meter, 3,103...Cylinder with potentiometer, 4,104,204...Wedge arm, 6,1
06,206... Upper small roll group, 7,107,
207... Upper filter cloth, 8,108,208... Lower roll group, 9,109,209... Lower filter cloth,
11,111,211...Mud supply hopper, 101...
... Level signal converter, 102 ... Float type level meter, 201 ... Electro-pneumatic converter, 214 ... Torque actuator with positioner.

Claims (1)

[Scope of utility model registration request] In a belt press type dehydrator that sandwiches the material between two moving filter cloths and dehydrates the material through a gravity filtration dehydration zone, a wedge effect dehydration zone, and a filter cloth compression dehydration zone, the material is separated from the filter cloth in the gravity filtration dehydration zone. Belt press type dehydration characterized by being equipped with a detector that detects the liquid level of the processed material, and configured to automatically adjust the wedge height according to the detected value to always maintain a constant wedge effect length. Machine.