JPH0140637Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a belt filter type dehydrator.
In particular, the present invention relates to a belt filter type dehydrator that can wash a dirty filter cloth while it is attached to the dehydrator.

A belt filter type dehydrator (hereinafter simply referred to as a dehydrator) is equipped with at least a hopper mechanism for dewatering sludge on a filter cloth and a pressurizing mechanism for squeezing the filter cloth and main drum, and is used for domestic wastewater and various industrial applications. It is used to dewater large amounts of thickened sludge generated when treating wastewater.

However, due to its mechanical characteristics, the filter cloth is very easily soiled, and the filter cloth is washed by, for example, applying a low-pressure shower or a high-pressure shower to the filter cloth after separating the dehydrated cake. However, even if such washing is carried out constantly, the dirt on the filter cloth gradually increases, and eventually it becomes clogged, and the processing capacity of the dehydrator falls below its limit. In particular, when the wastewater to be treated is paint wastewater generated during the production of special papers such as pressure-sensitive recording paper, heat-sensitive recording paper, and sublimation transfer paper, adhesive substances contained in the paint,
Wax and the like quickly adhere to the filter cloth and cause clogging in a short period of time.

Dirty filter cloth needs to be washed using a cleaning solution; generally, first, the operation of the dehydrator is stopped, the dirty filter cloth is removed, and it is placed in a plastic container, etc., in the washing solution. It is soaked for over 24 hours to remove dirt. Note that a spare clean filter cloth is attached to the dehydrator from which the dirty filter cloth has been removed and the operation is restarted, but the time required to replace the filter cloth becomes a complete loss. Moreover, since the work of replacing the filter cloth requires the hands of a worker, the processing efficiency of the dehydrator is extremely reduced.

In view of this current situation, the inventors of the present invention have conducted extensive research into a dehydrator equipped with a washing mechanism that eliminates the need to temporarily stop the operation of the dehydrator in order to replace a dirty filter cloth, as in the case of conventional methods, and have developed the present invention. We have achieved this goal. The present invention provides a belt filter type dehydrator equipped with at least a hopper mechanism for dewatering sludge on a filter cloth, a pressure mechanism for squeezing the filter cloth and a main drum, and a washing mechanism for washing the filter cloth. This belt filter type dehydrator is characterized in that a shower mechanism for dripping cleaning liquid is provided on the upper part of the main drum.

In the dehydrator of the present invention, the washing liquid shower mechanism is provided above the main drum, so that the washing liquid is spread out before the filter cloth and the washing liquid come into contact with each other at the nip between the filter cloth and the main drum. A sufficiently uniform layer is formed in all directions, and the increased void ratio inside the filter cloth, which has been pre-dehydrated by the vacuum hopper, also contributes to the fact that the cleaning solution is uniformly and sufficiently distributed inside the filter cloth. infiltrate. Furthermore, immediately after the nip, the filter cloth and the cleaning liquid layer are squeezed between the outer surface of the main drum and the pressure roll, so the cleaning liquid is permeated into the filter cloth at once, and the cleaning liquid layer is squeezed between the outer surface of the main drum and the pressure roll, so that the cleaning liquid is absorbed into the inside of the filter cloth at once. It exhibits an extremely excellent cleaning effect, and by simply stopping the supply of sludge from the charge chute and performing the cleaning process with a cleaning solution for a short period of time, the filter can be filtered efficiently without the need to remove the filter cloth from the dehydrator. It is used to wash cloth.

The present invention will be explained in more detail below based on the drawings.

FIG. 1 is a schematic diagram showing an embodiment of a dehydrator equipped with a washing liquid shower mechanism according to the present invention. By manually operating the charge valve 1, the sludge 2 whose supply amount is regulated is spread on the charge chute 4 in order to supply it over the entire width of the filter cloth 3.
The sludge 2 on the filter cloth 3 is initially dehydrated by its own gravity and the suction force of the vacuum hopper 6 whose pressure is reduced to, for example, 20 to 40 mmHg by the suction blower 5, and then passed through the pressure roll on the main drum 7. 8 for further dehydration. The filter cloth after separating the dehydrated cake 9 is washed, for example, by a low pressure shower 10 of 2 kg/cm ² and a high pressure shower 11 of 10 kg/cm ² . New sludge 2 is supplied again to the filter cloth 3 after the washing operation by the charge chute 4.
The same operation as above is repeated.

When such equipment was used to treat paint wastewater generated during the manufacture of thermal recording paper, it was found that only 1.
The dewatering ability decreased over time, the water content of the dehydrated cake 9 exceeded the specified value, and it became impossible to separate the dehydrated cake from the filter cloth, making it necessary to wash the dirty filter cloth. After stopping the supply of sludge 2, the cleaning liquid was supplied to the upper part of the main drum 7 by the cleaning liquid shower mechanism of the present invention.

In such a washing liquid shower mechanism, as the washing liquid, for example, dilute caustic liquid, dilute hydrochloric acid, or a commercially available neutral detergent can be used as appropriate depending on the purpose, and in this example, dilute caustic liquid was used. The cleaning liquid shower pipe 12, which is the main part of the present invention, is
Depending on the type of cleaning liquid, for example, vinyl chloride, iron,
Manufactured from materials such as gun metal and stainless steel.
The pipe is also provided with a shower hole of an appropriate size. Further, in order to obtain a uniform layer of cleaning liquid, the cleaning liquid shower pipe 12 may be slid by an electric sliding mechanism.

The cleaning liquid was supplied to the cleaning liquid shower pipe 12 by connecting a cleaning liquid tank 13 having a sufficient capacity to the cleaning liquid shower pipe 12, and utilizing the gravity of the cleaning liquid 14. However, the cleaning liquid tank 1
Of course, it is also possible to supply the cleaning liquid by operating the cleaning liquid pump from step 3.

The amount of cleaning liquid dripped from the cleaning liquid shower pipe 12 to the upper part of the main drum 7 is adjusted by adjusting the opening degree of the cleaning liquid valve 15.

In this way, the cleaning liquid dripped onto the top of the main drum uniformly permeates inside the filter cloth, as described above.
It exhibited an excellent cleaning effect, and a dirty filter cloth could be reused after approximately 20 minutes of cleaning, and continuous operation for two months was possible.

FIG. 2 shows an embodiment in which processes such as starting and stopping the supply of sludge and starting and stopping the application of the washing liquid shower mechanism are automatically performed based on pre-programmed signals issued from the control unit. .

That is, in order to detect the degree of dirt on the filter cloth 3, a box 19 having an opening on one side and having, for example, a diaphragm sensor 18 as a detection means is placed at an appropriate position after the high-pressure shower 11, with the opening facing the filter cloth surface. It is provided. The inside of this box 19 is always degassed at a constant deaeration rate, and the vacuum pressure value is detected by the diaphragm sensor 18.
The degree of dirt on dirty cloth can be determined. In this embodiment, piping is provided between the box 19 and the suction header 20 in order to maintain the inside of the box 19 in a vacuum state, but a dedicated vacuum pump may be provided separately.

Furthermore, it is of course possible to detect the degree of dirt on the dirty cloth as a change in the amount of light.

The operation of the dehydrator is started by inputting a "start operation" signal to the adjustment section 21. The adjustment unit 21 causes the cleaning liquid pump 17 to “stop operation”.
An "open" signal is issued to the control valve 16, and an appropriate amount of sludge 2 is supplied onto the charge chute 4 for dewatering. During this time, the degree of contamination of the filter cloth 3 is constantly detected by the diaphragm sensor 18 as a vacuum pressure value in the box 19, and is inputted to the controller via the converter 22 and the transmitter 23. As time passes, the filter cloth 3 becomes more dirty and when the vacuum pressure value set in the adjustment section 21 is exceeded, the adjustment section 21 stops supplying the sludge 2 and cleans the filter cloth 3. It issues signals to the control valve 16 to "close", and to the washing liquid pump 17 to "start operation". When cleaning of the dirty filter cloth 3 is completed within the timer setting time and the filter cloth 3 can be reused, the diaphragm sensor 18 inputs this information to the adjustment section 21, and the adjustment section 21 starts the filter cloth cleaning operation. In order to stop the water and restart the dehydration work, set the timer to ``stop,'' control valve 16 to ``open,'' and wash liquid pump 1.
7, transmits each signal of "stop operation". However, if the dirt on the filter cloth cannot be washed forever and the "set time" on the timer is exceeded, this indicates that the filter cloth needs to be replaced, and the control unit 21 notifies the operator of the situation. Therefore, a "blow" signal is issued to the alarm 24, and a "stop operation" signal is issued to the cleaning liquid pump 17.

The belt filter type dehydrator equipped with the cleaning liquid shower mechanism of the present invention has an excellent cleaning effect on dirty filter cloth, and can be operated continuously, reducing the time and labor required for replacing filter cloth. Not only is it almost unnecessary, but the burden on workers can be greatly reduced, especially by automating the work process.

[Brief explanation of the drawing]

FIGS. 1 and 2 show an embodiment of the belt filter type dehydrator of the present invention, which is equipped with a washing liquid shower mechanism. 1... Charge valve, 2... Sludge, 3... Filter cloth, 4... Charge chute, 5... Suction blower, 6... Vacuum hopper, 7... Main drum, 8... Pressure roll, 9... ...Dehydrated cake, 1
0...Low pressure shower, 11...High pressure shower, 1
2...Washing liquid shower pipe, 13...Washing liquid tank, 14...Washing liquid, 15...Washing liquid valve,
16...Control valve, 17...Washing liquid pump, 18...Diaphragm sensor, 19...
...Box, 20...Suction header, 21
...adjustment section, 22 ... exchanger, 23 ... transmitter,
24...Warning.

Claims (1)

[Scope of utility model registration request] A belt filter type dewatering machine comprising at least a hopper mechanism for dewatering sludge on a filter cloth, a pressure mechanism for squeezing the filter cloth and the main drum, and a washing mechanism for washing the filter cloth. A belt filter type dehydrator characterized by having a shower mechanism installed at the top for dripping washing liquid.