JPS586490Y2 - sludge dehydrator - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a band press type sludge dehydrator.

The treatment of sludge generated from various types of wastewater treatment, water supply and sewage treatment, etc. is an extremely important issue these days, and the sludge generated from these treatments is usually dehydrated using a vacuum filter, press filter, or centrifugal separator. Methods include removing most of the water and then disposing of it, or in some cases, incinerating it and then disposing of it.

In this case, the biggest problem is the sludge dewatering process, and how to dewater sludge efficiently and economically is an important issue.

Various methods of dewatering sludge have been proposed in addition to those described above, one of which is a band press type dewatering machine.

As shown in FIG. 1, an example of this dewatering machine has an endless filter cloth 1 that runs horizontally, is rotatably supported by a drum 4 and a support roller 3, and sludge is fed to a feeder 2 at one end.
While the filter cloth 1 runs horizontally on the support roller 3 in the direction of the arrow, that is, in the gravity dewatering section of the filter cloth 1, most of the water in the sludge undergoes gravity dewatering and capillary dehydration. removed by

Next, the filter cloth 1 is guided between a drum 4 and a press band 5 which is supported by a pulley 7 and rotates endlessly, and is further dewatered in a press dewatering section l of the filter cloth 1. Since the gap 5 becomes smaller as the running surface goes forward, the sludge is gradually pressed and dehydrated, and the cake-like material is removed by the scraper 6.
It is scraped off at 6'.

In this way, the band press type dehydrator effectively dehydrates water by both gravity dehydration action and compression dehydration action, so it has a good dehydration effect, and the power required is lower than that of a conventional vacuum filtration machine, press filtration machine, or centrifugal separator. It has the advantage of being much smaller than others.

The present invention is intended to improve the performance of this band press type filter, and aims to dewater sludge more effectively and to do this economically.

In other words, conventionally, the filter cloth was run horizontally in the gravity dewatering section of a band press type filter, but in the present invention, as shown in Fig. 2, the filter cloth surface of the gravity dewatering section of the filter cloth is moved in the running direction. It is characterized in that gravity dehydration is performed with an upward inclination angle of 5 to 20 degrees with respect to the horizontal plane.

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 2, reference numeral 1 denotes an endless filter cloth, which is rotatably supported by a drum 4 and a support roller 3.

The filter cloth 1 travels in the direction of the arrow, and sludge is supplied from the feeder 2 to the drum 4.
In other words, the gravity dewatering portion of the filter cloth 1 is made to have an upward inclination angle of 5 to 20 degrees with respect to the horizontal plane H in the running direction of the filter cloth.

When the filter cloth 1 further travels, it is guided between the drum 4 and the endlessly rotating press band 5, that is, to the press dewatering section l of the filter cloth 1, and the gap between the drum 4 and the press band 5 is Other aspects of the structure and operation, such as the fact that the surfaces become smaller as they go forward, are the same as those of conventional band press type dehydrators.

As described above, by giving the gravity dewatering part of the filter cloth 1 of the band press type filter an upward slope, gravity dewatering in this part can be performed more effectively, and before the filter cloth 1 enters the press dewatering part l. This brings about advantages such as improving the dewatering rate of sludge or shortening the length of this gravity dewatering section.

In the present invention, the inclination angle of the gravity dewatering part of the filter cloth 1 is
Although it cannot be specified in part because it varies depending on the type and properties of the sludge to be dewatered, such as water content, viscosity, fluidity, etc., if the angle of inclination is less than 5°, it is difficult to obtain the dewatering effect that is the purpose of this invention. If it exceeds 20', it is not preferable because it becomes difficult to transfer the sludge in many cases.

In the present invention, the dewatering effect is improved not only because the water to be dehydrated is removed vertically through the filter cloth 1 when the gravity dewatering portion of the filter cloth 1 is horizontal as in the conventional case. This is probably because part of the water flows toward the sludge supply section because the filter cloth 1 is tilted upward in the running direction.

Next, the inclination angle of the gravity dewatering section of the filter cloth of the present invention and its dewatering effect will be explained.

Comparative experiment example 1 The sludge is wastewater sludge from waterworks (97.8% water content).

The target is sludge in which 50 g of cationic polymer flocculation aid Primafloc (registered trademark) C-7 (trade name) is added per 1 m3 of sludge to the sludge (solid content 2.2%). A band press type dehydrator with a length of 1 m, a gravity dewatering section of 3 m in length, and a press dehydrating section of 0.9 m in length was used.

and when the gravity dewatering part of the filter cloth is positioned horizontally (conventional device) and 5°.

Each sample collection location (points A, B, and C in Figures 1 and 2) with an upward inclination angle of 10° (this invention)
Table 1 shows the comparison of the moisture content in the following cases.

However, the moving speed of the filter cloth was 0.5 m/min in both cases, and the sludge supply rate was 5 m3/hour.

Comparative Experiment Example 2 A band press type dehydrator similar to Comparative Experiment Example 1 was used, and the sludge was a mixture of sludge from the initial settling tank discharged at a sewage treatment plant and surplus activated sludge (solid content concentration 5). .6%) to which 55 g of polymer flocculation aid Primerfloc C-7 was added per 1 m'' of sludge was used, and the sample was supplied to a band press type filter at a flow rate of 3.5 m3/hour.

The moving speed of the filter cloth was 1 m/min in all cases.

Then, when the gravity dewatering part of the filter cloth is positioned horizontally (conventional device) and the upward inclination angle of the gravity dewatering part is 5° and 10°.
The moisture content of each sample collection location (A, B, C) was compared when the angle was changed to 15° and 15° (this invention), and the results are shown in Table 2.

As is clear from the above, when sludge is dehydrated using the dehydrator of the present invention, the moisture content of the cake-shaped dehydrated sludge is lower than when dewatering is performed using a conventional dehydrator. It is clear that dehydration using a dehydrator is superior.

[Brief explanation of the drawing]

Figure 1 is an explanatory side view of a conventional band press type dehydrator in which the gravity dewatering part of the filter cloth is horizontal, and Figure 2 shows an example of the present invention, in which the gravity dewatering part of the filter cloth has an inclined angle. FIG. 2 is an explanatory side view of a band press type dehydrator. 1...Filter cloth, 2...Feeder, 3.
...Support roller, 4...Tram, 5.
...Press band, 6,6'...Scraper, 7...Pulley

Claims (1)

[Scope of utility model registration request] The filter cloth surface of the gravity dewatering part of the filter cloth is 55 mm with respect to the horizontal plane in the running direction.
A band press type sludge dewatering machine characterized by performing gravity dewatering of sludge with an upward inclination angle of 20° to 20°.