JPH0113887B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a belt press type dehydrator.

For example, if sludge with a high moisture content is disposed of as is, it will pollute rivers, oceans, etc.
Effective treatment of sewage sludge is desired from the viewpoint of preventing pollution.

Normally, sludge is dehydrated under pressure and then incinerated or directly disposed of.However, conventional dewatering mechanisms have been to remove sludge, such as sewage sludge, between two pieces of cloth that are tensioned by multiple rolls. A dehydrator is widely used in which sludge is sequentially dewatered by the compression pressure of two cloths by inserting a cloth into the cloth and rotating the cloths in the same direction. There are two types of dehydrators: one that uses only the tension between two cloths as described above, and one that uses rolls directly facing each other and in contact with each other. In the former method, the maximum tension is applied to relatively soft sludge, taking into account the protrusion of the sludge from both sides of the cloth, and the maximum pressure possible is applied to the sludge. The limit lies in the fact that the fabric will break if a certain amount of tension is applied to it. This limit is about 30 kg, and the pressure on the fabric on the roll obtained from this tension is 100 to 300 mm depending on the roll diameter.
In this case, it is 2 to 3 Kg/cm ² . There is a limit to how many types of sludge can be dehydrated in response to such pressure, and this has been considered the limit of belt press type dewatering machines.

As an improvement to the above, a mechanism has been developed in which a high-tension belt, such as a V-belt, is externally pressed onto two rolls of cloth through three rolls. This method uses a belt with higher tension than the cloth, so the compression pressure is higher than that of the cloth itself, but there is a limit to this, and the actual pressure measured is 4 to 5 kg/cm ² . Therefore, since the subsequent operation is a thermal operation such as drying or incineration, even stronger compression pressure is required in order to save energy by removing as much moisture from the sludge as possible.

SUMMARY OF THE INVENTION An object of the present invention is to provide a dehydrator that overcomes the drawbacks of the prior art as described above and meets the requirements as described above.

The present invention will be described in detail below with reference to the drawings.

FIG. 1 is an overall view showing one embodiment of the dewatering machine of the present invention, in which two upper and lower endless cloths 1 and 2 are connected to a dewatering roller 3 that is located apart from a plurality of tension rollers.
The sheets are stretched between tension rollers so that they can be laminated and rotated at. As shown in FIGS. 2 and 3, the roller 3 has a shaft 4 protruding from both ends rotatably supported by a bearing 6 of a pedestal 5, and the roller 3 is rotated by electrical or mechanical operation. This allows the two cloths 1 and 2 to be continuously circulated in the same direction, and the sludge compressed as they rotate is dehydrated.

The diameter of the dewatering roller 3 is the same as that of the two rollers close to the roller 3 among the plural tension roller groups, that is,
It is larger than the space between the roller 3a that sends the cloths 1 and 2 to the roller 3 and the roller 3b that receives the cloths 1 and 2 from the roller 3.

A pressure mechanism 7 is installed adjacent to the dewatering roller 3. As shown in FIGS. 2 and 3, this pressure mechanism 7 is formed in the same arc shape as the roller 3, and has an elongated diaphragm plate 8 having approximately the same length as the roller 3. The periphery of a diaphragm 9 made of a flexible material such as rubber and having grooves formed therein is closely placed. The pressure mechanism 7 has both ends swingably suspended from the shaft 4 of the roller 3 and is directly connected to the cylinder 10 . In a normal state, a gap is formed between the circumferential surface of the roller 3 and the diaphragm 9.

The present invention is constructed as described above, and the sludge 11 such as sewage sludge is continuously supplied between the two cloths 1 and 2 while the dewatering roller 3 is rotated almost continuously throughout the entire process. Then, the sludge is dehydrated to some extent between the plurality of tension rollers located in the middle up to the roller 3, and the sludge becomes a viscous body.

When the sludge that has become viscous in this way moves to the roller 3, if pressure water is injected between the diaphragm plate 8 and the diaphragm 9, the diaphragm 9 expands and simultaneously pushes the two cloths 1 and 2 against the roller 3. Apply pressure. The entire pressure mechanism 7 rotates in the same direction as the roller 3 due to the pressure friction between the cloths 1 and 2 and the diaphragm 9, and final dewatering of the viscous sludge is performed during this period.

When the pressurizing mechanism 7 is rotated to a predetermined position, pressurized water is released by, for example, the switching valve 12 to reduce the surface of the diaphragm 9. This results in
The diaphragm 9 is separated from the cloths 1 and 2 to release the cloths 1 and 2 from being pressed against the roller 3, and at the same time the pressure mechanism 7 is rapidly reversely rotated by the cylinder 10 to a home position.

As mentioned above, the diameter of the dewatering roller 3 is larger than that between the two tension rollers 3a and 3b adjacent to it, so the circumferential area in contact with the fabrics 1 and 2 is large, and the diameter of the roller 3 is A large amount of free space can be secured outside the circumferential surface. Therefore, the operating range of the pressure mechanism 7 with respect to the circumferential surface of the roller 3 is wide, and the usage efficiency of the pressure mechanism 7 is increased.

After rotating the pressure mechanism 7 in the opposite direction to a predetermined position,
Furthermore, if pressurized water is injected between the diaphragm plate 8 and the diaphragm 9, the viscous sludge can be dehydrated by the same operation as described above.

The sludge dehydrated as described above is taken out to the outside when the two cloths 1 and 2 are separated.

FIGS. 4 and 5 show other embodiments of the present invention, and the same parts as described above are given the same reference numerals.

In this embodiment, a plurality of holes 13 are bored in the circumferential surface of a rotatably supported roller 3, and a sealing member 14 is installed inside the roller 3 to make sliding contact with the inner surface of the roller 3. Discharge pipe 1
5 is directly connected and fixed to, for example, a vacuum pump (not shown) outside the roller 3.

Therefore, the water coming out of the sludge compressed by the pressure mechanism 7 is absorbed into the roller 3, passes through the seal member 14, and is absorbed and discharged to the outside. This prevents compressed water from flowing out.

According to the present invention described above, since the cloths 1 and 2 are stretched with the dewatering roller 3 separated from the tensioning roller group, the rotation of the dewatering roller can be stopped from the perspective of the overall process. Pressurized dehydration by the pressurizing mechanism 7 can be repeated and performed almost continuously in the entire process by following the rotation with little or no stopping. Therefore, pressure can be applied to the sludge regardless of the tension of the cloths 1 and 2, and the dewatering efficiency is extremely good.Moreover, since the diaphragm 9 is a flexible member, the compressed sludge surface has an uneven surface. Also, the entire surface can be compressed uniformly in response to the pressurized water pressure injected into the pressurizing mechanism 7.

Note that the pressure mechanism 7 is not limited to one unit, but may be installed in a plurality of units so as to be able to press against the roller 3. This is best used when it is effective to gradually increase the compression pressure from the first stage.

[Brief explanation of drawings]

Fig. 1 is an overall front view showing an embodiment of the dehydrator of the present invention, Fig. 2 is a partially cutaway front view showing the rollers and pressure mechanism, Fig. 3 is a side view of the same, and Fig. 4 is the present invention. FIG. 5 is a partial sectional view showing another embodiment, and FIG. 5 is a side view of the same. 1 and 2 are cloth, 3 is a roller, 7 is a pressure mechanism, 8
is a diaphragm plate, and 9 is a diaphragm.

Claims (1)

[Claims] 1. Sludge is supplied between two endless cloths 1 and 2 stretched so that it can be continuously circulated, and is compressed by a group of stretching rollers, and the sludge is applied to the dewatering roller of the main part of the roller group. In a belt press type dehydrator that can be pressurized from the outside, cloths 1 and 2 are laminated and circulated around a dewatering roller 3 that is placed apart from a group of stretched rollers, and as the dewatering roller 3 rotates, the sludge is dehydrated and expanded. A pressure mechanism 7 consisting of a diaphragm plate 8 having a diaphragm 9 is installed close to the dewatering roller 3. A belt press type dehydrator characterized by being able to separate and rotate in reverse.