JPS6117599B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotating drum-type press dewatering apparatus mainly intended for continuous dehydration of sludge discharged from equipment such as industrial wastewater treatment and sewage treatment.

The main component of the sludge mentioned above is often aluminum hydroxide or surplus sludge generated from biological treatment processes, and the dehydrated cake is usually mostly water, making it difficult to handle when transporting and dumping it to a remote location. There are also problems in terms of transportation costs and fuel consumption when the dehydrated cake is further dried and incinerated, so it is desirable to reduce the moisture content of the dehydrated cake as much as possible during the dehydration process.

Various methods are used for the dehydration process for these sludges, and among them, the pressure-pressing method represented by the filter press is the most excellent in terms of reducing the moisture content of the cake. Since the operation is batchwise, it is necessary to increase the thickness of the cake in order to ensure the throughput and to improve the peelability of the cake, so it requires a long pressing time. The weak point is that it requires a lot of auxiliary equipment and it is difficult to make the dewatering process continuous.

On the other hand, as continuous dewatering devices, vacuum dewatering or centrifugal dewatering methods are currently most widely used, but these methods have a limit in terms of the moisture content that can be achieved when the target is the sludge.

In addition, there is a belt-type pressure dewatering machine such as Utility Model Publication No. 45-25717, which has the simplest device configuration and can obtain powerful squeezing pressure, but the decrease in the moisture content of the cake is mainly due to the squeezing pressure and squeezing time. Considering this, the effective compression time is shortened and the moisture content of the cake does not decrease because the compression pressure does not continuously act on the cake passing through the entire compression area but is limited to the contact area of the rollers. Take enough. Therefore, if you try to lower the moisture content of the cake by increasing the squeezing pressure with the rollers, especially if the pre-concentration of the sludge is insufficient, the sludge will be subject to strong squeezing pressure at the first roller section, causing problems such as spreading thinly. There was a problem that dehydration could not be carried out effectively.

Therefore, the present invention solves the above-mentioned problems in belt-type pressurized dehydrators by eliminating localized squeezing by rollers and maintaining substantially uniform squeezing pressure over the entire squeezing area to increase the effective squeezing time. It is an object. In other words, a rotating drum made of a hollow tube made of a flexible pressure-resistant material such as rubber is glued to the entire outer periphery, and a liquid made of a non-stretchable material such as a wire mesh or a caterpillar supported by a number of receiving rollers is placed on the drum. A back-up belt capable of discharging water is stretched around the circumference, and a substantially uniform and continuous squeezing pressure is applied to the entire surface of the contact area between the hollow tube expanded by the introduction of pressure fluid and the back-up belt. By forming a pressing section and passing the sludge held between the cloth belt and the pressing cloth belt between the two, an effective dewatering effect can be exerted over the entire pressing section.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the continuous compression dewatering apparatus according to the present invention will be described below with reference to the drawings.

The rotating drum 1 has a cylindrical shape, and a main shaft 2 at the center is supported horizontally by bearings 4, 4 provided on a pair of machine frames 3, 3 on both sides, and a chain from a driving part 6 is connected to a sprocket 5 provided on the main shaft. Rotationally driven by winding 7.

In the embodiment shown in FIG. 1, a flexible pressure-resistant hollow tube 9 is fitted into a receiving groove spirally formed by ribs 8 etc. on the outer periphery of the rotating drum 1, and both ends of the hollow tube 9 are connected to the rotating drum. is fixed.

The flexible pressure-resistant hollow tubes may be arranged in other embodiments, for example, as shown in FIG. If the space is narrow, a single hollow tube 9b with a flat cross section may be installed as shown in FIG.

Pressure fluid, such as compressed air, is introduced into the hollow tube 9 from a supply source 10 via a rotary joint 11 and a pressure guiding tube 2, and is maintained at a constant pressure during operation of the device.

As shown in FIG. 2, on the outer periphery of the lower part of the rotary drum 1 equipped with the hollow tube 9, there is an endless pressing cloth belt 13 and an endless cloth belt 14 from the rotary drum side, which are non-stretchable and allow liquid to be discharged. A group of endless belts stretched separately is wound around the endless back-up belt 15 so as to overlap in this order, and in the winding section, the outside of the group of endless bands receives a pressing force from the hollow tube. A large number of receiving rollers 16, 16... parallel to the main axis of the rotating drum are arranged at small intervals, and each receiving roller 16, 16...
Both ends of the bearings 17, 1 provided on the machine frames 3, 3
It is rotatably supported by 7. As is clear from FIG. 2, the distance between the rotating drum 1 and each of the receiving rollers 16, 16, . are arranged to form a wide and virtually continuous arc-shaped contact surface, thus connecting the rotating drum 1, the back-up belt 15, the cloth belt 14, and the receiving rollers 16, 16.
A continuous compressed portion is formed between the two parts over the entire area of the wrapping section.

The backup belt 15 stretched by the feed rollers 18 and 19 is compressed by the presser cloth belt stretched by the tension adjustment rollers 20 and 21, respectively, while receiving compression pressure from the hollow tube 9 by the drive of the rotating drum 1. Both the belt 13 and the cloth belt 14 pass through the pressing section at a speed approximately equal to the circumferential speed of the outer periphery of the hollow tube.

The sludge is continuously supplied onto the cloth belt 14 from the supply section 22, is held between the cloth belt 14 and the pressing cloth belt 13 by the roller 23 section, passes through the pressing section, becomes a plate-shaped cake, and is discharged outside the machine. The cake remaining on the presser cloth belt 13 and cloth belt 14 is removed by scrapers 26 and 27 at peeling rollers 24 and 25, respectively.
28 and 29 are washing devices for the presser cloth belt 13 and the cloth belt 14, respectively, and 30 is a washing water receiver. Further, a meandering prevention roller 31 and a cloth squeezing roller 32 are provided on the cloth belt side.

With the above configuration, the flexible pressure-resistant hollow tube 9 expanded by introducing pressure fluid, and the non-stretchable back-up belt 15 supported by a large number of receiving rollers 16, 16... Due to the surface contact between the cloth belt 14 and the presser cloth belt 13, almost uniform pressing pressure is applied over the entire pressing section.
When the sludge held in the sludge passes through the pressing section, efficient dewatering becomes possible.

As is clear from the above explanation, the continuous compression dehydrator according to the present invention can achieve a substantially uniform compression effect over the entire pressing section, so the effective compression time is shorter than that of the conventional belt-type pressure dehydrator. This increases the dewatering efficiency and lowers the moisture content of the cake, while also minimizing the need for pre-concentration of the supplied sludge as it is not subject to locally strong squeezing force. can. In addition, compared to pressure pressing methods such as filter presses, this device has good cake peeling properties because the presser cloth belt and cloth belt are bent at the peeling roller section, and the throughput is reduced because it is a continuous type. It is easy to secure the cake, and since the thickness of the cake is small, it has the advantage of being able to obtain the same moisture content of the cake as with a filter press in a relatively short time and at low pressure. The pressure-resistant hollow tube can be kept pressurized at all times during operation, so compared to the segmented compression diaphragm method in which pressure fluid is supplied and pressurized only in the compression section, the entire wrapped section of the endless band group can be It can be used as an effective compression section, and there is no need to switch the pressure fluid at all, so there are noteworthy advantages in terms of processing efficiency, manufacturing cost, and maintenance management.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of an embodiment of the continuous compression dewatering device according to the present invention, Fig. 2 is a cross sectional view, and Figs. It is a partial sectional view showing the mounting state of other Examples 9a, 9a... and 9b of the empty tube 9. In the figure, 1 is a rotating drum, 2 is a main shaft, 3 is a machine frame,
4 is a bearing for the main shaft, 5 is a sprocket, 6 is a driving part, 7 is a chain, 8 is a rib, 9, 9a, 9b are hollow tubes, 10 is a pressure fluid supply source, 11 is a rotary joint, 12 is a impulse tube , 13 is a presser cloth belt, 14 is a cloth belt, 15 is a backup belt, 16 is a receiving roller, 17 is a bearing for the receiving roller, 18 and 19 are feed rollers, 20 and 21 are tension adjustment rollers, and 22 is a sludge supply Part, 24,
25 is a cake peeling roller, 26 and 27 are scrapers, 28 and 29 are washing devices, 30 is a washing water tray, 31 is a cloth meandering prevention roller, and 32 is a cloth squeezing roller.

Claims (1)

[Claims] 1 A rotating drum equipped with flexible pressure-resistant hollow tubes arranged in parallel in the direction of the main axis and attached to the entire outer circumference, and a presser cloth belt, a cloth belt, and a non-stretchable material attached from the rotating drum side in the winding section on the rotating drum. A group of endless belts formed by back-up belts that are capable of draining liquid in order and stretched separately so as to circumscribe them, and an outer circumferential portion of a hollow tube expanded in the winding section of the endless belt group. 1. A continuous pressing device comprising a series of receiving rollers which are arranged to deform in cooperation with the endless bands and form a substantially continuous long arc-shaped pressing section.