JPH0214880Y2 - - Google Patents

Description

[Detailed explanation of the idea]

[Industrial Field of Application] The present invention relates to a dewatering device for sludge produced in the treatment of sewage, human waste, various industrial wastewaters, and the like. [Conventional technology] Conventionally, vacuum dehydrators, centrifugal dehydrators,
There are screw press type dehydrators, filter press type dehydrators, belt press type dehydrators, etc., but in recent years, belt press type dehydrators have attracted attention as energy-saving dehydrators and have become widely used. A belt press type dewatering machine sandwiches sludge between two endless pieces of cloth, upper and lower, and runs a number of rolls arranged in a zigzag pattern along them. This method dewaters sludge using the pressing force caused by the tension of the cloth, and the pressure applied to the sludge is gradually increased by gradually decreasing the roll diameter of a group of rolls arranged in a zigzag pattern around which two sheets of cloth are wound as the cloth advances. while doing,
This is a dehydrator that can perform dewatering while preventing sludge leaks. Furthermore, in order to further increase the dewatering efficiency, a large diameter and strong roll made by wrapping two upper and lower cloths with sludge sandwiched thereon is placed as a high-pressure part in the final stage of the above-mentioned process. An endless pressure belt or wire mesh, etc. having a significantly higher tensile strength than the cloth is placed along the outer side of the two cloths along the outer side of the cloth, and a second belt that applies high tension to the pressure belt or wire mesh, etc. By pressurizing means,
A method of dewatering sludge by applying high pressure to sludge, which could not be achieved with cloth alone, has been invented and put into practice. (Special Publication No. 56-15292). Further, the present applicant has proposed that the second pressurizing means is as follows:
We devised a device that includes at least a pair of large-diameter press rolls, passes two pieces of cloth holding sludge through the nip section formed by the press rolls, and pressurizes and dewaters the sludge using high nip pressure between the rolls. .
(Jitsugan No. 59-5175). However, the 2
A piece of cloth is tightly woven from relatively thick monofilament or multifilament yarns such as nylon or polyester, and the holes are only between the yarns, so dehydrated water can be quickly discharged. Moreover, since the cloth is smooth, even if pressure is applied to the sludge, the sludge is likely to deform, move outside the cloth, and leak, and it is actually impossible to apply large pressure to the sludge. Improvements in sludge treatment volume and dewatering efficiency have not been sufficiently achieved. In addition, in a mechanism in which sludge is run between two upper and lower cloths, when winding around the roll surface, the two cloths have different circumferential speeds due to the thickness of the cloth and the thickness of the sludge. Each time the cloth is wound around the roll, the cloth rubs against each other on the sludge surface and at the ends of the cloth. Due to this friction and the tension applied to the cloth, the sludge digs into the cloth and causes stains, and the cloth wears out and becomes unusable quickly, requiring frequent replacement of the cloth. ,
If two pieces of cloth are used, it is troublesome to hang the cloth, and it is also difficult to adjust and maintenance is not easy. Furthermore, a complicated structure is required to ensure stable running of the two sheets of cloth, resulting in an increased size and cost of the device. Furthermore, the present applicant has previously developed a method in which a concentration section is provided in the first stage and a dewatering section is provided in the subsequent stage. A plurality of rolls consisting of a bar press roll, a perforated press roll, or a combination thereof are arranged around the large diameter roll with a blank, and another large diameter roll is arranged behind the large diameter roll with a blank. However, there is a sludge concentration and dewatering device in which the large-diameter roll is covered with upper and lower flocked blankets, and a porous pressure belt is placed so as to press against the lower flocked blanket from the outside.
(See Publication No. 49494). However, in this product, two sheets of flocked cloth hold a bar roll, perforated roll, etc. for dehydration, but the dehydration principle uses a roll press method, and the two sheets of flocked cloth are However, when dewatering has not yet progressed, side leaks or leaks in the opposite direction occur in response to the force of the press rolls that attempts to change the volume of the sludge rapidly. The problem was that the effect of the flocked cloth could not be maximized. Further, although the sludge concentration and dewatering apparatus includes a roll press section and a high-pressure belt press section, the sludge thickness decreases as dewatering progresses. Therefore, if the angular velocity of the two cloths relative to the roll center is set to be the same in the high-pressure belt press section, which has no degree of freedom, the angular velocity will be different in the other roll press section, causing shear flow to the sludge. becomes. This shear flow causes the sludge particles to collapse and actively collapse the sludge passageway, which has the disadvantage of increasing excessive resistance and reducing the throughput of sludge. In order to simplify the structure, attempts have been made to use only one piece of running cloth.
There is a publication. However, if only one cloth is used, the sludge will be sandwiched between the cloth and the roll with a smooth surface, resulting in greater sludge leakage compared to the dehydrator using the two cloths mentioned above. Since the sludge is only on the cloth side, the sludge throughput and dewatering efficiency are reduced, and although the structure is simpler, the performance is reduced, so it is not widely used. [Purpose of the invention] The present invention eliminates the drawbacks of the conventional belt press dewatering machine, and eliminates side leakage and leakage in the opposite direction even when dewatering fluidized sludge. Eliminate shedding flow against sludge,
It reduces sludge resistance at the stage of high moisture content, increases sludge throughput, and has a much simpler mechanism than a belt press dehydrator that uses two sheets of cloth, making it easier to operate.
The object of this invention is to provide excellent workability and to achieve high throughput comparable to the belt press dewatering machine using two sheets of cloth. [Structure of the invention] The invention is based on the invention when a piece of endless cloth running on a guide roll, with sludge placed on the cloth, is wound around one main roll or a plurality of main rolls in sequence. The tension applied to the endless fabric is applied to a first pressure means that applies a pressing force in the direction of the main roll, or the tension applied to a plurality of pressure belts spaced apart from the outside of the fabric causes the fabric to be compressed. and an apparatus for dewatering sludge using a second pressurizing means that presses the sludge against the roll side, or a second pressurizing means that includes press rolls that sandwich cloth and sludge from above and below, the surface of at least one of the rolls being The main roll is covered with napped fibers that are inclined in a direction opposite to the rotational direction of the roll, and the main roll covered with the napped fibers is driven by a passive drive mechanism that drives through a running endless cloth and sludge. At the same time, the main roll covered with the napped fibers is a bar roll in which bars with a square or round cross section are arranged on the same circumference at equal intervals along the width direction of the roll, or a bar roll with bars that penetrate the roll surface. This is a sludge dewatering device with a perforated roll structure. [Example] Hereinafter, the present invention will be explained in detail with reference to the drawings. In FIG. 1 showing the first embodiment of the present invention, the concentrated sludge is supplied to a retention tank 11 located above the running cloth 10 to prevent the sludge from leaking from both ends in the width direction of the cloth. , and proceed to the dehydration section while being passed by gravity. In the dewatering section, cloth 1 is used to gradually increase the pressure.
Main roll 1 whose diameter decreases as the roller 0 runs
2, 13, 14, a plurality of pressurizing belts 15 running along the lower peripheral surface of the roll 14 in an arc shape and spaced apart from each other;
a second pressurizing means consisting of a napped fiber 16 covering the surface of the main roll, and a guide roll 17,1.
8, 19, retention tanks 20, 21, 22 that prevent sludge from leaking from the front and rear of the guide roll, main roll 1
It is composed of scrapers 23, 24, and 25 for peeling off the sludge cake adhering to surfaces 2 to 14. The main rolls 12, 13, and 14 are arranged with diameters decreasing sequentially, and napped fibers 16 are formed on these surfaces, uniformly covering the roll surfaces and tilting in a direction opposite to the roll rotation direction. has been done. Even if the main rolls 12 to 14 are plain rolls with smooth surfaces, the main rolls 12 are located at locations where sludge is likely to move in the direction of the cloth when pressurizing the sludge (for example, locations where the sludge water content is high and the fluidity of the sludge is high). ,1
If the napped fibers 16 inclined in the direction opposite to the roll rotation direction are formed on the roll surface in 3), the movement of sludge can be prevented due to the frictional resistance of the napped fibers that fall down to the roll side when sludge is pressurized. So,
Even in a sludge dewatering machine that uses a single piece of cloth running, sufficient pressure can be applied, making it possible to create a single cloth dewatering machine. In addition, if napped fibers are formed to cover the roll surface to prevent sludge from entering the voids on the roll surface, the dewatered water that has passed through the voids of the napped fibers on the roll surface during sludge dewatering can also be discharged toward the inside of the roll. This is preferable because the dewatering efficiency can be improved as the sludge throughput is improved. Since the width of the running cloth is usually smaller than the width of the roll, the moisture that has migrated inside the roll is discharged from the roll voids near both ends of the roll where the cloth is not covered. As shown in Figure 5, a discharge port 28 is provided as appropriate on the end plate of the roll.
It can also be discharged to the outside through. Examples of rolls with voids include a bar roll 26 in which square or round cross-sectional bars are arranged on the same circumference at equal intervals along the width direction of the roll, as shown in FIG. A perforated roll 27 with a large number of holes penetrated through the roll surface as shown in FIGS. 4 and 5.
is used. When there are multiple main rolls, it is preferable that the size of the void provided on the roll surface be larger at the front stage and smaller toward the rear stage. This is because the front stage is small, so there is no problem in terms of strength. That is, the first stage is preferably a bar roll, and the second stage is preferably a perforated roll. As a means of forming the napped fibers 16 on the roll surface, as in the roll shown in FIG. 5, an adhesive is applied so as not to block the holes on the roll surface, and short synthetic fibers are directly electrostatically flocked. Or, as in the roll shown in FIGS. 3 and 4, a base fabric 29 made of woven or knitted fabric
Napped fabric 1 with napped fibers formed on the surface of
6' on a roll. In particular, as shown in FIG. 6, a flocked fabric 32 in which an adhesive 30 is applied to the surface of a coarse base fabric 29 and synthetic short fibers 31 are flocked at an angle in a certain direction is produced by the action of the adhesive. The base fabric is strong and durable,
Flocked short fibers have less settling and are excellent in preventing sludge leakage, and since the flocked fibers have a large number of short fibers, sludge does not penetrate into the base fabric, making clogging less likely to occur, and the openings of the base fabric can be enlarged to a certain extent. Therefore, when using a roll with an empty surface as described above,
It has excellent moisture permeability and the flocked cloth itself has the advantage of being easily regenerated by washing, making it the most suitable material for the raised cloth used in the present invention. The method of attaching these raised blankets 16' to the rolls is to use fasteners or loops provided at the edges of the fabric, or use heat-shrinkable fibers as the base fabric of the raised blanket, cover the rolls, and then remove the base fabric with warm water. A method of deflating and attaching the device is used. Even though the endless cloth 10 is a conventional cloth that is tightly woven from relatively thick monofilament or multifilament yarns such as nylon or polyester, it has napped fibers on the roll side, which prevents sludge from leaking. However, this endless cloth 10
When a flocked cloth 32 in which short synthetic fibers are flocked on the surface of a coarse base cloth 29 shown in FIG. 6 is used,
Since the sludge water is quickly discharged from the coarse base fabric 29, the amount of sludge treated can be increased, and since the sludge is sandwiched between the short fibers with high frictional resistance from above and below, it is prevented from moving in the direction of the cloth. This prevents sludge leakage, and when the sludge is transported, the short fibers pierce the inside of the sludge, prompting the discharge of water from the inside of the sludge through capillary action, and reducing the water content of the sludge. The sludge is dehydrated by being sandwiched between the main roll on which the napped fibers 16 are formed and the single endless cloth 10, but the roll is equipped with scrapers 23 to 25 for pasting the sludge on the surface and scraping it off. Retention tank 2 is installed to prevent scraped sludge from leaking outside the system.
0 to 22 are provided. FIG. 2 shows a second embodiment of the present invention, in which a roll 14 is used to constitute a pair of press rolls instead of the pressure belt 15, which is the second pressure means.
A roll 15' is placed below the roll 15', and the same reference numerals indicate the same parts. With the configuration described above, the thickened sludge is transferred to the running cloth 1.
The sludge is supplied to a retention tank 11 located at the upper part of the cloth to prevent it from leaking from both sides in the width direction of the cloth, and then passed through gravity to the dewatering section where it is passed through the main roll 12 with napped fibers formed on the roll surface. 13,1
4, and a plurality of pressure belts 15 spaced apart and running along an arc along the lower peripheral surface of the roll 14. The cloth and sludge are gradually pressurized by a second pressurizing means consisting of press rolls that sandwich the cloth and sludge from above and below.
Movement of the sludge during pressurization is prevented by the frictional resistance of the napped fibers, so the pressure can be increased sufficiently to dehydrate the sludge, and a sludge cake with a low water content is discharged outside the machine. Further, the dehydrated water is discharged to the liquid receiver 33 at the bottom of the cloth 10. If a void is provided on the surface of the main roll covered with napped fibers, the dehydrated water will also move inside the roll and be discharged from the roll void near both ends of the roll where the running fabric is not covered, or from the discharge port provided on the roll end plate. It will be discharged outside. Although this example shows the case where there are three main rolls, the number of main rolls is determined by the sludge properties, and in the case of sludge that is easy to squeeze, such as papermaking sludge, one main roll is sufficient. Sometimes it is. In addition, a configuration in which the second pressure means made of a pressure belt is continuous after the main roll arranged in a zigzag pattern, or a structure in which the second pressure means made of a press roll is continuous is shown. The present invention is not limited to this, and a pressure belt may be used as the second pressure means, and a press roll may be provided as the third pressure means at the subsequent stage. Next, the amount of sludge treated and the water content were compared using the dewatering apparatus according to the present invention and the conventional dehydrating apparatus, and the results were as shown in the following table.

[Effect of idea]

As described above, the present invention has the following excellent effects. The sludge is placed on a sheet of endless flocked cloth and run, and the flocked cloth is wound around a main roll, and the main roll is made to have a structure that allows water to be drained, and the surface of the main roll is turned against the direction of rotation of the roll. Because the sludge is covered with napped fibers that are inclined in the direction of Since there is no need to apply rolls, there is no side leak or leak phenomenon in the opposite direction of travel, and water is quickly dewatered from each side of the cloth and main roll. Also, shear flow against sludge is eliminated, and it is Sludge resistance can be reduced and sludge throughput can be increased. In addition, it has a much simpler mechanism than a belt press dehydrator that uses two flocked fabrics, and is superior in operability, ease of maintenance, and workability, and is comparable to a belt press dehydrator that uses two flocked fabrics. can achieve high throughput. By making the main roll covered with napped fibers a bar roll or perforated roll, water from the sludge is passed through the napped fibers formed on the roll surface and into the inside of the roll. The amount of sludge throughput can be improved because water can be discharged from the machine or from an appropriate discharge port provided on the end plate of the roll. If a flocked cloth is used as an endless cloth, in which short synthetic fibers are flocked at an angle in a certain direction on the surface of a coarse base fabric, the sludge will be sandwiched between the napped fibers from above and below, preventing sludge leakage. This increases the effectiveness of the sludge treatment and increases the throughput, and when the sludge is transported, the nap fibers of the cloth pierce the inside of the sludge, and the water contained inside the sludge can be discharged by capillary action, which improves the dewatering rate and treatment of the sludge. The amount can be greatly increased.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention;
The figure is a schematic side view of the dewatering device of the present invention, Figure 3 is a schematic perspective view of the main roll being a bar roll with napped fiber cloth attached to the roll surface, and Figure 4 is the main roll being a perforated roll. Figure 5 is a schematic perspective view of a roll with napped fiber cloth attached to the roll surface. Figure 5 is a schematic perspective view of a main roll with perforated rolls and napped fibers are directly planted on the roll surface. FIG. 2 is a cross-sectional view of a flocked material in which short synthetic fibers are flocked at an angle in a certain direction on the surface thereof. In addition, the symbol in the figure is 10...endless cloth, 12-1
4... Main roll, 16... Napped fiber, 26... Bar roll, 27... Porous roll, 29... Base fabric,
31... Short fiber, 32... Flocked material, respectively.

Claims (1)

[Scope of utility model registration request] A piece of endless cloth running on a guide roll,
A first pressurizing means that applies tension to the endless cloth when one main roll or a plurality of main rolls are sequentially wound with sludge placed on the cloth, or further A second pressurizing means presses the cloth and sludge against the roll side using tension applied to a plurality of pressure belts spaced apart from the outside of the cloth, or a second pressurizing means uses press rolls that sandwich the cloth and sludge from above and below. In an apparatus for dewatering sludge using pressure means, the endless cloth is formed of a flocked material made by flocking short synthetic fibers tilted in a certain direction on the surface of a coarse base cloth, and the main roll is The surface of at least one main roll is covered with napped fibers that are inclined in a direction opposite to the rotational direction of the roll, and the main roll covered with the napped fibers has a square or round cross section bar in the width direction of the roll. A sludge dewatering device characterized in that it is formed of bar rolls arranged on the same circumference at equal intervals along the same circumference, or a perforated roll having through holes provided on the roll surface.