JPS6178598A - Sludge dehydrating device - Google Patents

Abstract

PURPOSE:To dehydrate rationally a sludge, and to form a dehydrated cake having a high strength by increasing gradually the hardness of the rubber layer of the peripheral surface of a pressure roll, when dehydrating the part between the main roll having a large diameter and plural pressure rolls having the rubber layer on the peripheral surface, through a filter cloth belt on which the sludge is placed. CONSTITUTION:Plural pressure rolls 2 are placed on the outside periphery of a main roll 1 having a large diameter, and a filter cloth belt 3 to which a sludge is fed from a feed sludge frame 4 is pressed and dehydrated by the main roll 1 and the pressure rolls 2. In this case, a rubber layer 2' whose hardness becomes large gradually extending from the first pressure roll 2-1 to the final pressure roll 2-n is installed to the outside periphery of the roll. Even if the sludge is dehydrated successively and becomes hard, since the rubber layer of the pressure roll becomes hard successively, a compressive force by the main roll and the pressure roll increases successively, the dehydration advances smoothly, and the sludge is scraped off by a scraper 5 as a dehydrated cake having a small water content and a high strength.

Description

Detailed Description of the Invention (Industrial Application Field) This invention has a main roll having a large diameter, and a rubber layer having a smaller diameter than the main roll and having rubber layers on a plurality of surfaces arranged along the circumference of the main roll. It has a pressure roll, and an endless P cloth belt that is passed between the main roll and a plurality of pressure rolls and is folded around the final stage pressure roll that is furthest in the direction of rotation of the main roll, and the above-mentioned A dewatering device for various types of sludge that presses each pressure roll against the circumferential surface of the main roll using the tension of the P cloth belt or other auxiliary belt, and dewaters the sludge supplied onto the R cloth belt! Regarding.

(Prior Art) The applicant of the present patent proposed in Japanese Patent Application Laid-Open No. 59-150698 a single cloth type sludge dewatering device in which each pressure roll is pressed against the peripheral surface of a main roll by the tension of a cloth belt. This supports each pressure roll so that it can be moved and adjusted along the circumferential surface of the main roll, and adjusts the angle of the r-fabric belt wrapped around each pressure roll to the direction of rotation of the main roll to the pressure roll near the final stage. As dehydration progresses, strong pressure is applied to the sludge that is sandwiched between the lower circumferential surface of the main roll and the r-cloth belt to dewater the sludge, effectively dewatering the sludge. There is.

(Problem to be Solved by the Invention) However, even if the above-mentioned conventional device supports each pressure roll so that it can be moved and adjusted along the circumference of the main roll, all the pressure rolls are supported at the center of rotation of the main roll. Instead of supporting each pressure roll individually with support arms pivoted to the main roll, each pressure roll is supported by individual support arms pivoted at an eccentric position away from the center of rotation of the main roll. The amount of movement that can be made is extremely small, and the range of pressurizing force in mm is limited.

(Means for Solving the Problems) Therefore, the present invention utilizes the tension of a P cloth belt or the like to press the pressure roll against the main marl. It is characterized in that the pressure rolls gradually increase in size from the pressure rolls in the stages to the pressure rolls in the final stage.

(Function) As a result, even if the pressure force that presses each pressure whirl against the circumferential surface of the main rule by the tension of the r cloth belt is temporarily constant, the hardness of the rubber layer on the surface of each pressure roll is the first. Since the pressure roll gradually increases in size from the first stage to the final stage, the area where the pressure roll is compressed and deformed due to the difference in hardness of the rubber layer and contacts the circumferential surface of the main roll via the cloth belt is the same as that of the first stage. The pressure roll is the largest, and the contact area decreases toward the final stage, and the pressure used to squeeze the cake gradually increases from the first stage to the final stage in inverse proportion to the difference in area.

(Example) In each of the illustrated examples, l is the main roll, 2...
3 is a pressure roll arranged along the circumference of the main roll;
1 shows an endless filter cloth belt, Hiroshi shows a sludge supply frame that supplies sludge onto the R cloth belt, and 5 shows a scraper that strips the sludge from the dehydrated K+KP cloth belt.

Each pressure roll has a rubber layer on the circumference, and the P cloth belt 3 extends between the circumference of the main roll and the pressure roll λ-7 at the first stage to the pressure roll λ-n at the final stage. It passes through the final stage pressure roll, returns while contacting the remaining previous stage pressure rolls, and applies 2-/...λ-R to each pressure row based on the tension adjusted by the tension adjustment roll ≦. 'The sludge S supplied from the sludge supply frame is dewatered by pressing on the peripheral surface of the main roll (C) through the cloth heald.

Of course, it is possible to change the diameter of each pressure roll and adjust the wrapping angle at which the cloth belt contacts the pressure roll when it returns to NtJ (Japanese Patent Laid-Open No. 184500/1983).
, or, as in the above-mentioned known example (Japanese Unexamined Patent Publication No. 59-150698), each pressure roll is made movable along the circumferential surface of the main roll, and the distance between adjacent pressure rolls is varied widely. However, the pressure applied by each pressure roll to the surface of the main roll may be gradually increased from the first stage pressure roll to the final stage pressure roll.

Now, as described above, in the present invention, the hardness of the rubber layer on the circumferential surface of each pressure roll is gradually increased from the first stage pressure roll λ-niC to the last stage pressure roll λ-niC. For example, the hardness of the rubber layer of the pressure roll 2-/ of the first stage is Shore 400, the hardness of the second stage rubber layer is Shore 600, and the hardness of the final stage rubber layer is Shore 800.

Assuming that the pressing force I that presses each pressure roll toward the circumferential surface of the main roll is constant, the rubber layer of the first processing roll, which has the lowest hardness, is the most compressed, as shown in Figure 2. The contact area W, which deforms and contacts the curved surface of the main roll becomes large, and the contact area W,, W, of the subsequent pressure rolls having higher hardness sequentially becomes smaller. Therefore, even if the pressing force is constant, the pressing force P exerted by the first stage pressure roll with a large contact area to squeeze the cake is dispersed and becomes small, and the pressure roll of the second stage with a small contact area compresses the cake. Force Pt l Pn
As the cake becomes larger and dehydration progresses, the moisture content of the cake decreases and the strength of the cake increases.By applying strong force, it is possible to ideally dehydrate the cake.

The present invention is not limited to a sludge dewatering apparatus using one VCP cloth belt as shown in the embodiment shown in FIG. 2, but for example, as shown in FIG. Endless cloth belt person.

B along with the auxiliary belt 3 is passed between the main roll/and the pressure roll, and the auxiliary belt 3 is passed between the pressure roll VCF! ! !
The method of strongly dewatering the cake between the r cloth belts by contacting the cloth belt (Japanese Patent Application No. 58-1 proposed by the present applicant)
58497) K can also be adopted.

(Effect) When dewatering sludge, simply applying strong force to the cake will cause r
Since there are problems in terms of clogging of the cloth belt and peeling, it is considered ideal to apply a strong constriction force that will increase dehydration and reduce the moisture content of the cake and increase the strength of the inverted nine cake.

According to the present invention, sludge can be easily dehydrated to the above-mentioned ideal state by increasing the hardness of the rubber layer on the roll surface sequentially from the first stage pressure roll to the last stage pressure roll. Has excellent effects.

[Brief explanation of the drawing]

FIG. 1 is an overall side view of one embodiment of the present invention, FIG. 2 is an enlarged explanatory view of the same essential parts, and FIG. 3 is a side view of another embodiment of the present invention. is the main rule, 2 is the pressure roll, 2-/ is the first stage pressure roll, λ- is the final stage pressure roll, 2' is the rubber layer on the circumferential surface of each pressure roll, 3 is P A cloth belt is shown.

Claims (1)

[Scope of Claims] A main roll having a large diameter; a pressure roll having a diameter smaller than the main roll and having a plurality of rubber layers on the circumferential surface arranged along the circumferential surface of the main roll; It has an endless filter cloth belt that is passed between the pressure rolls of the In a sludge dewatering device that dewaters sludge fed to a filter cloth belt by pressing it against a filter cloth belt, the hardness of the rubber layer on the circumferential surface of each pressure roll is increased from the first stage pressure roll to the last stage pressure roll. A sludge dewatering device characterized by successively larger sizes.