JPS5870813A - Filter cloth for dehydrating sludge - Google Patents

Abstract

PURPOSE:To prolong filtering life to a large extent, by preventing the leakage of sludge through mesh and by reducing the generation of a fiber removing phenomenon of a flocked staple fiber even if pressing force for dehydrating sludge is increased. CONSTITUTION:Coarse fibers 2 are flocked on one surface of a fabric 1 with water permeability consisting of weft yarns 1A and warp yarns 1B so as to be inclined toward a definite direction and, between gaps of said coarse fibers 2, fine fibers 3 having a diameter smaller than that of said coarse fibers 2 are parallelly flocked. As the fabric 1, a fabric made of a synthetic fiber comprising nylon or polyester is pref. used and, as the coarse fiber 2, the synthetic fiber having a length of 3-20mm. and a thickness of 50-200 denier is preferred. In the state applied with pressing force as shown by the drawing, because the coarse fibers 2 are supported by the weft yarns 1A at free ends thereof as well as has rigidity tolerable to pressing force, they are not protruded externally through the mesh of the fabric 1. The fine fibers 3 are supported by the coarse fibers 2 when they receive pressing force due to sludge and are not protruded externally through the mesh of the fabric 1.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is an F cloth for sludge dewatering used in a belt press type dehydrator. The present invention relates to a sludge dewatering fabric having a structure in which short fibers are flocked at an angle on the surface of a woven fabric having water permeability suitable for removing moisture from sludge.

Conventionally, this type of F fabric is made by flocking short fibers having a constant fiber diameter at an angle onto a relatively coarse mesh woven fabric (base fabric). When mud is sandwiched between these twisted F fabrics and squeezed, the short fibers are tilted, so they are pushed down by the sludge, overlap each other, and densely cover the surface of the base fabric. That's what happens. Therefore, sludge is prevented from leaking through the mesh-like base fabric, and only water in the sludge can pass through the mesh-like base fabric. In order to prevent sludge from leaking, the short fibers are pushed down by the sludge and pushed down against each other. D It is necessary that the distance between the short fibers be sufficiently small when they are aligned. For this purpose, short fibers of usually 20 to 50 deniers are used.

However, in the case of v-fabric flocked with short fibers, when the squeezing force for dewatering sludge increases, the overlapping short fibers cannot resist the pressing force from the sludge, and the silk of the base fabric Dust particles protrude outward from the eye space. As a result, short 111
The mutual separation between the two is pushed out, making it difficult to prevent dirt from leaking. In addition, when the ninth squeezing force for dewatering the sludge increases, the white end of the flocked short fibers becomes 11CR<< in the sludge layer.
When peeled from the dehydrated cloth, short fibers are pulled out from the base fabric by being pulled by the dehydrated cloth (the so-called hair removal phenomenon becomes noticeable), and the life of the F cloth is shortened.

The purpose of the present invention is to prevent sludge from leaking even when the squeezing force for sludge dewatering increases, and to greatly extend the life of P fabric by reducing the occurrence of hair loss of flocked short fibers. The purpose of the present invention is to provide a P cloth for sludge dewatering that can be used for dewatering sludge.

In the present invention, as flocked short fibers that resist the squeezing force for dewatering sludge, relatively thick M-thin diameter coarse fibers are effective, and the coarse fibers are pushed down by the sludge and overlap each other. By supplementing the gaps between the coarse fibers that occur when the coarse fibers are mixed with fine fibers with small diameters, the gaps between the short fibers as a whole can be made sufficiently small.
Furthermore, the thin fibers that are prone to hair loss are reduced, thereby preventing the hair loss phenomenon.

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

FIG. 11 is a schematic sectional view showing an embodiment of the present invention,
Crude fibers 2 are flocked on one side of a water-permeable woven fabric 1 made up of weft yarns IA and warp yarns IB so as to be inclined in a certain direction.

In the gaps between these coarse fibers 2, coarse fibers 2 and small diameter fine fibers 3 are inserted.
are flocked parallel to the crude fibers 3.

As the woven fabric 1, a synthetic fiber woven fabric such as nylon or polyester is suitable, and the crude fiber 2 has a length of 3 to 20w1 and a
~200 denier synthetic fibers such as nylon, fine fibers 3
The fiber has a length of 2 to 20,111 mm, and is preferably made of synthetic fiber such as nylon with a denier of 5 to 20.

FIG. 2 is an explanatory diagram showing the state of short fibers when sludge is sandwiched between the ν cloths shown in FIG. 1 and a squeezing force is applied. As shown in FIG. 2, both the rolled coarse fibers 2 and the fine fibers 3 are pushed down by the pressing force of the sludge 4, but the rough fibers 2 have their plain ends supported by one weft of the woven fabric l, and are pushed down by the pressing force. KFi does not protrude outward from the mesh of the woven fabric 1 because it has a rigidity that can withstand KFi.

On the other hand, when the fine fibers 3 fall under the pressure of the sludge 4, they are supported by the KIN fibers 3 and do not protrude outside the mesh of the woven fabric 1, thereby dewatering the sludge. Even if the squeezing force increases, the gaps between the short fibers are not expanded, so sludge leakage is prevented. After nine hairs are removed, the medium-sized thin fibers 3 are reduced to approximately half the amount of hair transplanted in the entire short fibers, so the occurrence of hair loss in the fine fibers M3 is prevented.

Further, as another example of the present invention, a thin wire #O length t-2 to 15 m
In this case, when the short #I fibers are pushed down by the pressing force of the sludge, the surface that comes into contact with the sludge, i.e. Since the tip of the flocked group consists of only coarse fibers,
Only the coarse fibers are embedded in the sludge, and the fine fibers are not embedded in the sludge. Therefore, the effect of preventing short fiber hair loss is remarkable.

As described above, according to the present invention, the short fibers do not protrude outward from the mesh of the woven fabric even when the squeezing force increases during sludge dewatering, and the screen between the short fibers is kept small and thin. This makes it possible to prevent sludge from leaking, and since coarse fibers that are difficult to shed are implanted in the running fibers, hair loss can be prevented and the life of the F fabric can be extended.

[Brief explanation of drawings]

FIG. 1 is a schematic sectional view showing an example of the present invention, and FIG. 11g2 is an explanatory view showing the state of the F cloth shown in FIG. 11 during sludge dewatering. 1... Woven fabric, 2... Crude fiber, 3... φ fine fiber. 4...Sludge. Agent Tatsuyuki Unuma (and 2 others)

Claims (3)

[Claims] (1) Water-permeable woven fabric Table 11 In the F cloth for sludge dewatering in which iK short fibers are flocked in an inclined state, the short fibers are coarse fibers, coarse fibers, small-diameter fine fibers, and the like. F cloth for sludge dewatering, characterized in that coarse fibers and fine fibers are almost uniformly dispersed. (2) The F cloth for sludge dewatering according to claim 1, wherein the cone has a diameter of 50 to 200 deniers, and the fine fibers have a diameter of 5 to 20 deniers. (3) The p-cloth for sludge dewatering according to claim 1, wherein the front wiring fibers are shorter than the crude fibers.