JPH0717312U - Filter cloth for belt press type dehydrator - Google Patents

Abstract

(57) [Summary] [Object] To provide a filter cloth for a belt press type dehydrator, which has good filtration performance and good cake peeling property. [Structure] In a filter cloth for a belt press type dewatering machine, which comprises a multi-woven fabric of two or more double woven fabrics, a multifilament is used for the surface layer warp of the filter cloth, and two components such as nylon / polyester or polyester / polypropylene for the surface layer weft. A filter cloth for a belt press type dewatering machine, characterized in that a spun yarn made of a split type conjugate fiber composed of is used. [Effect] The spun yarn of the splittable conjugate fiber used for the surface layer weft is divided into fine denier by splitting the splittable conjugate fiber in the spinning process without using a special splitting means, and sludge and fine particles are mixed with the surface layer warp. It is trapped and moisture is returned by the capillary phenomenon to improve the cake peeling property.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a filter cloth for a belt press type dehydrator.

[0002]

[Prior art]

 A belt press type dehydrator usually uses two upper and lower filter cloths.After gravity dehydration, sludge is squeezed between the upper and lower filter cloths and then squeezed with mechanical force to dehydrate. Work is performed and the residue is taken out as a dehydrated product, a so-called cake. For this reason, the filter cloth is required to have not only a dewatering function but also a smooth surface and an appropriate compactness in order to facilitate the peeling of the cake.

In conventional filter cloths, sludge is apt to be pressed into the tissue as it is dehydrated during pressing, and solid components in the sludge are accumulated in the tissue, causing clogging, and shortening the life of the filter cloth.

Therefore, as a countermeasure, for example, in Japanese Utility Model Laid-Open No. 3-86012, in a double woven fabric, polypropylene spun yarn is used as a yarn for covering the surface layer, and fine particles are trapped to press sludge into the tissue. It is difficult to be peeled off and the cake is easily peeled off.

[0005]

[Problems to be solved by the device]

 However, the filter cloth that uses polypropylene spun yarn as the yarn that covers the surface layer has excellent shape retention and durability, but the single yarn denier of the fibers that make up the yarn is usually as thick as about 2 denier. However, there is a problem that the surface is not dense and the gaps between the fibers become large due to repeated use, and fine particles or sticky sludge is pressed into the inner layer of the cake and gradually accumulates, causing clogging. However, there is a problem in that the peeling property of the cake becomes poor due to the synergistic effect that the water-recalling action due to the capillary phenomenon is weak. The present invention is provided for the purpose of eliminating such inconveniences and problems.

[0006]

[Means for Solving the Problems]

 The present invention is a filter cloth for a belt press type dewatering machine, which is composed of multiple weaves of double weave or more, and uses a multifilament and a spun yarn of a splittable conjugate fiber composed of two kinds of components as a yarn for covering the surface layer. Solved this problem.

That is, the present invention is a filter cloth for a belt press type dewatering machine, which is composed of multiple weaves of double weave or more, in which multifilaments are used as the surface layer warp of the filter cloth, and the surface layer weft comprises two kinds of components. A filter cloth for a belt press type dewatering machine, characterized in that spun yarn made of splittable conjugate fibers is used.

Splittable conjugate fibers composed of two kinds of components, A component and B component, have atypical cross-sectional shape having an acute angle after splitting, for example, splittable conjugate fibers having a shape as shown in FIGS. 3 and 4. It is more preferable to use hydrophilic materials such as nylon / polyester or polyester / polypropylene rather than hydrophobic materials.

Further, the splittable conjugate fiber spun yarn, which is the weft forming the surface layer of the filter cloth for a belt press type dehydrator according to the present invention, is preferably such that the proportion of fiber splitting is large, and at least 20 It is more preferable that the fiber division be at least%, and if it is less than that, no significant difference is recognized as compared with the ordinary spun yarn.

In addition, since the split type composite fiber spun yarn has a low yarn strength, it is preferable to reinforce the weft yarns of the intermediate layer and the back layer with monofilaments of synthetic fibers when the multi-woven fabric is used, and use the multifilament for the surface warp In this case, as a reinforcing measure, it is preferable to use synthetic filament monofilaments for the reinforcing back warp or back layer warp, and it is preferable to use at least ⅓ or more of the warp structure composition number.

[0011]

[Action]

 In multi-woven fabrics with double or more weaves, the multifilaments and spun yarns that cover the surface layer generally block the entanglement points of the warp and weft yarns to prevent sludge from passing to the back side and to trap fine particles. In particular, the spun yarn of the splittable conjugate fiber composed of two components used for the surface layer weft is a splittable conjugate fiber without using a special splitting means from the raw cotton through the series of spinning steps to the twisted yarn. 40 to 50% is divided into ultrafine denier, and some of them are in a cracked state.

Since the cross-sectional shape of the split splittable conjugate fiber is a modified cross-section with a sharp acute angle, the solid content in the sludge is captured more efficiently than the ordinary spun yarn, and the sludge is the back surface. In addition to preventing it from passing to the side, it becomes a fiber aggregate that is even thinner than general spun yarn, so it is easy to recall water due to the capillary phenomenon. Since it retains water by retaining water, the cake peeling property is further improved.

[0013]

【Example】

 [Example 1]; FIG. 1 is a cross-sectional structure diagram of the double woven structure filter cloth in Example 1. In Example 1, a polyester multifilament was used for the main body warp (3), a polyester monofilament was used for the reinforcing back warp (4) and the back layer weft (2), and a nylon / polyester split type composite fiber was used for the surface layer weft (1). A filter cloth for a belt press type dewatering machine, which is made of spun yarn consisting of: and its specifications are as shown in Table 1.

[0014]

[Table 1]

[Example 2]; Example 2 is a belt press type in which a spun yarn made of polyester / polypropylene split type conjugate fiber is used for the surface layer weft (1) in the same constitution as in Example 1. It is a filter cloth for a dehydrator, and its specifications are as shown in Table 2.

[0016]

[Table 2]

[Embodiment 3] FIG. 2 is a cross-sectional structure diagram of the triple woven structure filter cloth in Embodiment 3. In Example 3, polyester multifilament was used for the front warp (6), polyester monofilament was used for the back warp (7), the middle layer weft (5) and the back layer weft (2), and the surface weft (1) A filter cloth for a belt press type dewatering machine, in which a spun yarn made of nylon / polyester split type conjugate fiber is used for the specification, and its specifications are as shown in Table 3.

[0018]

[Table 3]

Comparative Example: A comparative example is a filter cloth for a belt press type dewatering machine, which has the same construction as that of Example 1 except that a spun yarn of polypropylene is used for the surface layer weft (1). The specifications are as shown in Table 4.

[0020]

[Table 4]

A comparative test of filtration performance and cake peeling performance was carried out using these Examples 1, 2 and Comparative Example. The filtration rate was measured by using a constant pressure filtration tester to pass a 0.5% JIS 7 type powder (fine particles) slurry solution through the sample at a filtration pressure of 3 Kg / cm ^2. The filtrate SS concentration is the amount of suspended solids contained in 1 liter of the filtrate at this time.

Further, in the cake peeling test, a 10% kaolin solution was poured onto a sample using a press filtration tester, press filtered, and then the cake was peeled off from the sample using a scraper and visually judged. The criteria were as follows: 1st grade was "cleanly peeled", 2nd grade was "peeled but there was residue", and 3rd grade was "a large amount adhered to the filter cloth". Table 5 shows the results of the comparative test of the filtering performance and the cake peeling performance.

[0023]

[Table 5]

As can be seen from the test results in Table 5 above, the filter cloth for a belt press dewatering device of the present invention has a significant difference in the filtration amount as compared with the conventional one, and the filtrate SS concentration is remarkably good, and the cake Good peelability.

[0025]

[Effect of device]

 In multi-woven fabrics of double woven or more, the multi-filament covering the surface layer and the spun yarn of the splittable conjugate fiber composed of two kinds of components are configured so as to close the entanglement point of the warp and the weft, and have two kinds of components. The spun yarn of the splittable conjugate fiber made of consists of extra fine denier and has a modified cross-section with a sharp acute angle, so it captures solids in sludge more efficiently than general spun yarn and traps fine particles. As a result, the sludge does not enter the tissue and the anchoring effect is blocked, and the cake peelability improves. Further, the splittable conjugate fiber composed of two kinds of components is automatically divided into fibers after a series of spinning steps and is made into an ultrafine denier, so that the inside is a fiber aggregate having a thinner inner diameter than a general spun yarn. It has the effect of regaining water by capillarity to retain water and improve cake peeling.

[0026]

[Brief description of drawings]

FIG. 1 is a sectional structure diagram of the double woven structure filter cloth in Example 1.

FIG. 2 is a sectional structure diagram of the triple woven structure filter cloth in Example 3.

FIG. 3 is a sectional shape view of the splittable conjugate fiber.

FIG. 4 is a sectional shape view of the splittable conjugate fiber.

[Explanation of symbols]

(1); Front layer weft, (2); Back layer weft, (3); Main body warp, (4); Reinforcing back warp, (5); Middle layer weft, (6); Front warp, (7); Back warp

Claims (1)

[Scope of utility model registration request] 1. A filter cloth for a belt press type dewatering machine, comprising a double woven or more than a multiple woven cloth, wherein a multifilament is used as a surface warp of the filter cloth, and a split type composite having two kinds of components as a surface weft. A filter cloth for a belt press type dehydrator, characterized in that spun yarn of fibers is used.