Device for dewatering and method of making same

Abstract

The present disclosure generally relates to a device for dewatering a material. The device comprises a biodegradable, permeable enclosure configured for receiving the material through an inlet. The permeable enclosure comprises layered biodegradable textiles, an inner portion and an outer portion, derived from renewable resources. The inner portion has an apparent opening size between about 0.5 mm and 3 mm. The outer portion has a ratio of the minimum tensile strength in the warp direction to the minimum tensile strength in the weft direction of about 2.5.

1 . A device for dewatering, the device comprising:
 a. a permeable enclosure, the permeable enclosure comprising:
 i. at least two inner layers of a first woven material; and 
 ii. at least one outer layer of a second woven material, 
   b. an inlet port;   
       wherein, the first woven material has an apparent opening size (AOS) when measured according to ASTM D4751 of between about 0.5 mm and about 3 mm, 
       wherein the second woven material has a ratio of a minimum tensile strength in a warp direction of the second woven material to a minimum tensile strength in a weft direction of the second woven material when measured according to ASTM 4595 (minimum tensile strength ratio) of at least about 2.5. 
     
     
         2 . The device according to  claim 1 , wherein the AOS of the first woven material is between about 1 mm and about 2 mm. 
     
     
         3 . The device according to  claim 1 , wherein the second woven material has an AOS of between about 1 mm and about 5 mm. 
     
     
         4 . The device according to  claim 1 , wherein the minimum tensile strength in the warp direction of the second woven material is at least about 36 kN/m. 
     
     
         5 . The device according to  claim 1 , wherein the minimum tensile strength in the weft direction of the second woven material is at least about 13 kN/m. 
     
     
         6 . The device according to  claim 1 , wherein the second woven material has an AOS of between about 1 mm and about 5 mm. 
     
     
         7 . The device according to  claim 1 , wherein the first woven material has a minimum tensile strength ratio of at least about 1.2. 
     
     
         8 . The device according to  claim 7 , wherein the minimum tensile strength in the warp direction of the first woven material is at least about 8 kN/m. 
     
     
         9 . The device according to  claim 7 , wherein the minimum tensile strength in the weft direction of the first woven material is at least about 6 kN/m. 
     
     
         10 . The device according to  claim 1 , wherein the first woven material and the second woven material are monofilament materials. 
     
     
         11 . The device according to  claim 10 , wherein the first woven material and the second woven material are biodegradable. 
     
     
         12 . The device according to  claim 11 , wherein the first woven material and the second woven material are derived from renewable sources. 
     
     
         13 . The device according to  claim 12 , wherein the first woven material is selected from the group consisting of woven jute, woven hemp and woven flax. 
     
     
         14 . The device according to  claim 12 , wherein the second woven material is woven coir. 
     
     
         15 . The device according to  claim 1 , wherein the device comprises borders reinforced with polypropylene. 
     
     
         16 . The device according to  claim 1 , wherein the device comprises borders of at least two inner layers of a first woven material are folded over the least one outer layer of a second woven material and are sewn together. 
     
     
         17 . The device according to  claim 1 , wherein the inlet is generally positioned at one of a central location, midpoint of the longitudinal extent, or midpoint of the transverse extent of the device. 
     
     
         18 . Use of the device according to  claim 1  for sludge dewatering. 
     
     
         19 . A device for dewatering, the device comprising:
 a. a permeable enclosure, the permeable enclosure comprising:
 i. at least two inner layers of a first woven material; 
 ii. at least one outer layer of a second woven material, and 
   b. an inlet port;   
       wherein the second woven material has an apparent opening size (AOS) when measured according to ASTM D4751 that is greater than an AOS of the first woven material, 
       wherein the second woven material has a minimum tensile strength in a warp direction of the second woven material when measured according to ASTM 4595 that is greater than a minimum tensile strength in a warp direction of the first woven material, 
       wherein the second woven material has a minimum tensile strength in a weft direction of the second woven material when measured according to ASTM 4595 that is greater than a minimum tensile strength in a weft direction of the first woven material, 
       wherein the first woven material and the second woven material are biodegradable and derived from renewable sources. 
     
     
         20 . A device for dewatering, the device comprising:
 a. a permeable enclosure, the permeable enclosure comprising:
 i. at least two inner layers of a first woven material; 
 ii. at least one outer layer of a second woven material, and 
   b. an inlet port;   
       wherein the first woven material and the second woven material are biodegradable and derived from renewable sources, 
       wherein the device has a surface area of about 71 cm 2  device and exhibits an initial dewatering rate of at least about 0.16 min −1  for a solids content of about 11 wt %.