摘要:
A twin-wire belt press is disclosed for dewatering a fiber suspension and forming a continuous web of the fiber suspension. The twin wire belt includes a plurality of upper and lower rolls, a perforated roll and endless upper and lower wire belts. Dewatering tables are used to support the endless upper and lower wire belts and form a wedge-shaped pressure space between the endless upper and lower wire belts for initially pressing and dewatering the fiber suspension and forming a web therebetween. Roll members, including at least two press rolls which form press roll nips with the perforated roll and another roll, press and dewater the web between the endless upper and lower wire belts.
摘要:
The invention relates to a method of washing a fiber pulp mixture, in which method the fiber pulp mixture is fed between two filter wires running in the same direction. There is a convergent dewatering space in the direction of travel of the wires, where water is removed from the pulp. According to the idea of the invention, the thickness of the pulp layer being fed between the wires is adjusted during operation, since the ash and fines content of the washed fiber pulp is essentially dependent on the basis weight of the fiber web being washed. In a preferred embodiment of the invention, the height of the slice at the output end of the dewatering space is adjusted. The essential idea of another preferred embodiment of the invention is that the speed of the wires is adjusted. The invention also relates to an arrangement comprising means for adjusting the thickness of the pulp layer being fed between the wires, i.e. the basis weight of the fiber web being washed.
摘要:
Process and device for draining a fibrous pulp suspension. The process may include positioning two surfaces to converge in a downstream direction, feeding the fibrous pulp suspension between the two converging surfaces, driving at least one of the two converging surfaces to move the suspension with a relative translational velocity, and draining the fibrous pulp suspension through each of the two surfaces. The device may include two arcuate surfaces positioned to form converging surfaces. One of the two arcuate surfaces may include a drivable, pivotable, and rotatable cylinder having an outer sleeve with openings, the other of the two arcuate surfaces may include a screen positioned to be guided around at least a portion of the outer sleeve. The screen and the openings may form drains for draining the fluid pulp suspension.
摘要:
Methods and apparatus for concentrating a liquid suspension of solid particles are disclosed including providing a screening web moving in an endless path, folding the screening web into a tubular configuration at a first location along that path, unfolding the screening web from that tubular configuration at a second location along that path, introducing the liquid suspension into the tubular configuration of the screening web proximate to the first location so that liquid can pass outwardly through the tubular configuration of the screening web and a concentrate of the solid particles can be formed therein, and removing the concentrate from the screening web proximate to the second location.
摘要:
The method of weaving a dimensionally stable fabric filter medium having particular use in a pressure filter apparatus. The fabric is woven with tension on the warp and weft yarns and the woven fabric is heat set outside the weaving loom to create a desired crimp in the warp and weft yarns and thus to produce a dimensionally stable filter medium. The fabric is woven in a pattern and of materials that provide the desired permeability while being capable of capture of the solids in a slurry and permitting the fluids of the slurry to flow through the medium.
摘要:
A method for thickening a liquid suspension of solid particles, such as papermaking pulp in water, uses a pair of spaced apart rolls and a woven wire or plastic wire belt trained around these rolls. The suspension is supplied at the first roll for centrifugal extraction and is carried by the belt to the second roll for further water extraction and thickening, and is then discharged from the apparatus. In one embodiment, the first roll is formed with an open surface, and the suspension is delivered to the web at least partially by flowing both into and out a roll chamber via the first roll openings, from a headbox in the on-running wedge zone. The apparatus may also include a second roll which is porous and has auxiliary water-removing appliances associated therewith, including blow boxes for forcing air either radially inwardly or radially outwardly of the second roll, and an auxiliary nip roll for creating a zone of higher compression for mechanical extraction of water from the mat of solid particles between the belt and second roll. Rewetting of the mat caused by water entrained in the wire mesh cavities is reduced by the impingement of air jets to remove such water.
摘要:
A high speed stock thickener has a foraminous endless wire. The stock thickener is of the type in which an open mesh endless wire is trained over a pair of rolls and paper stock to be thickened is applied between the wire and the rolls and is carried on an inside surface of the wire for dewatering, particularly at the regions where the stock is carried between the wire and a roll. The improved wire is formed with a width greater than that of the rolls with a marginal edge of the wire extending beyond the face of the rolls. A guide belt is attached at each of the marginal edges of the wire and runs with a side wall in engagement with the end of the adjacent roll. The guide belts are attached to the wire by an adhesive bond between the backs of the belts and the adjacent wire surfaces, and by a continous thread which is sewn through each belt from the bottom of the belt and through the back thereof and into the wire.
摘要:
Apparatus for thickening a suspension of pulp material employs a single pair of liquid-impervious rolls and a single loop of wire trained around both rolls which are spaced from each other in substantially the same horizontal plane. The pulp stock to be thickened is delivered into the wedge zone defined by the upper wire run approaching the top of one roll and the surface of that roll, so that the pulp is trapped between the wire and roll as it travels around the roll with the wire, and the rolls are driven at sufficient speed to develop centrifugal forces which cause liquid to be expressed through the wire from the pulp trapped against the roll. The resulting partially dewatered pulp is redeposited from the first roll onto the lower wire run for travel to the other roll, where it is similarly subjected to centrifugal force for further expression of liquid through the wire, after which the pulp is removed from the surface of the second roll in the wedge zone defined by the surface of that roll and the wire run travelling therefrom to the first roll.
摘要:
A wire machine, especially for washing stock suspensions, contains one or a number of dewatering cylinders about which there is trained an endless wire or filter band. There is provided at least one stock infeed device which infeeds a substantially flat jet of the suspension which is to be dewatered into a substantially wedge-shaped space or throat located between the wire band and the dewatering cylinder. The dewatering cylinder has a longitudinal axis which is essentially vertically arranged. There are possible different arrangements of the dewatering cylinder or cylinders, the stock infeed devices and material removal devices for removing from the rotatable dewatering cylinder solid constituents or the like contained in the stock suspension. Also there are possible different arrangements and uses of guide rolls for guiding the wire or wire band.
摘要:
A method of, and wire machine for, washing stock suspensions is disclosed wherein a cylinder having a solid smooth surface is encircled along a portion of its circumference by an endless wire or filter band. The stock suspension which is to be dewatered is infed between the solid cylinder and the wire by means of a flat jet nozzle. After throughflow of the stock suspension between the cylinder and the wire the dewatered fiber material is removed from the wire and the cylinder, respectively, collected in a collecting container and delivered for further processing.