摘要:
The invention relates to apparatus for the dewatering of a web of cellulosic matter or a web of material for the pasteboard or cardboard production, having endless screen belts or the like circulating in opposite directions between which the web is made to pass for dewatering, the web being made to pass through at least one first dewatering zone with at least two screen belts or the like and thereupon to at least one further dewatering zone, in particular a compresion zone, with at least two screen belts. The invention is mainly characterized in that the web is made to pass at least largely unsupported from at least one dewatering zone serving as a pre-dewatering zone and in particular formed as a double screen belt press to at least one further dewatering zone, in particular to a compression zone in particular formed as a double screen belt press, preferably as a high-pressure press, one or a plurality of heating means, in particular means for applying a heating medium, conveniently one or a plurality of steam-blowing box(es), being provided behind the at least one first dewatering zone serving for pre-dewatering on the web or on the path of the web, in particular above it, one or a plurality of suction site(s), suction box(es) or/and heating means, in particular means for applying a heating medium, conveniently (a) suction box(es), being provided opposite to said steam-blowing box(es) on the other side, in particular underneath, the web or the path of the web, heating means and suction sites conveniently being disposed above and underneath the web opposite to one another and thus forming pairs.
摘要:
Method for pressing and dewatering a paper web, in which a hot-pressing stage is utilized where the wet paper web is pressed in direct contact with a cylinder face that has been heated to a temperature higher than about 100.degree. C. A relatively long pressing time and a relatively low compression pressure are applied in a pre-heating/pre-pressing stage. In this preliminary stage, a surface layer of the cylinder that heats the paper web is heated to a temperature higher than about 100.degree. C. In the immediately following stage, the compression pressure applied to the paper web is lowered so that vaporization of the water present in the paper web is intensified. Next, the web is passed substantially immediately into an intensive nip-pressing stage in which the web is pressed with a peak pressure, preferably higher by one order, so that water vapor is blown through the paper web, thereby causing some of the water present in intermediate spaces between fibers in the web to be blown out, and intensifying dewatering.
摘要:
An apparatus and method is disclosed for removing fluid from a fibrous web. The apparatus includes a press member and a blanket which cooperates with the press member for defining therebetween an elongate pressing section such that the web is pressed between the press member and the blanket during passage through the pressing section. An elongate shoe urges the blanket towards the press member such that when the web passes through the pressing section, fluid is removed from the web. A heater is disposed adjacent to the press member for transferring heat to the web such that when the web passes through the press section, the web is subjected for an extended period to increased pressure and temperature so that water vapor generated within the pressing section during passage through the pressing section forces the fluid in the liquid phase away from the web. The press member defines a pressing surface which is porous so that delamination of the web is inhibited.
摘要:
The invention is a fluid heated drum especially well adapted for use with a drum press in which high press roll nip loading and high heat flux to a pressed web are both encountered. A press of this type is disclosed in detail. However, the drum is more broadly useful in any application combining heavy mechanical drum loading and high heat flux through the drum surface. The drum is constructed with a thin outer shell spaced radially apart from an inner cylindrical body. Radial supports provide load bearing connections between the two. The annulus between the shell and inner body may be arranged in various patterns as a conduit for the flow of heating fluid. By using a thin outer shell which does not have to sustain high bending stresses a high rate of heat transfer is permitted. The outer shell may be made of copper or other high thermal flux but lower strength metal to obtain additional heat transfer advantages.
摘要:
A method for drying a moist fibre web (6), particularly a paper web, in which the moist fibre web, subsequent to having passed a wire (9), a couch roll (10), a pick-up felt (11) and a suction press roll (8), is advanced to a press nip (13) where the fibre web is transferred to a drying cylinder (1) and remains on the cylinder until drying of the web is completed, wherein the fibre web on the drying cylinder is passed to a drying press, where a heated permeable press is pressed against the moist fibre web, whereupon moisture in the fibre web is transferred to the press by the pressure and the heat, the water pressed from the fibre web to the press being subsequently extracted therefrom with the aid of suction boxes (5, 16, 19) arranged on the inside of the press.
摘要:
A Yankee paper machine, particularly for the production of MG (machine glazed) paper and creped tissue, in which the formed paper web is sandwiched between a Yankee felt and a lower felt, pressed in a first nip between a suction roll and a dewatering roll, carried on the Yankee felt around the suction roll and pressed in a second nip between the suction roll and a Yankee cylinder. The web is adhered to the Yankee cylinder and the Yankee felt is detached from the web, passed around separate rolls and returned to the web on the Yankee cylinder in a third nip which in which adherance of the web to the Yankee cylinder is assured.
摘要:
PAPERMAKING APPARATUS IS DISCLOSED WHICH INCLUDES STEAM SUPPLY MEANS ADAPTED TO APPLY STEAM TO THE SURFACE OF A WET PAPER WEB TO BE DRIED IN THE REGION IMMEDIATELY PRECEDING THE POINT WHERE THE PAPER WEB CONTACTS THE SURFACE OF THE YANKEE DRYER. ONE EMBODIMENT OF THE METHOD AND APPARATUS DISCLOSED INVOLVES CONTACTING A WET PAPER WEB WITH STEAM IMMEDIATELY BEFORE IT PASSES INTO THE ON-RUNNING SIDE OF A DRYING NIP FORMED BY A PRESSURE ROLL IN CONTACT WITH THE YANKEE DRYER. EMBODIMENTS OF THE METHOD AND APLPARATUS ARE DISCLOSED IN WHICH THE ABOVE FEATURE IS UTILIZED IN CONJUNCTION WITH SUCTION PRESSURE ROLLS, AND SOLID ROLLS, SUCH AS BLIND DRILLED ROLLS AND GROOVED ROLLS. A FURTHER EMBODIMENT IS DISCLOSED IN WHICH STEAM IS ALSO APPLIED TO THE EXPOSED SURFACE OF A WET PAPER WEB CARRIED ON A YANKEE DRYER BETWEEN TWO SUCCESSIVE PRESSURE ROLLS. ONE DISCLOSED FORM OF THIS EMBODIMENT INVILVES THE USE OF A HOOD BETWEEN THE PAPER WEB AND THE FELT LOOP RUNNING FROM ONE PRESSSURE ROLL, AROUND A GUIDE ROLL AND TO A SUCCESSIVE PRESSURE ROLL. ANOTHER DISCLOSED FORM OF THIS EMBODIMENT INVOLVES ENCLOSING THE ENDS OF THE SPACE DEFINED BY THE FELT LOOP AND THE SURFACE OF THE YANKEE DRYER AND THE INSERTION OF STEAM INTO THAT SPACE TO ELEVATE THE VAPOR PRESSURE INSIDE THE SPACE AT LEAST TO THE VAPOR PRESSURE OF THE WET PAPER WEB CARRIED ON THE YANKEE DRYER AND, PREFERABLY, SUBSTANTIALLY TO ATMOSPHERIC PRESSURE.
摘要:
A bend for introducing a steam-and-fibers stream into a dryer or a pulp chest of a fibers-processing plant, a blow line with such a bend, and a fibers-processing plant with such a blow line are provided to reduce the energy consumption in a fiberboard plant or another fibers-processing plant, such as a pulp mill or a board mill. The bend includes an inlet socket for the steam-and-fibers stream, a first outlet socket for emptying into the dryer or the pulp chest, a bent section that connects the inlet socket to the first outlet socket, and a second outlet socket arranged radially inwardly with respect to the first outlet socket. The bent section connects the inlet socket to the second outlet socket.