Abstract: A twin screen paper forming apparatus is provided having upper and lower screens moving in a first direction and wrapping around a portion of a leading forming roller positioned at the beginning of a forming zone where the upper and lower screens converge to form a twin screen. At least one stationary forming element is positioned downstream of the leading forming roller to contact with the lower screen. A water guide element is also located in the region of the forming zone approximately at the start of the forming zone. At least one forming rail contacts the upper screen and a pulp suspension discharge nozzle is positioned, to prevent preliminary draining, upstream of the location where the upper and lower screens converge.

Abstract: A blow extruder for producing hoses made of plastic material has, at the outlet of its nozzle arrangement for producing hoses, a cooling air nozzle ring which encompasses hoses exiting from the nozzle arrangement and to which air is delivered from a blower. An apparatus for cooling air delivered to the cooling air nozzle ring includes a direct evaporator provided with a refrigeration plant and arranged between the blower and the cooling air nozzle ring. The direct evaporator includes a plate fin element and an injection device for a cooling agent and hot air. The cooling apparatus further includes a regulation device for controlling the temperature of the cooling air by controlling operation of the cooling apparatus.

Abstract: A pusher centrifuge which includes a housing and at least two screening drums for dewatering infed material. The screening drums and a pusher ring are mounted for rotary movement about a longitudinal axis. The pusher ring is further mounted for oscillatory movement, with respect to the longitudinal axis. During advancing movement of the pusher ring, the screening drums are rotated relative to each other about the longitudinal axis.

Abstract: In a roll arrangement having a material web travelling between a controlled deflection roll and a counter roll, an increased edge compression of the material web at the edges is prevented in that there are provided additional spreading elements effective transverse to the pressing plane (E), which elliptically deform the roll shell, and thus, cause a reduction of the pressing force of the hydraulic support elements which are effective in the pressing plane. By means of a control device, e.g. partition walls which are synchronously axially displaceable by spindles there is achieved the result that upon altering of the working width only the required support elements receive pressurized medium, and equally, only the spreading elements located externally of the working width.

Abstract: In a calender (1) one or several rollers (2) can be positioned by being raised or lowered jointly with the roller stack disposed therebelow; and vertically displaceable sliding members (3) connected with the roller journals are jointly driven, and are blocked when the roller to be positioned (2) is adjacent the desired working position by way of a separate fixation device (6) supported on the frame (4). In a development of the method the rollers are brought in a desired working position after blocking of the fixation device.

Abstract: The de-watering apparatus for a two-wire paper machine is constructed in such a manner that following the convergence of both wires, firstly, a uniform pressure at a forming roll is exerted on the suspension layer located between the wires. Subsequently, both wires pass de-watering rails which may be located in the upper and/or the lower wire. In this case, an under-pressure is exerted at least at the rails located in the upper wire. At least one further de-watering member then follows before both wires are separated again. The de-watering apparatus can also be used after a preliminary de-watering section, for example an endless wire, and also in the direct vicinity of a head box.

Abstract: Calendering takes place in a calendering zone which operates under pressure with application of temperature and moisture. The desired smoothness is achieved with a correspondingly long dwell time of the material web in a correspondingly long calendering zone in view of the speed of web travel. A web which is still wet is guided between parallel heatable surfaces which are arranged on both sides of the web and face each other through the web and can each be pressed against the web. The surfaces are designed to form and hold a given precise contour of the calendering zone over its full length. One surface is constructed e.g. as a casing of a heated roller and the second surface is constructed as an endless flexible belt which can be pressed in a direction towards the roller casing by means of a concave supporting element. If wished, the web can be calendered on both sides with the method.

Abstract: Apparatus and process are provided wherein pressure is exerted on a web by at least two rollers. One roller includes a roll shell which is rotatable around a stationary beam, wherein the roll shell is supported against the beam by hydraulic operational support elements on the side of the press, as well as by counterpressure elements exerting pressure in the opposite direction. A particularly rapid and safe opening of the roller device, without damaging the supporting elements or the roll shell because of detached supporting elements, is achieved because the hydraulic pressure medium from the pressure areas of at least part of the operational support elements is routed as directly as possible without detours to the pressure areas of counterpressure elements, such as by a multiple sliding valve located at the beam end.

Abstract: In a controlled deflection roll comprising a roll shell rotatable about a stationary support and braced or supported by support elements at the stationary support, a rotational moment is intentionally exerted at the opposite ends of the roll shell by force-exerting elements. These force-exerting elements extend in axial direction of the controlled deflection roll but are offset in spaced relation with respect to the lengthwise axis of the controlled deflection roll. These force-exerting elements operate in pairs in opposite directions with respect to one another. A lever arm is formed by the distance or spacing between the force-exerting elements and such lever arm exerts a greater rotational moment in the presence of modest space requirements and without deformation of the roll shell.

Abstract: To achieve desired treatment results at both sides of a material web to be calendered, the material web is initially guided through a first nip formed between yieldable elastic surfaces confronting the throughpassing material web. In the first nip there is predominantly applied a relatively high pressure to the material web. Then the material web is guided through a successively arranged second nip formed between practically non-yieldable hard surfaces confronting the throughpassing material web. In the second nip there is applied, apart from pressure, in particular heat to the material web. The treatment result achieved in the first nip, namely the smoothness and glaze values of the treated material web, are augmented at both sides of the material web to achieve desired treatment effects.

Abstract: An extended drainage strip (3) is placed next to the primary sieve (5) of a double-sieve mold. It has a liquid-intake space (2), which is disposed between the part of the surface (4) facing the sieve and the sieve (5). Disposed next to the other sieve (6) is at least one adjustable strip (7) arranged so that it can be placed opposite the intake space (2). Intake space (2) has a cross-sectional size that increases, if necessary, in the direction in which the liquid flows. By pressing the adjustable strip (7) against the intake space (2) of the extended strip (3), the shape of the intake space (2) can be controlled, and the suction or intake of the liquid in the intake space (2) is regulated. One object is to achieve steadily increasing suction in the flow direction. This result assists in preventing undesired pressure surges. The drainage device is simplified and thus easy to monitor. Drainage proceeds carefully, with higher retention of fine particles in the sheet of material between the sieves.

Abstract: In a controlled deflection roll having a roll shell rotatable about a stationary carrier and braced by one or more support elements against the stationary carrier, the roll shell comprises an inner roll shell part and an outer roll shell part which, during operation of the controlled deflection roll, form a press or force fit with respect to one another, for instance, due to excess pressure in the interior of the controlled deflection roll or due to elastic pre-biasing of the parts of the roll shell. Upon pressure relief or the existence of negative pressure within the controlled deflection roll a play or clearance is formed between the outer roll shell part and the inner roll shell part of the roll shell which enables dismantling and exchange of the outer roll shell part of the roll shell without the need to dismantle the controlled deflection roll or to remove such from the machine.

Abstract: Within the impression cylinder of a rotogravure press and within the roll shell thereof there are provided over the width of the impression cylinder a number of layer packages which can be separately supplied with electrical charge in order to apply electrostatic charges to the impression cylinder surface for the purpose of augmenting printing of a material web. By differently controlling segments of the impression cylinder, there can be accommodated different widths of the material web to be processed. In order to concentrate the electric charge at the actually used region of the impression cylinder and for protecting the zones of the impression cylinder which are not currently being used, there are provided internally of the roll jacket, in axial direction thereof, a number of support elements arranged adjacent one another and braced against a central carrier.

Abstract: The present invention is directed to a heated sag-compensation roller, with short heat-up and cool-down times and a more even temperature distribution, which reduces the risk of damage to the roller shell. These improvement are achieved by the roller shell being heated or cooled from the inside and the outside simultaneously. The heating devices can be controlled so that the temperature difference between the inside and outside does not exceed a particular value.

Abstract: In a roll with a roll shell or jacket which is rotatable about a support or beam, the inner side of the rotatable roll shell or jacket is heated by means of an induction coil which is operated at high frequency and provided, for example, at a support element. The heating is effected directly at the press or work nip or in the proximity thereof without substantial loss of energy and without the use of a thermo-sensitive hydraulic medium.

Abstract: At least two substantially parallel rows of adjustable pressure elements cooperate with a heatable counter element like a counter roll and are arranged immediately consecutive but separate from each other to define at least two pressing sections of an extended pressing zone through which a water-containing fibrous web is passed conjointly with a water absorbing porous band or felt in a predeterminate travel direction. Pressures and temperatures in each one of the at least two pressing sections of the extended pressing zone are adjusted such that water is displaced from the fibrous web under the combined action of pressure and steam which is formed in the extended pressing zone in a controlled manner and without damage to the fibrous web due to explosion-like flash evaporation.

Abstract: Titanium slag and ilmenite are subjected to a parallel treatment with sulphuric acid obtained by mixing different proportions of sulphuric acid having concentrations of about 98.5% by weight and about 85% by weight, respectively. The reaction mixtures have a temperature slightly below a predetermined starting temperature and the reactions are started by adding small quantities of superheated steam having a temperature above the predetermined starting temperature. The thus obtained solutions are separated from the respective treatment residues and combined. The combined solutions are further processed for obtaining titanium dioxide. The mother liquor constitutes sulphuric acid of a concentration in the range of about 23% by weight and containing metal sulphates. This mother liquor is concentrated to a sulphuric acid concentration of approximately 85% by weight and recycled.

Abstract: The ledge is arranged transverse to the machine direction in a substantially flexure resistant manner and is adjustable for guiding the wires between which a web of material is formed. The ledge contains a guide surface which faces the wires and has a special contour. For improved control of the pressure changes occurring in the region of the ledge, the ledge contains a supporting member and a pressing member which contains the guide surface. A pressing device is supported at the supporting member and the pressing member can be adjusted in a direction relative to the wires as well as relative to the supporting member by using the pressing device for simultaneously elevating the pressing member and inclining the pressing member with respect to the machine direction. Advantageously the pressing device constitutes a hose which is subjected to a pressurizing medium and thereby deformable.

Abstract: The apparatus for neutralizing overhanging loads is supported at the roll stand of a calender which opens in downward direction. This apparatus is arranged at both sides of a roll and, during operation, presses from below against the roll suspensions in a predetermined or required position of the roll. This is accomplished by a force which compensates for the overhanging loads. This force is generated or set by movable force transmitters, dimensionally deformable force transmitters or displaceable force transmitters. Upon opening the calender, a force greater than the set force acts upon the load neutralizing apparatus and the force transmitters are moved, dimensionally deformed or displaced, as the case may be, such that a displacement path of the roll into a lower lowered position is provided. The force transmitters for generating the force which compensates for the overhanging loads can be a spring assembly, an air spring or a column or head of liquid supported by a gas cushion.

Abstract: To remove disturbing wax particles and for increasing the specific volume the short fiber fraction is subjected to a thermal treatment, especially by application of water vapor or steam, in a heater, such as a worm heater throughout a defined residence time and a defined temperature. With relatively low energy expenditure the distrubing wax particles are eliminated in such a manner that no wax spots or speckles can be discerned in the finished product. The specific volume of the short fiber fraction is appreciably increased while obtaining a predetermined strength.