摘要:
A wedge wire for use in a wire type screen for screening papermaker's stock is formed with an elongated body (12) having an enlarged head (20) at the inlet surface of the screen. The head (20) is formed with tapered walls (30, 33) that cooperate to define grooves (28) at the inlet surface between adjacent elements including an upstream wall (30) and a downstream wall (33). A radiused protuberance or projection (37) defines one wall of a screening slot (15), with a wall surface (22) of an adjacent wedge wire element. The slot wall formed by the projection (37) is free of sharp edges and is limited in length, in the direction of flow through the slot (15), not substantially exceeding the gap width of the slot. The upstream wall (30) defining the groove (28) provides protection for the slot (15) against impact and damage by contaminants that may be contained in the papermaker's stock. The slot (15) is free of sharp corners so as not to impede flow through the slot.
摘要:
Pressure screening apparatus for screening a suspension of paper fiber stock employs a rotor in which a single impulse or foil member is carried or positioned to move along a discrete portion of the screen surface. This arrangement improves efficiency of operation of the pressure screen by reducing the rotational effect of the rotor on the stock suspension being screened and by providing a less disturbed screening region through which the single foil operates. Embodiments are shown in which multiple single impulse elements sweep over discrete portions of a screen and in which a single foil is combined, in screening apparatus, with multiple foils in accordance with the increase in consistency of the stock as it passes through the screen.
摘要:
Broke handling and reducing apparatus and method for comminuting a moving continuous sheet or web material such as paper broke in the dryer or converter section of a papermaking machine, includes a plurality of high pressure water jet cutting nozzles mounted in spaced-apart relation transversely to the direction of movement of the material and are mounted so as to direct high pressure cutting jets into the path of movement. The nozzles are mounted so that at least some of the nozzles are cyclically moved with respect to others of said nozzles to form a plurality of mutually intersecting jet cutter paths to reduce the material into a multiplicity of smaller discrete or easily separable pieces.
摘要:
A flat bed, Fourdrinier-type, countercurrent washer for cellulosic pulp incorporates a pressing section at the downstream end thereof which includes the couch roll and additional rolls that carry out multiple mechanical pressing operations on the pulp after it has been subjected to multiple stages of displacement washing without mechanical treatment. As a result, where such washers without mechanical pressing deliver pulp of a consistency of the order of 15% solids, this washer increases the pulp consistency to as high as 40% while correspondingly increasing the effectiveness of the washing operation as a whole.
摘要:
Screening apparatus for separately removing knots and heavy reject particles from paper making stock comprises a generally cylindrical vertical housing having the interior thereof separated by a cylindrical perforated screening member into an annular screening chamber and an accepts space on the outer and inner sides of the screening cylinder respectively. Separate outlets for light and heavy reject particles are located at the top and bottom of the screening chamber, the supply flow of feed stock enters the screening chamber at the bottom thereof, and special provision is made to insure that maximum separation of the knots and other lighter reject particles from the heavy reject materials will be effected within the screening chamber with minimum contact with the screening cylinder itself.
摘要:
Apparatus for screening papermaking stock comprises two annular flat screening plates arranged in parallel spaced relation to form a screening chamber therebetween which is bounded on its outer periphery by a cylindrical wall, and wherein a rotor includes vane portions which extend into this screening chamber to agitate the stock so that particles of sufficiently small size can pass through the screening plates into annular compartments outside the screening plates from which they flow into a peripheral chamber having an outlet port. The screening chamber includes an annular space which is surrounded by the accepts chamber and is radially beyond the vane portions of the rotor wherein reject material collects for discharge through an outlet tube which extends through the accepts chamber to the outside of the apparatus. The apparatus as a whole comprises a main assembly which includes one of the screening plates and the rotor, and a subassembly which includes the other screening plate and can be removed from the main portion to expose the screening plates for replacement or other servicing.
摘要:
The invention relates to solutions of(A) from 3 to 60% by weight, based on the combined ether-polyol content, of separately prepared oligo-urethane ethers containing terminal OH.sup.- groups in the form of reaction products of(a) diisocyanates with(b) dialcohols having an average molecular weight of from 200 to 800, the stoichiometric ratio of (a) to (b) amounting to various values based on the average molecular weight of the dialcohols, in(B) polyether polyols containing at least 2 hydroxyl groups and having an average molecular weight of from 1000 to 12,000 and to their use in a proess for the production of polyurethane foams capable of being effectively flame-laminated and (high-frequency) welded without any adverse effect upon their other properties. The process for producing flame-laminatable and high-frequency-weldable flexible polyurethane foams is characterized by the reaction of(i) polyisocyanates with(ii) relatively high molecular weight compounds containing at least 2 hydroxyl groups,(iii) optionally other relatively high molecular weight and/or low molecular weight compounds containing isocyanate-reactive hydrogen atoms and water,(iv) optionally in the presence of other blowing agents, catalysts, foam stabilizers and other additives,such solutions described above being exclusively or partly used as the relatively high molecular weight compounds which contain hydroxyl groups.
摘要:
A press, including a frame, a pair of rigid side structures, means for pivotally connecting the side structures to said frame, a pair of rotor assemblies having confronting faces arranged at an angle to each other and defining a pressing zone, each of the rotor assemblies being mounted for rotation in a respective side member, means interconnecting the side structures to one another and serving to apply yieldable force to urge the side structures toward one another, the improvements basically comprising means for adjusting the pivotal connecting means to vary the pressing action of the rotor assemblies, a hydrostatic bearing means, which may be used in association with an annular thrust bearing, for lubricating and minimizing the friction between the rotor assemblies and the side structures, and a biased sealing means for preventing moisture in the feed materials from rewetting the pressed solids leaving the press.
摘要:
Wheel-mounted brake disks which are arranged on both sides of a wheel base of a railway wheel and are fastened by through bolts, the bolt head of every through bolt lying in a countersink of one wheel-mounted brake disk and a nut screwed onto the through bolt lying in a countersink of the other wheel-mounted brake disk, each resting either directly or indirectly on the bottom of the countersink. The wheel-mounted brake disks are designed so that every countersink has an undercut portion that extends down to the bottom.
摘要:
The invention relates to a gasification reactor (1) and associated method for the entrained-flow gasification of solid fuels under pressure. The reactor essentially consists of a pressure vessel (4) that can be cooled and an inner jacket (7) that is equipped with a heat shield. At least one crude gas outflow (8) is located at the upper end of the cylindrical pressure vessel and at least one bottoms withdrawal outlet (30) is located at the lower end, the pressure vessel having at least enough space for a moving bed (13), an entrained flow (11) that circulates internally above the surface of the moving bed and a buffer zone (3) situated above said entrained bed. Feed connections for the solid fuels (15) and gasification agent nozzles for the supply of first gasification agents (16) are situated at a height of between approximately 1 and 3 meters above the surface of the moving bed, said gasification agent nozzles being designed to inject the first gasification agents into the entrained flow in such a way that a hot central upward flow and a “cold” downward wall flow are formed. At least one feed device for second gasification agents (28) is located at the bottoms withdrawal outlet.