Apart from the mechanical contrivances which are referred to in various parts of this work, in which their application is explained, it will be necessary to direct attention to certain machines and appliances which are adopted at some of the more advanced paper-mills in this country and in America; but since the various makers of paper-makers' machinery are constantly introducing improvements to meet the requirements of the manufacturer, we must refer the reader to these firms for fuller information than can be given in the limited scope of this treatise. Many of the improvements in paper-making machinery consist in modifications—sometimes of a very important nature—in the construction of certain parts of a machine, whereby the efficiency of the machine as a whole is in some cases considerably augmented. Without offering any critical remarks upon the merits of the respective improvements which have been introduced, it will be sufficient to direct attention to the manufacturer's own description of the principal features of the special mechanical contrivance which he produces for the use of the paper-maker. It may also be said that innumerable patents have been obtained for various improvements in machinery, or parts of machines, engines, etc., which can readily be referred to at the Library of the Patent Office, or any of the public libraries throughout the Kingdom.

Bentley and Jackson's Drum-Washer.—This drum-washer, for use in the rag-engine, is shown in Fig. 43. It has cast-iron ends, strong copper buckets, shaft, stands, lifting-gear, and driving-wheel, but instead of the drum being covered with the ordinary strong brass backing-wire, it is covered with their improved "honey-comb" backing-plates, over which the fine wire is wrapped as usual. The honey-comb backing consists of tough rolled brass or copper plates, curved to suit the diameter of the drum, and secured to its ends by cross-bars. It is practicably indestructible, strengthens the drum, and by maintaining its cylindrical form, adds considerably to the durability of the fine covering-wire.

Drying Cylinders.—These cylinders, by the same firm, for which patents were obtained in 1872 and 1887, are made with concave and convex ends, the latter type being shown in Fig. 44. The cylinder body is made of hard cast-iron, turned and polished on outside surface. The ends and trunnions are of tough cast iron, turned to fit into their places, and there secured by bolts and nuts by a patented method, whereby no bolts (excepting for the manhole) are put through the metal, an unbroken surface is preserved, and the annoyance of leakage through the bolt-holes is avoided. A manhole and cover is fitted to all cylinders 3 feet in diameter and upwards, and a water-lifter and pipe to remove the condensed steam. The trunnions are bored to receive nozzles or junctions for admitting steam, and the whole, when completed, is carefully balanced and tested by steam pressure to 35 lbs. per square inch. The firm state that they have made cylinders from 2 to 10 feet in diameter by this system.

Self-acting Dry Felt Regulator.—This contrivance, which is manufactured by Messrs. Bentley and Jackson, is represented in front and side elevation in Fig. 45. A is the framing of the paper-machine, B the felt-rollers, C the dry felt; D is a slide carrying one end of the felt guide-roller B; C is a shaft across the machine, with a pulley F, two-keyed on one end, and a bevel pinion two-keyed on the other end. The pulley F and pinion H are keyed together, and run loose upon the shaft G; I is a bevel-wheel, gearing into the pinions H and 2. The wheel I is connected by a spindle and a pair of bevel-wheels to a screw E, which works through a threaded bush. When the machine is at work, if the felt C should run on one side, it will pass between the pulley F and the guide-roller B, causing the pulley to revolve, and turning the screw E in the threaded bush, thereby moving the slide fixing D and the guide-roller B, which causes the felt to run back. Should the felt run to the other side, it will run in contact with the pulley F 2, and thus reverse the motion of the guide-roller B.

Paper-cutting Machine.—This machine (Fig. 46), which is manufactured by the same firm, is constructed to cut from one to eight webs simultaneously, in sheets of any required length, from 8 to 60 inches. It is built on the "Verny" principle, and its operation is as follows:—The webs of paper from the reel-rolls are carried by an endless felt, and the paper is drawn off the rolls by travelling cast-iron gripper beams, which firmly grasp the felt and the webs of paper to be cut, the travel of the beams being equal to the length of the sheet of paper to be cut. When the required length of the sheet is drawn from the rolls, a cast-iron clamp, placed close to the dead cross-cut knife, descends and firmly holds the paper until the movable cross-cut knife has cut off the sheets, which fall on a second endless felt, and are placed by the catchers in the usual manner. As soon as the sheets are cut, the clamp is released, and the travelling-grippers are again ready to seize the paper and repeat the operation.

Single Web Winding Machine.—This machine (Fig. 47) is constructed for preparing webs of paper for continuous printing-presses. The roll of paper to be prepared is carried by brass bearings having vertical and horizontal screw adjustments attached to standards mounted on a slide, and movable by a screw transversely on the machine to accommodate the deckle edges. The paper web is taken through a pair of iron draw-rolls, carried by brass bearings, fitted in cast-iron stands; there are two pairs of ripping-knives with bosses, springs, and collars, mounted on turned wrought-iron shafts running in brass bearings carried by cast-iron stands; a wrought-iron leading-roll and carrying brackets fitted with brass bushes; a copper measuring roll counter, geared to indicate up to 10,000 yards, with disengaging apparatus to cease measuring when the paper breaks; a friction-drum 2 feet in diameter, made of wood, mounted on cast-iron rings, and a wrought-iron shaft, all carefully turned and balanced; two cast-iron swivelling arms, with brass sliding bearings to carry the mandrel on which the prepared web is to be wound, with screws, struts, wheels and shaft to regulate the angular pressure of the roll of paper against the wood drum, according to its weight and the quantity of paper.

Cooling and Damping Rolls.—The illustration (Fig. 48) represents an apparatus, constructed by Messrs. Bentley and Jackson, for cooling and damping paper after leaving the drying cylinders and before passing through the calenders. It consists of two brass rolls bored and fitted with cast-iron ends, brass nozzles, and regulating taps, through which the rolls are supplied with a constant flow of water. The rolls are carried by cast-iron standards, fitted with brass steps and cast-iron caps. Jets of steam are blown on each of the rolls from a perforated copper pipe running parallel with, and at a little distance from, the body of the roll. The steam is condensed on the cold surfaces of the brass rolls, and absorbed by the web of paper, which passes around and in contact with their surfaces, and is consequently damped on both sides. The perforated steam-pipes are enclosed by copper hoods, to prevent the steam from spreading, and the supply of steam is regulated by ordinary brass valves or cocks. The rolls are geared together by a pair of spur-wheels, and driven by a pulley of suitable diameter.

Reversing or Plate-glazing Calender.—This machine, which is shown in Figs. 49 and 50, is also made by the firm referred to, and consists of two hammered iron rolls, each about twelve inches in diameter, of any suitable length, carefully turned and carried by strong cast-iron standards, fitted with bell-metal steps. The top roll is provided with setting-down blocks and brasses, compound levers and weights to regulate the pressure required. The two rolls are geared together by strong shrouded wheels, and driven by a strong cast-iron spur-wheel and pinion, a driving-shaft, fast and loose pulleys, carried by cast-iron stands and pedestals fitted with brass steps. The machine is fitted with two metal feed-tables, and a self-acting apparatus for returning the sheets to the rolls, and a handle-lever, slide-bar, and strap-forks for starting and reversing.

Plate-planing Machine.—This machine, which is manufactured by Messrs. Bryan Donkin and Co., of Bermondsey, is shown in Fig. 51. By its aid the plates of rag-engines can be sharpened without being taken to pieces. The slide of the machine is made exactly like the roll-bar planing machine (see below), and is so arranged that it can easily be taken off and used for sharpening roll-bars.

Roll-Ear Planing Machine.—In the accompanying engraving (Fig. 52) is shown an apparatus fitted to a rag-engine for sharpening rag-engine roll-bars, and it will be seen that by means of it the operation can be performed without removing the roll from its usual position. The edges of the bars are first planed by a tool supplied by the manufacturers to render the whole cylindrical before sharpening them; the bevelled sides are then planed by suitable tools, two of which accompany the apparatus. This method of sharpening renders the bars uniform in shape, the roll is kept in better working order, and it can be dressed in considerably less time, and at less expense, than can be done by chipping by hand.

Washing-Cylinder for Rag-Engine.—The illustration at Fig. 53 represents the machine as manufactured by Messrs. Bryan Donkin and Co. It is so made that the water is delivered on the driving side of the rag-engine, thus avoiding any trough across the engine, and admitting of the midfeather being thin, as is usual in cast-iron engines. It is all self-contained, and the driving apparatus is wholly on the outside of the engine. The raising and lowering are effected by a worm and worm-wheel, so that the cylinder will stop at any point required.

Bleach Pump.—In the accompanying engraving (Fig. 54) is shown a pump, manufactured by Bryan Donkin and Co., which is arranged expressly for the purpose of pumping up bleach-liquor. Each pump is all self-contained, and merely requires a drum and strap to drive it. The live and dead riggers upon the pump allow it to be started and stopped at pleasure. "In all paper-mills," say the manufacturers, "the bleach-liquor should be used over and over again, not only to save bleach, which amounts to a considerable sum in the course of a year, but also to keep the paper clean."

Three-Roll Smoothing-Presses.—The engraving (Fig. 55) shows a damp smoothing-press, with rolls for smoothing the paper between the two sections of drying cylinders of a paper-machine. The makers are Messrs. Bryan Donkin and Co. A three-roll smoothing press, for smoothing the paper at the end of a paper-machine, also by the same makers, is shown in Fig. 56.

Back-water Pump.—The engraving (Fig. 57) shows a pair of back or size-water pumps, manufactured by Bertrams, Limited. The barrels are of cast-iron, lined with copper. The suction and discharge valves are each contained in a chamber with covers, so that every valve could be easily got at by simply releasing the cover. The valve-seats are of brass, with brass guards and rubber clacks. The plungers are of brass, with cup-leathers. All is fitted up on a cast-iron sole-plate, with tall standards, disc-cranks, and driving-pulley between frames.

Web-glazing Calender.—Fig. 58 represents Bertrams' web-glazing calender, with steam-engine attached. The illustration shows the machine in front elevation. The steam-engine is specially designed for this class of work, having two cylinders 10 inches in diameter by 16 inches stroke, fitted on a double-hooded sole-plate, with double-throw crank-shaft, fly-wheel, two eccentrics, wrought-iron piston-rods, connecting-rods and valve-rods, steam and exhaust branch pipes with one inlet valve, lubricators, and the cylinders cased with teak legging and brass hoops.

Reeling Machine.—One form of reeling machine manufactured by Bertrams, Limited, is shown in Fig. 59, and is used for slitting and re-reeling webs of paper, especially where large webs are requisite for web-calendering, web-printing, and suchlike. The reel of paper from the paper-machine is placed on a sliding-carriage arrangement, the brackets of which are planed and fitted to a planed sole, with wedge or dove-tail corners, and controlled by screws, hand-wheel, etc., so that the reel can quickly and easily be moved forward or backward to suit any unequal reeling that may have taken place on the paper or the machine. A hot cast-iron is provided for mending breaks in the web, and a measuring-roll and counter is also applied. The machine has an important application of drawing-in or regulating rolls of cast iron, with arrangement of expanding pulley for regulating the tension on the paper. Slitting-knives, regulating, dancing, or leading-rolls, of cast iron, etc., are applied for separating the edges and guiding the webs after they are slit. The reeling is performed by a 3-feet diameter drum, cross-shafts, and arms, to which regulating heads are fitted, so that several webs can be run up at one operation.

Web-Ripping Machine.—This machine, which is manufactured by Messrs. Bentley and Jackson, is shown in Fig. 60, and is constructed to divide webs of paper into two or more widths. It consists of two brass bearings on cast-iron standards, with screw adjustments, a break-pulley and friction-regulator, all mounted on cast-iron slides, movable transversely by means of a screw, geared-wheels, shaft and hand-wheel; a wood guide-roll, about 7 inches diameter, with wrought-iron centres, carried by brass bearings with screw adjustment; three skeleton drums, each 2 feet in diameter, on wrought-iron shafts, carried by brass bearings, and driven by spur-wheels and pinions; two wrought-iron leading-rolls, with brass bearings and cast-iron stands; a pair of strong wrought-iron ripper shafts with circular steel knives, bosses, springs, and collars; cast-iron stands and brass bearings, spur-wheels and driving-pulley; two (or more) changeable wood drums 1 foot 6 inches in diameter, each with wrought-iron shaft and catch-box, carried by brackets fitted with brass steps for easily changing, driven by wrought-iron shafts with pedestals and friction-pulleys, 2 feet in diameter, with regulating screws and lock-nuts, all carried by strong cast-iron framing and standards, and driven by a wrought-iron driving-shaft, with fast and loose driving-pulleys, strap-fork and levers for starting and stopping.

Roeckner's Clarifier.—In this apparatus, of which an illustration is given in Fig. 61, Mr. Roeckner has taken advantage of the fact that if a column of liquid is ascending very slowly and quietly within a vessel, it will not be able to carry up with it the solid particles which it contains, which will gradually fall back and sink to the bottom under the action of gravity, without ever reaching the top of the vessel, provided this be of sufficient height. The illustration shows the arrangement of the apparatus on a small scale; the liquor to be clarified is run into a well or reservoir b; into this dip a wrought-iron cylinder c, which is open at the lower end, but hermetically closed at the top by means of the casing d. From this casing air can be withdrawn through a pipe, h, by means of an air-pump i. As soon as this is done the liquid will begin to ascend the cylinder c, and if the height of this is below that to which the water will rise at the atmospheric pressure (say 25 feet), the liquid will ascend until it fills the cylinder and the casing. Into the pocket at the side of the casing there dips a pipe g, which passes out through the opposite side of the casing, descends below the level of the water in the tank, and ends in a discharge-cock. When this cock is opened, the cylinder c and the pipe g form between them a syphon, of which, however, the descending leg is of very small diameter compared with the ascending leg. In consequence, the liquid will rise in the cylinder c very slowly. The sediment it contains will sink back and collect in the bottom of the tank b, and clear water will flow out at the outlet. A sludge-cock at the bottom of the tank allows the solid matter to be drawn off at intervals and conveyed to any convenient place for drying, etc.[30] For drawing clear water from a river, the clarifier would simply be placed in the river, dipping 2 or 3 inches into it below the lowest water-level. The clear water will then be drawn through the clarifier, while the heavier matters will fall down and be carried away by the river current. It is stated that this has proved a great advantage to a paper-mill which used a river, and had, prior to its use, been much troubled through the dirt being pumped with the water. The clarifier to receive the waste from paper-machinery, or from washings in the engines, can be placed in any convenient corner, and by its action the water can be re-used, and the otherwise lost fibres collected, without its action ever being stopped.

Marshall's Perfecting Engine.—This engine, a longitudinal section of which is shown in Fig. 62, has been introduced into this country by Messrs. Bentley and Jackson, and is described in Industries[31] as follows:—"The machine, which is the invention of Mr. F. Marshall, of Turner's Falls, Mass., U.S.A., is used in one of the processes of paper manufacture, and has for its purpose the more effectual drawing of the pulp fibre, the clearance of knots from the pulp previous to its delivery on to the paper-making machine, and the saving of time in the treatment of the material. As will be seen in the illustration (Fig. 62), the machine consists essentially of a cast-iron conical casing, bored, and fitted with about two hundred elbowed steel knives, G, placed in sections. At the large end of this conical casing is placed a movable disc, also fitted with about two hundred and ten steel knives, F, and capable of adjustment by means of a screw, worm, worm-wheel, and hand-wheel, E. The revolving cone and disc are of cast iron, fitted with straight steel knives firmly keyed upon a hammered iron shaft, and carefully balanced to prevent vibration. The knives of the revolving cone and disc are brought into contact with the stationary knives by means of the hand-wheel, E, and the disc-knives can be independently adjusted by means of the hand-wheel C, which actuates a screw on the conical casing by means of the worm and worm-wheel shown. The machine is driven by means of a pulley A, and the whole machine is mounted on a cast-iron base-plate. The pulp material enters the engine in the direction indicated by the arrow, B, at the small end of the cone, and is by the rotary and centrifugal action of the revolving cone, propelled to its large end, and during its passage is reduced to a fine pulp by the action of the knives. It then passes through the knives, F, of the stationary and rotating discs, by which the fibres are further crushed or split up, all knots or strings rubbed out, and the pulp effectually cleared previous to its exit through the passage D." We are informed that the machine is capable of treating from 900 lbs. to 1,200 lbs. of pulp per hour. The power required to drive it is estimated at from 40 i.h.p. to 50 i.h.p. when making 300 revolutions per minute. This, however, is dependent on the amount of friction caused between the surfaces of the fixed and revolving knives. The flow space occupied is 12ft. 6in. in length, and 4ft. in width. The perfecting machine, in its complete form, is shown in Fig. 63.

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