US390727A - Lining for pulp-digesters - Google Patents

Description

2 Sheets-Sheet 1.

(No Model.)

f s. R. WAGG.

LINING FOR PULP DIGESTERS.

No. 390,727. Patented Oct. 9, 1888.

l@ fr? Solomon,

2 Sheets-Sheet 2.

Patented Oct. 9, 1888.

- (No Model.)

S. R. WAGG.

LINING Foe PULP DIGESTERS.

N. PETERS. Pnewunwgmpher. washingum n. c.

. with varying degrees of success.

NiTnn STATES PATENT intera SOLOMON n. wade, OF NEENAH, WISCONSIN.

LINING FOR PULP-DIGESTERS.

SPECIFICATION forming part of Letters Patent No. 390,727, dated October 9, 1888.

(No model.)

.To @ZZ whom t may concern: l

Bc it known that I, SOLOMON R. Whoo, a citizen of the United States of America, residing at Neenah, in the county of Winnebago and State of Wisconsin, have invented certain new and useful Improvements in Lining for Boilers and Pulp-Digesters or other Vessels Exposed to the Action of Acids, of which the following is a specification.

Heretofore boilers used in the treatment of wood fiber by the bisulphite process have been lined with lead in sheets to protect the shell from corrosion and the contents *from stain; but a defect in all boilers thus lined has been that the steel or iron shell and the lead lining do not expand and contract equally, and that after short use the lining begins to creep and crack and admits the acid to contact with they shell. To Obviate the effects of this unequal expansion and contraction of the lead and prevent cracks and consequent leakage and injury to the shell and to the contents of the boiler or material under treatment, numerous devices have been placed before the publie Some manufacturers have supplied boilers with an interior lining made in practically one homogeneous piece by soldering the edges of one or more sheets together. Others have divided the lining into sections and covered the joints with strips. Others have inclosed finely-perforated sheet-iron in a casing of lead, making plates or broad sheets to be applied as lining. Still others have covered woven-wire cloth with lead. None of these constructions, however', have been entirely free from objections or have been entirely satisfactory in use.

In my improvement I propose, first, to apply the lead lining in small sections or tiles, each of these sections in itself containing several independent anchors or local resistances to the expansion and contraction, and practically shutting off the areas so confined from being affected by other areas and more nearly harmonizing them with the expansion and contraction of the shell; second, I partition the interior of the boiler-Shell,by means of ribs or stays of metal bolted to the interior wall of said shell, into a number of practically equal shallow compartments, each of which will be independently lined by tiles coated with lead or other acid resistant, so that any leak or defeet may be readily remedied within the com-l partment in which it is found without disturbing the tiles in the other compartment; third, I employ a peculiar bolt and nut for securing the tiles independently to the boiler-shell, having a groove cut in said nut and bolt, so that leak age is at once conducted to the outside and the locality of leakage indicated, for which purpose the exterior may have designatinglines corresponding with those of the interior partitions, and, if desired, be furnished with a number reproduced on the interior; fourth, I propose to electroplate the interior of the iron or steel boiler-shell with phosphor-bronze or other equivalent composition before applying the lead or acid-resistant lining to more perfectly guard against damage by leakage; fifth, I have found that an alloy hereinafter stated expands and contracts in nearly equal Ineasure with the iron and steel shell of the boiler while resisting the destructive effects of acids as well as or even better than lead, and such I propose to use and to claim herein.

Other features of my invention will appear from the ensuing description.

In the drawings, Figure I is a side elevation of a boiler embodying my invention, the shell being partly broken away to expose the internal construction; Fig. 2, a transverse section therethrough; Fig. 3, an enlarged detail of a portion of the inside of the boiler, showing at the right hand a lining-tile with lead covering in place and at the left the adjacent tile uncovered; Fig. 4, a longitudinal section on the correspondingly-numbered line in the preceding figure; Fig. 5, a bottom plan view of one of my improved tiles, showing the channels or ducts to conduct air or leakage to the boltholes through the boiler-shell; Figs. 6 and 7, respectively, enlarged details in perspective of a fastening-bolt and its nut for .securing the lining to the boiler-shell, and Figs. 8 and 9 enlarged details of alternative forms of washers which may be used with said nut.

A represents a boiler-shell, of iron, steel, or other suitable material, of any approved outline, depending in some measure upon whether it is to be stationary or rotary. To the interior walls of this shell are bolted longitudinal bars or stays B and transverse bars or stays B', of metal, dividing said walls off into a number of shallow and independent com- IOO partments or cells, C, rectangular in outline. These compartments may be indicated upon the exterior of the boiler by lines or marks C, corresponding with the longitudinal and transverse stays which define their limits, and by numerals l, 2, Snc., to be reproduced on the interior, so that any compartment may be immediately located from the outside. Each compartment is to be filled with acid-resistant tiles, as will presently appear, and one or more tiles, or every tile, will advisably have communications with the exterior surface of the shell that will permit leaks within the compartment to be traced on the outside and immediately located by the designating-number of the compartment. t

So far as the division ofthe shell into inde pendent internal compartments is concerned, any suitable form of acid-resistant tile or lining may be employed without departing from my invention; but the tile which I have devised and prefer to use is constructed as follows: I form a frame, D, of hard metal, preferably of angle'iron, ofthe shape desired for t-he outside margin or edge of the tile or section, either rectangular, as shown in the drawings, or a polygon, that will allow the tiles to be laid and matched edge to edge-for instance, a hexagon or octagonal and square tiles may be combined in the same structure. The upright ange of this frame will be recessed, grooved, or undercut around its exteriorside, as described in an application heretofore iiled by me, in order to admit between it and the adjacent tile when in position a sort of dovetail seam or tamping of acid-resistant material, and the stays which define the compartments to be filled by these tiles orseetions may also be undercut along their sides, that with the tiles coming adjacent to them such a seam or tamping may be formed.

Within the angleiron frame llay a series of strongiron, steel, or other metal rings, E, ofsuccessively diminishing diameter. These rings will be comparatively thin and shallow and ordinarily will not rise to the height of the angleiron frame which incloses them. A large ring is lirst taken, having such diameter as to just lie within the frame without touching its walls, giving a minimum clearance all around of, say,onehalf an inch to a full inch. The next ring is laid within the first with a clearance all around from said first ring of about the same, care being taken that their walls shall be equidistant at every point. The next smaller ringislaid within the seeond,with like clearance, and so on until the full series of rings are interposed, the last or central ring preferably being not over three inches in diameter. Vhen the inelosing-frame is rectangular in outline, the outer ring will leave large triangular spaces at the corners, which will be iilled with smaller series, E', of diminishing rings; but when it is hexagonal or octagonal the outer ring will practically correspond with be immaterial.

rings having been previously prepared with a coating of any suitable solder to cause the lead to adhere firmly when poured upon them in its molten state, the next proceeding after they are thus assembled is to pour upon them, while they rest uponasuitable table to ent oill escape of the fluid metal, molten lead or equivalent acid'resistant alloy, lforming the whole into a single section or tile, and protecting all the exposed iron or steel parts with an unbroken covering.

The tile-table,when square, should preferably have at each corner a bolt-hole with a bolt, F, set therein before the reception ofthe lead covering, such bolt to be of sufficient length to reach to the outside of the boiler-shell. A4 small' groove or channel, f, is made from the edge ot' the angle-iron to the bolt-hole, and such groove may be extended over the under side ofthe plate or tile and may branch there beneath. The shank or spindle of the boit is channeled, grooved, or tinted longitudinally, as at f', to afford one or more ducts leading from the head to the exterior wall of the boilershell and to or adjacent to its end, which is screw-threaded, so that alter being passed through the shell it may receive a nut., 1i', whereby the tile can be firmly clamped to said shell. Il" this nntalone is used it will have an annular undercut groove, f2, or be countersunk on its inner face, so as to connect with the groove or flutes in the spindle of the bolt, and will have ductsf" leading from this countersink or groove to its exterior; but prefera bly a washer, F2, is employed, either grooved similarly to the inner face ofthe nut and having ducts or else struck up with three or more feet, f3, to lift it somewhat from the boilershell. Thus any leakage which finds its way beneath the tile and attacks the inner wall of the boiler will eventually enter the ducts or channels on the under side of the tile and be conducted to the bolt at one or the other corner, then pass along its grooved spindle to the exterior wall of theshell, and eventually escape from beneath the washer or nut, making its presence at once known, when it will be 1ocated according to the compartment where it makes its appearance. Another purpose of this grooving and iluting is that when placing the tile or section in position any air confined underneath it may escape to the exterior as the bolts are tightened. Such air, if permitted to remain confined beneath the section, would expand as soon as the boiler became heated in use, and would in the end, by repeated expansion and contraction, cause bubbles or bulging in the tile and cracking in the plate.

In case it should be desired to leave out the fastening-bolts while casting the lead lining about the angleiron frame and rings, the boltholes can be filled with clay and the lining cast over them, and when cool, or when ready to place in position, the lining can be partially out with a suitable tool and turned up, leaving the bolt-hole clear. The bolt can then be in sertcd and the lining tu rned to its original posi- IOO IIO

tion and fused acidtight; or the bolt-hole can be elongated and the bolt-head formed. as a sort of T, so that this hole being stopped up with clay while the lining is being poured can be cleared out without puncturing the lining after it becomes cool, the bolt-head t-hen being inserted and given a quarter-turn, thus contining it. The lining may be hammered down upon it to prevent its escaping by a reverse movement. A series of these sections prepared with rings and acid-proof linings will be laid in each compartment of the internal wall of the shell, the diameter of the tiles or sections being so proportioned to the size of the compartments that a given number may perfectly iill a compartment. The seams between these tiles and between the tiles and stay-rods or partition-bars will be filled and tamped with lead, which will also be carried over the stay-rods, so that no destruct-ible material may be exposed to the action of the acids within the boiler.

As an additional precaution against buck ling or bulging or warping, I propose to employ a hard-metal radial-armed frame or spider, G, its arm g extending close up to the edge of the angleiron frame, and having a common center or hub, g', corresponding with the axis of the central ring in the tile. This will be placed in position upon the rings and their lead covering and secured by a bolt, g2, passing through the axis of the central ring and the exterior ofthe boiler-shell, and, if desired, by other bolts passing through the ends of the radial arms, as shown. Then the frame or spider itself, including the heads of its securing-bolts, will be covered with lead or other acid resist-ant, unless this has previously been done. A lead washer may be placed beneath the spider at the point where its bolt passes through the lead lining of the tile, so that when the bolt is tightened up the washer may be jammed down upon thc lining and make a tight joint. The spider holds all the rings dat down against the boiler-wall, thereby assist ing to keep said rings in position, so they can work in harmony to counteract the expansion of the lead or alloy and establish a uniform rate of expansion for the lining and boilen Walls as near as may be. Instead of this spider frame, however, I may employ one or more straight bars laid over the rings parallel to each other and bolted at their ends or centers to the boiler shell; but as ordinarily a single bolt at the centerof the tile alone will be suffr cient when the radial -arm spider is used, I prefer this, as it diminishes the chances of leakage.

Over all of the seams, after the filling and calking are completed, I place a ribbon, II, of lead or alloy, and by solder or any other convenient method unite the same to each of the conjoining tiles at the upper edges or outside oftheir leadcovered angleiron frames, making the union acid-tight by using blow-pipe or solder-iron, thereby causing the seam to form a compound joint and preventing against possible leakage. When desirable, the filling can be fused at its edges with the covering of the angle-iron walls before placi ng the ribbon over such filled seam.

As an additional security against acid attacking the boiler-shell, as it may sometimes do by leaking through the tiles or seams, or

through the lead or otherlining in case no tiles are used, I propose to clean the boiler-walls and prepare them in a suitable manner for receiving a cover of any acidresistant metal or material by electro plating or deposition applied in the usual way, or by such means and appliances as are in use and best suited forthe purpose. Such electroplate deposition can be made on sheets or sections of the shell before making up or upon the shell after construction. The material I propose to employ for this electro deposition is phosphor-bronze or deoxidized copper or alloy. This, as above intimated, should be applied to the walls before the lead lining` or acid-resisting tiles are placed thereon. Thus' 'far I have described a lining of lead or acid-resisting surface of lead alone, although it has been suggested that any y other acid-resistant metal or alloy might be utilized. Lead, when heated, expands much more than iron or steel, which are the usual materials for boiler-shells of this nature, (in this art,) and when it cools it does not return quite to its original form or size like iron or steel, but cach time it is heated it stretches out or creeps, thickening u p in one place, thinning down in another, and buckles up and soon cracks through, admitting the corrosive liquor to contact with the shell, which, being vulnerable to acid, is speedily destroyed, while conversely the pulp in the process of being cooked is spoiled by the result-ing metallic salts. I have ascertained that an alloy composed of lead, bismuth, and antimony, which may be so regulated as to expand and contract in practically the same degree as or in harmony with the expansion and contraction of the metal boiler-shell, whether that be iron, steel, or other metal, by varying the propor tions of the bismuthor the antimony to the lead,will at the same time resist effectively the, corrosive action of the powerful acids employed in the bisul-phite process. Bismuth and anti-l mony are both what is known as volatile, and must be melted with care and not leftlongexposed to the heat, or the nature ofthe eX- pected expansion will be affected thereby. It will therefore be advisable to melt the bismuth and antimony in inclosed tight vessels, and to pour them, when tiuid, into the melted lead and stir quickly together therewith.

A precise and arbitrary rule of weights and proportions is not practicable, and as results will be only closely approximate I can only give au approximate statement of such proportions, bearing in mind that if melted in an open vessel the fluid metals will lose slightly more than in a covered Vessel, and in such case a little more must be used to get the samelresult.

IOG

IIO

` that is a superior acid resistant.

In forming an alloy for the lining, if iron, I combine the stated metals in about the following proportions, towit: Of leadI take eightyfour parts, of antimony twelve parts, and of bismuth fou r parts, thus obtaining an alloy that has but a very slight expansion over iron and By the addition of slightly more antimony and bismuth the alloy can be made to expand less. Should a very tough alloy be required, I propose to add a small quantity of phosphor-bronze or deoxidized copper. This will interfere with the unity of expansion and contraction, if much is used, and to bring the expansion and contraction down to the point aimed at there must be an increase in the amount of antimony and bismuth according to the quantityofphosphor-bronze used. The proportions, for instance, may then be stated as follows for lining an iron shell, towit: lead, seventy-tive per cent.; antimony, fourteen per cent.; bismuth, iive per cent., and phosphonbronze six per cent. I have used copper in place of phosphor-bronze with fair results, but not as good, and give the bronze preference.

I do not intend to limit myself lo the employment of separate and independent rings in constructing my improved tile, nor to the material of which they are made, provided that material expands and contracts iu correlation with the expansion and contraction of the boiler-shell, but may form these rings (and their frame as well) by sinking orindentation in a homogeneous plate 0r by raising or strilc ing up the same from the surface, and upon said plate or surface cast the acid-resistant coating or lining, or place it thereon by other or equivalent means; nor do I confine myself to the precise means for fastening said tiles, nor to the precise shape of the divisions or compartments on the inner wall of the boilershell, since these can be materially varied without departing from the principle of my invention.

I claim- 1. A boiler-shell having its interior walls divided into shallow compartments by ribs or stays, combined with independent acid-resistant lining in each of said compartments and acid-resistant covering to said stays.

2. A boiler-shell havingits interior wallsdivided by ribs or stays into shallow compartments independently iilled with acid-resistant lining and its exterior walls marked to correspend with said compartments.

3. Aboilereshell having its interior walls divided into shallow compartments by ribs or stays bolted to said Walls,combined with acidresistant lining for said ribs or stays and with acidresistant tiles lining the walls within said independent compartments.

4. rIhe tile herein described, consisting of a border-frame of hard metal, a series of diminishing rings of steel or iron, andan acid-resist-ant covering incorporating said rings and the borderframe.

5. The tile herein described, consisting of a frame of angle-iron, a series of diminishing rings of steel or iron, and an acid-resistant covering incorporating said rings and the angle-iron.

6. The tile herein described, consisting ofa frame of angle'iron, a series of independent rings of steel or iron diminishing in size and set within said frame, and a lead covering incorporating the exposed faces of the frame and rings.

7. The combinatiomwilh tiles for the lining of boilers grooved at the inner side, of fasteningbolts having their spindles grooved to connect with the grooves of the tiles and secured by channeled nuts on the outside ofthe boiler.

8. The combination,with atile composed of an angleAirou fran1c,a series of diminishing rings placed therein, and an acid resistant covering incorporating said ring and frame,ofan acid-resistant covered spider composed of radial bars or equivalents, and having a central bolt passing centrally through the tile and covering the rings, and itself covered with acid resistant.

9. The combination, substantially as herein` before set forth, with the boiler-shell, of an electroplating of phosphor-bronze or equivalent material covering its internal walls and an acid resistant lining secured over said plating.

10. The combination, substantially as here inbefore set forth, with the shell of a paperpulp boiler or digester, of an acid-resistant lining composed of antimony, bismuth, and lead, in about the proportions set forth, and with or without phosphorbronzc or equivalent.

S( lLOM'( )N It. W A GG.

\V it ncsscs:

H. Gv. FRJMQMAN, ll. KUcHUnsoNn.

ICO

Images