US681242A - Lining for pulp-digesters. - Google Patents

Description

` Patented Aug. 27, 190|` NITED TATES" ATENT Meriem ROBERT MORGENEIER, OF ASHLAND, WISCONSIN.

LINING FOR PULP-DIGESTERS.

SPECIFICATION forming part of Letters Patent No. 681,242, dated August 27, 1901.

Application filed December 26,1909. Serial No. 41,112- (No modelJ To LZ-Z whom t may concern: y

Beit known that I, ROBERT MORGENEIER,

`a citizen of the-United States, residing at Ashland, county of Ashland, State of Wisconsin, have invented certain new and usefulImprovements in Acid-Resisting Linings Y `for Sulte Pulp-Digesters, of which the foli Io l lowing is a specification, reference being had therein to the accompanying drawings, in

Figure 1 is a vertical section view of` a pori view ofone of the lead-backed bricks, and

Figs. 3 and l detail sections of portions ot' y the Shen and lining enlarged.

Theobject of my invention is to interpose f between the steel or iron shell of a digester y and its steam-heated, compressed, corroding,

` 2O l sisting wall or lining which shall effectively and oxidizing contents a protective acid-re` i prevent the contents coming in contact with the shell, which shall be practically permanent, and which shall not be cracked by reason of the different ratios of expansion and contraction of the shell' and the lininfr as y `more fully hereinafter set forth.

Referring to the drawings by letters, A is the sheet iron or steel shell of the digester, tted with the bronze or iron necks B B C, a

y sheet-lead lining fitting Within the crown and upper neck B and turned down upon the upper `face of said neck, thereby forming a gasl ,i i ket c, against which the cover shall bear when putin place; C', a sheet-lead lining similar 1 to lining C, but fitting the basin of the digester and the lower neck B', its lower edge being bent up against the lower face of said 3 lower neck to forma gasket e', against which the usual bottom piece shall bear when `attached; D, a series of/acid-resisting vitried i brick or tile composing the outer or shell wall of the lining; E, the acid-resisting brick or y tile composing the inner wall of the lining.

Each ofthe tiles D is backed by a coating j of lead, which is cast thereon or consists of sheet-lead fastened thereon, said lead backing extending partially over upon the side l a l ledges of the tile.

These lead-cased tiles extend over the entire interior surface of the shell and are shaped to conform to the curvai ture thereof, those on the main or vertical part of the shell being substantially square and those in the dome and basin being tapered, as shown. The tiles in the dome and the basin and the necks thereof have their lead backs fitted to the respective linings C C', and those in the vertical part of the digester are fitted directly against the shell, these latter or their lead backs being sufliciently thicker than the tiles in the dome and the basin to compensate for the lead lining C C and bring the faces of all the tiles D Hush with each other. When these tiles are in place, their lead-cased side edges abut against each other and are soldered or calked or fused or otherwise secured together to form steam and acid proof joints land a practically continuous and permanent wall extending over the entire interior of the shell. As the edges of the lead backings terminate short of the inner faces of the tiles, it will be observed that connected grooves are Aformed around the edges of the tiles, and

these grooves are filled with suitable acid-resisting cement, this cement filling coming flush with the inner surfaces of the tiles, and in order to provide ample space for the cement and for convenience in soldering or fusing the joints the front corners of the tiles In addithe linings C C are also soldered or fused around their edges to their linings.

The tiles E composing the inner wall of the lining are curved to fit against the outer wall and are substantially the same shape as the tiles composing the same and are so placed as to break joints with said outer tiles. These Binner tiles are not incasedin lead, but are `recessed around their inner or front corners, as at E', to form connected grooves for the reception of a suitable acid-resisting cement. This inner Wall covers the entire surface of -the outer wall except in the necks, andthey lie directly against said outer tiles except in 'the dome, where a layerF of cement is interposed between the two walls.

In building the lining I begin at thebottom and first secure the neck-tiles D in place by soldering or fusing their lower and vertical edges toplining C', and as these neck-tiles project above the upper end of the neck I am also enabled to solder or fuse them alongv IOO their backs to said lining. The joints between these neck-tiles are calked down and soldered or fused to render them absolutely steam-tight. The first course of the basintiles is soldered to the backs of the neck-tiles and to the lead lining C all around their edges, and when the course is complete the joints between these tiles are calked and soldered or fused to render them steam-tight, and in this manner all the tiles in the basin are secured permanently in place. The tiles in the main part of the shell are fitted in substantially the same manner except that they are not soldered or fused except at their edges. These intermediate tiles are fitted closely to the respective well-trimmed edges of the linings C C', the uppermost course of these tiles being soldered or fused to the lower edge of the upper lining C. The tiles in the crown and upper neckare secured to the lining C in substantially the same way as described for the basintilesthat is, they are securely soldered along their edges to the lining and their joints. are suitably calked and soldered or fused together. After completion of this work and before applying any cement I thoroughly wash it with hot water, to which I add about ten per cent. of carbonate of soda or any other substance soluble in water and which will remove dirt and grease. A final washing with clean hot water prepares the lining for the work of cementing. Between the tiles as set are channels about two inches deep and three-quarters of an inch wide.

vThese are now to be filled with the best quality of Portland cement or its equivalent. I preferably employ the finest-ground Portland cemen t, in which the proportions of lime, clay, and other ingredients are such that the cement will set in about two hours, harden perfectly in about seven days, and neither shrink nor expand. I prefer to use the finest-ground fresh Portland cement and thoroughly purge same of any traces of lime by exposure to the atmosphere several days before using. Starting at the top, I mix small quantities of the cement and thoroughly trowel the same into the channels, discardingI any part which may show signs of setting on the mixing-board. After setting the work should be repeatedly sprinkled with water, and when finished the digester` should be filled with warm water and allowed to stand not less than three days. After draining oif the water the cemented fjoints should again be troweled over with fresh-mixed cement, whereupon the second or protective lining can be put in. These tiles E are shaped to conform to the interior of the digester, are not incased with lead, but have formed around their sides a narrow projecting ledge, so that when laid in the basin and set up against the vertical walls with their respective ledges in contact channels are formed which I fill with cement, thus cementing the tiles to each other as fast as they are laid. Arriving at the point where the dome seis in, I use a tile somewhat thincereza ner, cover the back thereof with quick-setting cement, and seal it to the first lining. When all the crown-tiles are so putin place, I finish the remaining channels with slower-setting cement. After finishing the inner protective lining I ll the digester with water and allow it to remain therein until the cement isv thoroughly hardened.

When a digester lined as herein described is put into operation, it should be slowly steamed up, so that the heat may reach the steel shell before the lining is unduly expanded. After the first heating up the shell and linings will contract and expand in a measure independently of each other, and the ratio of expansion will be such that the shell will not be subjected to undue stress and the linings will not crack.

The boiling contents of digester slowly eats away the cement in the channels of the inner or protective lining, and my observation has shown it to be prudent to put new cement into said channels about once in two months, to the end that the lining proper will never be reached by the cooking liquor or by the gas.

I lineJ the basin and crown with sheet-lead, not only to provide a base for fusing on the lead-backed tiles, but also to more thoroughly protect those parts of the digester-shell. The basin is subjected to extra pressure and weight, and the steam entering during cook ing strikes the walls of the digester within said basin,while, on the other hand,the crown is more subject to the destroying action of the snlfurous-acid gas liberated during the cooking process, and I prefer taking extra precaution to prevent any of the said gas from reaching the steel crown. The vertical walls are sufficiently protected by the leadbacked tiles covered by the protective lining. By thus lining the dome and the basin with separate lead sheets I am enabled to employ the lead in such different form and arrangement on the Vertical Wall-surface that the strain due to expansion and contraction will be harmonious throughout the entire lead lining. By reason of the fact that the motion under expansion and contraction is less in the dome and the basin than in the main body of the digester I can fuse the tiles di- :rectly upon sheets of lead therein, as such v sheets will never move enough to injure themselves, while by reason of the fact that the motion under expansion and contraction is greater in the main part of the shell I provide a more expansible lining for that portion, preferably employing a series of lead cases fused to each other and tothe edges of the dome and the basin linings, as set forth. It is important that the dome and basin linings should extend to the point where the vertical wall begins and no farther, as at this point the movements under expansion and contraction are equal. The inner dome-tiles are backed and set with quick-setting cement, as this is the most expeditious way of holding them in position for edge cementing with IIO . sloW-settingcement. This layer of cement of the strata and interpose no appreciable hindrance to their free independent expansion and contraction. If a digester-lining of Y any considerable thickness is composed of a j solid mass, the heat acting upon it from the inside will cause it to expand and being encompassed by therigid shell not yet reached 1 by the heat the solid mass will buckle inward i 1` l at its weakest point and a fracture will result, and, moreover, such a lining in cooling `off (which cooling off `takes place from the interior every time the digester is opened for l refilling) will contract at its interior surface at the same time it is still held expanded at 2O` the part `neXtto the shell, and as a consej quence the lining will tear apart at its Weaki est point. This protective stratum not being j; `a part of the outer stratum can move over` the latter Without injuring the same, so that 1 25 `by the heat it presses againstthe back or "outer stratum and becomes slightly wavy.

when said protective stratu mis first expanded lWhen theheat is communicated to the outer l lead-backed lining, it intnrn moves out of a "145 jf theshell and theliningamounts tobutasmall e fraction of an inch and that therefore the `strata of the lining move out of a true circle i when `first expanded butvery little; but this the strata cracking, and it `Willbe further true circle. Then as the heat reaches and `expands the shell the strata of the lining In cooling` j each stratum returns to its original position "without hindrance or Ainjury from its neighagain assume a concentric shape.

bor, and when the entire digester is cold there` isa slight space between the strata of the lining and the lining and the shell. Should the e. digester be suddenly and improperly cooled j idownby throwing streams of Coldwater into the same, the lining Will stand even this, for

upon sudden and excessive shrinkage of the ,e tiles and cement the fused lead joints will act as a sort of hinge or iiexilole joint, and thus preserve the integrity of the lining.

\ It will be understood that the expansion of small amount of play is sufficient to prevent 1noted thatthis action of the strata is facilii ltated by the fact that the cement `fillings or keys between the inner` corners of the tiles extend a considerable distance in toward the backs of the tiles, abutting against each other lneartheir backs, so that as the tiles shift out of the circle the cement fillings, being more j elastic than the tiles and being numerous, act

"somewhat in the nature of cushions. compression and expansion of the-iillings will e be very slight-in fact, practically imperceptible-in any onejoint, but the aggregate of 3 the play they permit in practice has been suf- This icient to prevent the strata fracturing. This cushioning of the titles at numerous points is l of course mostly required in the inner straexpansion of the tiles of the outer stratum of,

the lining resulting from the first heating of the digester presses the lead against the shell, and thereby compacts the layer of lead Vsuficiently to avoid providingfor but a slight buckling of this stratum. Hence the cement fillings in this stratum need not be as deep as j in the inner stratum. It will be understood that I do not mean that the lead will be condensed, but simply that the lead layer will be pressed into the slight space that is necessarily formed around the digester by fitting the tiles in the manner hereinbefore described, and it will be seen that the play thus provided for the outer stratum will be considerable in comparison with the amount of play required when it is remembered that the outer surfaces of the lead backings are comparatively rough and irregular and that they extend entirely around the digester. After the digester is once heated up and the lead lining is compacted to its utmost, the outer stratum will then have considerable free play between the shell and the inner stratum, and therefore in the subsequent expansions and contractions of the lining it is found that this outer stratum will buckle but very little, if any. This expansion and contraction ofthe outer stratum is aided materially bythe hingelike joints between the lead cases, these hingejoints being formed by fusingor soldering only the inner edges of the cases and not to any appreciableextent their abutting sides.

lt will be observed that the lead backings of the tiles-form shallow trays or pockets for the reception of the tiles and when fused together and to the dome and basin linings the whole forms a continuous ribbed framework of lead which is self-supporting, and is therefore eXpansible independently of the shell and the inner stratum of tiles, and it will be further observed that the `filling of cement in the channels formed between the tiles not` only seals the tiles together, but forms a sort of pressure-resisting key which prevents the expansion of the tiles from forcing the lead ont at the joints.

Having thus described myinvention, what I claim isl. In combination, a digester-shell having a dome portion and a basin portion, a sheetlead lining in the dome and another sheet-lead lining in the basin, these linings being eX- tended from the respective necks of the shell approximately to the points where the concaved parts of the dome and the basin respectively terminate and merge intothe ver- IOO IIO

IZO

tical part of the shell, another lead lining covering the shell between the dome-lining and the basin-lining and being connected thereto at its respective upper and lower edges, this intermediate connecting-lining being more expansible than the dome and the basin linings and all three linings being expansible independently of the shell, and protective tiling covering all said linings, substantially as and for the purposes set forth.

2. In combination a digester-shell, a lead lining in the dome thereof and another lead lining in the basin thereof, these linings being separated from each other and being expansible independently of the shell, a series of lead cases fused together and to the aforesaid linings and covering the shell intermediate the linings, all said cases forming a selfsupporting non-attached ribbed shell within the digester-shell, and acid-resistin g material within said cases.

3. Atile for pulp-digesters havingabacking of lead and a recess around its front or inner corners, for the purpose set forth.

4. A tile for pulp-digesters having a lead backing which extends over upon and partially incases its side edges, the front or inner corner'of the tile beyond the extended edges of the lead being cut away or recessed, for the purposes set forth.

5. A lining for pulp-digesters consisting of a lead backing or lining, a series of lead cases fastened thereto and fused together, a series of tiles fitted into said leadcases and recessed around their inner or front corners to form channels coincident with the fused joints of the lead cases, and a cement filling in said channels, for the purposes set forth.

6. Alining for pulp-digesters, consisting of a continuous framework of lead and a series of tiles carried thereby and secured to each other by cement, the cement lying between the joints of the tiles and against the lead, whereby the cement serves not only to secu re the tiles together but also to prevent the lead being squeezed out at the joints.

7. A pulp-digester lining consisting of a lead backing or lining, a series of abutting lead cases fused thereto and to each other, and a series of recessed tiles fitted in these cases and joined together by cement.

8. A digester-shell having a self-supporting non-attached lead lining provided with ribs of lead forming shallow trays, recessed tiles iitting in said trays, and a seal of cement in the channels formed by said recesses, this cement connecting the tiles together and protecting the edges ofthe ribs.

9. A pulp-digester shell, in combination with a sheet-lead lining fitted in its crown 6o and charging-neck and bent down upon the face of the neck, said lining being otherwise unattached to the shell and being therefore expansible independently thereof, and a series of lead-backed tiles fused thereon and extending up into the neck.

10. In combination with a digester-shell, of a lining therefor consisting of an outer stratum of tiles next to the shell and an inner or protective stratum of tiles lying against said 7o outer stratum, the shell and the strata of tiles being independently expansible and contractible.

1l. In combination with a digester-shell, of a lining therefor consisting of two unconnected strata of tiles, the joints between the tiles of the inner strata being slightly iiexible, in order that this strata may become slightly wavy when expanded from within.

12. In combination with a digester-shell, of 8o a lining therefor consisting of two unconnected abutting strata of tiles having numerous joints, these joints beingsuiciently iiexible to allow the strata to become slightly wavy in turn as they are expanded by heat from within.

13. In combination with a digester-shell, of a lining consisting of two independent strata, abutting against each other, and the inner vstrata being made up of numerous tiles hav- 9o ing their adjacent edges abutting against each other near their backs and their adjacent edges connected together at their front or inner faces by a comparatively elastic sealing substance, for the purposes set forth.

In testimony whereof I hereunto affix my signature, in the presence of two witnesses, this 22d day of December, 1900.

ROBERT MORGENEIER.

Witnesses:

JACOB SEGLER, PETER LAMAL.

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