US1188730A

US1188730A - Apparatus for recovering pulp from printed paper.

Info

Publication number: US1188730A
Application number: US66?6715A
Authority: US
Inventors: Robert D Carter
Original assignee: Individual
Current assignee: Individual
Priority date: 1915-12-14
Filing date: 1915-12-14
Publication date: 1916-06-27
Anticipated expiration: 1933-06-27

Description

R. D. CARTER.

APPARATUS FOR RECOVERING PULP FROM PRINTED PAPER.

APPLICATION FILED DEC-l4, I915- Patented June 27, 1916.

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Specification qr Letters Patent. t t a June 2'1 11 at a.

Application filed December 14,1915. I sea-11a. saw.

To all whom it may concern Beit known that I, ROBERT D. CARTER, a citizen of the United States, residing at Wanaque, county of Passaic, and State of New Jersey, have invented certain new and useful Improvements in Apparatus for Becovering ulp from Printed Paper, fully described and represented in the following specification and the accompanying drawin s, forming a part of the same.'

his invention relates to a means for treating printed paper to remove the ink therefrom and produce a pulp which can be used again to manufacture white paper.

It is comparatively easy to treat soft paper, like printed newspaper, toremove the ink therefrom, but the same treatment will not efi'ectually loosen and remove the ink from hard sized papers, like some bookpapers; and I have therefore devised the present invention to accomplish that result. It has been common to out such papers into small fragments and feed the same in a heated state to a rotary devil with a considerable proportion of soda-ash, so as to affect the paper chemically and mechanically in its passage through the devil; and the devil is so constructed as to discharge the material rapidly, so that it is subjected but a short time to the disintegrating action of the teeth upon the drum and casing of the devil, and such treatment is wholly inadequate to remove printers ink from hard sized papers. I

To completely effect the removal, I combine with the devil or similar disintegrator a horizontal cylindrical digester having.

means, as rotary arms, for mixing or rubbing its contents, with a heatingtank interposed between the devil and the digester, and connected with both and serving to reheat the pulp that is discharged from the devil, and deliver it in a highly heated state to the lower part of the digester. After the pulp has passed through the digester it is delivered from the upper part of the same, thus keeping the digester solidly full of the stock under treatment. This is not the case with the devil operated in the usual manner, in which the stock is fed into the upper part of the casing and discharged from the lower part, so that it moves rapidly through the.

steam caiinot be injected into the casing of the devil 'or the casing of the digester which I connect thereto, as the steam entering the casing tends to scatter the stock and force 1t backward tothe inlet or forward to the outlet, so that the stock is not fully subected to the action of the disintegrating agents. The heating-tank is interposed between the devil and digester so as to thoroughly reheat the stock discharged from the devil, before it is subjected to treatment in the digester where steam cannot be advantageously mtroduced. Owing to the use of a conlcal drum'in an ordinary devil, very little space is left between the drum and casing for the passage of the stock, and I secure a much longer treatment of the stock in the digester which I employ, by making it three or four times the capacity of the devil so that the material moves through the same three or four times more slowly, and is thus subjected much longer to the chemical and mechanical agencies. By combining the heating-tank and the cylindrical digester with the devil, I am enabled to reduce the stock to fine pulp, and loosen the particles of ink therefrom, so that a suitable after-treatment readily separates the ink from the fibers. An additional washing operation with a suitable bleaching agent can thus produce stock entirely white.

The invention will be understood by reference to the annexed drawing, in which Figure 1 is a side elevation of the apparatus with the top casing near the top of the steam-tank broken away; Fig. 2 is a plan of the apparatus with one corner of casing upon the devil broken away; and Fig. 3 is a section of one of the elbow connections to or from the tank, with a steam injector applied thereto; Fig. 4 is an end view of the digester. The devil is shown with the usual conical casing a and conical drum 6, each having teeth 0 thereon to tear and disintegrate the stock. The drum is revolved by a shaft 1).

The casing is shown with a hopper d and inlet at its smaller end and an outlet-pipe 0 connected near its larger end, and extended to the lower part of the heating-tank 7". An elbow e is shown upon the pipe 6 with a steam-pipe 8 connected to its outer side, as shown in Fig. 3', and directing a jet of steam toward the inlet of the heating'tank, so as to force the stock from the pipe into thorough mixing of the contents, by driving the same around.

The heating-tank is shown with an open vapor-outlet g in the top, beneath which a bafiie-plate h is secured to prevent any solid matter being blown out from the boiling mass in the tank, which usually stands at the level i above the outlet-pipe y. This pipe is taken from the side of the tank intermediate to the steam-inlet and steam-outlet, and is connected to the lower part of the disintegrator-casing k. This casing is formed cylindrical, with a row of prongs I at each side ofthe center, and is provided with a central shaft m carrying a series of hubs n each having two opposite arms 0 which rotate between adjacent prongs Z.

It will be noticed in Fig. 4 that the prongs and arms are made very numerous and fitted close -to one another so as to most forcibly rub the fibers which pass between them, and thus remove the ink from the stock by abrasion rather than by chemical action. This saves much alkali and the weakening of the stock by chemical action. To prevent the stock from evading the action of the rotating arms, they are extended as nearly as practicable tothe inner wall it is' obvious that the construction of the arms is adapted to contact with the stock and rub it most effectively.

The shaft is fitted to stufiing-boxes 9 upon the heads of the casing and is also supported in bearings 9 attached to the heads, and has a pulley p for rotating it. An outlet 1' is shown near the upper edge of one of the heads [6 at the opposite end from the inlet 3', and the stock entering the casing upon its lower part, thus fills the casing before it can be discharged from the outlet 1', and is therefore solidly in contact with the prongs Z and arms 0 during its passage through the digester. To facilitate the connection of the digester with other parts of the apparatus, each head is formed with three holes marked 1, 2 and 3 in Fig. 4, any of which holes not required for connections being closed by a blank flange. The hole 1 close to the top of the casing serves for the outlet, and the hole 2 or 3 upon either side of the bearing 9 may be used for the inlet, as proves most convenient, the pipeflange 4 over the hole 2 serving to connect the pipe 3' in. that figure. A supply-pipe t is shown over the hopper d of the devil, by which the divided stock is fed into the soda-ash solution. 7

The operation of the entire apparatus is as follows: The conical form of the devil induces a centrifugal movement of the stock and drives it to the larger end of the casing iafrom which it escapes by the pipe 6. From this pipe it is delivered into the lower part of the heating-tank f, where steam is admitted by the pipe f to give the stock a thorough heating on its passage to the diester-casing 70. When required, steam may lie introduced into the pipe 6 by the injectorpipe 8 to drive the stock forward. The pipe 7' discharges the stock from the heating-tank at a considerable distance above the bottom, so that the tank must fill up to that-level, or higher, before it will operateby gravity to move into the lower part of the casing 70. In suchmov'ement through the pipe j,

.steam may be introduced into the pipe by a steam-pipe s to drive the material forward. In the casing k the material is forced to fill the casing from the bottom to the outlet before it is discharged, and as its capacity is many times greater than that of the small space between the drum and the casing of the devil, the'stock moves slowly from the inlet-end to the outlet-end of the digester, and is thus kept solidly in contact with the arms 0, which in cooperation with the teeth Z thoroughly mix the stock and beat it so as to loosen the ink therefrom, and mix it with the alkali. The soda-ash thus operates during the time the stock is moving through the digester, to loosen and separate the ink from the fibers, so that when the stock is delivered from the digester the ink can be wholly separated by a suitable washing and settling.

The invention includes the treatment of the stock mixed with heated alkaline solution, first in a disintegrator where the stock may be violently torn and the fibers separated from one another, and beaten at such velocity as to partly loosen the ink, then reheating the stock, as described, and further subjecting it to mechanical and chemical treatment in the digester, to loosen the ink from the fibers and rub the particles of ink therefrom, such digester having mixingarms rotated close to stationary prongs, and

level to discharge the stock more freely to the tank and digester.

The use of steam-injectors in the connecting-pipes, by their propelling force, permits the setting of the several parts at nearly the same level, if desired. The stock may, if required, be subjected to two or more of the digesters successively, the stock being delivered from the upper part of one to the lower part of the next in the series, so that the casing 70 of each digester is filled by the stock before it escapes.

The object of the invention is to remove the printers ink from the paper with as little injury as possible to the fiber, and the use of as little chemical as is possible, as any reduction in the chemical not only makes a saving in the expense but leaves the fiber with greater strength.

It will be noticed that the alkali is brought into contact with the fiber mechanically in the digester, and the continuance of this contact, for the length of time it can be practised in the digester, renders the alkali so much more eifective, that I find in practice only twothirds of the alkali heretofore used is required in the use of my improved apparatus. It will be noticed that the casing is provided with prongs Z only at its opposite sides, and the shaft in like manner has arms only upon its opposite sides. With this construction the arms pass between the have pointed out that my arms differ from those heretofore used in operating close to the prongs upon the casing and in extending between those prongs almost into contact with the inner wall of the casing, so that the pulp and stock thrown outward against such wall by centrifugal force cannot escape the rubbing operation of the arms; which is designed to, and does in practice, remove the ink from the fiber largely by mechanical action, thus avoiding the use of so much alkali.

Having thus set forth the nature of the invention what is claimed herein is: i

1. The combination, with a devil or similar disintegrator. and a horizontal cylindrical digester havin means for mixing its contents, of a heating-tank intermediate to the devil and the digester and receiving the pulp from the devil and delivering it to the lower part of the digester and provided with 2. The combination, with a devil or other similar disintegrator and a horizontal cylindrical digester having means for mixing its contents, of a heating-tank intermediate to the devil and the digester and receiving the pulp into its lower part from the devil and discharging the pulp at a higher level tothe lower part of the digester, and the pulp being delivered from the upper part of the digester, whereby the digester is kept filled with the hot pulp and its delivery regulated by the supply to the devil.

3. The combination, with a devil or similar disintegrator and a horizontal cylindrical digester having means for mixing its contents, of a heating-tank intermediate to the devil and the digester and receiving the pulp into its lower part from the devil'and havlng a supply-pipe at the bottom and a steam-vent at the top with a baffle-plate adjacent to such vent and having an outlet intermediate to the steam-pipe and the vent connected to the lower part of the digester, and the pulp discharged from the upper part of the digester, as and for the purpose set forth.

4. The combination,- with a devil and a heating-tank having its lower part connected thereto by an elbow-pipe, of a cylindrical digester provided with means for mixing the contents and connectedto the heating-tank by an elbow-pipe, at least one of the said elbows having a steam-injector applied thereto for propelling the contents from the pipe into the adjacent receptacle.

5. A digester for continuous mechanical and chemical treatment of paper fiber,

. consisting of the cylindrical casing 70 having a row of prongs projected inward from each of its opposite sides, a rotary shaft having arms upon its opposite sides operating between the said prongs, the prongs and arms having their opposed sides near to one another and the arms extended closely to the wall of the casing, and means for supplying the stock continuously to the lower. part of the digester at one end and discharging it continuously from the upper part of the digester at the opposite end.

In testimony whereof I have hereunto set my hand.

ROBERT D. CARTER.