US429097A - Charles ramsey - Google Patents

Description

(No Model.)

0 RAMSEY PROCESS OF MANUFACTURING AND BLEAGHING PULP.

Patented May 27, 1890.

perforated filter-plate A UNITED STATES PATENT OFFICE.

CHARLES RAMSEY, OF LEEDS, COUNTY OF YORK, ENGLAND.

PROCESS OF MANUFACTURING AND BLEACHING PULP.

SPECIFICATION forming part of Letters Patent No. 429,097, dated May 27, 1890.

Application filed April 9, 1889. Serial No. 306,585. (lilo model.) Patented in England February 1, 1889, No. 1,834, and in Norway April 4, 1889, No. 1,281.

To all whom it may concern:

Be it known that I, CHARLES RAMSEY, a citizen of England, residing at New Wortley, Leeds, county of York, England, have invented a new and useful Process of Manufacturing and Bleaching Pulp, (for which I have obtained patentin Great Britain, No. 1,834, dated Fbruary 1, 1889, and in Norway, No. 1,281, dated April 4, 1889,) of which the following is a specification.

My invention relates to a process of manufacturing and bleaching wood, straw, rag, and other pulps for paper-making and such like purposes. The process naturally divides itself into two parts or operations, the one being the preparation of the crude pulp, the other the bleaching of the crude pulp. Usually the crude pulp is first prepared and this is afterward bleached. In many cases, however, fibers, chips, rags, &c., adapted for pulp-making may be bleached in the first instance, and the bleached material may be afterward made into pulp. I shall describe these two operations separately, and in order that they may be better understood I illustrate by the accompanying drawings an arrangement of apparatus whereby the two operations can be conveniently carried on either separately or consecutively.

Figure 1 is a plan, and Fig.2 a verticalsection, of a pulping-boiler. Fig. 3 is a plan of two bleaching-vessels, one of them shown in section; and Fig. 4 is a vertical section of one of them.

Referring first to Figs. 1 and 2, A is a boiler, which is preferably mounted on trunnions A, so that it can be turned obliquely or inverted to give convenience for repairs. In the center of the boiler there is a vertical pipe A open at the top and terminating at the bottom in a perforated cone A \Vithin the pipe A is an inner pipe A which is open at the top and the bottom, and within its lower end there is a jet-nozzle A for steam. Near the bottom of the vessel A is a perforated floor A, and nearly close to the bot-tom is a The vessel A is provided with water-gages A a man-hole A safety-valve and pressuregage A and a discharge-outlet with valve A. A steam-pipe B with valve leads to the jet-nozzle A and a blow-off pipe B with valve leads from the bottom of the boiler A. Above the top of the vessel A are situated two or more tanks 0, containing the chemical substances which I employ, these tanks communicating with the bottom of the vessel A by a pipe 0, having a branch from each tank provided with a stop cook or valve.

I operate with this apparatus for making pulp in the followingmanner: Having charged the boilerA up to nearly the top of the pipe A with the wood or other vegetable material in chips, fragments, or small pieces, I let saturated lime-water flow from one of the tanks 0 into the bottom of the vessel A till it rises a little above the perforated floor A. 1 then admit steam to the et-nozzle A and thereby cause the lime-water to flow up the central pipe to impinge against the cover or against a spreading plate under the cover, by which the current of lime-Water is broken and distributed over the pulp material. The liquid percolating through the interstices of the material returns to the bottom compartment, is again caused to flow up the pipe and so on continuously for six or eight hours until it is ascertained by sampling that the material has undergone sufficient treatment.

The steam-supply is then out 01f, the liquid is run off by the pipe B, and, if necessary, water can be passed through the material to wash it. The Washing-water having been withdrawn, the bottom compartment is charged with a solution of hypochlorite of magnesia, formed by mixing sulphate of magnesia and chloride of lime. These maybe used in various proportions with water, according to the character of the material operated on. I find a good proportion for most ordinary pulp materials to be a solution of the strength of about 3 Baum, consisting of about seventy per cent. of sulphate of magnesia to about thirty per cent. of chloride of lime. This solution is caused to circulate by means of the steam-jet for about six to eight hours. The hypochlorite solution having been run off, the material may again be washed with water, and it can then be discharged by the outlet-valve A ready for being beaten up into pulp.

In most cases it is desirable to bleach the pulp material prepared as above described, and for this purpose it may be run direct into either of thebleaching'vesselsshownby Figs.

3 and 4. Each of these vessels D is of cylindrical form,having within it a revolving agitator I). At one side of the vessel is formed 5 a pocket, having in front. of it a perforated plate D and having at its bottom a valve D which can be opened by a lever D", mounted on the cover. A tank E contains a strong solution of hypochlorite of magnesia, which may consist of equal parts of sulphate of magnesia and chloride of lime. This tank E communicates with the valveopening D and through a rotary pump E and pipe E with either of the vessels D. The pulp in the vessel I) is kept agitated for several hours by the revolution of the agitator D, while the hypoehlorite of magnesia is kept circulating through it by means of the pump E The bleached pulp is then run off by the pipe D Although I have described the bleaching in vessel D as being applied to the crude pulp delivered from the boiler A, pulps otherwise preparedsuch as those prepared by treat ment with soda, sulphate of soda, or sulphite of lim e-1nay be similarly bleached also,fi bers, fine chips, rags, and the like can be bleached, as described, before being made into pulp.

Having thus described the nature of my invention and the best means I know of carrying it out in practice, I claim- 1. The process of manufacturing bleached pulp by causing to circulate through the pulp material first lime-water, then a solution of sulphate of magnesia and chloride of lime, and afterward agitating the material thus treated while a solution of sulphate of mag nesia and chloride of lime is caused to circulate through it, substantially as described.

2. The process of manufacturing partiallybleached pulp by causing to eireulatethrough the pulp material first limevater, and then a solution of sulphate of magnesia and chloride of lime, substantially as described.

The process of bleaching pulp or pulp material by agitating it while a solution of sulphate of magnesia and chloride of lime is caused to circulate through the material, substantially as described.

In testimony whereof I have signed my name to this specification, in the presence of two subscribing witnesses, this 20th day of March, A. D. 1889.

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