US51433A - Improved process for making - Google Patents

Description

UNITED STATES PATENT OFFICE.

JOHN W. DIXON, OF PHILADELPHIA, PENNSYLVANIA.

IMPROVED PROCESS FOR MAKINGPAPER-PULP.

Specification forming part of Letters Patent No. 51,433, dated December 12, 1865.

To all '1r-hom fit may concern:

Be it known that I, JOHN W. DIXON, ofthe city of Philadelphia, State of Pennsylvania, have invented a new and useful Process ot Making Paper-Pulp from Vood, Straw, and Vegetable Fibrous Materials 5 and I do hereby declare the following to be at'ull and exact description of the same.

My process consists in treating straw, wood, or other vegetable fibrous materials by highlyheated water in a liquid state under pressure forced by a pump to pass into and through the vegetable matter to be pulped, as a process or preparatory process for making paper-pulp; and also in forcing into the digester at i11- tervals fresh water, highly heated and under pressure, for the purpose ot' more elteetually acting upon and dissolving the glutinous and other matters contained in the vegetable matters usually used for making pulp, by means of a pump; and I now proceed to describe the same, reference being had to the annexed drawing, which represents, by way of illustratiou, one .convenient form of carrying on my process.

A represents the pnlp-digester, which is a boiler made ot' strong iron, (capable ot' resisting a pressure of from one hundred to three hundred pounds,) say four feet diameter and twelve feet high. Itis furnished with a luanhole cover, B, and a perforated diaphragm, O, a central removable cover, D, and a lower perforated diaphragm, E, with a sliding valve, as described fully in a former application for patent made by me.

F is a conical coil builtin a furnace, and connecting at its lower extremity with the lower part of the pulp-digester A by means ot' the tubes l, 2, and 3. At 4 a rotary pump is placed in the course of this tube. 'Ihe upper part ot' the coil F is connected by the tube 6 with the interior of the digester A at its top.

G is an iron or wooden tanksay four feet diameter and ten or twelve feet high-open or closed. The tube 7 passes from the lower part of the digester A through the walls of the tank G, and thence coils up and down a number of times in that tank, and passes out through the wall ofthe tank at S. The interior ofthe tank is connected by the tube et with the tube 2 and the pump.

The operation of this apparatus is as follows: rI he digester A is to be filled with the vegetable fibrous matter to be pulped through the mau-hole B. The cocks J and K are closed A iire is made aud the cocks L and M opened.

under the coil F vaud the digester and coil filled with fresh water. Fire is then applied under the coil F and maintained until the desired pressuresay from eighty pounds to two hundred and fifty or three hundred poundsis obtained, according to the nature ofthe substance to be acted upon. The pumpt is then started and made to circulate the highly-heated water from the bottom of the digester through the heating-coil F into the top. After this liquid has circulated some time the cock L is to be closed and the cock J is opened. Thus the liquid will pass through the coil of pipe 9, 10, 11, and 12 and escape at S. The tank is filled with fresh water, which is heated by the liquid passing through the coil. The cock K bein gopened, the water thus heated in the tank passes on through the tubes 5 and 2, the pump 4, and the coil F into the top of the digester A. By this means the water filled with gummy and other matters can be freely removed and its temperature imparted to a fresh supply ot water as it passes out. After the contents ofthe boiler A have been thus changed the cocks J and K are to be closed and the cock L opened, whereupon the circulation produced by the pump will be resumed. as at the first, from the bottom to the top, and so continued until the liquid becomes again surcharged with the gummy matter.

By this means the vegetable material can be pulped without mechanical aid in from five to twelve hours, depending on the material operated on and the pressure used.

Good results with this apparatus can be obtained with straw at one hundred and twentyfive pounds pressure, and perhaps less. With wood and other harder materials it would be preferable to use a higher te m perature-say one hundred and fifty to three hundred poundsalthough wood can be pulped to a considerable extentat 1250 Baume, and lower, by prolonging the time.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

The process of treating wood, straw, and similar vegetable substances by forcing highly-heated water under pressure to circulate continuously through the mass to be pulped by means ot` a pump, as a process or preparatory process for making paper-pulp, substantially as described.

Witnesses: JOHN W. DIXON.

M. G. HUBBARD, J. WM. KREPPS.

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