US1329824A - Apparatus for bleaching cellulose and like substances - Google Patents

Description

A. D. BERGLIND.

APPARATUS FOR BLEACHING CELLULOSE AND LIKE SUBSTANCES. APPucATxoN FILED NIM/3.1918.

l p .Patented Feb. 3,1920.

2 SHEETS-SHEET l.

A. D. BERGLIND. l APPARATUS FOR BLEACHING cELLuLosE AND LlKE suBsTANcEs.

APPLICATION FILED `MAYB. 1918.

1,329,824. Peeeneed Feb. 3,1920.

2 SHEETS-SHEET 2- ANDERS DAVID BERGLIND, F KLOSTERPOSSEN,VSKIEN, NRWAY.

APPARATUS FOR BLEACI-IING CELLULOSE AND LIKE, SUBSTANCES'.

. Specification of Letters Patent.

Patented Feb. s, 1920.

Application led May 3, 1918. Serial No. 232,423.

,To all whom t may concern:

Be it known that I, ANDERS IDAvi-D BERG- LIND, a subject of the King of Sweden, re-` siding at Klosterpossen, Skien, Norway,

have invented an Improvement in Apparatus for Bleaching Cellulose and like Substances, of which the following description, in connection with the )accompanying drawings, is a specification, like characters on the drawings representing like parts.

In the bleaching of cellulose and like substances with chlorin, the mass is generally treated in open vats, where the air has free access and in which steamvisemployed to produce the desired whiteness. rl`hat hereby much chlorin is wasted and the consumption of steam is great will easily bed understood.

It has been tried to perform the bleaching in closed vessels, but this method has not given the desired result, as at a certain point of the process air and water have to come into action in order to obtain the desired whiteness of the mass.

The present invention has for its objectl an apparatus for bleaching, washing and lairing of the mass in a most economical According to my' process'the treatment with chlorin `is carried out in a closed vessel, and then the mass is subjected to a repeated alternate washing and airing. The apparatus employed is illustrated on the appended drawing, where vFigure 1 represents the apparatus viewed from one end showing a cross section of the washing and airing devices, and Fig. 2 is a side view of the apparatus showing a longitudinal section of the said devices.

A is the ordinary rotating closed vessel in which the mass is treated with bleaching liquid, said vessel havin charging and dis- '(or both) of the vat is provided with a lin- .ing 2 of filtering stone through which the wash-wateris filtered, a chamber 3 being provided behind said lining for collecting said water. The chamber 3 has a drain 4 I with valve 5 for stopping the iow. By the arrangement of the filter stone lining 2 the waste of libers is obviated. In the vat 1 is a stirrer 6 on a shaft 6a, which extends outside the vat and has a cog'- wheel 6b for i power transmission. from a motor or otherwise. 7 is a pipe extending along the top of the vat and provided with perforations Jfor sprinkling water into the vat. In order to increase the action of the stirrer 6 the cross section of the bottom of the vat is semicircular corresponding to the circumference of the stirrer 6. The bottom of the vat is inclined towardy one end vwhere an outlet 8 isprovided. A slide 21 is provided for shutting o' said outlet. From the outlet 8 a pipe 9 leads to a centrifugal pump 10, and :tromthe latter a pipe 11 leads to the place where the product is to be used. The pipe 11 is provided with a cut-oli' valve 12 below which isvlocated a branch leading i to the airing device, the flow through which is controlled by the valve 13. i,

The airing device consists of a hoodshaped casing- 14, which is affixed to a base 14sl resting on the edge of the vat 1. The

18, said tube being at 19 connected to a fanblower 20.

The working of the apparatus is as follows:

The mass is treated in the cylinder A for i about live hours, and is ythen discharged into the vat 1. The stirrer v6 is now rotated and watery is introduced through pipe `7. During this treatment the outlet 8 is closed. After the lapse of a suitable time the valve 21 is opened, the pump 10 is started, the

Valve 12 is closed and the valve 13 is now opened. The mass is now drawn through pipe 9 to pump 10, and thence up through` the standpipe 11, passes into the branch 1,3, and thence into the casing `14, ,where it is distributed 'on the plate 16, and on dropping from the edge of the latter the mass is penetrated by currents of air from. the apertures 18 and drops then into the vat 1A, where it is subjected to a renewed washing operation.

This alternate washing and airing bf the mass is carried on until the mass after about two hours treatment is quite White and free from lye and gases. y

When thewashing and airing operations are finished, the valve 13 'is shut oil and the valve l2 is opened so that the mass may be forwarded to the-place Where it is to be used.l

What l claim as my invention is i 1; In apparatus for bleaching cellulose,

a bleaching vessel, a vat to receive bleached material, stirring means in the vat, means for sprinkling Water into the vat, a pump, a valved connection between the pump and the bottom of the vat, a discharge pipe leading from the pump, and arranged to discharge material .drawn from the vat by the pump back into the vat, and means to force air through said material as the same is discharged by the pump into the vat.

2. Apparatus for bleaching cellulose7 Lacasse comprising a vat, stirrin means in the vat, means to draiv material trom the bottom of the vat and to discharge the same at an elevated'point back into the vat, and means to force air through such material as the same is discharged back into the vat.

3. ln apparatus for bleaching cellulose, a vat, stirring means in the vat, a spreading plate arranged above the vat, means to withdraw material from the bottom of the vat and `to discharge the same onto said spreading plate so that such material falls from the spreading plate back into the vat, and means to force air through such material as the same falls back into the vat.

In testimony whereof I have. signed my name to this specification.

ANDERS DAVD BERGLIND. Witnesses v J. W. PEDERSEN, JOH. UsLER,

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