US1634388A - Plant for bleaching and like purposes - Google Patents

Description

.July 1927 c. B. THORNE PLANT FOR BLEACHING A D LIKE PURPOSES Sheets-Sheet 1 Filed Dec. 15, 1924 Union" u u IN vnwr x Jr-rarne v will July 1927 c. B. THORNE PLANT FOR- BLEACHING AND LIKE PURPOSES Filed Dec. 13. 1924 ZS hfis-Sheet 2 IllllllIl-l Fbtented July 5, 1927. I

UNITED STATES,

OABL BUSGH THORNE, OF HAWKESBUBY, ONTARIO, CANADA.

PLANT FOR IBLEACHING AND LIKE PURPOSES.

Application filed December 13, 1924. Serial No. 755,691.

The invention relates to a plant for bleachmg and like purposes as descr1bed n the present specification and illustrated in the accompanying drawings that form part of the same.

The invention consists essentlally of the novel features of construction pointed out broadly and specifically in the claims for novelty following a description containing an explanation in detail of an acceptable form of the invention.

The objects of the invention are to produce a superior quality of pulp such as 1s required for the many purposes to Wl11Cl1 that product is at present applied 1n the manufacture of paper, silk, and various articles of commerce; to evenly distribute the bleaching liquor throughout the mass of pulp and at the same time save the fibre from deleterious influences of accumulations liable to destroy .its physical properties; to effect the operation of bleaching in a simple manner and thereby increase the efficiency of a mill; to facilitate the manufacture of'the numerous productions made from pulp; to insure uniformity in the color of the bleaching; and generally to provide a bleaching applicable in many directions in which the mass will be properly penetrated and the bleaching perfectly distributed. In the drawings Figure 1 is a diagrammatic view showing the preferable means employed.

Figure 2 is a diagrammatic View showing a modification of the means employed.

Figure 3 is a detail of the aerating tank in the means illustrated in Figure 1.

Figure 4 is a detail of the means illustrated in Figure 2 showing the aerating tank.

Like numerals of reference indicate corresponding parts in the various figures.

Referring to the drawings, the mixer 5 is preferably formed of a casing circular in cross section and having an inlet 6 at the small end leading through the top thereof and outlet 7 at the larger end leading through the bottom thereof and adjacent to the inlet the hot water inlet 8 and bleaching liquor inlet 9.

The shaft 10 is journalled in suitable bearings in the heads of mixer 5 and carries a pulley 11, which is connected to the power installation adapted to run the plant.

The paddles or stir-about sticks 12 proough penetration and distribution of the bleaching liquor Without, destroying its physical properties which is liable to happen under some conditions of handling, especially if the pulp is of a dense nature for then stirring is about the only way of mixing without injuring the fibrous nature of the substance.

The bleaching liquor head box 13 is situated at an elevation in relation to the mixers 5 and is formed with the inlet 14 and outlet 15 and the overflow outlet 16, the inlet 14 being adjacent to the lower end and connected to the supply by the piping 17, the overflow outlet 16 emptying through. the piping 18 and the outlet 15 being connected by the piping 19 to the measuring box 20 and having the control valve 21 in said piping 19.

The measuring box 20 is a well known device and is formed in the interior to empty the liquid at a predetermined level into the piping 22, which leads to the bleaching liquor inlet 9 to the mixer 5, thereby furnishing the bleaching liquor to the pulp just asit reaches the mixer-s.

The hot water head box 23 is connected to a hot water supply by the piping 24 leading to inlet at the upper end the overflow outlet and piping 25 being adjacent and through the side wall.

At the opposite end the piping 26 joins the head box 23 to a measuring box 27, which is joined to the hot water inlet 8 of the mixer 5 by the piping 28, thereby furnishing heat and water to accompany the bleaching liquor to the pulp after it reaches the mixer.

The chute 29 leads from the mixer outlet 7 to the tank, tower or vat 30 which has the inlet 31 through the upper and smaller end 32 and the outlet 33 through the lower or larger hopper bottom 34, from which the chute 35 leads to the combined washer and thickener 36. The outlet 38 of the washer tank 46 having a chute therefrom .eventuall leading to the washer stock chest,

The vertical shaft 47 extendsupwardly and centrally through thetanks 46, 42 and 30 and is journalled in suitable bearings and at its lower end driven through the gears 49 and 50 rotated by the shaft 38 connected to a suitable motor. This. shaft 47 is hollow and inside eachtank has one or more outlets for air, gasor other fluid and ,at its upper end is connected to the stat onary pipe 51 through the coupling 52, th s stationary pipe .51 leading from a tank 53 here shown as fed from an air compressor 54, though naturally other gaseousfiuids in liquids may be fed to the tank 53 according to the articular process to be carried out, but to give a clearer understanding of the inventionthis description is more particularly confined to the use of air in bleaching pulp.

The interior of the tanks 30, 42 and 46 arethe same, so the description will cover the three or more where used, besides one may be sufficient for some purposes.

The nozzle 55 extends from the sleeve 56 fixedly mounted on the shaft 47 and is formed with perforations 57 and preferably curved.

This nozzle 55 turnswith the shaft and passes throufgh the dense pulp and the compressed. air ows swiftly through the perforations into the pulp mass and percolates therethrough driving out the accumulations of decomposition gases. I The nozzle 55 is situated intermediate of the height of the shaft 47 within a tank prefpulp has the shaft 47 and projects in the opposite di-' rection to the nozzle 55, and is intended to scrape the hopper bottom 34 and keep the pulp moving to the central outlet 35 and 33.

In Figures 2 and 4 another form of tank is shown and this tank 62 may be square orrectangular shape in cross section and re- ..ceives the pulp through the inlet 63 at the upper end and discharges through the chute 64 at the-lower end. The air supply pipe 65 is connected to the horizontal air pipe 66 atthe upper end and the, nozzle pipes 67 extend downwardly into the tank 62 and have the perforations 68 through which the compressed air flows into of the shafts 72 which rotate freely in their bearings.

The provision of a primary mixer, bleaching liquor supply, hot Water feed and washer and thickener is the same as for the rotatable aerator.

In the operation of this plant the bleaching liquor and hot water are fed separately and coincidently into the mixerwhich stirs the dense mass of pulp fed thereinto, so that the pulp and the bleaching liquor get a primary mixing aided by the heated water, which acts not only as a vehicle in promoting the flow of the bleach but brings the temperature up to a proper degree for efficiency in the treatment.

The treated pulp progresses to the larger end of the mixer and passes out through the chute to the aerating tank which fills up and is kept levelled by the upper rotating arm. Intermediately the nozzle rotates through the mass and delivers air under pressure,

thereby making the pulp porous allowing a perfect distribution of the air the same driving out the decomposition gases.

It will be thus seen that facilities are provided for the thorough distribution of the bleach in the mass and for the expulsion of impurities tending to promote decomposi-' tion.

The aerated npulp is disturbed at the bottom ofthe ta by the scraper, which aids the discharge through the central outlet into the chute, and from this chute it enters a.

combined washer-Hand thickener and if finished passes on to the stock chest, but in most plants it will pass into another washer and thickener, then to another mixing tank, continuing this in as many stages as may be found necessary. The bleaching liquor and hot water are fed through feed pipes to each one of the mixers receiving the pulp from a washer and thickener as the operation is just the same at each stage and is repeated until the condition of the pulp is satisfactory.

In the rectangular tank the operation only differs in regard to the feed of air and the grate means for facilitating the discharge.

The apparatus described is mostly for use in the pulp industry though it may-be used in other arts, no doubt with advantage and economy to the user. Further it is of considerable importance to the pulp indust in regard to refining methods especially w ere it is desirable to introduce other'chemicals. It is not possible to detail all the ossible uses and it is sufiicient to say that t e-mere through said upper end and through said shaft.

fact that one use is described herein will in no way confine the invention to any particular purpose.

What I claim is 1. In a bleaching plant, a plurality of vertical casings having inlet and discharge passages through the upper and lower ends re spectively, said casings being indirectly connected with one another and means for feeding material to the upper casing continually during the operation at a rate consistent with the constant discharge of the lowermost casing.

2. In a plant for bleaching pur uses, a tower having contracted passages or inlet and discharge through the respective ends and having a chute inlet and achute outlet formed to regulate the speed of the passing material within the tower, and a scavenging member within the tower connected to a compressed fluid supply.

3. In a bleaching apparatus, a bleaching tower having a permanent inlet at the upper end and having a contracted discharge opening at the lower end and a hollow shaft forming an air chamber and extendin said discharge opening and suitably driven.

4. In a bleaching apparatus, a bleaching tower having inlet and discharge passages through the respective ends, a hollow shaft suitably driven and extending through said ends and having a jet communicating with the interior and rotated within the tower and adapted to be fed through said shaft with a fluid under pressure connected with 5. In a bleaching apparatus, a bleaching tower having inlet and discharge passages through the respective ends, bearlngs beyond said ends, a hollow shaft journaled in said bearings and having an outlet within the tower, a compressed air tank connected to said shaft, a hollow arm forming a nozzle and having a plurality of jets and a hub mounted fixedly on said shaft over said out-. let and means for driving said shaft.

6. In a bleaching apparatus, a bleaching tower having a chute inlet and hopper out let, a shaft centrally situated in said tower and journaled in bearings above and below, having an outlet intermediate of the height of the tower and forming an air passage, a crooked hollow arm having jet openings therealong and ahub encircling said shaft and fixedly secured thereto over said outlet, an air inlet connected to said shaft and "means for rotating the latter.

feed inlets for water and bleaching agent, and a rotating separator for reducing the bundles to exposed fibers for impregnation and fixing the density of the material constantly passing through.

8. In a plant for bleaching purposes, a chain of vertical towers indirectly connected and fed with material from the upper end and having feed inlets and discharge outlets adapted to cause in each tower slowly' of the towers and means for supplying fluid under pressure to the hollow shaft.

10. In a bleaching apparatus, a vessel having a hopper bottom centralizing a discharge opening and a chute from said discharge opening and a rotatable hollow air shaft connected to a compressed air supply and carrying a scraper arm rotatable around said hopper bottom, a nozzle arm having a plurality of jets communicating with the interior of said shaft and a levelling arm towards the up er end. i

11. In a bleac ing apparatus, a plurality of towers arranged one above the other and having free inlets through upper ends adapted to receive the falling material and converging lower discharge ends leading to chutes formin diverting channels, intermediate vessels introduced in the communications between the said towers, fixed bearings above and below the topmost and lowermost towers, a shaft journalled in said bearings and extending through all towers and forming an air'passage, means for feeding air to said shaft, means for delivering air from said shaft within the towers and means for driving said shaft.

12. In a bleaching apparatus, a plurality of towers in vertical alignment having lower open ends and diverting channels therefrom,

communicating vessels between said towers, a vertical shaft running centrally through each tower and being journalled above and below the towers and suitably driven and forming an air passage into said towers and levelling arms, air arms and scraper arms carried by said shafts in the towers.

Signed at Montreal, Canada, this 19th day of November 1924.

CARL BUSCH THORNE.

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