IL30336A

IL30336A - Method and apparatus for agglomerating dusts and the like

Info

Publication number: IL30336A
Application number: IL30336A
Authority: IL
Original assignee: Stauffer Chemical Co
Priority date: 1967-07-12
Filing date: 1968-07-09
Publication date: 1971-05-26
Also published as: NL6809890A; FR1573610A; GB1236974A; BE718045A; DE1792014B2; CH492475A; IL30336A0; NL153443B; DE1792014A1

Description

30336/2 STAUFFER CHEMICAL COMPAN .28604 - 2 - 30336 3 According to the present invention there is provide apparatus for agglomerating dusts or the like comprising a drum having an inlet and an outlet, conveyor means disposed within he drum and responsive to rotative movement to move particulate material through the drum from adjacent said inlet toward said outlet, firs means for imparting rotative movement to said conveyor means, and second means disposed within the drum radially inwardly of the radially inner margi of said conveyor means and rotatable when said conveyor mea is rotated to move through a radially interniediate region o said partioulate ma erial so as to lift malt©Hal withi said region and to cause a portion of said particulate material to cascade downwardly onto the remainder of. said particulate material in the form of one or more curtains.

Known apparatus for the purpose specified is distinguished from the apparatus in accordance with the Invention is that the former are not provided with the second means provided in accordance with the present invention. iin':3_eu Cif thwe jaeans, prior art apparatus have been used in various configurations and types, lifter elements directly attached to the inside drum surface. These extend substantiall longitudinally on the inside surface of the drum. These lifter elements funotion differently than these novel means of the apparatus in accordance with the invention in that they move through a radially outer region of the particulate material to be agglomerated and although they lift the material within this outer region/ however, they cause it to cascade downwardly onto the particulate material in the form of intermittent curtains of the material. Agglomeration from prior art apparatus is inferior to that which can be obtained with ■-■■■>. Preferably means can be provided for screening ou fines adjacent the output end of the drum and for , returning them lengthwise pf the drum into the. input end of the drum.

Referring to the drawings, with particular initial reference to Fig. 1, the apparatus may generally comprise a frame 10 having an angularly adjustable bed 12, two-way acting power means 14 to selectively position bed 12 at any desired angle relative to the horizontal, a cylindrical drum 16, means 18 and 20 to rotatably support the drum on bed 12, and variable speed drive means 22, 24 and 26 to rotate the drum.

Drum 16 comprises: an outer cylindrical shell or wall 28; an inner cylindrical shell or wall 30; an annular end plate 32 defining an input opening 34 for the base particulate material 36; an annular end plate 38 defining an output opening 40 disposed in feed relation to a receiver 42 for the agglomerate material 44; a spiral conveyor vane 46 to move the material 36 through the drum; a cylindrical screen 48 of a mesh size to pass fines 49 (Fig. 2) to the annular chamber 50 between shells 28 and 30; a spiral conveyor vane 52 in chamber 50 to return the fines to the input end of the drum; ports 54 at the input end of inner shell 30 to permit the fines to re-feed into the inner shell for re-passage therethrough; a surfactant feed line 56 provided with a plurality of spaced spray nozzles 58 (Fig. 2); and a cylindrical bundle of parallel spaced cylindrical rods 60 carried by end rings 62 positioned against drum end plates 32 and 38.

It will be appreciated that, except for feed line 56, all of the above-described components of drum 16 rotate together as an integrated construction. " With reference to Fig. 2, the drum is shown as rotating in a counter-clockwise direction, the material 36 therefore tending to assume an overall sloped configuration, being piled up toward the right in Fig. 2. The lower strata of material 36 moves in a counter-clockwise direction under the influences of vane 46 and" a drag effect imparted by shell 30. The upper strata of material 36 moves in a clockwise direction under the influence of gravity acting on the sloping pile. Between these oppositely moving upper and lower strata the central strata or region of the material 36 tends to be stationary or dormant between the counter-moving upper and lower strata.

One of the functions served by the rods 60 is to move through the dormant region and impart movement to the material within this region, thereby causing this normally dormant material to be moved upwardly and to thereafter become mixed with the normally moving upper and lox«?er strata material. Thus, the rods 60 act as a mixing and homogenizing means. Because of this function of the rods 60, none of the particulate base or feed material may remain covered over and dormant, and therefore none of the base material passes through the drum without adequate exposure to the surfactant, whether the latter be spray-applied, as in Figs. 2-5, or whether it be injection-applied, as' in Fig. 6, hereinafter described.

Further important functions served by the rods 60 are as follows: ' they lift or convey the base material upwardly along the wall of the drum (Figs. 2 and 3) to a greater extent than would occur in their absence; and they permit the material to cascade over and around them, i.e. through the spaces between adjacent rods (Figs. 2 and 3), thereby causing the formation of a plurality of vertically disposed and horizontally spaced curtains, into which the surfactant is sprayed (Figs. 2-5).

As indicated in Figs. 2 and 3, the spray heads or nozzles 58 emit the surfactant, normally and typically a sticky liquid, in a vertically harrow and horizontally broad spray pattern. There are a plurality of curtains of falling material between the nozzles and the particular rod or rods disposed in the path of movement of the surfactant spray.

An important consequence of this is neither the rods, nor any of the other components of the drum, become wetted or contacted by the surfactant. Thus, no gumming up of the equipment occurs, and need for equipment stoppages for clean-outs is eliminated. It is of importance, relatively to the protection of the rods against, wetting by the surfactant, that the surfactant liquid not be atomized by the spray head system. Hence, conventional spray heads are selected to provide a flat,, fan-shaped, droplet spray pattern.

A further important consequence of spraying the surfacta into one or more active, moving curtains of particulate material is that the end product agglomerate is obtained with a minimum of lumps .

Typical dimensional, operational and other data concerning the apparatus are as follows: a sixty inch diameter drum is a practical size; the rods 60 may be formed of metal and be relatively stiff, or they can be resilient, e.g. formed of a flexible rubber; for a sixty inch diameter drum and spray application of surfactant, the rods 60 can, for example, be three-quarter inch in diameter, and adjacent rods can, for example, be located on two and a half inch centers; the surface speed of the drum can be, for example, from about fifteen to about sixty feet per minute; concentric rows of rods 60 can be employed, as shown in Fig. 5; in lieu of the rods 60, the dormant material can be moved and the falling curtains formed by a cylindrical plate member 62 (Fig. 4), on the order of about one-fourth inch in thickness, having closely spaced staggered ranks and rows of cylindrical holes 64 through which the material falls for spray application; the surfactant may be injected directly into the normally dormant region, as by the feed tube 56 and injection tubes 66 shown in Fig. 6, so that the mixing of surfactant- and particulate material takes place by way of panning action; in the panning action operation of the unit of Fig. 6 adjacent rods 60 may be located on eight inch centers; and dust can be sprayed on sticky particulate matter to form, for example, prills.

As an example of results obtained from use of the herein described apparatus, a detergent dust of about 200 mesh was converted into a detergent agglomerate by following the formulation used in the production of the detergent identified as "Tide", a. trademark owned by Proctor and Gamble. The end product had the following screen analysis: ,% on 9 mesh : 0,6 7c on 12 mesh: 1.0 % on 30 mesh: 61.2 on 60 mesh: 24.0 7o through 60 mesh: WHAT IS CLAIMED IS:

Claims

1. insufficientOCRQuality