Abstract:
An improved flotation separation apparatus for separating and classifying diverse, liquid-suspended solids having a plurality of high volume air bubble infusers. Each infuser includes a circular cavity defined by an interior circumferential wall. A plurality of stationary impinging plates projecting from the interior circumferential wall into the circular cavity and equally spaced circumferentially in series therealong. An injecting stream of water and air impinges upon the impinging plates in series to repeatedly create, divide and subdivide air bubbles as the injection stream transverses the series of impinging plates.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to floatation separation apparatuses and, more particularly, to an improved flotation separation apparatus which includes a plurality of unique high volume air bubble infusers to create a high multiplicity of strong finely divided bubbles. 
     2. General Background 
     Today&#39;s coal and mineral producers like all industry is faces with rising costs accompanied by customer resistance to increases in price and competition from imported raw material. In order to maintain the competitive edge an operator must seek means in acquiring processing units which afford lower capital investment cost, lower power and maintenance requirements along with higher recovery of valued products. 
     An example of an existing separating and classifying flotation system is described in U.S. Pat. No. 4,212,730, to Brooks et al., entitled “APPARATUS FOR SEPARATING AND CLASSIFYING DIVERSE, LIQUID-SUSPENDED SOLIDS”, incorporated herein by reference as if set forth in full below. The Brooks patent discloses a floatation separation apparatus which includes air bubble infusers each of which are fed by air and water pipes. 
     SUMMARY OF THE PRESENT INVENTION 
     The preferred embodiment of the flotation separation apparatus of the present invention solves the aforementioned problems in a straight forward and simple manner. What is provided is an improved flotation separation apparatus which includes a plurality of unique high volume air bubble infusers to create a high multiplicity of strong, finely divided bubbles. Thereby, such multiplicity of strong, finely divided bubbles provides that means required for the transport of recoverable minerals in the flotation process. 
     Broadly, the unique high volume air bubble infuser of the present invention includes a circular cavity and a plurality of stationary impinging plates projecting from the interior circumferential wall into the circular cavity and equally spaced circumferentially in series therealong. Thereby, an injecting stream impinges upon the impinging plates in series to repeatedly create, divide and subdivide air bubbles as the injection stream transverses the series of impinging plates. 
     In general, the improved flotation separation apparatus for separating and classifying diverse, liquid-suspended solids comprises a first chamber and a second chamber stacked below said first chamber in fluid communication with said first chamber, the improvement comprising a first set of a plurality of high volume air bubble infusers spaced in said first chamber; and, a second set of a plurality of unique high volume air bubble infusers spaced in said second chamber. 
     Each unique high volume air bubble infuser comprises a structure having formed centrally in a top surface thereof a circular cavity defining an interior circumferential wall and centrally in a bottom surface parallel to said top surface a bubble-water discharge outlet coaxial with an axis of said circular cavity; a lid member secured to said top surface of said structure; a water inlet port formed in said circular cavity for injecting a water steam into said circular cavity offset from said axis and perpendicular to said axis; an air inlet port formed in said circular cavity for injecting an air stream into said water stream at an acute angle; and, a plurality of stationary impinging plates projecting from said interior circumferential wall into said circular cavity and spaced circumferentially in series therealong. 
     In view of the above, it is an object of the present invention to provide a unique high volume air bubble infuser which maximizes the creation of the transport means (strong air bubbles) required for the transport of recoverable minerals in the flotation process and thus increases the recovery efficiency at the lowest possible power consumption per ton. 
     Another object of the invention is to provide an injection stream which impinges in series upon the stationary impinging plates to create, divide and subdivide repeatedly in series air bubbles. 
     A further object of the present invention is to provide the infuser with a circular cavity which is a relatively narrow circular cavity for injecting therein at a relatively high rate an injection stream to create a sufficient impact force through the series of stationary impinging plates to maximize the rate of the creation of said air bubbles and the discharge thereof through the bubble-water discharge outlet. 
     It is a still further object of the present invention to provide ten (10) impinging plates equally spaced incrementally over substantially 270 degrees of said circular cavity. 
     In view of the above objects, it is a feature of the present invention to provide a unique high volume air bubble infuser which is relatively simple structurally and thus simple to manufacture. 
     The above objects and other features of the present invention will become apparent from the drawing, the description given herein, and the appended claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     For a further understanding of the nature and objects of the present invention, reference should be had to the following description taken in conjunction with the accompanying drawing in which like parts are given like reference numerals and, wherein: 
     FIG. 1 illustrates a front elevational cross-section of the improved flotation separation apparatus of the present invention; 
     FIG. 2 illustrates a side elevational cross-section of the improved flotation separation apparatus of the present invention; 
     FIG. 3 illustrates a perspective bottom view of the unique high volume air bubble infuser of the present invention; 
     FIG. 4 illustrates a top view of the structure of the infuser; and, 
     FIG. 5 illustrates a cross-sectional view along the PLANE  4 — 4  of FIG. 4 of the unique high volume air bubble infuser. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the drawing, and in particular FIGS. 1 and 2, the improved floatation separation apparatus of the present invention is designated generally by the numeral  10 . The improved floatation separation apparatus  10  is generally comprised of a first chamber  12 , a second chamber  18 , an air distribution system  11 , a water distribution system  13  and a plurality of unique high volume air bubble infusers  60 . 
     The first chamber  12  is defined by a side wall  14  and a bulkhead  16 . The side wall  14  is generally cylindrical in shape. Nevertheless, other shapes may be employed. The second chamber  18  is defined by a side wall  20  and a floor  22 , the side wall  20  likewise being generally cylindrical in shape and axial with the cylindrical side wall  14  of the first chamber  12 . First and second chambers  12  and  18  are disposed in a stacked relationship, communication between the first chamber  12  and the second chamber  18  being effected by a throat  24  extending though the bulkhead  16 . 
     Referring to the top of the first chamber  12  as shown in FIG. 1, the improved flotation separation apparatus  10  further includes an intake feed well  26  supported by struts  28  extending to the side wall  14 . The intake feed well  26  includes a bottom plate  30  having holes (not shown) through which a slurry to be treated can enter the first chamber  12 . The lower second chamber  18  further includes a feed well  27  under the throat  24  having a similar purpose for allowing feed of the slurry from the first chamber  12  into the lower second chamber  18 . 
     Referring still to the top of FIG. 1, the air distribution system  11  includes an air compressor  32  driven by a motor  34  and having an associated air filter  36  is provided. The air compressor  32  pumps air through a supply pipe  38  to additional air pipes  40  extending through the respective side walls  14  and  20  and across the respective chambers  12  and  18 . The ends of the air pipes  40  are capped, so as to pressure feed air to each unique high volume air bubble infuser  60  via a respective air tube  48 , as is described in greater detail below. 
     The water distribution system  13  includes water feed pipes  42  which are likewise disposed through the respective side walls  14  and  20  and across the respective chambers  12  and  18 . Water is fed through the water feed pipes  42 , which are capped at the end so as to effect a pressure feed of water via a respective water tube  50  into a respective one of the unique high volume air bubble infusers  60 . 
     Referring now to FIG. 2, the plurality of unique high volume air bubble infusers  60  includes a first set of unique high volume air bubble infusers in the first chamber  12  and a second set of unique high volume air bubble infusers in the second chamber  18 . Pairs of infusers of the first set of unique high volume air bubble infusers are rigidly coupled to opposite sides a respective water feed pipe  42  via support brackets  46 . Likewise, pairs of infusers of the first set of unique high volume air bubble infusers are rigidly coupled to opposite sides a respective water feed pipe  42  via support brackets  46 . As shown, each of the chambers  12  and  18  each include two water feed pipes  42  in side-by-side spaced relation. 
     As shown in FIG. 1 there are four pairs of unique high volume air bubble infusers spaced along each respective of the two water feed pipes  42  in each chamber. Thus there are sixteen (16) infusers in first chamber  12  and chamber  18 . 
     The unique high volume air bubble infuser  60  is described in greater detail below with reference to FIGS. 3-5. As described above, each unique high volume air bubble infuser  60  is coupled via the respective air and water tubes  48  and  50  to the air and water pipes  40  and  42 . 
     As shown at the bottom of FIG. 1, the improved flotation separation apparatus  10  further includes tailings outlet  52  extending through the side wall  20  of the lower second chamber  18 , and a concentrate outlet  53  near the top of the lower second chamber  18 . 
     Again noting FIG. 1, a “dart” or plug  54  is positioned in the port  24  and is movable to control the amount of slurry flow from the upper first chamber  12  to the lower second chamber  18 . The plug  54  is provided with a shaft  56  which is attached to a rocker arm  59  coupled at one end to a pivot  55  mounted on the side wall  14  of the upper first chamber  12 . The other end of the rocker arm  59  is coupled to a vertical arm  57  which is threaded at the top thereof. The threaded end of the vertical arm  57  extends through a bracket  53  and is threaded through a rotatable hub  58 . Rotation of the hub  58  moves the vertical arm  57  up and down, likewise causing corresponding movement of the rocker arm  59 , thereby moving the plug  54  into and out of the throat  24  in the desired manner. 
     Referring now to FIGS. 3-5, the unique high volume air bubble infuser  60  of the present invention includes a solid structure  61 , generally square shaped, having formed in the top surface  62   a  thereof circular infuser cavity  63  and a lid member  64 . The top surface  62   a  has formed therein a plurality of holes  73  near the outer perimeter of the structure  61 . The lid member  64  is secured to top surface  62   a  via a plurality of bolts  75  threadably received in holes  73 . 
     Referring specifically to FIG. 5, the lid member  64  is fitted to the square area of the structure  61  and further includes extension  64   a  which projects beyond side wall  62   f  of structure  61 . Thereby, the lid member  64  is generally rectangularly shaped. The top surface of extension  64   a  has rigidly coupled thereto supporting bracket  46  for coupling the unique high volume air bubble infuser  60  to a side of one of the water feed pipes  42 . 
     The unique high volume air bubble infuser  60  further includes bubble-water discharge outlet  65  formed in the bottom surface  62   b  of structure  61 , a water inlet port  67   a  and an air inlet port  67   b . Both the water inlet port  67   a  and the air inlet port  67   b  are generally cylindrical channels form in side surfaces  62   c  and  62   d , respectively, of structure  61 . 
     Bubble-water discharge outlet  65  formed in the bottom surface  62   b  of structure  61  allows the created high volume of finely divide strong air bubbles and water to be expelled therethrough. 
     The axis of the channel of defining the water inlet port  67   a  is essentially perpendicularly to side wall  62   c  and is offset from the axis of circular cavity  63  so as to inject a water stream near the interior circumferential wall  66  defining the circular profile of cavity  63 . The axis of the channel of the air inlet port  67   b  intersects the water stream at an acute angle in close proximity to the entry of the water stream into the circular cavity  63 . The acute angle of the injected air stream allows such air stream to be carried with the water stream around the interior circumferential wall  66  to create an injection stream. The water steam flows at a rate significantly faster than the air stream. The air stream is injected into said water stream at an angle less than 90 degrees. 
     Projecting from the interior circumferential wall  66  into circular cavity  63  are a plurality of stationary impinging plates  68  equally spaced incrementally around such interior circumferential wall  66 . Said injection stream forcefully impacts repeatedly in series the stationary impinging plates  68  as the injection stream flows around the interior circumferential wall  66 . The rate of injection of the water stream serves to maintain the water stream and thus the injection stream flowing around the interior circumferential wall  66  in the direction of ARROW  1 . 
     As the injection stream forcefully impacts the stationary impinging plates  68 , the injection stream is divided into strong air bubbles. Therefore, as the injection stream impinges (impacts) upon each individual station impinging plate  68  air bubbles are created and divided. Hence, as the injection stream impinges on the series of impinging plates  68 , the created air bubbles have been repeated divided and subdivided as the injection stream completes its rotation through the plurality of stationary impinging plates  68 . 
     In the exemplary embodiment, there are ten impinging plates equally spaced incrementally over substantially 270 degrees of said circular cavity. The discharge outlet  65  has a diameter of 1½ inches. The air inlet port  67   b  has a diameter of approximately ⅜ of an inch and said water inlet port  67   a  has a diameter of approximately ¾ of an inch. The structure  61  is 8 inches×8 inches×1½ inches and said circular cavity  63  is approximately 1 inch deep. 
     The method of operation of the improved floatation separation apparatus  10  includes the removing from the ground in bulk phosphate, coal, or other substances and mixing the phosphate, coal or other substances in a slurry with well-known emulsifiers and surfactants. The slurry is then fed through the intake feed well  26  into the first chamber  12 . Air is fed through the feed pipes  28  and into pipes  40  to infusers  60  through tubing  48 . Water is likewise fed through the pipes  42  into the infusers  44  via the tubes  50 . 
     Air enters in feed pipes  38  flows at approximately 4-5 psi and water enters pipes  42  at a minimum of 30 psi. 
     The air bubbles (transportation means) passing out the plurality of unique high volume air bubble infusers  60  bubbles upward through the first chamber  12  and carries the desired minerals upward into the top of the first chamber  12 , in accordance with the standard procedure in a flotation separation process. Likewise, the heavier material sink to the bottom of the first chamber  12  and against the bulkhead  16 . However, as noted above, tailings frequently include heavier masses of desired mineral being extracted. In accordance with the present invention, the plug  54  is controlled so as to allow the tailings from the first chamber  12  to pass with the slurry into the lower second chamber  18  through the feed well  27 . After the lower second chamber  18  has been filled with the slurry, bubbling of air from the plurality of infusers  60  in the lower second chamber  18  is continue. Thereby, additional amounts of the desired mineral are likewise removed from the slurry and are passed out of the concentrated output port  53 . The remaining tailings sink to the bottom of the lower second chamber  18  and are passed out of the tailing outlet  52 . 
     It will be understood by those skilled in the art that, prior to operation of the plug  54 , a standard scraping or similar removal process takes place at the top of the first chamber  12  to remove the quantities of floated mineral which have been bubbled to the top of the first chamber  12  may be fed together with the output of the concentrated outlet  53  for storage or further refining. 
     Because many varying and differing embodiments may be made within the scope of the inventive concept herein taught and because many modifications may be made in the embodiment herein detailed in accordance with the descriptive requirement of the law, it is to be understood that the details herein are to be interpreted as illustrative and not in a limiting sense.