Abstract:
A portable mixing/delivery apparatus mixes dry pre-blended materials, such as homogeneous cementitious combinations of dry sand, cement, Lime, color pigments, etc., packaged in large bulk bags for use at a remote construction site. The bulk bag is lifted by a removable rack having plural lift eyes and the combination is positioned over a height adjustable frame. The granular material is then discharged into a continuous mixer having a dynamic input mixing stage, an output dry-to-wet mixing stage, and a transition stage therebetween. The entire assembly (bulk bag, frame and continuous mixer) is portable and can be lifted such as by a forklift to the height of a masonry scaffold for dispensing the mixed, wet granular material directly to the point of use. The apparatus allows the continuous mixer and its discharge tube to rotate to facilitate dispensing of the material directly to the point of use.

Description:
FIELD OF THE INVENTION 
     This invention relates generally to apparatus for mixing and dispensing granular materials and is particularly directed to portable apparatus for mixing, wetting and discharging pre-blended granular materials, such as cementitious-type materials, at a remote construction site. 
     BACKGROUND OF THE INVENTION 
     The products to which this invention applies can vary from concrete mixes, including bricklaying mortars and grouts. The traditional method of producing mortar or grout at a masonry job site is to count shovelfuls from a pile of sand, add mortar/cement by breaking open a 90 lb. paper bag, followed by adding water with a pail to a batch mixer. This method is still used on 80% of masonry construction jobs. Basic drawbacks of this approach are that it is labor-intensive and that the mix composition varies depending on type or condition of the sand, which when damp can increase the mixture volume by as much as 30%. Since sand is the predominant ingredient, variation in the mixture composition is inherent in the method of counting shovelfuls and cannot be precisely controlled. Mortar bond-strength, compressive strength, color and other factors of the mortar also vary. This can cause many serious problems that sometimes lead to removal of defective material, which, of course, is usually very costly. 
     Another method of producing mortar that addresses some of the aforementioned problems is to dry sand at a remote location and pre-blend the components, i.e., sand, mortar cement, lime and even color additives, and package the blend in bulk bags (2000 to 4000 lb.) and deliver the bags to a job site. In one approach, the bulk bags are individually placed in a silo that contains up to six bags of material. The contents of the silo is then dispensed into a batch-type mixer wherein water is added. This approach can be used to produce both grout and mortar, but requires at least two silos and two batch mixers (one for each type of material). The silo is portable only when empty to facilitate set-up delivery to a job-site. At the job site, it is set up as a fixed mixing operation remotely located from where the masonry brick laying operation is taking place. The mixing cycle is also labor intensive, requiring two workers, a forklift operator and a laborer to supply the masonry laying crew with mortar or grout. 
     This silo mixing operation begins with the forklift operator exchanging a full tub with an empty tub which the mixed contents are later emptied into. A laborer using a bucket pours half of the needed water into the empty batch mixer and opens a slide gate, where by gravity alone dry pre-blended mortar empties into the batch mixer below. The quantity of dry material cannot be accurately measured because opening and closing of the slide gate doesn&#39;t always cause the material to flow. The material bridges and does not flow easily. The laborer then uses a shovel to bang on the steel silo with the slide gate open which often results in the discharge of too much material. When this happens the equipment (mixer) is strained, can break down and material is wasted. This labor intensive mixing cycle continues with more water added as needed. Specifications require a minimum of five minutes mixing time. If the mix is too wet, more dry materials must be added resulting in opening and closing of the slide gate. 
     Another problem with this approach is in the variation in size between the various grades of sand and cement particles which promotes segregation because the material is handled and dispensed numerous times. One reason for this is that as the material flows into a silo, the material beneath the inlet of the silo piles up at the so-called “angle of response” of the material. In this case, the larger particles often roll down the peak towards the sides of the silo, leaving the finer particles in the central region. Inhomogeneity can also occur when the silo is filled and the material is drawn off through an outlet at the bottom of the silo or bulk bag. The material flows from the region directly above the opening and thus is not representative of the material in the originally packed bulk bag. To avoid this problem, the pre-blended suppliers use too fine a sand that meets only the minimum sand grading specifications as described in ASTM C144 “ Specifications for Aggregates for Masonry Mortar ”. A better product has a larger variation in sand gradation. 
     In addition to the problem of inconsistent mixture composition control, the silo approach also suffers from an unhealthy work environment because of the very dry sand falling on the laborer. Opening and closing of the overhead slide gate showers the laborer with very dry cementitious blended materials. The laborer ingests these sand and cement particles in the air he breathes which can cause silicosis and possibly cancer. This batch mixing operation cannot be made dust proof. The laborer&#39;s clothes are covered with dust which is brought home to possibly contaminate others. A batch mixer having a gasoline engine also endures further abuse by the intake of dust parties which can cause premature machine wear and necessitates more frequent replacement of air filters. 
     The mixing cycle continues and additional labor costs add up. The mixed contents are emptied into the mortar tub. The forklift operator now must stop other operations to exchange the full tub with an empty one, then carry the tub to the scaffold that may be hundreds of feet away from the mixing operation. This silo mixing operation is thus not portable, but rather is fixed in location. The 20,000 lb. weight of the forklift constantly traveling over dirt creates dust that slows the work. Another laborer at the top of the scaffold typically removes safety railings to allow the full tub to be placed on the scaffold. The forklift then moves over to pick up and lower an empty tub. The safety railings must then be reinstalled. The operation is not finished! The mortar must now be spread to the individual bricklayers by shoveling from the tub to the mortar boards so that the mortar is within easy reach of the individual bricklayers. 
     If the material is grout, labor costs to fill block is even a bigger factor because grout must be placed in buckets, then passed hand to hand, and poured into each individual block core by the bricklayers. This is wasteful because in addition to the time required to perform the needed operation, the bricklaying must stop in order to grout the block walls. In an attempt to address the high costs of this operation, a powered grout dispenser has been developed that must be filled at the mixing stage with all the accompanying labor intensive operations described for mixing mortar. This operation usually starts by elevating the batch mixer under the silo, charging the batch mixer with grout material, adding water and mixing for five minutes, then dumping the contents into the grout hopper. The wet mixture must then be transported to the work area where grout is dispensed from the holding hopper and directed to the block cores. The alternative to this is to fill the hopper with pre-mixed grout from a ready-mix cement truck, but this suffers from the problems of delivery truck availability and scheduling and additional costs. 
     Another type of mixing operation can be performed by a silo system using dry pre-blended material delivered to the job site by a bulk delivery truck that blows the material directly into the silo. The mixing can be performed by a continuous mixer installed under the silo. This approach is common in Europe and marketed as PFT, WAM. The mixed material is then typically pumped by a grout pump up to 200 ft. away where it is dispensed. The drawback in this approach is that additional equipment is required (pump and hoses), which must be cleaned and maintained. While this approach has been used in Europe for twenty years, it is not practical for masons in the United States who generally are capable of much higher levels of productivity and are less adapted for maintaining complicated machinery. 
     The various approaches discussed above each address specific problems encountered in the prior art, but also suffer from various limitations. There is currently no single mortar-blend delivery apparatus or method which combines the most advantageous features discussed above and allows for simple, efficient delivery of pre-mixed dry mortar-blended products. The present invention solves the problems and shortcomings of the prior art discussed above as described in the following paragraphs. 
     OBJECTS AND SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the present invention to provide improved apparatus for mixing and delivering pre-blended granular mixtures onsite where the granular mixtures are to be used. 
     It is another object of the present invention to reduce the costs of mixing and dispensing cementitious compositions such as used by bricklayers at construction job sites. 
     A further object of the present invention is to mix at a job site pre-blended cementitious-based granular mixture with water to form a viscous solid-liquid suspension for use in masonry work in building construction. 
     Still another object of the present invention is to provide portable apparatus for mixing and dispensing pre-blended cementitious granular mixtures such as mortar and grout which can be easily moved to and positioned at the site of use. 
     A still further object of the present invention is to provide an environmentally clean, cost saving mixing and delivery apparatus for pre-blended granular mixtures which affords precise control of the proportions of the granular mixture components, requires fewer workers to operate, and is lightweight and compact to permit it to be easily positioned immediately adjacent to where the mixture is to be used. 
     The present invention contemplates a portable mixing/delivery apparatus for pre-blended granular mixtures which is user friendly, saves labor and delivers a quality mix. The inventive mixing/delivery apparatus takes the guess work out of the mixing process that heretofore allowed too much variation in mortar consistency. The inventive mixing/delivery apparatus is dust-proof, can be turned on or off as needed, and is adjustable in height for supporting a bulk bag of pre-blended materials. The bulk bag can be placed on top of the apparatus&#39; steel framework by a forklift using a removable top frame and is safely held in place by the weight of the bulk bag. The discharge spout of the bulk bag empties into a receiving cylinder section that forms the intake of a hopper for receiving the dry pre-blended materials. The contents of the bag discharge into the dry end of a continuous mixer having a dynamic input mixing stage, an output dry-to-wet mixing stage, and a transition stage therebetween. An auger mixes the dry mortar that can segregate as it freely flows under gravity to the input stage and a horizontal metering screw moves the material forward in the continuous mixer. The metering screw extends into the tube-like transition stage. The entire assembly (bulk bag, support frame and continuous mixer) is portable and can be lifted to the desired height of a masonry scaffold by a forklift. Auxiliary hydraulic controls of the forklift with suitable hydraulic quick connects power the hydraulic motor of the continuous mixer. The inventive mixing/delivery apparatus allows the continuous mixer discharge tube end to rotate (90° either left or right) to facilitate material dispensing to either a mortar tub, or directly to mortar boards. Grout material can be poured directly into the hollow cores of cement blocks by extending the discharge tube with a flexible hose attached to the end of the tube. When the desired quantity is mixed, the apparatus is turned off, lowered and set on the ground, or moved where it can be reused at other work areas. The entire apparatus with optional gasoline, electric or hydraulic motor and controls can be set up on a heavy duty scaffold where it can be used as needed without lowering to the ground. A source of water is connected to the continuous mixer&#39;s mixing tube for forming a wetted mortar slurry. The auger and mixing tube combination is detachably connected to facilitate dismantling and clean up. A pair of closure plates are disposed adjacent to the aperture in the hopper for adjusting or shutting off the flow of mortar from the hopper to the transition tube. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The appended claims set forth those novel features which characterize the invention. However, the invention itself, as well as further objects and advantages thereof, will best be understood by reference to the following detailed description of a preferred embodiment taken in conjunction with the accompanying drawings, where like reference characters identify like elements through the various figures, in which: 
     FIG. 1 is an upper perspective view of a portable mixing/delivery apparatus in accordance with the principles of the present invention; 
     FIGS. 2 and 3 are side elevation views of another embodiment of a portable mixing/delivery apparatus in accordance with the present invention; 
     FIG. 4 is a vertical sectional view of one embodiment of a mixing apparatus for use in the portable mixing/delivery apparatus of the present invention; 
     FIG. 5 is a top plan view of the mixing apparatus shown in FIG. 4; 
     FIG. 6 is a sectional view of the mixing apparatus shown in FIG. 4 taken along site line  6 — 6  therein; 
     FIGS. 7 and 8 are upper perspective views of another embodiment of a portable mixing/delivery apparatus in accordance with the present invention showing the mixer in two different positions for facilitating dispensing of the mixed, wet granular material directly to the point of use at a work site; 
     FIGS. 9 and 10 are side elevation views of another embodiment of a portable/mixing delivery apparatus in accordance with the principles of the present invention which includes the hopper for storing the dry pre-blended materials prior to mixing, wetting and dispensing to the point of use; 
     FIG. 11 is an upper perspective view of a removable top frame for use in supporting a bulk bag containing dry pre-blended materials for use in the portable mixing/delivery apparatus of the present invention; 
     FIG. 12 is a top plan view of the top frame structure shown in FIG. 11; and 
     FIG. 13 is a side elevation view of the top frame structure shown in FIGS. 11 and 12 illustrating the manner in which a bulk bag is attached and supported by the top frame as well as the manner in which the top frame is positioned on a support frame of the portable mixing/delivery apparatus of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to FIG. 1, there is shown an upper perspective view of a portable mixing/delivery apparatus  10  in accordance with one embodiment of the present invention. The portable mixing/delivery apparatus  10  includes a generally upright support frame  11  comprised of lower frame members  12 , intermediate frame members  14 , and upper frame members  16 . Each of the lower, intermediate and upper frame members  12 ,  14  and  16  is generally square, or rectangular, in shape and includes four elongated, generally linear tubes preferably comprised of a high-strength steel. The lower, intermediate and upper frame members  12 ,  14  and  16  are connected by means of the combination of first through fourth vertical frame members  20   a - 20   d  and fifth through eighth vertical frame members  22   a - 22   d . Each of the first through fourth vertical frame members  20   a - 20   d  is connected in a telescoping manner to a respective one of the fifth through eighth vertical frame members  22   a - 22   d . Each of the first through fourth vertical frame members  20   a - 20   d  is also provided with plural spaced, aligned apertures  26   a  along its length. Similarly, each of the fifth through eighth vertical frame members  22   a - 22   d  is provided with plural spaced, aligned apertures  24  along its length. The height of the support frame  11  may be adjusted by sliding the first through fourth vertical frame members  20   a - 20   d  up or down along a corresponding one of the fifth through eighth vertical frame members  22   a - 22   d . Locking pins are inserted through aligned apertures in each pair of vertical frame members connected in a telescoping manner for maintaining the connected vertical frame members at a fixed length. Thus, locking pin  28   a  is inserted through aligned apertures in the first and fifth vertical frame members  20   a ,  22   a  for maintaining these frame members in fixed position relative to one another. Similarly, locking pin  28   b  is inserted through aligned apertures in the second and sixth vertical frame members  20   b ,  22   b , while locking pin  28   c  is inserted through aligned apertures in the third and seventh vertical frame members  20   c ,  22   c . It is in this manner that the height of the support frame  11  may be adjusted as desired to accommodate a range of sizes of a bulk bag attached to the support frame  11  which is not shown in FIG. 1, but which is described in detail below. The bulk bag contains dry pre-blended granular material which is converted to and dispensed as a mixed, wet granular material by the present invention. 
     Attached to the lower frame members  12  by conventional coupling means such as weldment or bolts (not shown for simplicity) are first and second base beams  18   a  and  18   b . Each of the base beams  18   a ,  18   b  is tube-like in structure and is adapted to receive a respective fork  27   a  and  27   b  (shown in dotted line form) of a forklift. By means of the forklift, the portable mixing/delivery apparatus  10  may be easily lifted to an elevated location, such as a scaffold or other elevated support structure, adjacent to where the mixed, wet granular material produced by the portable mixing/delivery apparatus  10  is to be used. 
     Disposed on and supported by the intermediate frame members  14  of the support frame  11  is a mixer  30  for mixing dry pre-blended materials for producing and dispensing the mixed, wet granular material directly to the point of use, i.e., a mortar board, tub block core, etc. Mixer  30  includes an intake tube  29  disposed above and connected to a hopper  34 . Dry pre-blended materials are deposited in hopper  34  via the intake tube  29  and are mixed by the mixer  30  and discharged from the hopper into a mixing tube  36 . Water is added to the dry mixture in the mixing tube  36  via a water fitting  35 . The mixed, wet granular material is discharged from the distal end of the mixing tube  36  into a flexible discharge tube  38  for discharge at the point of use. Mixer  30  is attached to a rotation ring  32 , which, in turn, is positioned upon and supported by the intermediate frame members  14 . Rotation ring  32  allows the mixer  30  to be rotated within the support frame  11  to facilitate discharge of the mixed, wet granular material at the point of use as described in greater detail below. 
     Referring to FIGS. 2 and 3, there are shown side elevation views of another embodiment of a portable mixing/delivery apparatus  40  in accordance with the present invention. As in the previously described embodiment, the portable mixing/delivery apparatus  40  includes a generally vertical support frame  42 . Attached to a lower portion of the support frame  42  is a lower pair of forklift tubes  44   a  and  44   b . Attached to an upper portion of the support frame are an upper pair of forklift tubes  46   a  and  46   b . Each of the aforementioned forklift tubes is adapted to receive and engage a fork of a forklift to allow the portable mixing/delivery apparatus  40  to be lifted to an elevated position to facilitate discharge of the mixed, wet granular material at a point of use. As in the previously described embodiment, disposed within and attached to the support frame  42  is a mixing apparatus  48 . Mixing apparatus  48  includes on an upper portion thereof an intake tube  59  which is attached to the discharge spout  52   a  of a bulk bag  52  by means of coupler ring  51 . The bulk bag  52  contains dry pre-blended granular materials. A slide gate  50  disposed at the interface of the intake tube  59  and an upper portion of a dry material hopper  62  of the mixing apparatus  48  allows for controlling the flow of dry granular material from the bulk bag  52  into the hopper. The bulk bag  52  is supported by and suspended from an upper portion of the support frame  42  as described below. Support frame  42  is comprised of various elongated, generally linear structural members, as in the previously described embodiment, including four vertical support members with one each corner of the support frame. Three of these vertical support members are shown as elements  54   a ,  54   b  and  54   c , with the fourth vertical support member not shown in the figures for simplicity. The mixing apparatus  48  includes an elongated, generally V-shaped hopper  62  to which is attached a motor  64  for mixing the dry pre-blended materials deposited in the hopper. Motor  64  may be electrical, gas driven, hydraulic or other type of drive mechanism for mixing and displacing the dry pre-blended granular materials deposited in the hopper  62 . In the example shown in FIGS. 2 and 3, first and second hydraulic lines  66   a  and  66   b  are connected to a hydraulic motor  64  for rotationally displacing the motor and mixing the dry pre-blended materials within the hopper  62 . An auger/agitator arrangement within the hopper  62  rotationally driven by the hydraulic motor  64  displaces the dry pre-blended materials out of the hopper into a mixing tube  68  where the material is further mixed, wetted and then discharged into a flexible discharge tube  70 . The distal end of the flexible discharge tube  70  is preferably positioned at the point of use of the discharged material. 
     Disposed in a lower portion of the support frame  42  is a water tank  56  including a water pump  58  therein. The water pump  58  is connected to the mixing tube  68  of the mixing apparatus  48  by means of a water line  60 . By means of pump  58  and water line  60 , water is injected into the dry pre-blended material displaced from the hopper  62  toward the distal end of the mixing tube  68 . The dry pre-blended materials are converted with the addition of water to a mixed, wet granular material which is discharged from the distal end of the flexible discharge tube  70  for use at the work site. 
     Referring to FIGS. 4 and 5, there are respectively shown lateral sectional and top plan views of one embodiment of a continuous mixing apparatus  80  for use in the portable mixing/delivery apparatus of the present invention. A sectional view of the mixing apparatus  80  illustrated in FIG.  4  and taken along site line  6 — 6  therein is shown in FIG.  6 . It should be noted that while a specific mixing apparatus  80  is shown in FIGS. 4-6 for use in the present invention, various mixing apparatus arrangements which provide for the continuous mixing of dry pre-blended granular materials, the wetting of these materials, and the formation and discharge of mixed, wet granular material could be used equally as well in the present invention. Therefore, the description of the mixing apparatus  80  set forth herein is not to be taken as a limitation of the present invention, but rather merely as a description of one embodiment of a mixing apparatus which could be used in the present invention. The mixing apparatus  80  disclosed herein is the subject of U.S. Pat. No. 6,123,445, entitled “Dual Stage Continuous Mixing Apparatus”, which issued on Sep. 26, 2000, in the name of the present applicant. 
     Mixing apparatus  80  includes a dry material hopper  82  open at the top, which preferably includes a cylindrical intake tube for the deposit of granular materials in the hopper. The intake tube, which is described in the embodiments shown in FIGS. 1-3, is not shown in FIGS. 4-6 and is not described in terms of the embodiment shown in these latter figures for the sake of simplicity. Disposed within dry material hopper  82  is a metering screw  92  including a linear, elongated shaft  92   a . One end of the shaft  92   a  is connected to a hydraulic motor  84  to which hydraulic fluid under pressure is provided via first and second hydraulic lines  86   a  and  86   b . Also attached to the metering screw&#39;s shaft  92   a  is an inner helical agitator  94 . The combination of metering screw  92  and inner helical agitator  94  mix the dry pre-blended materials deposited within the dry material hopper  82  and displace the thus mixed material leftward as viewed in FIGS. 4 and 5 toward a transition tube  90  attached to and extending from a lateral wall of the dry material hopper  82 . Metering screw  92  is aligned with and extends through the transition tube  90  through which the dry pre-blended materials are directed after they had been mixed within the dry material hopper  82 . Also attached to and disposed about the metering screw&#39;s shaft  92  is an outer agitator  96 . The function of the inner helical agitator  94  is to promote a right-to-left flow as viewed in FIGS. 4 and 5 of granular material within the dry material hopper  82  when the metering screw  92  is rotating. The inner helical agitator  94  has the same angular direction as metering screw  92 . The metering screw continually moves granular material in a right-to-left direction, such that there is a tendency for material in the dry material hopper  82  proximate to the exit opening leading to the hopper&#39;s transition tube  90  to be depleted to an undesirable extent. Granular material surrounding the metering screw has to flow into the space formed by the flutes of the screw in order for the screw to deliver a relatively constant quantity of material to the transition tube  90 . The inner helical agitator  94  produces a leftward flow of granular material toward the exit wall of the dry material hopper  82 . The inner helical agitator  94  also achieves an anti-cavitation effect, to maintain the metering screw  92  relatively full of dry, pre-blended material and effective for granule pumping purposes. 
     The function of the outer agitator  96  is to promote a left-to-right flow of material within the dry material hopper  82  especially when closure plates (not shown for simplicity) disposed adjacent the inlet of the transition tube  90  are in the closed position. The outer agitator  96  has a helix direction that is opposite to the angular direction of the helical flutes of the metering screw  92  and is also opposite to the direction of the inner helical agitator  94 . While the metering screw  92  and the inner helical agitator  94  tend to move the granular material in a right-to-left direction, the outer agitator  96  tends to move the granular material in a left-to-right direction within the dry material hopper  82 . Metering screw  92  extends into and through the transition tube  90 ′ attached to a lateral wall of the dry material hopper  82 . 
     The dry pre-blended granular material passes through the transition tube  90  into a water mixing tube  88 . Mixing tube  88  is provided with a water fitting  106  which is connected to a water hose  107 . Pressurized water flows from hose  107  into the mixing tube  88 , such that the water is mixed with the dry pre-blended granular material being transported through the mixing tube. Water flow control is provided by conventional volumetric flow control means, including an on-off valve, which is not shown in the figures for simplicity. Mixing tube  88  has a larger diameter than the transition tube  90  to promote a satisfactory mixing action. 
     A screw-type auger  98  is provided within the mixing tube  88  for mixing the water with the dry pre-blended granular material, and for transporting the mixture along the mixing tube  88  in a right-to-left direction. Auger  98  is shown as an elongated cylindrical rod formed into a coil configuration so that the outer surface of each coil convolution has a sliding fit on the inner surface of the mixing tube  88 , with the tube supporting the auger weight. Auger  98  is connected to and powered by the metering screw shaft  92   a . There is disposed within and along the length of the mixing tube  88  a baffle mechanism  104  comprised of an axial rod  100  and plural-spaced sets of baffle plates  102 . Axial rod  100  is connected to and rotates with the shaft  92   a  of the metering screw  92 . The baffle plates are spaced along the length of the axial rod, with the baffle plates arranged in pairs such that each baffle plate is acutely angled relative to the axial rod  100  at an angle of approximately 40°. Each baffle plate  102  has an inner edge extending through the axis of the axial rod  100  and an arcuate outer edge adapted to slidably rest on an inner edge surface of the auger  98  coil. Thus, the baffle mechanism is supported (partially) by auger  98 , and auger  98  is supported by mixing tube  88 . The baffle mechanism  104  is non-rotatable, whereas the auger  98  is rotatable via the combination of the rotating metering screw shaft  92   a  and axial rod  100 . 
     Referring to FIGS. 7 and 8, there are shown upper perspective views of another embodiment of a portable mixing/delivery apparatus  120  in accordance with the principles of the present invention. FIG. 8 shows the position of a mixer  130  after it has been rotationally displaced in the direction of arrow  142  from its position shown in FIG.  7 . As in the previously described embodiments, the portable mixing/delivery apparatus  120  includes a support frame  122  comprised of an upper frame  122   a  and a lower frame  122   b . The lower frame  122   b  includes a base  124  comprised of a flat bottom plate  125  and a pair of spaced forklift tubes mounted to opposed lateral edges of the bottom plate, where one of the forklift tubes is shown as element  127  in the figures. 
     The support frame  122  further includes a generally square, or rectangular, intermediate frame  128  which provides support for mixer  130 . As described above, mixer  130  may be conventional in design and operation and in the embodiment shown in FIGS. 7 and 8 includes an upper intake tube  132  for receiving dry pre-blended granular material for deposit in a hopper  136  of the mixer. Attached to and extending from the mixer&#39;s hopper  136  is a mixing tube  138  through which the pre-blended granular material is displaced and within which the material is mixed with water for discharge into a flexible discharge tube  140  attached to the distal end of the mixing tube. 
     In accordance with the embodiment of the invention shown in FIGS. 7 and 8, a rotation ring  134  is connected to the mixer&#39;s hopper  136  and positioned upon the generally linear, elongated structural members forming the intermediate frame  128 . Rotation ring  134  permits the mixer  130  to be angularly displaced about a vertical axis A-A′ (shown in dotted line form) aligned generally with the support frame  122  and passing through the mixer&#39;s intake tube  132  and hopper  136 . Lower frame  122   b  includes first and second angled support struts  126   a  and  126   b  disposed between and connected to the intermediate frame  128  and base  124 . The first and second angled support struts  126   a  and  126   b  are configured and positioned so as to permit the mixer  130  to be rotated over an angular displacement of approximately 180° about the aforementioned vertical axis A-A′ as shown by direction arrow  142  in FIG.  7 . This arrangement substantially increases the flexibility of the portable mixing/delivery apparatus  120  to deliver the mixed, wet granular material directly to the point of use. 
     Referring to FIGS. 9 and 10, there are shown side elevation views of yet another embodiment of a portable mixing/delivery apparatus  160  in accordance with the present invention. As in the previously described embodiments, the embodiment of the portable mixing/delivery apparatus  160  shown in FIGS. 9 and 10 includes a generally vertical support frame  162 . Attached to a lower portion of the support frame  162  are a pair of lower forklift tubes  182   a  and  182   b . Similarly, attached to an intermediate portion of the support frame  162  are a pair of upper forklift tubes  180   a  and  180   b . A portion of one of the upper forklift tubes  180   b  is partially cut away in FIG. 9 to show details of an upper portion of a mixer  164  and a lower portion of a bulk hopper  172  which are attached to the support frame  162 . Mixer  164  includes a dry granular material hopper  166  having extending therefrom a mixing tube  168 . Attached to a distal end of the mixing tube is a flexible discharge tube  170  through which the mixed, wet granular material provided by the mixer  164  is discharged to the point of use at a work site. 
     In the embodiment shown in FIGS. 9 and 10, the bulk hopper  172  containing a mixture of dry pre-blended granular materials is disposed above the mixer  166  and is securely attached to the support frame  162  by conventional means such as weldments or nut and bolt connections (which are not shown in the figures for simplicity). A coupling ring  178  connects a lower discharge end of the bulk hopper  172  to a flexible coupler  184  with a removable lid to permit the mixer&#39;s dry granular material hopper  166  to be filled by hand as an alternative. A refill lid  176  on the bulk bag  174  allows for re-filling of the bulk bag when empty. Bulk hopper  172  is preferably comprised of a lightweight, high strength material such as polyethylene. 
     Referring to FIGS. 11 and 12, there are shown respectively upper perspective and top plan views of a removable top frame  190  for use in the support frame of the portable mixing/delivery apparatus of the present invention. A side elevation view of the top frame  190  showing the manner in which it is positioned upon and supported by a support frame is shown in FIG.  13 . The removable top frame  190 , which is in the form of a tubular steel rack, provides support for a bulk bag  192  (shown in the figures in dotted line form) which contains the dry pre-blended granular material and includes a discharge spout  192   a  on a lower portion thereof. Securely attached to an upper portion of the bulk bag  192  are plural support loops, where three of the support loops are shown as elements  192   a ,  192   b  and  192   c  in the various figures. 
     Top frame  190  includes first and second forklift tubes  196   a  and  196   b , each adapted to receive and engage a respective fork of a forklift for loading the bulk bag  192  onto the support frame of the portable mixing/delivery apparatus of the present invention. The first and second forklift tubes  196   a ,  196   b  are connected by first and second cross members  194   a  and  194   b . First and second support members  188   a  and  198   b  are securely attached to respective adjacent ends of the first and second cross members  194   a ,  194   b . The aforementioned cross members, forklift tubes and support members may be connected together by conventional means such as weldments or nut and bolt combinations, which are not shown in the figures for simplicity. As shown in FIG. 13, the first and second support members  198   a ,  198   b  of the top frame  190  are adapted for positioning upon respective upper portions of the portable mixing/delivery apparatus support frame, a portion of which is shown in dotted line form as including a horizontal support frame member  204   a  and vertical support frame members  204   b  and  204   c . In this manner, the top frame  190  is securely and stably positioned upon the support frame, while easily removed such as by a forklift from the support frame. The height of the top frame  190  resting upon the upper portion of the support frame may be adjusted to accommodate a range of bulk bag sizes as shown in FIG.  1  and as described above. 
     In accordance with this aspect of the present invention, plural hooks are attached to the top frame  190  for securely suspending the bulk bag  192  containing dry pre-blended granular materials for discharge into the mixer of the portable mixing/delivery apparatus. Thus, first through fourth lower hooks  202   a - 202   d  are each attached to and suspended from one of the first and second cross members  194   a ,  194   b  of the top frame  190 . Similarly, first through fourth upper hooks  200   a  - 200   d  are each attached to one of the first or second forklift tubes  196   a ,  196   b . Thus, as shown in FIGS. 11 and 13, first, second and third support loops  192   a ,  192   b  and  192   c  of the bulk bag  192  respectively engage and are suspended from lower hooks  202   d ,  202   a  and  202   b . A fourth support loop and hook combination is used to suspend a fourth corner of the bulk bag  192  from the top frame  190 , although this is not shown in the figures for simplicity. 
     While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the relevant arts that changes and modifications may be made without departing from the invention in its broader aspects. Therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention. The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only and not as a limitation. The actual scope of the invention is intended to be defined in the following claims when viewed in their proper perspective based on the prior art.