Abstract:
A directional hopper tee has a fluted interior vertical pipe that merges into a horizontal pipe. The vertical pipe has an opening that connects to a hopper to receive bulk material, or product, and a horizontal pipe centered upon the end of the vertical pipe. The horizontal pipe has an inlet that also receives bulk material and pressurized air from ahead of the hopper and an opposite outlet that discharges the bulk material from the hopper tee. The vertical pipe has a flange that abuts the hopper and an opening in the flange that matches the opening of a valve on the hopper itself. At the opening, the vertical pipe begins to turn towards the outlet of the lower pipe with an internal flute. The flute begins immediately at the flange resulting in a vertical pipe with a curved shape towards the outlet and a square shape towards the inlet. The present invention raises the ground clearance of the horizontal pipe by at least an inch resulting in a hopper tee that clears at least 7 inches above the ground. The hopper tee of the invention also unloads at least 15% more product per minute at temperatures closer to product temperature. Alternate embodiments of the present invention provide a reinforced flange, a drop tee, and a low profile drop tee. The present invention aids in the unloading of bulk materials from various haulers.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This non-provisional application claims priority to the provisional application having Ser. No. 61/030,777 filed on Feb. 22, 2008 and is commonly owned by the same inventor. This application is related to U.S. Pat. No. 6,786,362 from the same inventor. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates generally to hopper tees used in bulk material handling, and more specifically pertains to a directional hopper tee that blends material dropping vertically therethrough with material entering and passing through horizontally. A unique aspect of this invention is a fluted vertical pipe that begins at the flange. The invention is especially useful for accelerating the unloading of a tank trailer hauling granular bulk material at higher ground clearance. 
     Hoppers, or tank trailers, regularly transport bulk commodities such as industrial and food products. When the hopper, or tank trailer, reaches its destination, the bulk commodity is unloaded, typically by a power take off driven truck mounted blower or a pneumatic system of a plant or factory. The bulk commodity generally unloads from the hopper and into a pipeline. To complete the unloading, hopper tees are mounted to the discharge outlet of the hoppers, or bins. The hopper tee conventionally has a vertical section of constant dimension and shape and a horizontal section also of constant dimension and shape forming the inverted T shape configuration. To transfer the bulk commodity, the material is moved out of the hopper, or bin, by gravity flow or air pressure vibration into the vertical section of the hopper tee. The clean discharge pipe is connected to the horizontal section of the tee. Pneumatic conveyance of the bulk material through the pipe occurs by establishing a pressure differential in the pipe. 
     The prior art hopper tees have a complete, one piece assembly that includes a vertical section, connecting to a hopper, and a horizontal section, connecting to a discharge pipe. The prior art hopper tee design fits on the bottom of the bins of pneumatic tank trailers. Typically, the valve of a bin bolts to the flange of the hopper tee. Although prior art hopper tees function well for their intended purposes, some hopper tees lack proper ground clearance for long trailers. Ground clearance has afflicted the tank trailer trucking industry for years. For example, as the hopper tee mounts the tank, ground clearance problems arise when a long trailer, such as a tank trailer, crosses railroad tracks or other uneven surfaces. The longer the trailer, the easier a hopper tee becomes stuck upon a railroad rail, berm, or other short height surface condition. A stuck trailer delays delivery of product to its destination, risks delay penalties to the trucking company, and increases recovery and repair costs of the tank trailers. 
     The Department of Transportation (DOT) and state highway departments have established heights, widths and lengths the tank trailers must meet. When the hauler transports light density products, such as plastic pellets, the hauler requires a larger cubic foot capacity, or volume, to haul a maximum payload and make hauling such products economically feasible. To increase the cubic foot capacity and remain within DOT height, width and length standards, the prior art and industry have dropped the bottom of the hopper. However, the bottom of the hopper requires angled walls (due to the angle of repose of the bulk material) that funnel down to the hopper tee to allow for emptying of bulk granular material. For most dry bulk products the angle of repose is approximately 45 degrees to the horizontal to obtain the maximum tank volume, in cubic feet, while remaining within the mandated dimensions. 
     DESCRIPTION OF THE PRIOR ART 
     A variety of patents have issued upon various devices to ease the transfer and unloading of bulk granular ingredients from a hopper or bin into a discharge line for delivery to a plant or factory. Prior art hopper tees have a construction of a vertical pipe welding to a horizontal pipe in a generally T shape. These tees remain subject to excessive internal wear by the friction of bulk materials and eventually fail as they wear away. Previously, the Applicant has addressed such wear problems. The U.S. Pat. No. 4,848,396 to Sisk discloses a cast hopper tee designed to provide a smooth and uninterrupted internal transitional surface. That patent also provides for such an improvement in a bottom drop hopper tee. 
     The U.S. Pat. to Campbell et al., U.S. Pat. No. 6,582,160 provides a hopper tee with a valve. This hopper tee has an inlet that connects to a hopper discharge opening and a perpendicular second hollow pipe section. The inlet has a cylindrical side wall, as in  FIGS. 8 ,  9  and the second hollow pipe section also has a cylindrical cross section as in  FIGS. 3 ,  10 .  FIGS. 9 ,  10  also show exterior tapering of the inlet and the second hollow pipe section. Unlike the present invention, the Campbell patent shows a straight sidewall at the flange, constrictions of the flow path in the second hollow pipe section as at  68  in  FIG. 8 , and no arcuate flutes upon the interior of the inlet and second hollow pipe section. 
     The U.S. published application to Kraenzle, No. 2006/0082138 shows a dual flange tee. One flange  24  goes beneath the perimeter of a valve and the other flange has two wings  14  and  16  that secure below the complete flange  24 . Below the wings, the flange tee has a generally cylindrical lower pipe section as in  FIG. 2 . The lower pipe section has a neck of little, if any, height. The connection between the upper pipe section and the lower pipe section is generally square, as in page 2 col. 21. 
     The U.S. Pat. No. 5,387,015 to Sisk has a single piece hopper tee with an elliptically shaped opening within the neck. Generally a first pipe with a flange joins perpendicular to an edge of a second pipe that then connects to pipeline tubing. The first pipe also has an elliptically shaped interior space and a pair of wear saddles creating double wall thicknesses at the transition areas between the vertical and horizontal pipes that resistant wear by materials sent through the tee. The first pipe has a neck at a square angle to the flange and then the neck flares outwardly upon the entire perimeter. The second pipe has a constant diameter without fluting. This patent lacks the immediate curvature along a portion of the neck, fluting within the second pipe, and single direction of flow as in the present invention. 
     Then the design patent, U.S. No. D376,416 to Sisk shows the physical appearance and ornamentation of a directional tee. This patent shows a round flange for connection to the hopper discharge and  FIGS. 3 ,  9  show part of the neck with a square angle to the flange and an opposite portion of the neck attaining a slope slightly below the flange.  FIGS. 7 ,  10  show slight bulging of the lower pipe below the hopper discharge with the bulging tapering towards the outlet. No interior fluting of the lower, or horizontal pipe, and no immediate curvature of the neck at the flange are shown by this patent. 
     The U.S. Pat. No. 5,676,404 again to Sisk, shows a low profile tee akin to Kraenzle above. Unlike Kraenzle, this patent shows a tee where the diameter of the hollow pipe section increases proximate the opening to the discharge hopper as in  FIG. 2 . This patent does not show fluting in the hollow pipe section, curvature of the neck at the flange, and single direction use. 
     The U.S. Pat. No. 5,842,681 also to Sisk describes a pivotal hopper tee. This hopper tee has a mounting frame that connects to the hopper discharge and a camming handle with a hook that swings upon pivot arms. Beneath the mounting frame, the hopper tee has a cylindrical cross section that increases in inside diameter near the valve opening, as in the upper dashed line in  FIG. 4 . 
     And then, the U.S. Pat. No. 6,786,362 to Sisk appears related to the &#39;681 patent. This swing away hopper tee has a mounting frame that connects to a tee assembly. The mounting frame provides a flange that extends well beyond the diameter of the hopper tee. The hopper tee geometry is mentioned briefly in this patent but no fluting or diameter changes are shown in  FIGS. 3 ,  6 ,  7 . FIG. 7 of the &#39;362 patent shows a hopper tee of constant diameter and its particular lever. 
     The prior art has various hopper tees with a flat door, large wings extending coplanar with the door, and carriage bolts and wing nuts connecting to the wings. Over time, with rugged usage, and subject to environmental factors, the wing nuts and carriage bolts become hard to open and make the door no longer fit flush with the bottom of the horizontal pipe. The improper fit of the prior art door causes excessive wear to the bottom of the horizontal pipe, shortening its useful life. The prior art shows various hopper tees to resist the abrasion of bulk materials and to provide bottom drop capability. However, the hopper tees remain subject to industry mandated clearance requirements. One clearance requirement remains 15.25 inches between the top of the flange of the hopper tee and the ground surface and a second clearance requirement is 4.25 inches between the top of the flange of the vertical pipe and the center of a 4 inch inside diameter horizontal pipe of a hopper tee. The 4 inch diameter horizontal pipe connects readily with existing 4 inch diameter plant and factory conveying systems. A third clearance requirement of 5.5 inches from the top of the flange to the center of the inside diameter of a horizontal pipe applies to a 5 inch diameter hopper tee. A hopper tee with high ground clearances remains desirable to the bulk material hauling industry. 
     SUMMARY OF THE INVENTION 
     This invention provides a directional hopper tee with an internally fluted vertical pipe blending into a horizontal pipe. The hopper tee has a vertical pipe with an opening that connects to a hopper, or bin, to receive bulk material into the tee and a horizontal pipe centered upon one end of the vertical pipe. The horizontal pipe has an inlet that receives bulk material and pressurized air from ahead of the hopper and an opposite outlet that discharges the bulk material already flowing in the horizontal pipe and that received from the hopper through the vertical pipe. The vertical pipe has a flange that abuts the hopper and an opening in the flange that matches the opening of a valve on the hopper itself. At the opening, the vertical pipe begins to turn towards the outlet of the lower pipe with a flute. The flute begins immediately at the flange resulting in a vertical pipe with a curved shape towards the outlet and a square shape towards the inlet. The present invention raises the ground clearance of the horizontal pipe by at least one inch resulting in a hopper tee that clears at least 7 inches above the ground. The hopper tee of the invention also unloads up to and including 22% more product per minute than prior art tees during field conditions. Alternate embodiments of the present invention provide a reinforced flange, a drop tee, and a low profile drop tee. The present invention aids in the unloading of bulk materials from various truck, rail, and ship transporters. 
     During unloading of bulk materials through the invention, the materials contact the tee and its various parts. Such contact induces friction between the materials and the tee along with friction within the materials, that is internal friction. The rise in friction during unloading creates heat, often measured as a rise in temperature of the tee. However, the present invention using its flute lessens the friction between the tee and materials and the internal friction of the materials during the turn from the vertical pipe to the horizontal pipe. The present invention causes a temperature rise in the tee generally 10° F. to 20° F. less than prior art tees, or an unloading temperature generally 10° F. to 20° F. closer to that of the product temperature. Drivers in the field report unloading hoses being cooler to the touch than before. Limiting the unloading temperature rise becomes important for heat sensitive bulk materials where higher temperatures may cause the bulk materials, to melt or to set or to congeal, such as to become “stringers” of melted plastic pellets, before departing the tank trailer. 
     Further, independent testing of the device flow capacity has found the invention increases flow by approximately 300 scfm more than prior art tees, or approximately 7300 scfm, see Appendix A. The increased flow results in faster unloading at a delivery site and a quicker turnaround for a tank trailer to deliver its next load. In field tests, drivers reported that surging of product during unloading ceased during usage of the present invention. Surging through the present invention has nearly vanished for usage with HDPE pellets, glass silica sand, soda ash, and flour along with other bulk materials. Reduction in product surges leads to less instances of plugged unloading lines and the resultant downtime during an unload cycle. 
     In a rising or high fuel cost environment, trucking companies, drivers, and their customers seek to minimize costs at any opportunity. The prior art has sought various devices to unload bulk material from a vertical hopper into a horizontal line. Those prior tees have performed however, the present invention also increases the rate of bulk material unloading. In doing so, the present invention allows a driver to complete an unloading fifteen to twenty three minutes sooner than before. Field tests using 1600 cubic foot trailers in dedicated local runs provided drivers up to twenty minute reductions in unloading times compared to existing tees. Faster unloading leads to more impressed customers, more satisfied drivers, and more loads, or hauls, per day, week or month thus improving revenues to trucking companies. 
     Further, during unloading of a hopper trailer, the truck remains idling as it provides blower air in some cases. An idling truck often consumes a gallon of diesel fuel per hour. During usage of the invention, unloading raises a truck&#39;s engine speed to three times that of ordinary idling, measured in RPM, and consumes three gallons of diesel fuel per hour of unloading. As diesel fuel prices fluctuate in the vicinity of $4 per gallon, reducing idling saves trucking companies a significant expense, at least $500 per year during unloading depending on loads per day. The present invention, lowering unloading times noticeably, reduces idling times of trucks thus, leading to fuel cost savings. The present invention increases the operating efficiencies of trucks when measured in miles per gallon or hours per gallon thanks to decreased unloading times. The present invention aids truckers and their companies in using less diesel fuel to accomplish the same unloading job. 
     It is, therefore, the principal object of this invention is to provide a fluted hopper tee for inducing directional flow that increases the rate of unloading bulk materials from a container by approximately twenty two per cent, where the increase in unloading rate varies by the type of bulk granular material unloaded. 
     Still another object of this fluted hopper tee is to increase the clearance from the lowest extent of the horizontal pipe to the ground surface when the invention is installed. 
     Still another object of this fluted hopper tee is to meet dimensional and clearance requirements of federal and state agencies along with trucking and material handling industry standards. 
     Still another object of this fluted hopper tee is to provide a bottom drop embodiment of the invention where the door provides a flush fit to the inside surface of the horizontal pipe. 
     Still another object of this fluted hopper tee is to provide a bottom drop embodiment of the invention where the door prevents leakage of fine particulate matter from the hopper tee. 
     Still another object of this fluted hopper tee is to provide a bottom drop embodiment of the invention where the gasket and door of the invention can be readily removed for cleaning, such as washing, and when changing between unloading of different materials. 
     Still another object of this fluted hopper tee is to improve the accessibility of the door and handle of the bottom drop embodiment of the invention, this accessibility includes door attachment ears arranged symmetrically with a symmetrical door and gasket allowing for installation facing either the left or the right side of a trailer. 
     Still another object of this fluted hopper tee is to improve the accessibility of the door and other moving parts of the bottom drop embodiment of the invention where the gasket can be removed by hand. 
     Still another object of this fluted hopper tee is to provide a bottom drop embodiment of the invention where the door is opened and later secured by an operator using a single handle, or cam lever. 
     Still another object of this fluted hopper tee is to provide a bottom drop embodiment of the invention where the door avoids securement by two or more bolts and retainers that formerly permitted misalignment of the door and leakage of bulk materials. 
     Still another object of this fluted hopper tee is to provide a bottom drop embodiment of the invention where the door opens readily after an extended period of non-usage, such as six months. 
     Still another object of this fluted hopper tee is to provide a bottom drop embodiment of the invention where the door opens readily, such as upon polymer bushings, with a minimum of lubrication and its risk of load contamination. 
     These and other objects may become more apparent to those skilled in the art upon review of the summary of the invention as provided herein, and upon undertaking a study of the description of its preferred embodiment, in view of the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In referring to the drawings, 
         FIG. 1  shows an isometric view of the present invention ready for installation upon a valve and into an unloading line; 
         FIG. 2  shows a side view of the present invention with the outlet to the left of the figure; 
         FIG. 3  describes an end view of the present invention through the outlet; 
         FIG. 4  shows longitudinal section view of the tee; 
         FIG. 5  shows a top view of the tee with the outlet to the left of the figure; 
         FIG. 6  shows an alternate embodiment of the invention where the flange has braces to the tee; 
         FIG. 7  describes an end view of the alternate embodiment; 
         FIG. 8  illustrates an end view of the drop tee embodiment of the present invention; 
         FIG. 9  describes a side view of the drop tee embodiment; 
         FIG. 10  illustrates a side view of the drop tee without the door; 
         FIG. 11  illustrates a sectional view of the drop tee also without the door; 
         FIG. 12  is a top view of the drop tee; 
         FIG. 13  illustrates a sectional view through the door and hinges of the drop tee; 
         FIG. 14  described an end view of the drop tee with the pivot hinges removed; 
         FIG. 15  then provides an exploded view of the drop tee; 
         FIGS. 16A and 16B  then show an alternate embodiment of the drop tee having a low profile; 
         FIG. 17  provides a sectional view of the low profile drop tee; 
         FIG. 18  shows an end view of the low profile drop tee; and, 
         FIG. 19  provides an exploded view of the low profile drop tee. 
     
    
    
     The same reference numerals refer to the same parts throughout the various figures. 
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     In referring to the drawings,  FIG. 1  shows an integral tee, generally known as a hopper tee, of the present invention  1  in a perspective view. The present invention has a generally transverse hollow pipe, hereinafter horizontal pipe  2 , round in cross section and of a known diameter. The horizontal pipe has two opposed ends, one end being an inlet  3  that receives material sent into the hopper tee under pneumatic pressures and the opposite end being an outlet  4  that discharges material from the inlet and material unloaded from a hopper, or bin, into the hopper tee. The inlet and the outlet each have a perimeter slot  5  for coupling the invention  1  into a pneumatic system for unloading. The coupling slots  5  generally extend around the entire circumference of the lower pipe proximate the inlet and the outlet. 
     Generally centered upon and perpendicular to the horizontal pipe, the fluted hopper tee  1  has a vertically directed hollow pipe, hereinafter vertical pipe  6 . The horizontal pipe is generally transverse, or perpendicular to the vertical pipe. The vertical pipe is also round in cross section and of a known diameter. The vertical pipe has a flange  7  at one end away from the horizontal pipe. The flange extends outwardly from the pipe in a planar form that is parallel to the longitudinal axis of the lower pipe. The flange has a top surface  7   a  and pattern of holes therethrough that mates with bolts present in valves commonly used in the bulk material hauling industry. In this embodiment, the flange has a truncated round shape where the flange has two mutually parallel straight edges  8 , also parallel to the longitudinal axis of the lower pipe. Centered upon the flange, the vertical pipe has an opening  9  that matches the inside diameter of the valves upon hopper used in the bulk material industry. 
     Where the flange adjoins the vertical pipe, generally as the top surface meets the opening  9 , like at a lip, the key feature of the invention begins. The invention provides a flute  10 , or a rounded groove, to the interior of the vertical pipe that begins at the flange and extends in a curvilinear manner into the horizontal pipe in the direction of the outlet. The flute has an initial width comparable to the diameter of the opening  9  then the width of the flute narrows as it approaches the outlet  4 . The path of the flute is generally shown with a flute line  11  that follows a radius of curvature with a center point proximate the outlet  4 . As the flute extends from the flange and curves towards the outlet, the flute tapers in its diameter over an area of transition  14  that may appear as a convex shape, or bulge, in later views of the invention. Where the flute intersects with the flange, the vertical pipe has a radius of curvature immediately. The intersection of the flange with the flute defines a fore edge  12  and where the vertical pipe has a typical connection, or square connection, to the flange an aft edge  13  exists. The fore edge extends for over 120 degrees of arc of the opening  9 , centered upon the horizontal pipe. The aft edge occupies the reminder of the perimeter of the opening. 
     From the side,  FIG. 2  shows the present invention and the location and shaping of the flute. The plane of the flange  7  is generally parallel to the centerline of the horizontal pipe  2 . Where the vertical pipe adjoins the flange proximate the inlet, the vertical pipe has a generally square or right angle joint to the flange. The square joint typically follows the aft edge  13  and has no downstream radius. Opposite the aft edge, the flange has the fore edge  12  which marks the upper extent of the flute  10 . The flute begins at the top surface of the flange and immediately curves as shown in a concave manner towards the outlet  4  through the transition  14 . Opposite the transition, the flute line  11  indicates the position and curvature of the flute as it curves from the flange, through the vertical pipe, and then attains the diameter of the horizontal pipe. The flute line indicates the path of the bulk material as it rounds the juncture of the vertically directed hollow pipe and the transverse hollow pipe. The flute provides an internal transition in the fluid like flow of bulk materials from the vertically directed hollow pipe through a substantially ninety degree turn into the transverse hollow pipe. 
     As described above, the transition  14  has a bulge like appearance as shown in  FIG. 3 . The flute  10  begins at the flange  7  and extends forward in the direction of the outlet  4  of the lower pipe  2 . The flute has an initial width similar to that of the valve opening in a hopper as at the fore edge  12 . The flute then narrows in width as it curves upon a radius until it reaches the diameter of the horizontal pipe. Generally, the hopper valve openings exceed the diameter of the horizontal pipe thus the transition  14  starts wide at the flange and tapers to the horizontal pipe  2 . The curvature of the transition also affects the bulge like appearance. The edge of the transition as in this figure defines the flute line  11 . 
       FIG. 4  shows a sectional view of the invention, lengthwise with the interior exposed, where the key feature operates to accelerate the flow of bulk granular material through the hopper tee. The flange  7  is generally shown horizontal and parallel to the longitudinal axis of the horizontal pipe. The flange has a fore edge  12  at the opening  9  towards the outlet  4  and an opposite aft edge  13  towards the inlet  3 . The aft edge defines a square edge that connects the flange, the vertical pipe, and the horizontal pipe. Then the fore edge begins the flute where the vertical pipe intersects the top surface of the flange. The flute curves in a concave manner from the fore edge, through the transition, and reaches the horizontal pipe behind the coupling slot  5  near the outlet  4 . Opposite the fore edge, the flute abuts the aft edge and extends as a curvilinear line  11  from the flange through the vertical pipe and partly into the horizontal pipe. As the flute extends across the diameter of the vertical pipe and partly around the circumference, the flute adjoins the inner wall of the vertical pipe, as at  6   a.    
     As soon as the bulk material, or product, leaves the tank, hopper, or tank valve, the bulk material enters the uniquely designed flute of this invention. The flute line begins at the top surface of the flange more than half way across the diameter of the opening  9  and descends at a slight curve towards the outlet through the vertical pipe and into the horizontal pipe. Inside the horizontal pipe, at less than half of the diameter of the horizontal pipe the flute line curves more sharply and attains an asymptotic angle to the centerline of the horizontal pipe. The flute line ends at a confluence point,  15 , proximate the outlet slightly below the centerline. At the end of the flute line  11 , the flute has reached a width identical to that of the inside diameter of the horizontal pipe. Where the flute begins to curve more sharply, an inflection point, as at  16 , starts an eddy line  17  that extends to the intersection of the vertical pipe with the horizontal pipe at  18 . Above the eddy line  17  within the aft edge  13  and outside the flute line  11 , eddies form in the bulk material flowing from the inlet into the horizontal pipe. The present invention creates less eddy currents and turbulence than prior art tees which leads to less friction between the bulk material and the invention and internal friction of the bulk material. The eddies in the material flow ease the merge of bulk material flowing from the opening  9  into the flute  10  and then follow a curved flow path induced by the flute  10 . The fewer eddy currents and more laminar like flow of the bulk material generates less friction and less heat imparted to the invention which allows for a longer useful life compared to prior art tees. The bulk material flow into the horizontal pipe from the inlet starts the bulk material immediately to drop through the opening  9  into a curved flow through the hopper. The bulk material flowing along a curve merges with that flowing along the horizontal pipe much like two watercourses at a confluence become one river. 
     Bernoulli&#39;s principle reminds us that energy is conserved across a straight pipe and through various joints including a hopper tee. Under the Bernoulli equation, the head of the fluidized bulk material entering the fluted hopper tee equals the head of the fluidized bulk material exiting the outlet  4  where head represents the pressure, kinetic, and potential energies. This relationship is shown in the following equation: 
                   p   1     γ     +       v   1   2       2   ⁢           ⁢   g       +     z   1     +       p   2     γ     +       v   2   2       2   ⁢   g       +     z   2       =         p   3     γ     +       v   3   2       2   ⁢   g       +     z   3             
Where the bulk material energies at the inlet 1  are added with those of the opening 2  to equal those energies of the outlet 3 . The inlet energies and the opening energies create two forces, one force from the tank pressure pushing the bulk material down the tank, and a second force from the line pressure pulling the bulk material down the line beneath the tank or hopper for distribution. The tank pressure is approximately 25 psi while the line pressure is approximately 20 psi. As the potential energy of the bulk material flowing through the opening adds to the kinetic energy of the material from the inlet, the combined material exits the outlet at a greater velocity and thus accelerates unloading of each hopper and an entire trailer of hoppers. Further, in the vicinity of the inner wall  6   a  of the vertical pipe, the flute causes a venturi, or siphon like, effect that aids in drawing, or pulling, bulk material from the hopper, through the valve, into the opening  9 , and thus into the horizontal pipe. Additionally, the bulk material within the flute attains a pressure of approximately 15 psi while the material arriving from the inlet has a pressure of approximately 20 psi. The pressure gradient between the two flows of material augments the siphoning effect of the curved flow and the eddies formed therein.
 
     And then  FIG. 5  shows a top view of the present invention looking through the opening  9  in the flange  7  into the hopper tee  1 , particularly the horizontal pipe  2 . The flange, as before, has a truncated round shape with edges  8  parallel to the length of the horizontal pipe. Within the flange, the opening has the aft edge  13  towards the inlet  3  and extending less than half way around the circumference of the opening. The remainder of the opening has the fore edge  12  that begins the flute  10  that descends through the vertical pipe into the horizontal pipe towards the outlet along the flute lines  11 . Inwardly and towards the inlet from the flute lines  11 , the inner wall  6   a  extends upwardly from the flute lines to the flange  7  and occupies the remaining circumference of the opening  9  as the aft edge. In this view, the flute lines define a partly parabolic curve with its vertex towards the inlet upon the centerline of the horizontal pipe. The flute lines widen outwardly reaching the inside diameter of the horizontal pipe towards the outlet. 
     Turning to  FIG. 6 , an alternate embodiment of the present invention is shown with a more rigid vertical pipe  6 . This hopper tee has a vertical pipe that merges with a horizontal pipe  2  as previously shown in  FIG. 2 . The vertical pipe has a flange  7  generally centered upon and perpendicular to the vertical pipe and parallel to the horizontal pipe. The flange has an opening as at  9  for admitting bulk material from the valve of a hopper. Beneath the flange, a plurality of braces  19  extend from the bottom surface  7   b  of the flange at an angle towards the vertical pipe. The braces, or gussets, are generally parallel to one another and perpendicular to the longitudinal axis of the horizontal pipe. The braces have a generally triangular shape of varying depth, as in  FIG. 7 , with the shortest depths locating forward in the transition  14  and the greatest depth locating proximate the aft edge  13  and towards the inlet  3 . As before, the vertical pipe has a flute  10  defining the transition  14  from the diameter of the opening  9  through an arc to the diameter of the horizontal pipe. The transition begins immediately at the top surface  7   a  of the flange at the opening  9  along a portion of the circumference of the opening, the fore edge  12 . This alternate embodiment applies generally when lighter weight materials are used for the construction of the invention such as aluminum and polymers. The braces serve to stiffen the flange in its connection to a hopper valve and during the vibrations of unloading. 
       FIG. 8  then shows a drop tee embodiment of the present invention. This embodiment has an opening as at  9  through the flange that receives bulk material from the hopper or bin. The opening has a known shape and width, round with a diameter in this description. Opposite the opening, this embodiment of the hopper tee has a door  101  that opens below a horizontal pipe  102 . As later shown, the door provides a full port opening, or a drop opening  120 , later shown in  FIG. 10 , of the same width and shape as opening  9  for unimpeded discharge of bulk material from the hopper or bin. Beneath the flange, the drop tee embodiment has a vertical pipe  106  that merges with the center of the horizontal pipe  102 . In this view, the vertical pipe has a flute  110  that curves from the opening  9  towards the inlet  3  in a transition  114  that contracts in width from that of the opening to that of the diameter of the horizontal pipe. Generally behind the transition towards the outlet, this embodiment has a pair of pivot ears  121  and an opposite pair of hinge ears  122  where each pair is collinear and extending perpendicular to the vertical pipe and to the horizontal pipe. Each member of a pair of pivot ears and hinge ears is coaxial and coplanar with its opposite counterpart. The pivot ears and hinge ears have a symmetric arrangement about the centerline that allows for changing the door position to either side of a trailer during usage. The pivot ears extend outwardly from the centerline of the horizontal pipe and provides a pivoting point for a pin  121   a  within a bushing  121   b  for a cam bolt  123 , wherein the bushing is generally a polymer. The cam bolt has a threaded end  123   a  in a bolted connection through the pin and bushing and opposite the threaded end it has a hook  123   b . Between the threaded end and the hook, the cam bolt has an off center bend defined by the threaded end approaching the hook or a generally convex shape as shown in the figure. The cam bolt  123  allows a cam lever  124  to pivot downwardly from one end of the door  101  as the door itself pivots beneath the horizontal pipe for opening to drop bulk material. The cam lever has a generally elongated shape with two opposed ends. One end is the pedal  124   a  that has a foot grip surface to receive a kick from a trucker during opening. A trucker steps on the pedal, or pulls it downward, which allows for easy opening of the door that swings downwardly out and away from the horizontal pipe. With the present invention, the trucker no longer deals with seized wing nuts, rusted bolts, and galled bolts that accumulated in prior art tees in field use. The pedal has a slight offset as shown in  FIG. 15 . On the other end, the pedal has a shoulder  124   b  generally curved upwardly partially around the door. Near the bottom of the shoulder, it has a groove  124   c  that receives the hook  123   b . Near the top of the shoulder, an aperture  124   d  admits a pin  124   f , through a bushing  124   g , that pivotally connects the shoulder and the cam lever to the door  101 . The cam lever also includes receives a safety pin, marking strap, or security seal through a second aperture  124   e  that secures the cam lever upwardly towards the hinge ear  122  to prevent inadvertent opening of the cam lever. 
     Then the hinge ear  122  extends outwardly from the vertical pipe along the same axis as the pivot ear  121  and provides a door hinge  125  with a bushing  125   a  and a coaxial pin  125   b . The door hinge allows the door to pivot upon one edge opposite the pivot ear  121  and opposite the aperture  124   d  but above the second aperture  124   e  of the cam lever from a closed to an open position. The cam bolt  123  has threaded rod like connections that allow for adjustments in positioning of the door upon the horizontal pipe. Here in  FIG. 8 , the door is shown in the closed position where the door  101  abuts a gasket  101   a  that compresses upon the lip  126  defining the drop opening  120 . The gasket seals the door in a positive seal to the door in one motion without adjusting the door at two places as in the prior art. The gasket can be readily replaced if damaged or worn. The door has at least two, preferably four, holes  101   e  that admit legs  101   b  through the door. The legs are generally elongated cylinders, round in cross section, that have a conically shaped bump out, or barb  101   d , proximate the main portion of the gasket. The barbs  101   d  are generally spaced away from the gasket slight less than the door  101  thickness for a snug fit of the gasket to the door. The molded gasket has a generally elliptical shape with an open interior and four legs equally spaced upon the inside face of the gasket. The legs align the gasket upon the door in position for a tight seal. When closed in particular, the door in cooperation with the gasket seals to the horizontal pipe so that the inside surface of the door  101   c  is flush with the inside diameter of the horizontal pipe. The smooth closure of the door upon the horizontal pipe provides for minimal interruption in the flow of bulk material and lessens the Reynolds number of the bulk material when passing through the horizontal pipe with the door closed. The lower Reynolds number leads to a more laminar like flow of the bulk material through the invention. 
     The drop tee embodiment appears from the side in  FIG. 9  where a vertical pipe  106  that merges with a horizontal pipe  102 . This embodiment has more ground clearance that prior art tees with generally approximately 1½ inches more between the lowest point of the door and the ground. The horizontal pipe has an inlet  3  and an opposite outlet  4  each with a coupling slot  5  as before. The vertical pipe  106  has a flange  7  with an opening  9  that receives bulk material from the hopper or bin above the drop tee. The flange has a top surface  7   a  that intersects along part of the perimeter of the opening with the vertical pipe defining the aft edge  13 . Upon the reminder of the opening  9 , the fore edge  12  defines the beginning of the flute  110 . The flute curves the vertical pipe forward towards the outlet and begins with a width that of the opening  9  in the flange and then narrows to the diameter of the horizontal pipe. In this embodiment, the flute extends to the immediate vicinity of the coupling slot  5 . 
     Generally centered between the wall  6   a  of the vertical pipe  106  and the transition  114  of the flute  110 , the pair of pivot ears  121  provides two parallel plates to which the cam bolt  123  secures upon the bushing  121   b  with its internal coaxial pin  121   a.  The cam bolt has its threaded end  123   a  passing through a hole in the bushing and the pin secured by two nuts equally spaced about the diameter of the bushing. The cam bolt extends outwardly from the horizontal pipe and bends around the shoulder  124   b  of the cam lever  124 , generally outside of the door. The cam bolt extends downwardly so that its hook  123   b  engages the groove  124   c  of the cam lever  124 . The cam lever extends beneath and across the door  101  to the opposite side of the drop tee. The door has an inverted saddle like shape that matches the curvature of the horizontal pipe but also rises to allow for a snug fit of the cam lever beneath the door but tight towards the tee. The door seals to the drop opening  120  upon the gasket  101   a  which compresses upon the lip  126 . The lip and the drop opening curve upwardly, as in a saddle, to slightly above the centerline of the horizontal pipe. The perimeter of the door, in this drop embodiment, extends slightly outwardly from the lip causing a reduction in ground clearance below the door of approximately one inch. 
       FIG. 10  then shows the drop tee with the door  101 , the cam bolt  123 , and the cam lever  124  removed.  FIG. 10  is in the opposite direction as  FIG. 9 . Beneath the hinge ears  122 , the drop tee has the drop opening  120  generally of similar diameter as the opening  9  in the flange  7  as later shown in  FIG. 12 . In this view, the drop opening is bounded by the lip  126  that has a curvi-linear shape upwardly into the lower pipe until the uppermost tangent to the arc is generally parallel to and slightly below the centerline of the horizontal pipe. Alternatively, the lip has a shape of one of parabolic, elliptic, or arcuate. The lip extends slightly outwardly from the surface of the horizontal pipe and provides a slightly concave surface forming a door bead  127  that accepts the gasket  101   a  in compression by the door  101  when closed upon the tee. The shape of the lip and the drop opening minimizes the potential disturbance to the inside surface of the horizontal pipe and impediment of bulk material during unloading. 
     The drop tee in regards to the door and its closure upon the horizontal pipe has a lengthwise sectional view shown in  FIG. 11  in the same direction as  FIG. 10 . This figure illustrates the immediate curvature of the flute  110  at the top surface  7   a  of the flange  7  that extends just short of the coupling slot  5 . Opposite the flute, the vertical pipe has an internal wall  106   a  generally square to the top surface of the flange and towards the inlet  3 . The flange has its opening  9  that abuts the valve of a hopper or bin. The opening has a known diameter, often 5 or 6 inches, and the drop tee locates the drop opening  120  directly opposite the opening  9  in the flange. The drop opening has the same inside diameter as the inside diameter of the opening in the flange and follows the circumference of the horizontal pipe. By providing the drop opening with the same diameter as the opening above, the bulk material falls vertically through the drop tee when the door is opened in a smooth flow without any hindrances. The falling bulk material does not constrict to pass through the door nor do eddy currents arise and nor does turbulence develop. This figure further shows the lip  126  extending outwardly from the surface of the horizontal pipe and having a rounded edge towards the drop opening  120 . The horizontal pipe  3  merges with the vertical pip  106  along the upright curvi-linear feature  3   a.  Alternatively, the feature has a shape of one of parabolic, elliptic, or arcuate. 
       FIG. 12  then provides a top view of the drop tee with the door, cam lever, cam bolt, and gasket removed. As can be seen, the opening  9  in the flange is concentric with the drop opening  120  located there below and of similar diameter. Bulk material dropping through the opening  9  and the drop opening  120  flows through the drop tee freely when the door is opened. As before, the drop tee has a flange  7  with a pattern of holes thereon for mounting to the valve of a hopper or bin. The flange has a generally round shape but for two parallel edges  8  each also parallel to the centerline of the horizontal pipe. Beneath the edges, the pair of pivot ears  121  and the pair of hinge ears  122  extend mutually opposite and outwardly from the vertical pipe. This view also shows the horizontal pipe widening slightly at its saddle, as at  102   a , with the vertical pipe. Then the horizontal pipe attains the diameter of the opening  9  across the junction with the vertical pipe. The horizontal pipe continues itself with the diameter of the opening  9  to for a length slightly less than the radius of the flange as at  102   b.  Then the horizontal pipe quickly narrows to the diameter proximate the outlet  4 . This widened horizontal pipe before the outlet differs from the preferred embodiment where the transition narrows gradually and further behind the outlet. 
     Turning the drop tee,  FIG. 13  shows a sectional view through the center of the pairs of pivot ears  121  and hinge ears  122 , looking through outlet  4  towards inlet  3  or upstream, where the door closes upon the gasket that compresses upon the lip  126 . The door has a radius of curvature that spans from a lip  126  to the opposite lip across the horizontal pipe. At the location of this section, the lips  126  are spaced apart by the diameter of the opening  9  that exceeds the diameter of the horizontal pipe and the lips are connected by the door bead  127  that in time abuts the gasket. The door radius of curvature and the arcuate length of the door cooperate so that the lowest portion of the door matches the arc at the bottom of the horizontal pipe. The matching of door curvature to the curvature of the horizontal pipe provides a flush and smooth surface to the interior of the drop tee when the door is closed and the tee functions as a hopper tee. Above and behind the door in this figure, the horizontal pipe widens into the flute that begins along the feature line  3   a  and that briefly widens into the flute  10  and then narrows to the bottom of the horizontal pipe along the flute line  11 . 
     Next,  FIG. 14  shows the drop tee embodiment in a sectional view towards the outlet  4  and with the pivot ears  121  and hinge ears  122  shown generally having the same horizontal centerline and symmetric positioning. This view is located slightly forward of the section in  FIG. 13  towards the outlet. In this location, the door closes upon the horizontal pipe and provides a flush and smooth interior surface. Upon the exterior, the door extends slightly outward from the surface of the horizontal pipe because of the lip. 
     And,  FIG. 15  shows an exploded view of the components of the drop tee. This description begins with the bottom of the figure and moves upwardly through the invention. Here, the invention is in the closed position with the cam lever  124  in a generally horizontal orientation but perpendicular to the line of flow through the invention. The cam lever has a foot pedal  124   a  used by truckers and others to open the invention for discharge of product through the opening  9  in the flange  7  and then the bottom opening  120 . Inward from the foot pedal, the cam lever has a second aperture  124   e  that receives a seal or other marking device. Opposite the foot pedal, the cam lever has its shoulder  124   b  that has a greater width than the remainder of the cam lever and curves upwardly. The shoulder has a groove  124   c  generally centered therein that receives the hook  123   b  of the cam bolt  123  as previously described. The shoulder curves upwardly above the level of the foot pedal and has an aperture  124   d  therethrough with an axis perpendicular to the length of the cam lever. The aperture receives a cam pin  124   f  that fits within a coaxial cam bushing  124   g.  The cam pin provides a pivotal connection of the cam lever to the door  101 . 
     The door has a generally saddle shape with an inside surface  101   c  having the same radius of curvature as the horizontal pipe  102 . The door curves upwardly and towards the cam shoulder in the figure, the door has two spaced apart door ears  101   h  that extend outwardly from the door. Each door ear has an aperture  101   g  therethrough that admits the cam bushing  124   g.  Opposite the door ears, the door has the door tab  101   j  that has an aperture  101   k  therethrough that admits a door bushing  101   f.  The door bushing cooperates with the hinge ears  122  for opening of the door from the remainder of the tee. The door tab extends from the top of the curve of the door generally outwardly from the door and the horizontal pipe when the door is closed. Within the saddle portion of the door, that is down slope from the door ears  101   h  and the door tab  101   j , at least two and preferably four holes  101   e  extend through the thickness of the door. The door holes  101   e  admit a part of the molded gasket  101   a    
     The molded gasket  101   a  also has a similar saddle shape as the inside face of the door. However, the molded gasket has a large opening therethrough for passage of product. The opening has a diameter of at least that of the opening  9  in the flange. Due to the saddle shape of the gasket, the opening attains a perimeter similar to a section through a spherical body. As described previously, the gasket compresses under closure of the door upon the lip  126  of the horizontal pipe. To prevent the gasket from sliding out of position, the gasket has two, and preferably four, legs  101   b  that extend radially outward from the gasket in the direction of the door. The legs align and enter the holes  101   e  which positions the gasket properly upon the door. Each leg has a barb  101   d  with a generally inverted tapered shape with maximum diameter towards the gasket tapering to the leg diameter away from the gasket. Each barb is also spaced down the leg a distance similar to the depth of the hole  101   e.  During installation, a worker pushes the leg into the hole until the barb engages and repeats that for each leg. To remove the gasket, the worker pulls on the leg, lengthening it and narrowing it enough for the barb to pass back through the hole  101   e.  Removing the gasket aids the trucker or other worker in cleaning the door and avoids cross contamination of loads. The removable gasket can be removed and cleaned in contrast to prior art drop doors that remained connected to a tee which hindered cleaning and raised the chance of cross contamination with its risk of rejecting a load. 
     The door with its installed gasket rotates upon its door tab  101   j  within the hinge ears  122  of the main portion of the tee. The hinge ears are mutually parallel and spaced apart generally proximate the top of the lower pipe  102 . Each hinge ear has its own aperture that admits a hinge ear bushing  125   a  that receives a spring clip pin  125  that passes through the bushing  125  and the door bushing  101   f  and allows the door to pivot or to drop away from the tee, as during unloading. Opposite the hinge ears  122 , the tee has the pivot ears  121  where each pivot ear has its own aperture. The apertures of the pivot ears and the hinge ears are spaced symmetrically about the line of flow of the invention to allow for reverse installation of the door if needed in the field. The door of the invention can be installed for right side or left side of trailer usage. Each aperture in a pivot ear receives a pivot bushing  121   b  that in turn admits a cam pin  121  generally centered within the pivot ears. The cam pin has a diametrical hole through its centered that admits the threaded end  123   a  of a cam bolt  123 . The threaded end has a jam nut  123   c  and a washer  123   d  inside of the jam nut located outside of the cam pin and a locking nut  123   e  inside of the cam pin. The locking nut secures the cam bolt upon the cam pin for hinge action of the cam bolt  123  to the cam lever  124  as previously described. 
     Inside of the pivot ears and the hinge ears, the invention has the lower pipe  102  with its outlet  4  to the right in this figure. Inside of the outlet, one can view a portion of the door bead  127  denoting the opening  120  in the bottom of the lower pipe. The outlet has its coupling slot  5  inward of the outlet and the lower pipe has the saddle shaped lip  126  below the hinge ears and the pivot ears. The lower pipe continues rearward to an opposite coupling slot  5  and the inlet  3 . The lower pipe merges with the vertical pipe  106  in a generally inverted T position. The lower pipe has a transition section, as at  114 , upon its top surface and towards the outlet that defines the outward appearance of the flute  110  locating upon the downstream portion of the tee. The flute commences at the forward inside edge  12  of the flange  7 . Opposite the forward edge  12 , the flange has an aft edge  13  generally square, or a right angle edge. The flange has two exterior, mutually parallel squared edges  8 , generally parallel to the length of the lower pipe  102 . And the flange  7  extends perpendicular and outwardly from the vertical pipe  106  with a pattern of holes therethrough for mechanical connection. 
     A further alternate embodiment of the invention is shown in  FIGS. 16A ,  16 B as a low profile drop tee. Similar to  FIG. 9 , this embodiment of the drop tee has a horizontal pipe  202  with a drop opening  220  as later shown in  FIG. 17  that is closed by a door. Opposite the door, this embodiment has a flange  7  with a top surface  7   a  outwardly from the horizontal pipe and the bottom surface  7   b  generally abutting the surface of the horizontal pipe tangentially. This low profile embodiment has more ground clearance that prior art tees with approximately ½ inch more between the lowest point of the door and the ground. The flange has an opening  9  that mates with a valve opening upon a hopper or bin. Upon more than the front half of the opening, the flange has a fore edge  12  that begins a flute that briefly curves in a concave manner from the diameter of the opening  9  to the diameter of the horizontal pipe. This curve begins immediately at the top surface  7   a  and then curves through a vertical distance equivalent to the thickness of the flange to attain a horizontal orientation at the horizontal pipe diameter. Opposite the fore edge, the flange has the aft edge  13  that generally provides a square shape. This embodiment effectively has no vertical pipe and thus a higher ground clearance, approximately 1½ inches higher than the previous embodiments. The fore edge and the aft edge generally have a height limited by the thickness of the flange  7 . 
     Generally behind the transition towards the outlet, this embodiment has a pair of pivot ears  221  and an opposite pair of hinge ears  222  where each pair is collinear and extending perpendicular to the vertical pipe and to the horizontal pipe. Each member of a pair of pivot ears,  FIG. 16A , and hinge ears,  FIG. 16B , is coaxial and coplanar with its opposite counterpart. The pivot ears and hinge ears have a symmetric arrangement about the centerline that allows for changing the door position to either side of a trailer during usage. Then the hinge ear  222  extends outwardly from the vertical pipe along the same axis as the pivot ear  221  and provides a door hinge  225  with a bushing  225   a  and a coaxial pin  225   b . A clevis pin spring retainer  225   c  may be optionally used to secure the pin  225   b  against dislodging from the bushings during rough movement of the invention beneath a trailer. Beneath the spring retainer, the figure shows a cam lever  224  of a generally elongated shape with two opposed ends. Particularly in  FIG. 16A , one end is the pedal  224   a  that has an offset foot grip surface to receive a kick from a trucker during opening. Unlike the pedals of  FIGS. 8 ,  15 , this pedal has a substantial offset as shown, moving the foot pedal to the side and upwardly around the curve of the door which generally contributes to raising the ground clearance of this embodiment of tee. 
     Here in this figure, the door is in the closed position where the door  201  abuts a gasket  201   a  that compresses upon the lip  226  defining the drop opening  220  as described above. The door has preferably four holes  201   e  that admit legs  201   b  from the gasket through the door. The legs are generally elongated cylinders, round in cross section, that have a conically shaped bump out, or barb  201   d , proximate the main portion of the gasket. The barbs  201   d  are generally spaced away from the gasket slight less than the door  201  thickness for a snug fit of the gasket to the door. The molded gasket has a generally elliptical shape with an open interior and four legs equally spaced upon the inside face of the gasket. The legs align the gasket upon the door in position for a tight seal. When closed, the door cooperates with the gasket as it seals to the horizontal pipe so that the inside surface of the door  201   c  is flush with the inside diameter of the horizontal pipe. The smooth closure of the door upon the horizontal pipe provides for minimal interruption in the flow of bulk material or change in the Reynolds number through the horizontal pipe with the door closed. The door hinge, shown here as at  222 , allows the door to pivot upon one edge opposite the pivot ears  221  and opposite the aperture  224   d  but above the second aperture  224   e  of the cam lever from a closed to an open position. 
     Turning to  FIG. 16B , opposite the pedal, the other end of the cam lever has a shoulder  224   b  generally curved upwardly partially around the door. Near the bottom of the shoulder, it has a groove  224   c  that receives the hook  223   b . Near the top of the shoulder, an aperture  224   d  admits a pin  224   f , through a bushing  224   g , that pivotally connects the shoulder and the cam lever to the door  201 . The cam lever also includes receives a safety pin, marking strap, or security seal through a second aperture  224   e  proximate the pedal  224   a  that secures the cam lever upwardly towards the hinge ear  222  to prevent inadvertent opening of the cam lever. 
     The drop tee low profile embodiment appears from the side in  FIG. 16B  where the flange  7  merges with a horizontal pipe  202 . The horizontal pipe has an inlet  3  and an opposite outlet  4  each with a coupling slot  5  as before. The flange  7  has its opening  9  as before that receives bulk material from the hopper or bin above the drop tee. The flange has a top surface  7   a  that intersects along part of the perimeter of the opening with the vertical pipe defining the aft edge  13 . Upon the reminder of the opening  9 , the fore edge  12  defines the beginning of the brief flute  210 . The flute curves the forward edge of the flange immediately towards the outlet and begins with a width that of the opening  9  in the flange and then narrows to the diameter of the horizontal pipe. In this embodiment, the flute extends in the direction of flow and towards the immediate vicinity of the coupling slot  5 . 
     Generally centered slightly beneath the flange  7  and below straight edges  8 , a pair of pivot ears  221  provides two parallel plates to which the cam bolt  223  secures upon the bushing  221   b  with its internal coaxial pin  221   a.  The cam bolt has its threaded end  223   a  passing through a hole in the bushing and the pin secured by two nuts equally spaced about the diameter of the bushing. The cam bolt  223  has threaded rod like connections that allow for adjustments in positioning of the door upon the horizontal pipe. The cam bolt extends outwardly from the horizontal pipe and bends around the shoulder  224   b  of the cam lever  224 , generally outside of the door. The cam bolt extends downwardly so that its hook  223   b  engages the groove  224   c  of the cam lever  224 . The cam lever extends within the depth of the door  201  to the opposite side of the drop tee. The door, as before, has an inverted saddle shape that matches the curvature of the horizontal pipe but also rises to allow for a recessed fit of the cam lever beneath the door but tight towards the tee. The door seals to the drop opening  220  upon the gasket  201   a  which compresses upon the lip  226 . The lip and the drop opening curve upwardly, as in a saddle, to slightly above the centerline of the horizontal pipe. The perimeter of the door extends slightly outwardly from the lip causing a reduction in ground clearance below the door of approximately one inch. 
     Similar to  FIG. 11 ,  FIG. 17  shows a lengthwise sectional view of the low profile embodiment of the present invention. This embodiment has an opening  9  in the flange and a drop opening  220  located opposite each other that have the same diameter when seen from above. Bulk material passes through the opening, the horizontal pipe, and then the drop opening without any constriction and thus has faster unloading than in previous drop tees. The opening has a fore edge  12  generally located towards the outlet  4 . The fore edge has a curve, generally concave, that begins at the top surface  7   a  and merges quickly with the inside surface of the horizontal pipe generally opposite the door  201 . Opposite the fore edge, the opening in the flange has the aft edge  13  that extends perpendicular to the top surface and has no curvature towards the inlet. Then opposite the opening  9 , this tee has the drop opening  220  bounded by the lip  226 . The lip extends slightly outward from the surface of the horizontal pipe but provides a flush surface with the interior of the horizontal pipe. The lip extends around the opening as the door bead  227 . The horizontal pipe  102  at the inlet  3  merges with the flange  7  along the upright curvi-linear feature  3   a.  Alternatively, the feature has a shape of one of parabolic, elliptic, or arcuate. 
     And similar to  FIG. 8 ,  FIG. 18  illustrates an end view of the low profile embodiment. This embodiment has an opening as at  9  through the flange that receives bulk material from the hopper or bin. The opening has a known shape and width, round with a diameter in this description. Opposite the opening, this embodiment of the hopper tee has a door  201  that opens below a horizontal pipe  202  and has a drop opening  220  of the same width and shape as opening  9  as in the prior figure for unimpeded discharge of bulk material from the hopper or bin. Beneath the flange, the drop tee embodiment has no vertical pipe but does have the pivot ears  221  and the opposite hinge ears  222  both being collinear and extending perpendicular to the flange and to the horizontal pipe. The pivot ears  221  extend perpendicular beneath the flange and outwardly of the horizontal pipe and provide a pivot point for a cam bolt  223 . The cam bolt turns upon a pin within bushing locating within apertures in the pivot ears. Then the hinge ears  222 , locating opposite the pivot ears in a symmetrically arrangement, allow a cammed handle  224  with a safety pin, or seal wire, removed to pivot downwardly from the horizontal pipe and thus allow the door  201  to open. Then the hinge ears  222  also extend perpendicular and beneath the flange and outwardly from the horizontal pipe and provides a door hinge  225 . The door hinge allows the door to pivot upon one end from a closed to an open position. The cam bolt has threaded rod connections, not shown but within the pivot ears, that allow for adjustments in positioning of the door upon the horizontal pipe. The door is shown here in the closed position where it rests upon the lip  226  defining the drop opening  220 . The door seals upon a gasket  201 , itself upon a raised bead  227 , affixed to the lip. More particularly, the door seals to the horizontal pipe so that the inside surface of the door  201   a  is flush with the inside diameter of the horizontal pipe. The smooth closing of the door upon the horizontal pipe provides for less interruption in the flow of bulk material through the horizontal pipe with the door closed. 
     And,  FIG. 19  shows an exploded view of the low profile version of the drop tee components. This description begins at the bottom of the figure and moves upwardly through the invention. Here, the invention is in the closed position with the cam lever  224  in a generally horizontal orientation but perpendicular to the line of flow through the invention. The cam lever has a foot pedal  224   a  used by truckers and others to open the invention for discharge of product through the opening  9  in the flange  7  and then the bottom opening  220 . As shown in  FIG. 16A , the foot pedal is generally offset in the direction of the outlet  4  thus reducing ground clearance. Inward from the foot pedal, the cam lever has a second aperture  224   e  that receives a seal, clip, or other marking device. Opposite the foot pedal, the cam lever has its shoulder  224   b  that has a greater width than the remainder of the cam lever and curves upwardly. The shoulder has a centered groove  224   c  generally centered therein that receives the hook  223   b  of the cam bolt  223  as previously described when the door is in the closed position and releases from the hook when the door is in the opened position (not shown). The shoulder curves upwardly above the level of the foot pedal and has an aperture  224   d  therethrough with an axis perpendicular to the length of the cam lever. The aperture receives a cam pin  224   f  that fits within a coaxial cam bushing  224   g.  The cam pin provides a pivotal connection of the cam lever to the door  201 . 
     As before, the door has a generally saddle shape with an inside surface  201   c  having the same radius of curvature as the horizontal pipe  202 . This horizontal pipe generally joins the flange without a vertical pipe as in the prior embodiment. The door curves upwardly and towards the cam shoulder in the figure and the door has two spaced apart door ears  201   h  that extend outwardly from the door. Each door ear has an aperture  201   g  therethrough that admits one cam bushing  224   g  between the door ears. Opposite the door ears, the door has the door tab  201   j  that has an aperture  201   k  therethrough that admits one door bushing  201   f  into the lone door tab. The door bushing cooperates with the hinge ears  222  for opening of the door from the horizontal pipe  202  and the remainder of this low profile tee. The door tab extends from the top of the curve of the door generally outwardly from the door and the horizontal pipe when the door is closed. Within the saddle portion of the door, that is down slope from the door ears  201   h  and the door tab  201   j , at least two and preferably four holes  201   e  extend through the thickness of the door. The door holes  201   e  admit a part of the molded gasket  201   a  and are arranged symmetrically. 
     The molded gasket  201   a  also has a similar saddle shape as the inside face of the door. However, the molded gasket has a large opening therethrough for passage of product. The opening has a diameter of at least that of the opening  9  in the flange. Due to the saddle shape of the gasket, the opening attains a perimeter similar to a section through a spherical body. As described previously, the gasket compresses under closure of the door upon the lip  226  of the horizontal pipe. To keep the gasket in position upon the door and upon the lip when the door is closed, the gasket has two, and preferably four, legs  201   b  that extend radially outward from the gasket in the direction of the door. The gasket has a generally symmetrical shape. The legs align and enter the holes  201   e  which positions the gasket properly upon the door. Each leg has a barb  201   d , or button head, with a generally inverted tapered shape with maximum diameter towards the gasket tapering to the leg diameter away from the gasket. Each barb is also spaced down the leg a distance similar to the depth of the hole  201   e.  During installation, a worker pushes the leg into the hole until the barb engages and repeats that for each leg. To remove the gasket, the worker pulls on the leg, stretching it while narrowing it enough for the barb to pass back through the hole  201   e.  Removing the gasket aids the trucker or other worker in cleaning the door and avoids cross contamination of loads. The removable gasket can be removed and cleaned in contrast to prior art drop doors that remained connected to a tee which hindered cleaning and raised the chance of cross contamination with its risk of rejecting a load. 
     The door with its installed gasket rotates upon its door tab  201   j  within the hinge ears  222  of the main portion of the tee. The hinge ears are mutually parallel and spaced apart generally proximate the top of the lower pipe  202 . Each hinge ear has its own aperture that admits a hinge ear bushing  225   a  that receives a spring clip pin  225  that passes through the bushing  225   a  and the door bushing  201   f  and allows the door to pivot away or to drop from the tee, as during unloading. Opposite the hinge ears  222 , the tee has the pivot ears  221  where each pivot ear has its own aperture. The apertures of the pivot ears and the hinge ears are spaced symmetrically about the line of flow of the invention to allow for reverse installation of the door if needed in the field. The door of the low profile tee can be installed for right side or left side of trailer usage. Each aperture in a pivot ear receives a pivot bushing  221   b  that in turn admits a cam pin  221   a  generally centered within the pivot ears. The cam pin has a diametrical hole through its centered that admits the threaded end  223   a  of a cam bolt  223 . The threaded end has a jam nut  223   c  and a washer  223   d  inside of the jam nut located outside of the cam pin and a locking nut  223   e  inside of the cam pin. The locking nut secures the cam bolt upon the cam pin for hinge action of the cam bolt  223  to the cam lever  224  as previously described. 
     Inside of the pivot ears and the hinge ears, the invention has the lower pipe  202  with its outlet  4  to the right in this figure. Inside of the outlet, one can view a portion of the door bead  227  denoting the opening  220  in the bottom of the lower pipe. The outlet has its coupling slot  5  inward of the outlet and the lower pipe has the saddle shaped lip  226  below the hinge ears and the pivot ears. The lower pipe continues rearward to an opposite coupling slot  5  and the inlet  3 . The lower pipe effectively has no vertical pipe in this embodiment as it merges with the flange  7 . One can see the flute line  11  intersecting with the circumference of the lower pipe slightly below the aft edge  13 . The lower pipe  202  in cooperation with the flange  7  at the forward edge  12  has its brief flute  210  locating upon the downstream portion of the tee. The flute begins immediately at the top surface  7   a  of the flange at the forward inside edge  12 . Opposite the forward edge  12 , the flange has an aft edge  13  generally square, or a right angle edge. The flange has two exterior, mutually parallel squared edges  8 , generally parallel to the length of the lower pipe  202 . And the flange  7  extends in a plane generally parallel to the direction of flow and to the length of the lower pipe while it has a pattern of holes therethrough for mechanical connection to a valve body or directly to the hopper, or bin. 
     In the various embodiments described above, each has a horizontal pipe as called a transverse hollow pipe. In the various embodiments with a vertical pipe, it is also called a vertically directed hollow pipe. And the low profile embodiments exclude a vertical pipe and generally merge the transverse hollow pipe directly to the flange. In the various embodiments, the integral tee has a flute, that is a rounded groove, that provides an internal transition in the flow of bulk material through a substantially ninety degree turn. The flute rounds the flow of bulk material where the vertically directed hollow pipe or the flange merges with the transverse hollow pipe. 
     The fluted hopper tee and its various components may be manufactured from many materials, including but not limited to, steel, aluminum, polymers, ferrous and non-ferrous metals, their alloys, polymers, high density polyethylene, polypropylene, silicone, nylon, rubber, ceramics, and composites. The door gasket is preferably made from rubber, silicone, nitrile, EPDM, or fluorocarbon, suitable for contact with food ingredients and of sufficient durometer to withstand increased air flow and pressures. The various bushings in the embodiments of this invention are generally polymer for inserting pins and for maintaining cleanliness. The horizontal pipe, vertical pipe, and flange may also have a zinc surface treatment that resists road grime, salts, other environmental conditions, heat, and abrasion more than existing tees. The tees also have a heat treated steel alloy that accelerates the unloading process unlike some existing tees where the prior alloy components contribute to slowing the unloading process. The heat treated steel alloy also resists abrasion more than prior art tees. Field tests report that the present invention lasts through approximately 98 loads of silica sand while prior steel tees wear away in approximately 80 loads of the same bulk material. The longer life of the present invention leads to a reduction in repair parts expenses and an increase in the time between replacements of tees due to wear from abrasive bulk materials. The metallic parts of the invention can be made of aluminum which lowers the weight of the bottom drop embodiment by seven pounds, or 40%, from existing aluminum drop tees. 
     Variations or modifications to the subject matter of this development may occur to those skilled in the art upon review of the invention and its various embodiments as described herein. Such variations, if within the spirit of this development, are intended to be encompassed within the scope of the invention as explained. The description of the preferred embodiment and as shown in the drawings, are set forth for illustrative purposes only to show the principles of this fluted hopper tee and its various embodiments.