HEAT EXCHANGER FOR BEVERAGE DISPENSER

Abstract: A conduit for use in a fluid circuit of a beverage dispenser. The conduit includes a sleeve positioned therein and a plug positioned within the sleeve. One or more fluid pathways are defined by the sleeve and the plug so as to permit fluid flow therethrough.

Description: HEAT EXCHANGER FOR BEVERAGE DISPENSER Technical Field The present invention relates to beverage dispensers and more particularly relates to beverage dispensers with modular components such as a plurality of modular syrup cooling coils and a modular carbonator tank. Background of the Invention Conventional beverage dispensers generally include several chilled water circuits, several chilled syrup circuits, and several dispensing valves. Each of the water and syrup circuits leads to a dispensing valve such that each dispensing valve has at least one syrup circuit and one or more water circuits connected thereto. Examples of conventional beverage dispensers include commonly-owned U.S. Patent No. 4,781,310 and U.S. Patent No. 4,801,048, both entitled "Beverage Dispenser", and commonly-owned U.S. Patent No. 5,190,188, entitled "Convertible Beverage Dispenser," incorporated herein by reference. More specifically described, known beverage dispensers generally include a series of water and syrup coils that are positioned within an ice water bath or within a cold plate. As the liquid travels through the coils, the liquid exchanges heat through the coils with the water in the ice water bath such that the liquid is chilled to the appropriate temperature by the time it reaches the dispensing valve. These coils generally are accordion-like in shape so as to provide as long a travel path as possible with as much surface area as possible in contact with the ice water bath. Examples of conventional water and syrup coils and ice water baths are found in the references described above. Further, an example of a cold plate construction includes U.S. Patent No. 4,617,807, entitled "Involute Coil Cold Plate," incorporated herein by reference. These known beverage dispensers generally also include a carbonator unit to produce carbonated soda water. The carbonator unit mixes carbon dioxide gas with the incoming water. The incoming water is mixed with the carbon dioxide gas such that soda water is provided to each of the water circuits and the dispensing valves. The carbonator unit is generally a welded stainless steel assembly or a similar construction. The carbonator unit, or some part of the unit, also may be chilled within the ice water bath. Although these conventional beverage dispensers as described above efficiently chill both the water and the syrup, the systems can be expensive to manufacture and to maintain. The use of the long syrup cooling coils and the long water cooling coils results in significant material costs because of the amount of tubing involved. Further, the tubing must be bent into the desired accordion shape. The coils are then generally welded into place within the circuits. The tubing usually must be passivated near the weld spots, again increasing the cost of construction. Conventional beverage dispensers also are difficult to retrofit or expand. Because of the expense of the tubing material, the actual number of dispensing valves, water circuits, and syrup circuits in a given unit is usually predetermined. The tubing material is too expensive to manufacture a unit with multiple circuits while only using one or two. In other words, it is simply too expensive to cast the maximum number of coils and then connect these coils only as needed. Finally, there is no commonality between the cooling coils used in the cold plates and the coils used in the ice water baths. What is needed, therefore, are improved beverage dispenser components that provide adequate cooling with less manufacturing and retrofitting expense. Further, the components should be easily interchangeable and upgradable and also be safe for use with various types of beverages. Summary of the Invention The present invention provides a conduit for use in a fluid circuit of a beverage dispenser. The conduit includes a sleeve positioned therein and a plug positioned within the sleeve. One or more fluid pathways are defined by the sleeve and the plug so as to permit fluid flow therethrough. Specific embodiments of the present invention include the plug having a core and one or more walls. The sleeve may be stainless steel and the plug may be a thermoplastic. The sleeve, the core, and the walls define the fluid pathways. The plug includes a first end and a second end such that the fluid pathway extends from the first end to the second end. The fluid pathway may be a single or a multiple helix pathway or any similar design. The fluid pathway may vary in size from the first end to the second end of the plug. The core also may include a central fluid chamber with an index positioned between the fluid pathway and the central fluid chamber so as to direct the fluid flow therethrough. The plug also may include a plurality of discs positioned about the core. Each disc may include a drain and a barrier. The fluid circuit may be a syrup circuit or a water circuit. A further embodiment of the present invention provides for a modular beverage dispenser having a number of syrup circuits and a means for cooling the syrup circuits. The beverage dispenser includes a number of syrup sleeves fixedly mounted within the cooling means and one or more plugs. The plugs are positioned within the syrup sleeves so as to form one or more syrup modules. One or more fluid pathways are defined within each syrup module by the plug and the syrup sleeve. The syrup modules are connected within the syrup circuits. The means for cooling the syrup circuits include an ice water bath and a cold plate. A further embodiment of the present invention provides for a modular carbonator unit for use in a fluid circuit of a beverage dispenser. The carbonator unit includes a sleeve positioned within the fluid circuit and a plug positioned within the sleeve. The plug includes a first end, a second end, and a central tie rod so as to define a mixing chamber. The plug also may include a plurality of baffles. The sleeve may be stainless steel and the plug may be a thermoplastic. The plug may include a central aperture. The carbonator unit may further include a float control device positioned therein. The float control device includes a switch and a float. The switch may be a magnetic sensor and the float may be an expanded polystyrene or similar material. The switch also may include a ferric metal layer while the float may include a magnet so as to provide magnetic attraction. A further embodiment of the present invention provides for a modular beverage dispenser having a number of water circuits and a means for cooling the water circuits. The beverage dispenser also includes a carbonator sleeve mounted within the cooling means. A carbonator plug is positioned within the carbonator sleeve so as to form a carbonator module. The carbonator module is connected to the water circuits. The means for cooling the water circuits include an ice water bath and a cold plate. A further embodiment of the present invention provides for a modular beverage dispenser having a number of syrup circuits, a number of water circuits, and a means for cooling the circuits. The beverage dispenser includes a number of syrup sleeves and a carbonator sleeve mounted within the cooling means. Syrup plugs are positioned within the syrup sleeves so as to form one or more syrup modules. A carbonator plug is positioned within the carbonator sleeve so as to form a carbonator module. The carbonator module is connected to the water circuits and each of the syrup modules is connected to one of the syrup circuits. Brief Description of the Drawings Fig. 1 is a side cross-sectional side view of a prior art beverage dispenser. Fig. 2 is a schematic view of a prior art water circuit with a carbonator tank. Fig. 3 is a perspective view of the syrup cooling module of the present invention with the plug elevated from the sleeve. Fig. 4 is a side cross-sectional side view of the syrup cooling module of Fig. 3. Fig. 5 is a perspective view of the plug showing the cooling path in partial phantom lines. Fig. 6 is an end view of the plug of Fig. 5. Fig. 7 is a perspective view of a triple helix plug of the present invention. Fig. 8 is an alternative embodiment of the present invention showing a perspective view of a plug with a plurality of discs. Fig. 9 is an alternative embodiment of the present invention showing a side cross-sectional side view of a syrup cooling module attached to a dispensing valve. Fig. 10 is a perspective view of the plug of the present invention used for ambient fluids. Fig. 1 1 is an end view of the plug of Fig. 10. Fig. 12 is a side cross-sectional view of the carbonator module of the present invention. Fig. 13 is a top cross-sectional view of the carbonator module of Fig. 12 taken along line 12-12. Fig. 14 is an alternative embodiment of the present invention showing a side cross-sectional view of an alternative carbonator module. Fig. 15 is a cut-away view of the beverage dispenser showing the ice water tank and the sleeves of the present invention. Fig. 16 is a cut-away view of the beverage dispenser showing the cold plate and the sleeves of the present invention. Detailed Description of the Invention Referring now to the drawings, in which like numerals refer to like elements throughout the several views, Figs. 1 and 2 show a prior art beverage dispenser 10. The beverage dispenser 10 generally includes a refrigeration system 20. The refrigeration system 20 usually includes a compressor 30 and a series of evaporator coils 40. The compressor 30 is positioned on a refrigeration deck 45. The evaporator coils 40 extend below the refrigeration deck 45 and into an ice water tank 50. The compressor 30 and the evaporator coils 40 of the refrigeration system 20 remove heat from the water within the ice water tank 50 as is known to those skilled in the art. The refrigeration system 20 also may include an agitator 55. The beverage dispenser 10 also includes a plurality of dispensing valves 60. The dispensing valves 60 are generally each connected to one or more water circuits 70 and at least one syrup circuit 80. The syrup circuits 80 generally extend from a syrup source 85, to a syrup pump 90, to a plurality of syrup coiling coils 100, and to one of the dispensing valves 60. The syrup source 85 may be a bag- in-box, a figal, a syrup tank, or any other type of conventional syrup storing device. The syrup cooling coils 100 are generally made from metal tubing. The metal may be stainless steel or other conventional types of substantially non-corrosive metals. Because the syrup usually arrives from the syrup source 85 at an ambient temperature, the syrup cooling coils 100 are positioned within the ice water tank 50 so as to chill the syrup to the appropriate temperature before the syrup reaches the dispensing valve 60. The syrup coiling coils 100 may be in an accordion-like shape. This accordion-like shape helps to maximize the travel path of the syrup within the ice water tank 50 and therefore maximize the heat transfer surface area so as to provide efficient cooling for the syrup. The water circuits 70 generally extend from a water intake 110, to a water pump 120, to a plurality of water cooling coils 130, to a carbonator unit 140, perhaps through additional water coiling coils 130, and to one of the dispensing valves 60. The carbonator unit 140 may be placed in any position within the water circuits 70. All of the water circuits 70 usually share the water intake 110, the water pump 120, at least a first set of water cooling coils 130, and the carbonator unit 140. The water circuits 70 then branch out individually through additional water cooling coils 130 and to the dispensing valves 60. At the dispensing valve 60, the soda water mixes with the syrup so as to provide a beverage such as a soft drink. As with the syrup cooling coils 100, the water coiling coils 90 are generally made from metal tubing. The metal may be stainless steel or other conventional types of substantially non-corrosive metals. The water cooling coils 130 are positioned within the ice water tank 50 so as to chill the water to the appropriate temperature. The water coiling coils 130 also may be in an accordion-like shape to maximize the travel path of the water and therefore maximize the heat transfer. As is shown in Fig. 2, the carbonator unit 140 generally includes a housing 150 with a carbon dioxide intake line 160 and ports for the water circuit 70, an intake water line 170 and a soda water line 180. The water from the intake water line 170 is mixed with the carbon dioxide gas from the carbon dioxide intake line 160 within the housing 150 as to create soda water. The housing 150 also may include baffles (not shown) therein to promote this mixing. The housing 150 itself also may be chilled by the ice water tank 50, by a cold plate, or by other conventional cooling means. Figs. 3 - 6 show a syrup cooling module 200 of the present invention. Although the syrup cooling module 200 is shown, the invention is equally applicable to a water cooling module used within the water circuits 70. The syrup cooling module 200 includes a plug 210, a sleeve 220, an inlet fitting 230, and an outlet fitting 240. The plug 210 is sized and positioned within the sleeve 220. The plug 210 forms a cooling path 250 within the sleeve 220 as is shown in Fig. 4. The cooling path 250 may include a series of walls 260 formed on a core 265 of the plug 210 that create one or more pathways 270. In the example of Figs. 3 - 6, a single wall 260 forms a helix down the length of the plug 210 and defines the pathway 270. Although a helix-shaped pathway 270 is shown, almost any shape can be used for the cooling path 250. The plug 210 also may have a central chamber 280. The central chamber 280 may have access to the cooling path 250 by one or more conduits 290. The conduits 290 may have a movable index 295 so as block the conduits 290 or the central chamber 280. The index 295 permits the syrup to flow down the pathway 270 and back up the central chamber 280, only down the central chamber 280, only down the pathway 270, or in any combination of routes in either direction. The plug 210 preferably is made of a molded thermoplastic such as nylon. The sleeve 220 is preferably made from stainless steel or other types of substantially non-corrosive metals with good heat transfer characteristics. The sleeve 220 may be pre-passivated. The plug 210 may be sealed within the sleeve 220 by upper and lower sealing rings 300. The inlet and outlet fittings, 230, 240 may be positioned on either end of the plug 200. Further, the fittings 230, 240 may be positioned within a notch 310 so as to securely retain the plug 210 within the sleeve 220. The height, thickness, and shape of the wall 260 or walls 260 of the plug 210 may be varied so as to change the cooling and flow characteristics of the syrup through the module 200. For example, a long but thin pathway 270 would provide increased surface area for more efficient cooling. Such a pathway 270, however, may result in a significant pressure drop through the module 200. Conversely, a short but wide pathway 270 would not create a significant pressure drop but also may not provide a sufficient amount of cooling. Further, the nature of the pathway 270 may vary within the sleeve 220 itself. For example, the pathway 270 near the inlet 230 may be long and thin so as to promote maximum heat transfer while the pathway 270 near the outlet 240 may be larger to allow for minimizing the pressure drop. In sum, the pathway 270 may be configured to maximize fluid contact with the inside of the sleeve 220; to maximize the syrup volume within the sleeve 220; to minimize the pressure drop through the module 200 as a whole; to maximize syrup agitation within the module 200; and other combinations of the above. Further, fluids that do not need to be cooled can travel straight through the central chamber 280. In the example of Fig. 5, the module 200 may be about 17.375 inches in length. The core 265 may be about 1.3 inches in thickness with the walls 260 being about 0.06 inches in height from the core 265. The core 265 fits securely within the sleeve 220 such that the walls 260 form the pathways 270. The pathway 270 may have a pitch of about 1.0 inch. This design may result in dropping the temperature of the syrup from about 75 degrees Fahrenheit to about 52.5 degrees with a pressure drop of about 9 psi. Numerous variations on the design of the plug 210 and the cooling path 250 are possible. For example, a multiple helix cooling path 250 may be used. As is shown in Fig. 7, a triple helix cooling path 250 is used with three (3) pathways 270 therein, a first pathway 320, a second pathway 330, and a third pathway 340. The pathways 320, 330, 340 may be substantially rectangular in shape. If the plug 210 itself is about sixteen (16) inches in length and the radius of the sleeve 220 is about 0.715 inches, the pathways 320, 330, 340 may each have a width of about 0.9375 inches and a height of about 0.16 inches. This design results in the total cold surface area of the module 200 being about 21.146 square inches or about 88.26 percent of the maximum surface area. This design may result may result in dropping the temperature of the syrup from about 75 degrees Fahrenheit to about 50 degrees with a pressure drop therein of only about 2 psi. A similar alternative would use a number of thin, narrow vertical splines or pathways as the cooling path 250. The plug 210 also may embody any number of alternative shapes. For example, the present invention could use a series of disks 350 positioned about the plug 210 as is shown in Fig. 8. Each of the disks 350 may have a drain 360 such that the syrup falls onto each disk 320, circulates therein, and then again passes through the drain 360 on to the next disk 320. Further, each disk 350 also may have a barrier 365 so as to provide for agitation of the syrup. This agitation results in a turbulent fluid flow and increased cooling efficiency. The barriers 365 and the drains 360 may alternate locations on each disc 350. The syrup entering the inlet fixture 230 would fall through the drain 360, run into and over the barrier 365, and circulate until it again falls through the next drain 360. As the syrup travels the cooling path 250, heat transfer takes place due to the contact of the syrup with the sleeve 220. The syrup travels along the length of the plug 210 and then either out the outlet fitting 240 or back up through the central pathway 280 and then out the outlet fitting 240. Fig. 9 shows a further embodiment of the present invention. In this case the sleeve 220 is directly attached to a dispensing valve or pump 370. The dispensing valve 370 may be similar to that described in commonly owned U.S. Serial No. 09/245,594, entitled "Modular Volumetric Valve System", incorporated herein by reference. By combining the sleeve 220 and the valve or pump 370, additional syrup circuits 80 are easily added to the beverage dispenser 10. This combination eliminates several parts, leak points, and provides a more compact assembly. As is shown in Figs. 10 and 11, the present invention also may be used to transport fluids at an ambient temperature. In this case, an ambient module 375 may include a plug 380 within the sleeve 220. The plug 380 may include a central chamber 385. Further, an outer pathway 390 may be defined by the sleeve 220 and the plug 380. The outer pathway 390 may be accessed by a conduit 395. Use of the outer pathway 390 is not required. Syrup or other types of fluids may pass through the ambient module 375 by either or both the central chamber 385 and the outer pathway 390. Because the ambient module 375 does not include the use of the walls 260 or other types of barriers to slow down the flow of syrup therethrough, no appreciable heat transfer may take place. Further, the ambient module 375 also may be insulated so as to limit any further heat transfer. The present invention further provides for a modular carbonator unit 400. As is shown in Figs. 12 and 13 the carbonator unit 400 includes a carbonator sleeve 410 and a carbonator plug 420. The plug 420 fits within the carbonator sleeve 410 and may be sealed by upper and lower O-rings 425. The carbonator sleeve 410 may be made from stainless steel or other types of substantially non-corrosive metals with good heat transfer characteristics. The sleeve 410 may be pre-passivated. The sleeve 410 also may be made from conventional thermoplastics. The sleeve 410 is generally cylindrical in shape. The carbonator plug 420 acts largely as an integral dip tube with a tie rod so as to hold the carbonator unit 400 together. The carbonator plug 420 is generally a molded thermoplastic unit. The carbonator plug 420 generally includes a first end 430, a second end 435, and a central tie rod 440. The first end 430, second end 435, and the central tie rod 440 preferably are formed as an integral piece. Alternatively, these elements may be fixedly attached by conventional means. The central tie rod 440 ties the first end 430 and the second end 435 together. The carbonator sleeve 410, the first end 430, the second end 435, and the central tie rod 440 form a mixing chamber 437. The first end 430 and the second end 435 are generally circular in shape so as to seal the carbonator unit 400 within the carbonator sleeve 410. The first end 430 and the second end 435 may have various apertures formed therein, such as a water port 445, a carbon dioxide port 450, and a soda water port 455. The first end 430 or the second end 435 also may have a float control port 460 for a float control device 465 as described in more detail below. The first end 430 or the second end 435 also may have one or more pressure relief valves (not shown) positioned therein. As is shown in Fig. 13, the tie rod 440 is preferably "H" shaped or "double T" shaped so as to provide stability. Various types of baffles 467 may be attached to the tie rod 440. The float control device 465 is used to control the operation of the water pump 120. The float control device generally includes a switch 470 and a float 475. The switch 470 may be a magnetic sensor or any type of conventional mechanism that breaks or creates an electrical circuit when activated. For example, a conventional contact switch may be used. A preferred magnetic switch may be manufactured by Reed Electronics, AG of Gewerbering, Switzerland. The float 475 may be any type of conventional buoyant material such as expanded polystyrene. The float 475 is attached to the switch 470 along a bar 480. The bar 480 may be an elongated rod or may be made from a flexible material such that the float 475 can be inserted thereon. The float 475 also includes a magnet 485 positioned therein. The magnet 485 may be any type of conventional magnetic or magnetizable metal material. The switch 470 is activated as the magnet 485 within the float 475 moves up and down with the water level towards and away from the switch 470. When the water level declines, the switch 470 activates the water pump 120. Likewise, the switch 470 turns the water pump 120 off as the water level in the carbonator unit 400 rises. The switch 470 also may include a ferric metal layer 487 thereon that is attracted to the magnet 485. As the water level within the carbonator unit 400 declines, the magnet 485 maintains the float 475 in contact with the switch 470 and the ferric metal layer 487 for a somewhat longer period of time than would be expected with only buoyancy supporting the float 475. Magnetic attraction alone, however, is not enough to hold the float 475 to the switch 470. Some buoyant force is required. The additional magnetic force limits the constant turning on and off of the water pump 120 with slight variations in the water level of the carbonator unit 400. Fig. 14 shows an alternative embodiment of the carbonator unit 400. In this embodiment, a carbonator plug 490 has a central aperture 495. As such, the water port 445 is positioned on the second end 435 of the carbonator unit 400. The water travels in through the water port 445 and then up the central aperture 495 before mixing within the carbonator unit 400. The use of this central aperture 495 allows for the water port 445 to be within the ice water bath so as to keep the water cold at all times. A dip tube also could be used so as to provide a water exit out of the top of the carbonator unit 400. In use, the carbonator plug 420 is positioned within the carbonator sleeve 410. The carbonator unit 400 is then attached to the water circuits 120. Water is introduced into the mixing chamber 437 of the carbonator unit 400 via the water port 445 while carbon dioxide is introduced into the carbonator unit 400 via the carbon dioxide port 450. The water and the carbon dioxide mix within the carbonator unit 400 so as to produce soda water. The baffles 467 may aid in this mixing. Further, the baffles 467 also prevent undissolved carbon dioxide bubbles from getting into the soda water port 465. Finally, soda water is removed from the carbonator unit via the soda water port 465. Fig. 15 shows a cut-away view of a conventional beverage dispenser 500 similar to that described above in Fig. 1. The valves and the refrigeration deck have been removed for clarity such that an ice water bath 510 may be seen. In this case, a plurality of the syrup sleeves 220 and one of the carbonator sleeves 420 are pre-installed into the dispenser 500. The syrup sleeves 220 are positioned where the syrup cooling coils 100 of Fig. 1 were located. Likewise, the carbonator sleeve 410 is located where the carbonator tank 140 of Fig. 1 was positioned. The sleeves 220, 410 may be held into place within the water bath 510 by conventional means. The plugs 210, 420 may then installed at any time, such as when the dispenser 500 is initially assembled or later when the dispenser 500 is in the field. The syrup plugs 210 may be inserted into any or all of the sleeves 220. The syrup cooling modules 200 are then hooked up via the inlets 230 and the outlets 240 to the syrup circuits 80 in a conventional fashion. Any unused sleeves 220 may be capped for future use. Alternatively, existing syrup coils may be removed from the dispenser 500 and replaced with the sleeves 220. Likewise, the carbonator module 400 is then hooked up to the water circuits 70 in a conventional fashion. Fig. 16 shows a similar set up using a cold plate 520. The sleeves 220, 410 are cast within the cold plate 520 itself. The plugs 210, 420 may then be added at any time with the unused syrup sleeves 220 capped for future use. The sleeves 220, 410 may be placed or pressed within the cold plate 520 after casting.

Claims: CLAIMS We claim: 1. A conduit for use in a fluid circuit of a beverage dispenser, comprising: a sleeve positioned within said fluid circuit; a plug positioned within said sleeve; and one or more fluid pathways defined by said sleeve and said plug so as to permit fluid flow therethrough. 2. The conduit of claim 1, wherein said one or more fluid pathways comprise at least one helix pathway. 3. The conduit of claim 1, wherein said core comprises a central fluid chamber and further wherein said plug comprises an index positioned between said fluid pathway and said central fluid chamber so as to direct said fluid flow. 4. The conduit of claim 1 , wherein said fluid circuit comprises a syrup circuit 5. The conduit of claim 1 , wherein said fluid circuit comprises a water circuit. 6. A modular beverage dispenser having a plurality of syrup circuits and a means for cooling said syrup circuits, comprising: a plurality of syrup sleeves mounted within said cooling means; one or more plugs; each of said one or more plug positioned within one of said plurality of syrup sleeves so as to form one or more syrup modules; one or more fluid pathways defined within each syrup module by said plug and said syrup sleeve; and each said syrup module connected to one of said syrup circuits. 7. A modular carbonator unit for use in a fluid circuit of a beverage dispenser, comprising: a sleeve positioned within said fluid circuit; a plug positioned within said sleeve; and said plug comprising a first end, a second end, and a central tie rod; wherein said sleeve, said first end, said second end, and said central tie rod comprise a mixing chamber and wherein said plug comprises a plurality of baffles. 8. The modular carbonator unit of claim 7, further comprising a float control device positioned therein, and wherein said float control device comprises a switch and a float. 9. A modular beverage dispenser having a plurality of water circuits and a means for cooling said water circuits, comprising: a carbonator sleeve mounted within said cooling means; a carbonator plug positioned within said carbonator sleeve so as to form a carbonator module; and said carbonator module connected to said water circuits. 10. A modular beverage dispenser having a plurality of syrup circuits, a plurality of water circuits, and a means for cooling said circuits, comprising: a plurality of syrup sleeves and a carbonator sleeve mounted within said cooling means; one or more syrup plugs; each of said one or more syrup plug positioned within one of said plurality of syrup sleeves so as to form one or more syrup modules; and a carbonator plug positioned within said carbonator sleeve so as to form a carbonator module; said carbonator module connected to said water circuits and each said syrup module connected to one of said syrup circuits.

Inventors: CREDLE WILLIAM S, DURHAM SAMUEL, EDWARDS WILLIAM A, LAUGHLIN RICHARD L, QUARTARONE DANIEL S, CREDLE, WILLIAM, S., DURHAM, SAMUEL, EDWARDS, WILLIAM, A., LAUGHLIN, RICHARD, L., QUARTARONE, DANIEL, S.
Applicants: COCA COLA CO, THE COCA-COLA COMPANY
Application year: 2000
Main classification: B67D1
IPC codes: B67D1, F25D11, F28D7, F28F13