the present disclosure is directed to a system and method for applying a fluid material to an article using a fluid distribution or rotary atomizing device , and to an apparatus that includes the device , and to a method of using the device and apparatus . the rotary atomizing device allows fluids of varying viscosities to be applied to a surface . regardless of the viscosity of the fluid , the rotary atomizing device is also useful for applying fluids that may include relatively large amounts of particulate material . the device has particular utility for applying batter to foods , especially relatively viscous batter , up to at least about 50 percent solids content . in a preferred embodiment , the device and method may be used to dispense a batter onto food products to coat the food products . the device and method allow an unexpectedly wide range of batter viscosities to be applied to the food products , as well as batters that include relatively large particles , without clogging the apparatus and minimizing contamination of the batter . one embodiment of a rotary atomizing device 10 according to the present disclosure is illustrated with reference to fig1 - 5 . fig1 illustrates device 10 in a perspective view including two spaced apart opposed discs 12 a , b . as shown in fig2 and 3 , spaced apart opposed discs 12 a , b are substantially symmetrical about plane “ p 1 ,” and each includes an inner surface 14 a , b , an outer surface 16 a , b , and a perimeter 18 a , b . in the present embodiment , the spacing s 1 between discs 12 a , b is preferably about 2 inches , and each disc 12 a , b preferably has a diameter d 1 of about 7 inches . a centrally disposed hub 20 having an outer surface 22 connects inner surfaces 14 a , b of discs 12 a , b . an axial bore 24 extends through hub 20 in coaxial alignment with axis “ a ,” which is substantially perpendicular to plane p 1 . preferably , bore 24 includes steps 24 a and 24 b , for engagement with bushing 26 and drive shaft 30 , as shown in fig3 the purpose of which will be explained in greater detail below . bushing 26 is preferably a quick - mount keyless bushing or transtorque bushing . a plurality of apertures 32 preferably may be disposed radially about bore 24 of central hub 20 to allow engagement of central hub 20 to each disc 12 a , b by fasteners 34 , which are illustrated herein as screws . as shown in fig2 - 4 taken together , outer surface 22 of central hub 20 includes two surfaces 22 a , b that intersect at plane p 1 . outer surfaces 22 a , b are substantially symmetrical with respect to plane p 1 , and extend from plane p 1 toward perimeter 18 a , b , respectively , to define an angle θ 1 , which is preferably less than about 90 degrees , more preferably in the range of about 30 degrees to about 60 degrees . thus , outer surfaces 22 a , b provide central hub 22 with a substantially vee - shaped , or hourglass - shaped outer surface 22 . the angle θ 1 of outer surface 22 of hub 20 may be important for maximizing the amount of fluid that may be distributed from device 10 , as will be explained in greater detail below . as shown in fig5 in the present embodiment , central hub 22 preferably has a diameter d 2 of about 2 . 5 inches . referring back to fig2 and 3 , flanges 36 a , b extend substantially perpendicularly from each inner surface 14 a , b along perimeter 18 a , b . flanges 36 a , b may have a width w 1 ranging from about ¼ inch to about 2 inch , more preferably about ½ inch to about 1½ inch . in the present embodiment , width w 1 is about ½ inch . for ease of machining , the intersection of inner surface of each disc 12 a , b with flanges 36 a , b preferably has a radius of about ¼ inch . it is thought that the radius enhances the movement of fluid towards the end of the flange , where it becomes atomized . however , a perpendicular intersection of inner surface of each disc 12 a , b with flanges 36 a , b is also possible . in some embodiments , inner surface 14 a , b of each disc 12 a , b may include a recess 38 a , b into which shoulder 39 a , b of central hub 20 may be received . preferably , recess 38 a , b may have a diameter sufficient to allow friction fitment of central hub 20 therein . discs 12 a , b and central hub 22 may be unitary or integral , depending on the material of construction and the method of constructing the discs . preferably , when used in the food industry , device 10 is machined or molded from a food - grade material including plastics such as delrin or ultra - high molecular weight polyethylene ( umhw - pe ) and metal such as 304 / 316 grade stainless steel . those of skill in the art will recognize that the dimensions of device 10 may vary as needed depending on the particular application in which it is used . all surfaces of device 10 , in the present embodiment , are substantially smooth and flat . those of skill in the art will also recognize that it is possible for any or all of the surfaces of device 10 to include patterns or grooves machined therein , as is known in the art of rotary atomizing , if it will improve the performance of the devices . another embodiment of a rotary atomizing device 100 according to the present disclosure will now be described with reference to fig6 - 10 . device 100 includes a plurality of sequentially arranged discs 102 . in preferred embodiment , capping discs 104 may be positioned at opposing ends of the sequence of discs 102 . the structure of discs 102 allow them to be coupled together in sequential arrangement , which increases the amount of fluid that may be applied to a surface or allows the application of fluid to a larger surface area than may be possible with device 10 . a single disc 102 will be described now with reference to fig7 - 8 . as shown , disc 102 is substantially symmetrical in construction about plane “ p 2 .”. each disc 102 includes opposing side surfaces 106 a , b having a perimeter 108 . a centrally disposed frustum 108 a , b may be disposed on each side surface 106 a , b . frustums 108 a , b each have a top surface 110 a , b and an outer surface 112 a , b . an axial bore 114 extends through frustums 108 a , b in coaxial alignment with axis “ a 2 ,” which is substantially perpendicular to plane p 2 . flanges 116 a , b extend substantially perpendicularly from each side surface 106 a , b along perimeter 108 . preferably , a plurality of apertures 118 are formed in top surfaces 110 a , b of each frustum 108 a , b for receiving pins 120 , as explained in greater detail below . a single capping disc 104 will now be illustrated with reference to fig9 - 10 . as shown , disc 104 includes a perimeter 108 and two opposing sides 120 a , b . side 120 a is substantially similar in construction to side surface 106 a of disc 102 , whereas side 120 b is substantially planar . thus , side 120 a includes centrally disposed frustum 108 a having atop surface 110 a and an outer surface 112 a . an axial bore 114 extends through frustum 108 a in coaxial alignment with axis “ a 3 ,” which is substantially perpendicular to plane p 3 . bore 114 includes a step 122 for receiving a transtorque bushing . flange 116 a extends substantially perpendicularly from side surface 120 a along perimeter 108 . preferably , a plurality of apertures 118 are formed in top surface 110 a of frustum 108 a for receiving pins 120 . as in the previous embodiment , the dimensions of discs 102 and capping discs 104 may vary depending on the particular application in which they are used . in the present embodiment , each disc 102 and 104 has an outer diameter d 1 of about 7 inches . the diameter d 2 of the central hub is preferably about 2 . 5 inches , and the spacing s 1 between each sequential disc 102 and between disc 102 and capping disc 104 and is preferably about 2 inches . as in the previous embodiment , discs 102 and 104 may have a unitary or integral construction , depending on the material of construction and the method of constructing the discs . preferably , when used in the food industry , device 100 is machined or molded from a food - grade material including plastics such as delrin or ultra - high molecular weight polyethylene ( umhw - pe ) and metal such as 304 / 316 grade stainless steel . those of skill in the art will recognize that the dimensions of device 100 may vary as needed depending on the particular application in which it is used . all surfaces of device 100 , in the present embodiment , are substantially smooth and flat . those of skill in the art will also recognize that it is possible for any or all of the surfaces of device 10 to include patterns or grooves machined therein , as is known in the art of rotary atomizing , if it will improve the performance of the devices . fig1 - 14 illustrate another aspect of the present disclosure , which is an apparatus 150 for coating articles with a fluid material , preferably for coating articles of food with batter . an exemplary apparatus 150 is shown in perspective view in fig1 and 12 . as shown , apparatus 150 includes a frame 152 supporting a chamber 154 having an inlet end 156 and an outlet end 158 . chamber 154 includes a base 160 connected to a cover 162 . base 160 preferably has downwardly sloping sides 160 a , b that intersect at the lower end 162 of base 160 above a fluid reservoir 164 . cover 162 may be hingedly connected to base 160 in preferred embodiments . a control panel 166 may be suitably disposed on cover 162 to enable an operator to operate various controls . power to apparatus 150 may be supplied by any suitable means . a plurality of the previously described rotary atomizing devices 10 are disposed within cover 162 and base 160 . although illustrated herein with several rotary atomizing devices , those of skill in the art will recognize that only one may be necessary , depending on the particular application . similarly , any number of devices 10 may be included in an apparatus , if needed or desired . as shown best in fig1 , two devices 10 a , b are disposed in cover 162 . each device 10 a , b is supported on drive shafts 168 a , b that extend through cover 162 to connect to motor 170 a , b which drives shafts 168 a , b . base 160 includes a support member 172 for supporting several of the foregoing rotary atomizing devices . as best shown in fig1 and 14 when taken together , support member 172 has a drawer - like construction which allows it to be slidably removed from base 160 using , for example , handle 174 . two devices 10 a and two devices 10 b are disposed on opposites of drawer 172 . each of the four devices 10 a , b are supported on drive shafts 176 a , b extending through the wall of drawer 172 to connect to motors 178 a , b , which rotatably drive shafts 176 a , b . a fluid dispensing tube 180 ( not illustrated in each drawing ) may be disposed within each device 10 a , b proximate the outer surface of the central hub . dispensing tube 180 may have a diameter ranging from about ⅛ inch to about 1 inch , more preferably about ¼ inch to about ¾ inch . in the present embodiment , the diameter of dispensing tube 180 is about ½ inch . one exemplary arrangement of a fluid dispensing tube 180 between discs 12 a , b is illustrated in fig1 . fluid dispensing tube 180 may distribute a fluid drawn from fluid reservoir 164 containing a source of fluid to be dispensed by a variety of suitably connected fluid dispensing lines . as illustrated in fig1 - 13 , two motor driven pumps 182 , 184 are supported on frame 152 . pump 182 draws fluid from reservoir 164 through line 186 and dispenses the fluid through lines 188 which extends through the face of drawer 172 to fluidly connect to devices 10 a , b , as shown best in fig1 . similarly , pump 184 draws fluid from reservoir 164 through line 190 ( see fig1 ) and dispenses the fluid through lines 192 a , b which are fluidly connected to devices 10 a , b within cover 162 . the foregoing dispensing lines may have a diameter ranging from about ½ inch to about 2 inch , more preferably about ¾ inch to about 1½ inch . in the present embodiment , the diameter of the dispensing lines is about ½ inch . a conveyancing assembly indicated generally at 194 includes a motor 196 for rotatably driving a plurality of rollers 198 disposed at various locations within base 160 and about which a conveyor member 199 , which is illustrated herein as a belt . belt 199 is operably disposed for transverse movement within base 160 from inlet end 156 to outlet end 158 . such conveyancing assemblies are well known in the art and will not be described in detail herein . preferably , rollers 198 are disposed such that conveyor member 199 substantially conforms to the sides 160 a , b of base 160 . preferably , when used in the food industry , the components of apparatus 150 that come into contact with food may be constructed from a food - grade material including plastics such as delrin or ultra - high molecular weight polyethylene ( umhw - pe ) and metal such as 304 / 316 grade stainless steel . those of skill in the art will recognize that the dimensions of apparatus 150 may vary as needed depending on the particular application in which it is used . in operation , power to the system is provided , and articles to be coated , preferably food articles , are placed on the conveyor belt . the rotary atomizing devices 10 a , b may be set to rotate at a rate of about 1500 rpm to about 2000 rpm , with about 1725 rpm being optimal . generally , at slower rates of rotation , large droplets are dispensed from the discs instead of a fine mist of batter . moreover , the direction in which the batter is dispensed is narrower , resulting in build - up of thicker , more uneven coating on the food product . also generally , at high rates of rotation , the dwell time of the batter in the device is insufficient to allow it to acquire sufficient momentum to be atomized and thereby dispensed as a fine mist . batter may then be drawn from the reservoir and distributed to each rotating rotary atomizing device in both the cover and the base , while the conveyor belt begins moving . typical line speeds in the food industry range from about 50 rpm to about 100 fpm . the present methods provide expanded lines speed capability ranging from about 5 fpm up to about 200 fpm or more , in some instances . the increased line speeds that are possible with the present method are due in part to the increased capacity of the present rotary atomizing devices and systems , as well as the increased dwell time of the batter in the rotary atomizing devices . those of skill in the art will recognize that modifications may be required to operate at such line speed . for example , it may be necessary to use a different conveyor belts , or to change the rotation rate of the atomizers , to changing the number and position of the rotary atomizing devices , to change the spacing between the rotary atomizing devices and the conveyor belt . such modifications will be apparent to those of ordinary skill in the art and may be achieved using routine experimentation . batter from the food distribution tubes in both the cover and the base is sprayed onto the central hub of each rotary atomizing device . when the batter comes into contact with the outer surface of the central hub , the batter is deflected such that it impacts the flanges of discs . the flanges increase the dwell time of the batter in the disc , allowing the batter to gain the momentum necessary to be atomized as the batter leaves the disc . thus , the inclusion of the flange in the disc design allows more viscous batters to be dispensed . the increased momentum provide the necessary energy for the batter to be atomized into a fine mist , resulting in a uniform coating on the articles to be coated . the flanges prevent batter from being dispensed too rapidly from the disc which would result in , for example , large droplets of batter , drips of batter , and non - uniform coating generally . typically , fluids having a viscosity of up to about 12 - 14 seconds in a # 3 stein cup ( available from stein / dsi , which is a subsidiary of fmc food tech , located in sandusky ohio ), and / or a solids content of about 50 percent may be dispensed using the present devices and methods . thus , using the present method , articles of food may be coated substantially uniformly on all sides , with a relatively viscous fluid or batter , at a relatively high rate that is compatible with most food production lines . the design of the rotary atomizing device allows relatively viscous fluids , or batters to be atomized . the design of the rotary atomizing device also accommodates a relatively high volume of fluid or batter without dripping onto the food . fig1 - 19 illustrate another exemplary embodiment of a coating apparatus . as seen in the figures , apparatus 250 differs from apparatus 150 in size and shape , but otherwise includes substantially the same components , with the exception of the inclusion of rotary atomizing devices 100 rather than devices 10 . where possible , reference numerals indicating the same or similar components as in the previous embodiment have been changed by replacing the number “ 1 ” with the number “ 2 .” thus , 152 becomes 252 , and so on . utilization of rotary atomizing devices 100 in apparatus 250 provides increased fluid distribution capacity , allowing the coating of relatively large amounts of articles or alternatively , coating at faster speed . as shown in fig1 - 20 when taken together , cover 262 of apparatus 250 includes a plurality of devices 100 mounted for rotation on drive shafts 268 which are rotatably driven by motor 270 . devices 100 may be spaced apart from one another within cover 262 ( best seen in fig1 ), and staggered with respect to one another within cover 262 so as not to interfere with the fluid distributed by adjacent devices 100 ( best seen in fig1 ). similarly , base 260 of apparatus 250 also includes a plurality of sequentially arranged rotary atomizing devices 100 which are mounted for rotation on drive shaft 276 driven by motor 278 . as in the previous apparatus , the components of apparatus 250 that come into contact with food may be constructed from a food - grade material including plastics such as delrin or ultra - high molecular weight polyethylene ( umhw - pe ), and metal such as 304 / 316 grade stainless steel . those of skill in the art will recognize that the dimensions of apparatus 250 may vary as needed depending on the particular application in which it is used . fig2 - 25 illustrate another aspect of the present disclosure which is directed to an accessory 300 for use in cooperation with either of devices 10 , 100 and thus with apparatus 150 , 250 . as shown in fig2 , accessory 300 may include a substantially ring shaped portion 302 . as shown in isometric view in fig2 , ring shaped portion 302 includes two sections 306 , 308 connected by fasteners 310 which are inserted into apertures 308 . section 308 includes and aperture 312 into which the fluid distribution tube 180 may be fixedly attached . as shown in fig2 - 23 , section 306 , 308 each have a substantially flat inner surface 314 a , b from which sloped surfaces 316 a , b and 318 a , b extend outwardly . section 306 preferably has a substantially curved outer surface 320 , whereas section 308 has a substantially flat outer surface 322 . fig2 - 25 illustrate one exemplary arrangement using ring - shaped portion 302 in cooperation with disc 102 and capping disc 104 . as shown , discs 102 , 104 may be mounted on a rotatable hollow drive shaft 324 , which may be coupled to , for example , a fluid distribution manifold to receive fluid or batter in the hollow drive shaft 324 . discs 102 , 104 are connected by pins inserted into the apertures on each opposing side of discs 102 , 104 . before the pins are inserted , the ring - shaped portion 302 must be mounted about the frustoconical portion . of course , although not illustrated herein , accessory 300 may also be disposed between discs 12 a , b of device 10 . during operation of an apparatus , fluid is distributed directly from hollow drive shaft 324 to ring - shaped portion 302 , which acts as a gutter to collect and distribute fluid to the interior surfaces of the rotating discs of devices 10 , 100 . thus , any fluid that is distributed from the hollow drive shaft 324 and which is not immediately flung onto the cone or inner surfaces of the discs is collected . this prevents fluid that does not yet have the required momentum to be atomized from dripping onto the articles to be coated . thus , accessory 302 effectively increases the dwell time within devices 10 , 100 , of fluid dispensed from fluid distribution tubes 180 . while there is shown and described herein certain specific structure embodying the invention , it will be manifest to those skilled in the art that various modifications and rearrangements of the parts may be made without departing from the spirit and scope of the underlying inventive concept and that the same is not limited to the particular forms herein shown and described except insofar as indicated by the scope of the appended claims .
a device for coating materials is provided . the device includes two opposing discs connected by a central hub . each disc includes an inwardly extending flange about its perimeter . the central hub has an exterior surface defining a v - shaped surface . when assembled in a coating apparatus , a fluid material , such as batter , may be dispensed toward the exterior surface of the hub while the disc is spinning . the resulting spray of fluid may be used to coat material effectively , while minimizing waste .