Classifications

• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03D—APPARATUS FOR PROCESSING EXPOSED PHOTOGRAPHIC MATERIALS; ACCESSORIES THEREFOR
  • G03D15/00—Apparatus for treating processed material
  • G03D15/02—Drying; Glazing
  • G03D15/022—Drying of filmstrips
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03D—APPARATUS FOR PROCESSING EXPOSED PHOTOGRAPHIC MATERIALS; ACCESSORIES THEREFOR
  • G03D5/00—Liquid processing apparatus in which no immersion is effected; Washing apparatus in which no immersion is effected
  • G03D5/04—Liquid processing apparatus in which no immersion is effected; Washing apparatus in which no immersion is effected using liquid sprays

Definitions

• This invention relates to apparatus for transferring thermal energy or chemical mass through a fluid medium and, more specifically, to such transfer in the processing of light sensitive material such as photographic film or paper.
• this boundary layer can influence both the rate at which photochemicals are transferred to and from the film, as well as their concentrations within the film. Either influence can affect the rate and quality of processing.
• processor including the dryer section.
• chemical concentrations in the processor boundary layer need to be excessively high to maintain reasonable mass transport rates resulting in inefficient utilization of the processing chemicals.
• temperatures need to be excessively high to maintain reasonable film drying rates resulting in inefficient utilization of thermal energy.
• the rate of chemical mass transfer through this boundary layer to the film surface can be any rate of chemical mass transfer through this boundary layer to the film surface.
• A Film Area (cm 2 )
• ⁇ C Concentration Gradient (Grams/CM 3 )
• the ratio of diffusivity/delta is typically called the mass transfer coefficient.
• a high mass transfer coefficient will result in a high chemical mass transfer rate, for a given concentration
• Diffusivity is a function of such variables as molecule size and temperature. While diffusivity can easily be increased by increasing processing solution temperatures (thereby increasing chemical mass transfer rates), this involves the use of complicated equipment and increased cost of processing. Alternatively the chemical mass transfer rate can be increased by decreasing the chemical boundary layer thickness independent of increasing temperature.
• turbulence or with jet impingement is that it is extremely difficult to achieve uniformity of the treatment process since any non-laminar fluid condition contains non-uniform fluid disturbances such as pockets of turbulence, eddy currents, etc. Also turbulent flows dissipate a great deal of energy in places where it does no useful work, specifically areas away from the film surface. This is due to the high "shearing" action that occurs within the turbulent flow field. Moreover, with turbulent flows and jet impingement it is
• processors in current use are typically roller transport processors where film or paper is transported by rollers through a tank of solution. While such processors provide more uniform processing than impinging jets or turbulent flows, they are massive in size, inefficient and thus subject to the boundary layer problems discussed above.
• this object is accomplished by providing a means which defines an elongated channel for receiving a web (in continuous or sheet form) to be treated with a fluid.
• the fluid is injected into the channel at one or more injection sites.
• Fluid is evacuated from the channel at spaced evacuation sites.
• Each injection site is positioned between two evacuation sites and spaced therefrom such that fluid will flow from the injection site to the evacuation sites with laminar flow and be evacuated when the boundary layer of the fluid reaches a
• Fig. 1 is a perspective view in partial section illustrating a portion of a parallel plate processor in accordance with the invention
• Fig. 2 is a schematic sectional view illustrating the basic fluid circulation paths of a parallel processor in accordance with the invention
• Fig. 3 is a section showing the end wall and . exit or entrance of the processor illustrated in Fig. 2;
• Fig. 4 is a schematic illustration of a plurality of serially arranged processors
• Fig. 5 is a sectional view illustrating another embodiment of the parallel plate processor
• Fig. 6 is a partial sectional view illustrating the application of the embodiment shown in Fig. 5 to the processing of light sensitive
• Fig. 7 is a graph illustrating boundary thickness of the processor illustrated in Fig. 2 compared with the boundary layer thickness of a prior art processor;
• Fig. 8 is a force curve illustrating the stabilizing action of the fluid cushions
• Fig. 9 is a perspective view of a dryer for photographic film or paper in accordance with the invention.
• Fig. 10 is a cross section of the air
• Fig. 11 shows actual measured heat transfer coefficient values for the apparatus depicted in Figs. 9 and 10 when constructed with a 4cm wide bearing versus the impingement jet system of a commercially available dryer;
• Fig. 12 is an exploded perspective view of a portion of a film dryer illustrating still another embodiment of
• Fig. 13 is a view similar to Fig. 12 with parts omitted to show the construction in more detail;
• Fig. 14 is a plan view of the manifold arrangement shown in Fig. 12 with the cover plate partially cutaway;
• Fig. 15 is a section taken along the line 15-15 of Fig. 14;
• Fig. 16 is an enlarged detail of the area 205 of Fig. 15;
• Fig. 17 is a plan view of the injection and evacuation openings of the dryer depicted in Figs. 12 and 13 with arrows indicating the fluid flow paths;
• Fig. 18 is a side view showing the corrugation of the web while transported through the dryer depicted in Figs. 12 and 13;
• Fig. 19 is side view of an assembled dryer of the type shown in Figs. 12 and 13 with film transport rollers;
• Fig. 20 is a schematic illustration of another embodiment of the dryer shown in Figs. 12 and 13;
• Fig. 21 is a sectional view of a film
• Fig. 22 is a schematic illustration of a film processor in accordance with still another embodiment of the invention.
• Fig. 23 is a perspective view of a processor in accordance with still another embodiment of the invention with the top removed and a portion of the sidewalls cut away to illustrate internal parts;
• Fig. 24 is an exploded perspective view of the processor shown in Fig. 23;
• Fig. 25 is an elevation view of portions of apparatus such as depicted in Figs. 23 and 24
• Fig. 26A-G are front views of the manifold plates or walls of the processor depicted in Figs. 23 and 24;
• Fig. 27 is a front view of the processor shown in Fig. 23 partially cut away to show the pump chamber;
• Fig. 28 is a side view of the processor shown in Fig. 23 partially cut away to show the pump chamber;
• Fig. 29 is an enlarged view of the bottom group of hydrostatic bearings of the processor shown in Fig. 23;
• Figs 30 and 31 are enlarged perspective views of portions of a hydrostatic bearing used in the processor of Fig. 23;
• Fig. 32A-C are enlarged cross-sections showing three configurations of the hydrostatic bearing used in the processor of Fig. 23;
• Fig. 33 is a side view of the hydrostatic bearings of another embodiment of the processor
• FIG. 1 of the drawings there is shown a basic parallel plate processor 8 for
• a processing fluid into contact with light sensitive material such as a photographic film (or paper) F.
• the processor illustrated in Fig. 1 The processor illustrated in Fig. 1
• a pair of manifold plates 20, 22 having openings 24, 26 aligned with injection slits 16, 18 respectively are attached to the processor plates 10, 12 for supplying solutions to the injection slits.
• manifold plates 20, 22 may be replaced with a direct feeding manifold such as that shown in Fig. 5.
• the system plumbing has been omitted to clarify the basic boundary layer concept.
• the basic solution flow path is indicated by the arrows in Fig. 1.
• Fluid under pressure will enter channel 13 on both sides of the film F and create a fluid cushion under pressure on opposite sides of the film which will support the film and permit it to be transported through the channel 13 without contact with the plates 10, 12.
• the fluid will move to the ends of the channel 13 with a laminar flow where it will be discharged.
• the treating fluid is a liquid, it may be collected in a sump (not shown) and be recirculated to the manifold by pumps and conduits (also not shown). Also, the solution may be replenished as described below.
• the processor may be used in a submerged state similar to the processor disclosed in Fig. 5 and 6.
• the fluid cushions on opposite side of the film apply pressure forces to the film which tend to stabilize it and support it in a position centered between the plates 10, 12. More specifically, if the film attempts to move off center, it will move closer to one plate than the other. The closer spacing to the one plate will decrease the thickness of the flow channel on that side of the film and decrease the flow within the channel on that side. The reduced flow rate will decrease the drop in pressure across the injection opening on that side of the film. This will increase the fluid pressure in the thinner channel relative to that of the thicker channel producing a net force on the film tending to restore it to its center position.
• This stabilizing concept is illustrated by the curve depicted in Fig. 8 which is a plot of force (Dynes) exerted against the film vs film distance from the center of the channel.
• the length L of channel 13 on each side of the injection slits will have a finite length related to the increase in thickness of the chemical boundary layer 13, so that the solution is discharged at the ends of the channel 13 when the boundary layer reaches a thickness at which the solution is no longer efficiently transferring chemicals (or heat). More specifically, in the region of the injection slits 16, 18, maximum transfer will occur. However, as the solution moves away from the injection slits in the paths depicted by the arrows, the chemical boundary layer B will gradually increase in thickness as indicated in Fig. 2. At the point where the boundary layer has a thickness which renders the chemical or heat transfer efficiency less than a desired value, it is preferably discharged at the ends of the channel 13 and recirculated or replenished.
• the effectiveness of the chemical or heat transfer process is enhanced in two ways. First by minimizing the length L, the distance over which the boundary layer is permitted to develop. Second, the system parameters are selected to establish reasonably high fluid velocities in the laminar fluid flow region to minimize the rate at which the boundary layer is allowed to grow. A small plate separation is used to achieve high fluid velocities with laminar flow. Short distance and high velocity laminar flow result in a slowly developing boundary layer and efficient chemical or heat transfer with laminar flow.
• the invention uniquely uses laminar flow to advantageously achieve chemical mass or heat transfer rates that actually exceed those provided by all but the most turbulent flows at a fraction of the power requirements.
• the power requirements are very low because most of the fluid flow energy is dissipated at the film surface due to shear forces between the liquid and the film.
• This is a unique alternative to the use of turbulent flows which dissipate their flow energy through shear forces within the fluid itself ⁇ not at the film surface.
• the length of the fluid path L was determined in the following manner. It was assumed that the similarities between heat and mass transfer permit conclusions derived from heat transfer studies render conditions of incompressible flow to be extended to the transfer of chemical mass in the liquid domain.
• this invention involved the realization that h CHEM is maximized by increasing u, decreasing y and decreasing x.
• h CHEM (x) will increase as x increases.
• the maximum thickness is such as to maintain an aqueous chemical mass transfer rate that exceeds the transfer rate within the film by a reasonable design margin.
• roller spacings of 1.0 cm would require very small rollers spaced very close together and many supporting parts.
• the above equalizers for the roller transport apparatus assume that the rollers reduce the chemical boundary layer thickness to zero as the film contacts each successive roller. This is not the case.
• the film "hydroplanes" on each roller leaving some residual chemical boundary layer in place. This increases the mass transfer coefficient by a fixed amount over the entire film surface.
• roller transport tank processors require the film to move at high speeds creating difficult transport reliability problems. Also, reasonable development times require very large machines.
• L would be 4 cm or more
• ⁇ would be in the range of 2.5-5.0 cm/sec and more likely 5.0 cm in the worst case situation.
• h CHEM would be .00048-84 percent less than the value of .0030 calculated for a parallel plate processor in accordance with the invention.
• Fig. 7 is a graph illustrating the results achieved with the invention incorporated into a chemical treating apparatus using hydroquinone as the treating fluid in comparison with a conventional roller transport processor.
• Curve A is a plot of boundary layer thickness vs. distance from the lead edge of a fluid path in a prior art roller transport processor.
• Curve B is a similar curve for a prototype processor incorporating the present invention. Curve B represents the boundary layer thickness with injection slits located at the far left and far right of the diagram and the evacuation slit located in the center.
• the difference in average boundary layer thickness (dashed lines A 1 and B 1 ) is large and indicates the unexpected results achieved with the invention.
• a parallel plate processor 28 which incorporates the invention described in connection with Fig. 1.
• This processor comprises a pair of spaced parallel plates 30, 32 having a pair of juxtaposed injection slits 34, 36 and two pairs of juxtaposed evacuation slits 38, 40 and 42, 44.
• the plates may be supported by end walls (not shown) similar to the Fig. 1 assembly to define a channel 48 therebetween through which the film F is transported such as by rollers as described below.
• the solution circulation paths are illustrated in Fig. 2 by the arrows which are also schematically representative of system plumbing. It is to be understood that the processor depicted may include additional injection and evacuation slits by extending the length of the plates 30 and 32. Thus, the circulation pattern depicted schematically may be repeated by providing additional alternating solution injections and evacuations depending on the
• solution is supplied to injection ports 34 and 36 from mixing tanks 48, 50 respectively. Fluid will exit channel 48 via evacuation slits 42, 44 and 38, 40 as indicated by the arrows. A portion of the solution exiting via slits 38 and 42 may be recirculated by pumps 52, 54, respectively, to mixing tank 49 and the remainder circulated to the adjacent mixing tanks (not shown) in the series, as indicated by the arrows, if a need for replenishment exists, fresh solution may be supplied to tank 49 by a pump 56. The need for such replenishment may be sensed by sensors 60, 62 connected to the return inlet conduits to the mixing tank 49 and coupled to a control means 64 which will activate pump 56 when the need exists. Control means 64 can also be arranged to control pumps 52, 54.
• Slits 36, 40, 44 are similarly connected to mixing tank 50, pumps 66, 68 and 70 being provided to accomplish such recirculation and replenishment in the identical manner described in connection with tank 49. Also pumps 68, 70, 72 may be controlled by control means (not shown) and sensors (not shown) identical to control means 64 and sensors 60 and 62.
• tanks 49, 50 may be replaced with a single tank connected to both injection slits 34, 36 and solution can be
• solution will be circulated from tanks 49, 50 to injection slits 34, 36 to thereby create solution cushions under pressure on both sides of the film.
• solution entering the channel 48 will have maximum chemical or heat transfer adjacent the injection slits 34, 36.
• the boundary layer B will increase in thickness, as indicated in Fig. 2.
• length of channel 48 between adjacent slits is sized to exit the solution into an evacuation slit when a predetermined boundary layer thickness exists.
• the maximum thickness is such as to maintain an aqueous chemical mass transfer rate that exceeds the transfer rate within the film by a
• the plate separation is made small to achieve high fluid velocities in the laminar flow region.
• the processor would be sized and spaced so that the distance between adjacent pairs of nip rollers is less than the length of the sheet.
• sheet film e.g., X-ray film
• FIG. 5 and 6 of the drawings still another embodiment of the invention is disclosed for use in a submersed condition.
• This embodiment comprises a parallel plate processing unit 82 having a pair of parallel plates 84, 86 positioned and supported by side walls 88 to define a channel 90 for receiving a web F of light sensitive material such as photographic film.
• the plates 84, 86 are provided with first and second pairs of juxtaposed injection slits 92, 94 and 96, 98 disposed on opposite sides of a pair of
• the injection and evacuation slits are sized and spaced as described above to evacuate fluid from the channel 90 when the boundary layer of the treatment fluid becomes thick enough to render its use inefficient.
• the plates 84, 86 are attached to manifold plates 104, 106 respective, which in turn are attached to outer plates 108, 110.
• Manifold housings 112, 114 are attached to plates 108, 110 respectively and have chambers for receiving treating fluid under pressure via conduits 116, 118, respectively.
• the pressurized fluid in housings 112, 114 will flow to the injection ports 92, 94 and 96, 98 via openings in plates 104, 108 and plates 106, 110 and will be injected into channel 90 to establish a laminar flow of fluid on opposite sides of the film in one direction to the evacuation ports and in the opposite direction to the open ends of channel 90.
• Fluid evacuated from the channel 90 by evacuation ports 100, 102 will flow out the sides of the unit via openings in plates 104, 106. It is to be understood that, as described in connection with Fig. 2, additional injection and evacuation ports may be provided depending on the requirements of a particular treatment process.
• Fig. 6 depicts the use of processors of the type shown in Fig. 5 or Fig. 1 to process photographic film. More specifically, an elongated housing 126 is provided with a plurality of treatment chambers 128, 130, 132, 134 for film development, fixing, washing and drying, respectively, as indicated in Fig. 6.
• a processing unit 82 is suitably supported in each chamber with the units 82 in chambers 128, 130, 132 submersed in the liquid processing solutions, as indicated.
• Each processing unit may be provided with a circulation system, such as that shown in connection with the unit 82 in chamber 128.
• the system would include a pump 136 having its inlet connected to the chamber 128 and its outlet connected to the manifold housings 112, 114 whereby fluid will be continuously circulated from the chamber to the injection ports 92, 94 and 96, 98. Fluid discharged from the evacuation ports 100, 102 and the ends of the channel 96 will mix with the fluid in chamber 128.
• the mixing action can be augmented by
• suitable replenishment means may be provided to periodically supply fresh fluid to the system.
• the film transport means comprises entrance and exit chutes 140, 142 for guiding the film into the first chamber 128 and exiting the film from the last chamber 134.
• Identical chutes 144 and pairs of nip rollers 146, 148 transport the film from chamber to chamber. At each processing unit, the associated chutes will guide the film into and out of the channel 90 and nip rollers.
• a film or paper dryer 160 comprising a pair of juxtaposed air bearings 162, 164.
• the bearings 162, 164 comprises rectangular housings having sidewalls, end walls and cover plates (not shown) attached to spaced parallel plates 166, 168 respectively.
• the plates are fixed together in spaced relationship with spacers 170 interposed to provide the desired spacing described below.
• the plates 166, 168 are provided with central elongated openings or slits 172, 174, for injecting air under pressure into the space between the plates from the interior of the bearing housings, respectively.
• a plenum 176 (one is shown in Fig. 10) connected to a source of air under pressure is attached to each housing.
• the bearings 162, 164 are spaced to define a channel 178 there between for a web W which may comprise light sensitive material.
• the web W may be transported to the channel 178 by a pair of nip rollers 30 which may comprise the exit squeegee rollers of a wash section of a film processor.
• the air bearings are skewed 10 to 15 degrees from the longitudal axis of the rollers to reduce aeroelastic flutter in the leading and trailing portions of the web.
• air under pressure will be injected from the plenums 176 into the bearings 162, 164 and through the slits 172, 174 into the channel 178 to establish regions of air under pressure on opposite sides of the film.
• a laminar flow of air will occur in opposite directions from each slit relative to the film path.
• the air streams will exit the channel 178 at the opposite sides of the plates 166, 168.
• the thickness and length of channel 178, width of slits 172, 174, air pressure with the bearings 162, 164 are parameters which are preferably selected to control the boundary layer thickness and to minimize the distance over which the boundary is permitted to develop. Also the system parameters are selected to establish reasonably high fluid velocities in the laminar flow region to minimize the rate at which the boundary layer is allowed to grow. The result is to establish a heat transfer rate in the fluid that exceeds the heat transfer rate within the film or paper. A small plate separation contributes to the achievement of high fluid velocities with laminar flow.
• the thickness of channel 178 is preferably .06-.09 inches.
• the length of the fluid path along the film direction is in the range of .3 to .8 inches depending on the total amount and transfer rate of heat needed.
• the slots 172, 174 in the plates 166, 168 are preferably .015 inches wide. Air within the bearing is typically at 3.4 inches of water pressure and a
• characteristics such as amount of gel, etc.
• the pressure drop in the slots 172, 174 is approximately 50 percent of the available pressure. Pressure at the film plane is dependant on the flow rate of air through the slot, the higher the flow rate the greater the pressure drop. As discussed above, if the film moves from a center position towards either plate a pressure differential is established above and below the film which restores it to a center position. With the film thus centered in the channel 178 the boundary layer thickness reduction discussed above, and thereby improved heat and water vapor flow, is provided by the high speed flow of air from the slits over the film and out the sides of the bearings. Control of boundary layer thickness is a function of the channel size, length of the channel and the pressure of the air injected through the slits. Heat flow to the film is a function of air temperature and also boundary layer thickness. Water vapor removal is primarily a function of boundary layer thickness and the rate heat can be supplied to vaporize water in the gel coat of the film or paper.
• Fig. 11 depicts curves plotted from actual measured heat transfer coefficient values for a dryer in accordance with the invention (curve A) having 4 cm wide bearing plates 166, 168 and a commercially
• Figs. 9-11 achieves higher heat transfer coefficiates which means faster drying, smaller simpler dryers, lower drying temperatures and less energy consumption.
• the air suspension of the film or paper in the dryer reduces the chance of film scratches/artifacts in the dryer.
• Less drying energy means less heat lost to the environment, less need to cool the processing chemicals and no need for special power connections to the processor.
• the simplicity and small size of the . dryer requires fewer parts and greatly reduces the cost of the dryer.
• Embodiments of Figs. 12-20 Embodiments of Figs. 12-20
• fluid is injected into and evacuated from the channel by means of juxtaposed injection slits and evacuated by means of juxtaposed evacuation slits.
• the slits extend transversely of the film axis in substantially
• Each juxtaposed path of injection slits is positioned between two pair of juxtaposed evacuation slits to cause fluid to flow in opposite directions from each injection site to adjacent evacuation sites.
• the web alternating regions of high and low pressure in the film channel.
• the pressure of the fluid on each side of the web is maximum at the injection sites and minimum at the evacuation sites.
• the web has maximum support at the injection sites and minimum support at the evacuation sites. If the injection and evacuation sites extend perpendicular to the film axis, then transversely extending low pressure regions exist which provide minimal support to the web and render it subject to displacement by gravity. Because of the alternating arrangement of these high and low pressure regions, the web can even vibrate or oscillate even though it remains out of contact with the surfaces of the channel.
• the condition described above is minimized by arranging the injection and evacuation slits at an angle relative to the longitudinal axis of the web. This causes the high pressure and low pressure regions to extend angularly across the film. With this arrangement each injection opening produces a fluid stream having one flow
• the components in the direction of web travel minimize lift of the web by the treating fluid and have a stabilizing effect.
• the pressure of the fluid emitted from the angled openings tends to produce pressure corrugations in the web extending angularly to the web longitudinal axis. Such corrugations tend to reinforce the web and make it more resistant to bending and less subject to
• FIG. 15 there is shown a pair of spaced plates 210, 212 adapted to be clamped together and separated by spacers 213 to define a channel 214 (Fig. 15)
• the plates 210, 212 each have a plurality of elongated spaced fluid injection openings or slits 216 and a plurality of elongated spaced fluid evacuation openings or slits 218.
• the openings 216 in plates 210 and 212 will be aligned and in juxtaposed relationship.
• openings 218 in plates 210 and 212 will be in aligned juxtaposed relationship.
• the openings 216 and 218 alternate so that each pair of juxtaposed injection openings is between two pairs of juxtaposed evacuation openings.
• openings 216 and 218 are positioned in parallel relationship and define an axis having an angular relationship with the longitudinal axis of the film. This angular relationship of the openings with the longitudinal axis of the film is most clearly apparent from Fig. 17. While an angle of 45 degrees is preferred enhanced positional stability can be achieved with angles as small as 15 degrees and as large as 90 degrees.
• a plurality of elongated hollow spacer members 222 are fixed to the plates 210 and 212 with the hollow interiors of the members in communication with the openings 216.
• a pair of plates 224, 226 are positioned over the members 222 on the sides opposite from the plates 210, 212 respectively. Slots 228 in the plates 224, 226 communicate with interiors of members 222 to supply fluid to the slots 216 via the interiors of members 222.
• a pair of housings 230, 232 are fixed to the plates 224, 226, respectively, to provide manifold chambers 234 and 236 for supplying air to the openings 228.
• the ends of the chambers 234, 236 may be sealed by end plates 238, one of which is depicted in Fig. 12.
• Each housing 230, 232 is provided with an air inlet opening 240. Blowers 242, 244 (Fig. 12) supply air under pressure to each inlet.
• 224, 226 may be formed integrally with its associated housing and thus comprises a wall of such housing to thus define a housing means having chambers for supplying fluid to the channel 214.
• fluid under pressure in this case, air
• air will be supplied to the chambers 234, 236 by blowers 242, 244 to pressurize the chambers.
• air will flow through slits 228 and the interior of members 222 to slits 216.
• Air will be injected through slits 216 into channel 214 on opposite sides of the film to create regions of air under pressure on opposite sides of the film.
• Air will flow from the slits 216 to the adjacent evacuation slits 218 as indicated by the arrows in Fig. 17 and be subsequently evacuated into the space between plates 210, 224 and between plates 212, 223.
• the slits 216 are preferably sized and spaced from the slits 218 by a distance such that the air is evacuated when the boundary layer reaches a thickness rendering the heat transfer between the air and film inefficient. More specifically, the heat transfer process is enhanced by minimizing the length of the flow path from an injection slit to an evacuation slit to minimize the distance over which the boundary layer is permitted to develop and by minimizing the rate at which the boundary layer is allowed to grow, the latter is achieved by using reasonably high fluid velocities in the laminar flow region. This concept is disclosed in more detail above.
• Fig. 19 is a side view of the assembled dryer
• the web W is transported through the processor by two pairs of nip rollers 250 and 252 adjacent the entrance and exit of the channel 214 respectively.
• Such rollers may be driven by motors 254, 256 as indicated.
• the rollers When drying webs in sheet form, the rollers would be spaced by a distance less than the length of the sheet so that the sheet is gripped by the exit rollers before it leaves the entrance rollers.
• the alternating high and low pressure regions extend angularly across the film and tend to produce a corrugated force pattern as shown in Fig. 18. Because this force pattern is angularly oriented relative to the film it tends to deform the film into a shape that has a higher bending moment that makes it more difficult to deform the film.
• the apparatus thus effectively adds to the basic stability achieved by having laminar air streams on opposite sides of a web as disclosed above by providing an singularly oriented force pattern across the web.
• FIG. 20 Another embodiment is depicted schematically in Fig. 20.
• a dryer 260 is provided with a channel 262 having a plurality of injection slits 264 and a plurality of evacuation slits 266 which are shown exaggerated in size.
• the injection and evacuation slits alternate on each side of the channel as in the previous embodiment.
• an evacuation slit 266 is always in
• Figs. 12-20 thus greatly improves the stability of a moving web during transport through a fluid treatment channel and have particular utility in a dryer.
• the fluid streams on opposite sides of the web tend to support and stabilize the web.
• the angled orientation of the fluid injection and evacuation openings further stabilize the web by minimizing web lift and producing a corrugated force pattern on the web to increase the strength of the web and reduce web vibration.
• FIG. 21 there is shown a portion of a parallel plate film processor 310
• a pair of spaced parallel plates 312, 314 defining an elongated fluid processing channel 316 adapted to receive a web (in continuous or sheet form) of photographic film.
• the plates are supported by a pair of end walls 317, 318 having slits 320, 322 respectively for the entrance and exit of the film.
• the film F is transported through the channel in the direction indicated by transport means
• nip rollers 324, 326 comprising two pairs of nip rollers 324, 326.
• One or both pairs of the nip rollers may be motor driven depending on whether the film F is in sheet or web form. If sheet film is being processed, the length of channel 316 will be less than the sheet length whereby rollers 324 will grasp the sheet before it leaves rollers 326. Also, if a liquid solution is applied to the film, the exit rollers 324 may comprise squeegee rollers to remove excess solution.
• the plates 312, 314 are provided with a plurality of pairs of spaced juxtaposed injection slits 330, 332, 334 and a plurality of pairs of spaced juxtaposed evacuation slits 336, 338, 340, 342, which define injection and evacuation sites.
• the injection and evacuation slits extend transversely of the channel and have a length at least equal to the width of the film.
• the slits are placed in an alternating pattern so that each pair of juxtaposed injection slits is between two spaced pairs of juxtaposed evacuation slits with equal spacing between adjacent slits along the film path.
• fluid injected into the channel 316 under pressure will form cushions of fluid under pressure on opposite sides of the film. This cushion will support the film and cause a laminar flow of fluid on each side of the film to the adjacent evacuation slits where it will be evacuated to the exterior of the processor.
• the spacing between adjacent slits is selected to cause evacuation of the flowing fluid when its boundary layer becomes thick enough to render the treatment of the film inefficient. Such conditions are more fully described above and further description here is deemed unnecessary.
• the recirculation system includes a mixing means comprising a pair of spaced parallel plates 350 and 352 defining an
• the plates 350 and 352 may be supported by end plates 356 and 358.
• plates 350 and 352 and one of the end plates may be formed as an integral molded housing and the other end plate attached to such structure.
• the end plate 358 may be provided with elongated funnel-like outlet fitting 360 which is coupled to a recirculation pump 362.
• the plate 352 is provided with a plurality of inlet ports 364, 366, 368, 370 connected with the evacuation ports 336, 338, 340, 342 respectively by suitable plumbing as indicated schematically.
• the pump 362 is connected by suitable plumbing and/or manifolds to the injection ports 330, 332, 334 and 336 as indicated schematically.
• a sensor 372 may be provided to determine the condition of the fluid being
• a control means 374 responsive to the output of the sensor may be arranged to open a
• replenishment valve 376 when the fluid condition in such as to require mixture with fresh solution.
• the fluid may be discarded or treated to remove undesirable byproducts, such as to minimize environmental discharges.
• a mixed stream containing portions of the fluid streams injected at ports 332 and 330 will enter the chamber and mix with fluid stream comprised of fluids from ports 368 and 370. This further combined mixed fluid stream will mix with the remainder of the stream injected at port 330 in the region of port 364. Thus, the fluid discharged at the outlet of the chamber will be thoroughly mixed and substantially uniform in composition.
• the apparatus thus comprises a closed loop processing system in which essentially all of the fluids are mixed and recirculated very
• An apparatus incorporating the concepts disclosed herein is capable of achieving total solution turnover every 5-10 seconds.
• a typical roller transport deep tank processor has stagnant regions which contain fluid that is turned over or recirculated only every 5-20 minutes. This comparison indicates the superior performance that is achieved with the closed loop mixing process in accordance with the invention.
• FIG. 22 of the drawings there is shown another embodiment of a closed loop mixing system.
• This embodiment would also include a pair of parallel plates similar to the Fig. 21 embodiment and would also have spaced slits in the plates to define a plurality of injection sites 310 and a plurality of evacuation sites 312, the sites alternating as in the case of the Fig. 21 embodiment so that an injection site is located between adjacent evacuation sites. The spacing between the sites is selected to cause
• Fig. 22 The plumbing for the system shown in Fig. 22 is indicated schematically to clarify the operation of the invention. It will be obvious, however, that arrangements of suitable manifolds and plumbing to accomplish the circulation indicated are within the capabilities of one skilled in the arts of fluid mechanics and plumbing. It is also to be understood that as in the case of the Fig. 21 embodiment, the systems on each side of the film are identical with juxtaposed injection and evacuation slits. According only the system on the upper side of the film is shown and described.
• the solid lines represent the flow paths of fluid from the pump 314 to the injection sites 310 and the dashed lines represent the flow paths of fluid from the evacuation sites to the inlet of the pump.
• the output of the pump is uniformly and sequentially divided at node or branch points 316 and that the evacuated fluid is uniformly and sequentially combined at node or branch points 318.
• the evacuation system all fluids are progressively mixed after contacting the film or paper. Also, all fluids pass through a single region (the pump) before being circulated. The high agitation within the pump assures that the fluid streams are completely mixed and the branch points or nodes provide sequential mixing of streams varying in chemical depletion and time phasing prior to entering the pump.
• Photosensitive Material there is disclosed a processor for photographic film or paper comprising a levitation chamber submersed in a tank. The film or paper is transported through the chamber. The static pressure of the fluid in the tank is used to circulate
• processing solution through the chamber.
• the film or paper web is fed into the end of a processing channel.
• Processing fluid is introduced at the opposite ends of the channel and discharged at the center of the
• a plurality of hydrostatic bearings are supported in spaced relationship in a processing chamber filled with processing solution.
• Processing solution is circulated by a pump from the chamber to a manifold and to the bearings. The solution is
• a film processor 410 comprising a container or tank 412 defining a chamber 413 for processing solution or wash water and a housing or tank 416 for a pump 418. Interposed between the tanks 414 and 416 are a
• the plate 422 may comprise one side wall of tank 412.
• the plates 424-432 are suitably attached to walls 422 of the container tank 412, as shown in Figs. 23 and 27.
• the tank 16 may be attached to end plate 432, as shown.
• Fig. 26G is a view of the end wall 422 with the bearings mounted on it, to produce a curved film path as
• the ends of the bearings 438 are fixed to the plate 422. As described in more detail below, the bearings 438 are immersed in processing solution in tank 412 and have internal cavities which are supplied with processing solution by pump 418 through the manifold defined by plates 422, 424, 426, 428, 430 and 432.
• Plate or wall 432 (Fig. 26F) comprises a pump face or pump inlet and outlet plate and has an inlet opening 440 communicating with an inlet or suction chamber 442 (Figs. 27 and 28) of the tank 416, and an outlet opening 444 for discharging solution from the high pressure or outlet chamber 446 of the tank 416.
• the pump impeller 448 is positioned in the outlet chamber 446 and is rotatable by pump shaft 450 to circulate solution from chamber 442 into chamber 446 through openings 449.
• Plate 430 (Fig. 26E), which comprises a solution return plate has an elongated rectangular opening 450 for circulating solution returned from the chamber 413 to the pump chamber 442 and has an opening 452 located to align with opening 444 of plate 432.
• Plate 428 (Fig. 26D) serves to provide positive to negative pressure insulation and is
• openings 454, 456 and 458 located to communicate with opening 450 in plate 430.
• the plate 428 is also provided with an opening 460 located to align with opening 452 of plate 430.
• Plate 426 (Fig. 26C) is provided with a horseshoe shaped opening 462 which communicates with the opening 460 in plate 428 and is provided with openings 463, 464 and 466, which are aligned with openings 454, 456 and 458, respectively, of plate 428.
• Plate 424 (Fig. 26B) comprises an allocation manifold having solution return openings 468, 470 and 472 aligned with openings 463, 464 and 466 of plate 426.
• the plate 424 also has a plurality of equally-sized openings 474 (two for each bearing) arranged in a horseshoe pattern in alignment with the openings in the ends of the bearings 438 to distribute solution to the ends of the bearings from the opening 462 in plate 426.
• Wall 422 (Fig. 26A) is almost identical to plate 424 and is provided with openings 476, 478 and 480 aligned with openings 468, 470 and 472,
• the plate 422 is also provided with a plurality of openings 482 (two for each bearing) aligned with but slightly smaller in size than openings 474 of plate 424 to gradually reduce the cross-section of fluid flow into the bearings 438.
• the bearings 438 are attached to the plate or wall 422 such as by welding of the bearing ends to the surfaces of wall 422 around the openings 482 whereby the openings 482 communicate with only the interiors of the
• pump 418 will pump fluid from chamber 446 through openings 444, 452 and 460 of plates 432, 430 and 428, respectively, into the manifold opening 462 of plate 426. From opening 462 of plate 426, solution will be distributed through openings 474 and 482 of plates 424 and wall 422, respectively, to the interior of the hydrostatic bearings 438.
• each bearing comprises a pair of identical elongated juxtaposed assemblies 490a and 490b (Figs. 30 and 31) positioned in spaced
• Each assembly defines an elongated channel shaped housing 491 having a rectangular cross section which receives solution under pressure from an opening 482 in plate 422.
• the channels 491a and 491b are fixed to flanges 492a and 492b, respectively, which are each provided with a plurality of spaced openings 494a and 494b, respectively, for discharging fluid from the interior of the channels to the area external of said flanges.
• a second pair of flanges 496a and 496b are fixed to flanges 492a and 492b, respectively, and are each provided with a plurality of spaced
• Each pair of juxtaposed assemblies are positioned in closely-spaced relationship with a small gap between the faces of flanges 496a and 496b for the passage of web W therebetween, as shown most clearly in Fig. 30.
• the spacing is preferably .050 inches. This spacing is achieved by positioning spacers 499 (Fig. 31) between the two assemblies at both ends thereof.
• the assembled bearings are then attached at one end to the plate 422 with the open ends of channels 490a and 490b aligned with a pair of openings 482.
• the other ends of the channels 490a and 490b are fixed together and sealed by an end cap 501 (Fig. 23) to restrict discharge of solution to openings 494.
• the bearings are preferably sized to define fluid path lengths within the bearing such as to evacuate solution into the tank when the fluid boundary layer reaches a predetermined thickness. Such criteria is disclosed above in connection with the embodiments of Figs. 1-8.
• the plumbing system is preferably structured to produce a fluid pressure of 2 - 6 inches of water in each of the rectangular openings 498a and 498b. With this arrangement, a liquid cushion will exist on each side of the web within each bearing to provide for smooth transport of the web without contact with the bearing surfaces.
• the juxtaposed face surfaces of the flanges 496a and 496b are flat, as shown in Fig. 30 and 31 and in detail in Fig. 32A.
• the juxtaposed face surfaces of the flanges 496a and 496b are curved to define a curved web path therebetween.
• one flange 496 will be provided with a concave surface 500, as shown in Fig. 32C and the opposing flange 496 will be provided with a complemental convex surface 502, as shown in Fig. 32B.
• the curved web path thus
• a bridging means is provided between adjacent bearings 438 to insure that the leading edge of the web leaving one bearing feeds correctly into the next bearing in the web path.
• an arcuate bridging member 504 is positioned between adjacent bearings. Flanges 506 and 508 of the member 504 are fixed to the flanges 492 of the adjacent bearings 438 to position the surface 510 of member 504 into contiguous relationship with the surfaces of the flanges 496b. The surface 510 thus defines a bridge between the gaps of adjacent bearings.
• the film path defined by the hydrostatic bearings 438 will be shorter than the length of the film sheets so that roller means at the entrance and exit to the path can transport the sheets into and out of the path without losing the sheet.
• a pair of rollers 520 as shown in Fig. 23., will be positioned at the entrance and exit of the tank chamber. If a series of processing chambers are provided, a pair of rollers 520 may be provided between adjacent tanks, as shown in Fig. 25. In this case, film guides 522 would be provided to facilitate transport between adjacent chambers.
• a roller means such as rollers 520, may be provided only at the entrance to the web path, such rollers being sufficient to transport the film through the bearings supported by the liquid cushions.
• the rollers 520 between adjacent chambers are not necessary and the rollers 520 at the entrance to the first chamber can be used to transport the web through the entire system.
• Figs. 23 and 29 of the drawings show an arrangement of hydrostatic bearings for a single chamber processor.
• the bearings 438 would be arranged in a simple horse shoe configuration.
• the bearings 438 would be arranged in a simple horse shoe configuration.
• bearings would preferably be arranged in the festooned configuration shown in Fig. 33 so that the web or sheet leaves each chamber along a smoothly curved film path.
• rollers between chambers of multiple chamber process to provide a squeegee effect for removing liquid from the material before it enters the next chamber.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Drying Of Solid Materials (AREA)
• Photographic Processing Devices Using Wet Methods (AREA)

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• 1991
  • 1991-12-18 EP EP92904285A patent/EP0564598B1/de not_active Expired - Lifetime
  • 1991-12-18 WO PCT/US1991/009488 patent/WO1992012465A1/en active IP Right Grant
  • 1991-12-18 DE DE69122125T patent/DE69122125T2/de not_active Expired - Fee Related
  • 1991-12-18 JP JP4504341A patent/JPH06504143A/ja active Pending

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