摘要:
The present invention is a method to add dry gelatin to a photographic emulsion in either a liquid or a solid form. The dry gelatin is added by entraining the dry gelatin in air to form a gaseous mixture of dry gelatin in air and directing this mixture into the solid or liquid photographic emulsion. An air eductor is used to deliver the dry gelatin. When adding dry gelatin to a solution, the rate is determined by the solution viscosity and volume. When adding the dry gelatin to a solid emulsion, the dry gelatin rate is not as critical but uniform addition is still needed to interdisperse the dry gel with the emulsion pellets.
摘要:
A process for degassing a continuously flowing liquid stream is executed using an apparatus that comprises an air-tight housing, in which is mounted for rotation a centrifuge bowl of circular cross-section and having an inner surface for spreading centrifugally impelled liquid to be degassed and an annular peripheral trough for retaining centrifugally impelled degassed liquid. The liquid stream is fed into the bowl and the degassed liquid is withdrawn through a tube extending from an exit line outside the housing to an open end of elongate cross-section which is positioned within the trough of the bowl and is immersible in the degassed liquid. The pressure of the exiting degassed liquid is measured, the pressure measurement being used to regulate the flow of liquid into the bowl so as to maintain a substantially constant level of the liquid therein. Gas is withdrawn to maintain a sub-atmospheric pressure within the apparatus housing, and the flow of the degassed liquid stream is regulated so that the liquid level in the bowl remains substantially constant.
摘要:
An apparatus for degassing a continuously flowing liquid stream comprising an air-tight housing, in which is mounted for rotation a centrifuge bowl of circular cross-section and having an inner surface for spreading centrifugally impelled liquid to be degassed and an annular peripheral trough for retaining centrifugally impelled degassed liquid. The liquid stream is fed into the bowl and the degassed liquid is withdrawn through a tube extending from an exit line outside the housing to an open end of elongate cross-section which is positioned within the trough of the bowl and is immersible in the degassed liquid. The apparatus further provides for measuring the pressure of the exiting degassed liquid, the pressure measurement being used to regulate the flow of liquid into the bowl so as to maintain a substantially constant level of liquid therein. The apparatus also provides for the withdrawal of gas to maintain a sub-atmospheric pressure within the apparatus housing, and for the regulation of the flow of the degassed liquid stream.
摘要:
The present invention describes a passive membrane degasser device in which solid chunks of photographic materials (15) are pumped past a hydrophobic membrane (10). Air from in between the chunks is forced through the membrane by pump pressure including a screw auger (11) and a vacuum (12) on the outer side of the membrane. The solid chunks of photographic material (15) are then transferred to a liquefier where conventional ultrasonic deaeration is performed. This device causes no sensitometric problems and permits using a continuous liquefaction system without the use of a centrifugal vacuum degasser.
摘要:
A method and apparatus for continuously liquefying a gelled photographic material for coating on a substrate is disclosed. The material is advanced throughout the liquefaction apparatus and on to the substrate coating system as a substantially undisrupted mass. The technique is particularly useful for liquefying small amounts of material at a time, because system hold-up volume and waste is minimized.