This is below the OSHA PEL (Permissible Exposure Limit, eight hour time-weight average) of 25 ppm. Ammonia vapors: Blueline machines are designed to emit less than 10 ppm ammonia to the workplace area.Waste management techniques for each type of waste are given below: With aqueous ammonia machines, generation of weak ammonia water is a sizeable waste stream. The wastes generated by both types of bluelining machines include ammonia vapors, spent filters, burned-out lamps, and paper that is aged, moist or wrinkled. The canister may contain citric acid, sulfuric acid, or phosphoric acid to neutralize the ammonia. The filter may be in the form of a cartridge that fits into the machine, or an external carbon adsorption canister that is attached to the exhaust. The high position is used when the ammonia is old and weak or when running large prints at rapid speed.Ī filter device is usually attached to aqueous ammonia machines to collect the ammonia exhaust. In the high position, air is bubbled into the ammonia to drive off the maximum amount of vapor. The low level allows the pump flow to recirculate in the top (vapor area) of the ammonia jug and is used for normal operation when the ammonia is reasonably fresh or when only a small number of prints are being run. On some machines, the pump speed can be adjusted to a high or low level. Ammonia vapor is pumped into the developer as long as the machine is running. On most aqueous ammonia machines, there is no separate power control for the pump. A third hose may be used to return the ammonia vapor to the bottle. One hose bubbles air into the liquid to drive the ammonia gas out of solution, another hose pumps the vapor from the bottle to the developer tank. The bottle is connected to the machine with two or three plastic hoses. The machines use one gallon bottles of aqueous ammonium hydroxide (aqua ammonia) to generate ammonia vapor. A vent is usually used to collect and remove the ammonia vapor to a control device.Īqueous ammonium hydroxide machines are more commonly used for low volume jobs, especially for engineering or architectural applications. Since the paper requires a humid environment for reaction, distilled water is also pumped into the chamber and heated to 150o - 180o F. In anhydrous machines, dry ammonia gas flows from high pressure storage tanks to the developer chamber. Anhydrous machines are used in printing shops for large volume reproduction applications. There are two main types of blueline machines, anhydrous ammonia machines and aqueous ammonium hydroxide machines. In the second step, the original is removed and the copy is re-fed into the developer chamber where the unexposed paper reacts with ammonia vapor and turns blue. In the first step, the translucent original drawing is placed over the blueline paper (paper coated with diazo salts) and fed through the machine where it is exposed to an ultraviolet (UV) light that turns the exposed parts of the paper white. The bluelining process occurs in two distinct steps. A main concern with the bluelining process is its use of ammonia and the production of ammonia vapors and waste ammonia solution. Blueline prints are also preferred for field use due to their durability and reduced glare compared to other types of prints. Bluelining is popular due to its relatively low operating and per print costs. Bluelining & Electrostatic Plottingįactsheet: Waste Management and Minimization for Bluelining and Electrostatic Plottingīluelining (blueprinting or whiteprinting), the process of making blueprint drawings, is performed widely in many engineering, architectural, mapping, and graphics departments throughout the Los Angeles area.
0 kommentar(er)
