| 摘要 |
338,941. Hercules Powder Co., (Assignees of Milliken, M. G.). May 29, 1929. Addition to 301,267. Digesters.-In apparatus of the kind described in the parent Specification for the digestion of nitrated cellulose or for the purification of cellulose, the material is forced under pressure together with water through a restricted passage such as a coil of substantial length and relatively small cross-section, a valve being provided for controlling the discharge from said passage, the valve being replaced by or employed in conjunction with a stand-pipe or chamber to effect a substantial equalization of the pressure in the coil between the inlet and discharge ends, As applied to the treatment of gun-cotton, the material is treated in a tube A, fitted with agitating gear, and is forced together with water by a pump B through the coil C at a pressure of 80 lbs. per square inch and a velocity of about 2 feet per second. The apparatus may be made of chrome steel. The coil is steam-heated at e, insulated at g, and provided with a cooling jacket at f, the preferred temperature range being 130-160‹ C. The material passes from the coil through a valve j to the stand pipe X, and from thence to the tank D. The valve j is a conical member pressed against its seat by a spring n positioned between the valve stem and an adjustable stop O so as to open wider in case jamming off the gun-cotton being forced through causes a building-up of pressure. The operation of the valve is ensured by a stream of water which is forced into the coil C through a pipe E adjacent to the valve casing H. A pipe is provided for releasing back-pressure in the stand-pipe, and by means of a pipe T the coil C may be discharged directly into the tank D. A vent pipe y controlled by a valve z is provided in the downward extension X<1> of the stand-pipe. |
