GB191315263A - An Improved Method and Apparatus for Protecting Closed Vessels in which Inflammable Liquid is Employed. - Google Patents

Abstract

15,263. Martini & H³neke Maschinenbau Akt.-Ges., and G³ngerich, P. July 2. Fats, extracting by solvents. In plant for dry-cleaning or for extracting fat by volatile solvents, in which an inert gas is introduced into the closed cleaning- chamber to prevent explosion of the inflammable cleaning-liquid, a system of interlocked valves or cocks is employed which prevents the various operations from being performed otherwise than in a predetermined order, and which is controlled by a main locking-member actuated by the pressure of the gas in the cleaning-chamber, and adapted to release the liquid-supply valves only when a predetermined safe working pressure is attained within the chamber. Fig. 1 shows diagrammatically, as an example, a benzene cleaning-apparatus, in which articles enclosed in a perforated cylinder in the tank 2 are treated successively with half-pure benzene from a tank 6, and with pure benzene from a tank 5. Three interlocked plug-cccks 21, 19, 12 are operated by crank-arms which engage cam-slots formed on disks carried by a common spindle provided with an operating-handle rotatable in one direction only. The operation of this spindle also rotates the locking-plate 58, which in one position engages the members 62 and prevents the benzene-supply valves 13. 14 from being opened. In the position shown, the valves 5, 6 are both in communication with a pipe 9 leading to a reservoir of inert gas under pressure, the cock 21 is locked by the stem of the weighted doublebeat valve 25, and the valves 13. 14 also are locked. The first quarter-turn of the operating- handle opens the cock 19 to admit gas from the pipe 9 to the chamber 2. No further operation of the handle is possible until the pressure in the chamber, transmitted through the pipe 20, is sufficient to raise the valve 25 and unlock the cock 21. A further quarter-turn of the handle then re-closes the cock 19, turns the cock 21 so as to put the chamber 2 into communication with the gas-holder 16, and releases the valves 13, 14. During this operation part of the gas escapes from the chamber into the tank 16. and is used for protecting the tank 7 of dirty benzene. The screw lift valve 4 is then opened by hand to allow the gas in the pine 9 to force a sufficient quantity of benzene from the tank 6 into the chamber. After treatment of the articles, the benzene is run off into the tank 7 through the cock 37. The valve 13 is then opened to permit the articles to be rinsed with pure benzene. To discharge this benzene into the tank 6, the operating-handle is given a third quarter-turn to reopen the cock 19, thus equalizing the pressure between the chamber and tank 6, so that the benzene can be discharged through the cock 35. The same movement of the handle returns the cock 21 to its original position, in which it is re-locked by the valve 25, and also re-locks the valves 13, 14. while the final quarter-turn restores the whole system to its original position by re-closing the cock 19 and re-opening the cock 12. At this stage, the articles are dried by evaporation of the adhering benzene, and the gas is then drawn off from the chamber by opening the cock 33 leading to the air pump 32. Finally, the cock 30 is opened to admit air to the chamber before the articles are removed. The weighted valve 25 may. be replaced by a float. a weighted diaphragm, or any other locking- means controlled by the pressure within the cleaning-chamber. The invention is shown applied to a low-pressure apparatus in which the sequence of operations is commenced by exhausting air from the cleaning-chamber. In this case the air valve 30 also is linked up to and controlled by the operating-handle. Another system of working is described in which the used gas drawn off bv the pump 32 is delivered to a holder, and, together with a fresh supply of pure gas, is re-admitted to the chamber during subsequent cleaning operations. In this case, the driving-gear for the pump and for the rotating cylinder in the cleaning- chamber also are controlled by the operating- spindle.