Specification of Samuel Hall : steam engines, boilers, furnaces, &c.

  • Hall, Samuel.
Date:
1854
Catalogue details

Licence: Public Domain Mark

Credit: Specification of Samuel Hall : steam engines, boilers, furnaces, &c. Source: Wellcome Collection.

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    Hall's Improvements in Steam Engines, Boilers, Furnaces, upper ends of the third or last set of fire tubes, thereby producing in them a partial vacuum. When the forcing process is adopted the air may be drawn by the hydraulic pneumatic apparatus from the top of the engine room (by which it will be ventilated) through pipe r, and forced through pipes s, s, and branch pipes t, t, into the closed ash-pits B, B, and through the fires, and from 5 thence the gases arising from the combustion of the fuel will be passed through the fire tubes j1, j2, f, into the chimney K, from whence they may escape into the atmosphere in the usual manner, or they may by shutting the damper m be made to pass away through pipe n in a horizontal or any other direction, and make their exit at any place that may be preferred. When this process 10 is adopted, and it is required to get access occasionally to the ash-pits to clean them out, or for any other purpose, the currents of air should be stopped off from them and turned into the chimney; for this purpose, there is a valve box v, containing two valves v1 and v2, shewn by dotted lines, and when they are placed in the situations here shewn, the air is forced into the ash-pit, and 15 through the fires and fire tubes in the manner above described; but when valve v1 is opened and valve v2 is closed the air will be forced into the chimney through pipe w without passing into the ash-pit, furnace, or fire tubes; but still an ample quantity of air will be drawn through them by the current of air projected into the chimney, in which it causes a considerable 20 draught, so considerable indeed that it may be desirable in some cases to draw the air through the furnaces altogether by this method, in preference to forcing it through them, as herein-before described. But when the above- mentioned method of creating currents of air through the furnaces and flues by exhaustion is adopted, the ash-pits must be opened and the damper m must 25 be closed, and the pipe n, instead of conveying the gases away from the chimney, must be connected with the inlet pipe r to the pneumatic hydraulic apparatus, and the gases drawn in by it may be forced through pipe S into the water or the atmosphere as may be preferred. The way in which the pneumatic hydraulic apparatus acts in its former capacity is as follows : the air and gases, 30 as the case may be, are drawn into and expelled out of the cylinders E, E, above the pistons, in same manner as is done with water below the pistons; for this purpose, each of those cylinders has a valve box H attached to and communicating with it, which box is furnished with an inlet pipe r and an inlet valve r\ and with an outlet pipe s and an outlet valve s3. On the descent 35 of the pistons the air or gases, as above described, are drawn into the cylinders through the pipes r, r, and the valves r3, r3, and on the ascent of the pistons they are expelled through the valves s3, s3, and the pipes s, s, the air being sent into the ash-pits or otherwise, and the gases into chambers at the bottoms of