Specification of Samuel Hall : apparatus for generating steam, gases, &c.

  • Hall, Samuel.
Date:
1854
Catalogue details

Licence: Public Domain Mark

Credit: Specification of Samuel Hall : apparatus for generating steam, gases, &c. Source: Wellcome Collection.

    12/28 (page 10)
    Hall's Improvements in Apparatus for Generating Steam, Qc. lever passes, and there is a screw that enters the top of the pillar to regulate the height to which the lever should be lifted when the steam becomes of too high pressure. Some of the peculiarities and excellences of the generator deserve pointing out. Common boilers, especially those of high-pressure steam engines, although at first they be sufficiently strong to be perfectly safe, 5 and even may be so after having been a considerable time subjected to and worn by the heat of an intense fire, will in process of time become so weak as to burst, and from the impossibility of ascertaining the precise time when that becomes the case, many serious accidents and explosions take place; but from the construction and application of this generator it is not so liable to those 10 evil consequences, for the exterior thereof is not exposed to the action of the fire, and the interior is protected therefrom, not only by the water, steam, and gasses contained in the surrounding tubes, but also by the portion of steam which is passed through the fuel, and which prevents such accumulation of heat taking place as would rapidly destroy the materials of which the generator, 15 as well as the grate supporting the fire, is formed. The abundant formation of scoria or slagg, which is produced from most kinds of coal by steam engine fires in general, is also by this means prevented. It is worthy, too, of remark, that one important peculiarity in this generator consists in the circumstance, that when the external part thereof is sufficiently strong there is no danger of 20 explosion, when at work, arising from its destruction by fire, even if the interior part thereof, which is alone exposed to the action of the fire, were to give way, as there is the same pressure, or nearly so, within the fire-place out¬ wards as there is within the tubes containing the water, steam, and gasses inwards, therefore the result of the giving way of the interior side would merely 25 be the passing of water, steam, and gasses from the tubes into the fire and extinguishing the same. I now proceed, thirdly, to describe the reservoir shewn by the letter C, Figures 1, 3, 4, 5. It is a plain cylinder or retort, with a hemispherical bottom, and closed with a cover a, r. There are two pipes branch from it, one 30 at the lower extremity b x, and the other near the top c x ; on the cover are fixed a safety valve and an apparatus for suspending a float within the reservoir to ascertain the height of the water therein. They are precisely the same as those belonging to the water tubes of the generator, except that the float and its counterbalance arc heavier and larger; it is therefore unnecessary to mark 35 the parts with letters or repeat the description thereof. The branch pipe b x, at the bottom of the reservoir, is to allow7 the gasses and steam from the generator to enter and pass through it in their way to the working cylinder, as wrell as to admit a supply of water from a force pump to the reservoir, and to