Specification of William Johnson : method of heating fluids.

  • Johnson, William.
Date:
1854
Catalogue details

Licence: Public Domain Mark

Credit: Specification of William Johnson : method of heating fluids. Source: Wellcome Collection.

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    Johnsons Improved Process for Heating Fluids. of steam from two surfaces at the same instant, and for protecting (by the evaporation being prevented) the bottom of the boiler in contact with the fire from injury. That one principle of this process for evaporating fluids, by employing close receptacles for the steam to be conveniently condens’d and 5 supply return’d (when requir’d) back to the boiler, I propose adopting by this forth of apparatus, when prefer’d by the employer, evaporating from two surfaces of the steam boiler at the same time, or employing two and evapo¬ rating only from the upper one. The advantage and convenience of steam to convey heat for many purposes has been long known; it has been a con- 10 siderable time adopted by a different process by dyers and others, who employ one common boiler to distribute the heat by steam to the different vessels of the manufactory, but in all of them with little variation in the form. The steam is convey’d through a pipe laid round the bottom of the fluid to be heated, with small holes in the pipe, to allow the steam to pass directly into 15 the fluid and mixing with it, by -which mode no material, if any, saving of fuel can arise than what results from the difference of waste by one considerable fire, in preference to the waste which wou’d arise from several fires being employ’d. This difference is found to be very considerable, which advantage, added to the avoiding the great inconvenience and charge for attendance and 20 repairs requir’d by several fires, is a sufficient inducement to them to adopt boiling by steam in the manner stated; and as heat convey’d by steam is already much adopted, every improvement that may conduce to its being introduced into other manufactorys cannot be too much explain’d; and to induce confidence in adopting the exact process here propos’d, it is proper to 25 make a few observations on two modes of employing steam that are most known and commonly adopted, which are by conveying the steam directly to the vessel to be boil’d; the other, by steam or heated water from the direct action of fire upon an outer vessel surrounding the vessel containing the liquid to be boil'd. First, on the employment of steam convey’d from a boiler 30 by a pipe to the vessel to be boiled, the great imperfection of this plan is, that it cannot save any material quantity of fuel but what arises from avoiding the waste occasion’d by a number of fires, as before stated; because, immediately that the steam enters the fluid in the vessel to be boiled, every excess of heat above the temperature of 212° passes off useless, in the same manner as first 35 stated respecting the direct action of fire, notwithstanding a pipe is used with small holes to check its waste and spread the heat; and the steam produced from a boiler of ten feet surface convey’d in this manner could but make another of ten feet surface boil, and with somewhat less rapidity, if the tern-