334 



SCIENCE. 



[Vol. XIII. No. 326 



IMPROVED STEAM APPARATUS FOR HEATING 

 AND VENTILATING. 



The house of B. F. Sturtevant, Boston, Mass., has just brought 

 out a new design of its steam hot-blast apparatus, which is now 

 well known. This apparatus, first placed upon the market a quar- 

 ter of a century ago, has been gradually improved and rapidly in- 

 troduced, until about 5,500 are now in use for various purposes. 



The apparatus is a practical embodiment of the principle that a 

 positive circulation of air is necessary to secure rapid and perfect 

 ventilation, heating, or drying. Although constructed in a great 

 variety of styles, to suit all conditions and requirements, it always 

 combines the essential elements, — a fan and a heater. It is 

 furthermore usually constructed with an engine directly connected 

 to the fan-shaft, as shown in Fig. i. The fan is designed espe- 



space connecting with the drips. By this time it has condensed, 

 and leaves the heater in the form of water of condensation. 



The sides of these heads are planed and fitted, and joints made 

 by copper gaskets ; so that, when drawn together by the through 

 bolts, there is no possibility of leakage. In connection with the 

 sections is bolted on, at one end of the group, a header for steam 

 inlet (A), and drip (B). Both of these are large, and allow of the 

 use of exhaust steam without placing back pressure upon the en- 

 gine. The pipes C and D are respectively exhaust-steam inlet and 

 drip, communicating with the outermost section, which has no 

 head, and is entirely independent of the remainder of the group. 

 It is designed to utilize the exhaust from the fan-engine. The. 

 head end of each section rests upon the wrought-angle-iron foun- 

 dation of the heater, while the opposite ends are supported by cast- 

 iron balls (E) so as to allow for expansion. 



cially for handling large volumes of air with a minimum expendi- 

 ture of power. The advantage of a special engine, for the sole 

 purpose of driving the fan, is evident. The fan may then be run at 

 any time and speed, independent of any other source of power. 

 The engines are of Mr. Sturtevant's design and construction, and 

 are equal to the trying duty of fan-propulsion and continuous run- 

 ning. 



Radical changes have been recently made in the heater. As 

 now constructed, the heater proper consists of a series of hollow 

 sectional bases, shown clearly in Figs. 2 and 3. Their sides are 

 corrugated so as to fit closely together and allow of no alternate 

 expansion and contraction of the air passing between the pipes. 

 At one end of each section is a circular head (see Fig. 2) divided 

 horizontally by a diaphragm, so that the upper portion is in com- 

 munication with the steam inlet, and the lower with the drip. 

 Steam, admitted at the left through the steam inlet, passes up the 

 series of pipes, through the horizontal pipes, and down into the 



After continued use of wrought-iron pipe, Mr. Sturtevant has 

 adopted steel. The adoption of steel pipe marks one of the great 

 improvements in these heaters. The heater is incased in a fire- 

 proof steel-plate jacket communicating with the inlet to the fan, so 

 that air is drawn by the fan equally across all parts of the heater. 

 The pipes in the sections being set staggering, the air is compelled 

 to take a tortuous course, and is brought into intimate contact 

 with every foot of pipe. 



In operation for heating and ventilatmg, the outlet of the fan is 

 connected with a system of ducts or pipes leading to the various 

 parts of the building. In the case of an ordinary manufactory 

 either the distribution takes place through galvanized-iron piping, 

 in the form of upright mains extending to the various floors, and 

 having one or more outlets near the ceiling on each floor, or in 

 other cases horizontal mains extend the entire length of the build- 

 ing just under the ceiling on each floor, and the air is discharged 

 through outlets in these. In schoolhouses, churches, theatres, etc. 



