w.1. BUBKART. AIR ELIMJNATOR.
APPLICATION HLED NOV. 20,1916
1,2 7,218. Patented No v. 20, 1917.
INVENTOR Willin.m I Bvrlmri' WI'IYNEBSES I invention will be more fully set forth in the UNITED STATES PATENT OFFICE.
.WIILLIAM J. BURKART, OE PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO PITTSBURGH ENGINEERING COMPANY, A CORPORATION OF PENNSYLVANIA.
AIR-ELIMINATOR.
Specification of Iletters Patent. Patentqd Nov. 20, 1917.
Application filed November 20, 1916. Serial No. 132,447.
To all whom it may concern:
Be it known that I, WVILLIAM J. Bummer, a resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in" escape, of air from a steam circulation system at a point in the return line; the prevention of the escape of water and steam; and mechanism for controlling the air passage for these purposes of simple construction and positive operation; Another ob eet of the invention is to provide means to prevent the drawingsof air' into the pipes through the escape-port; and thisis sealed device.
The various uses and advantages of the following specification, illustrated by the ae-' companying drawings, wherein an elevation of the apparatus is shown, the movable parts and their casings being shown in section.
Air eliminators are in use having in view the same general objects as here, but the construction has been different, and have had defects in operation which have been eliminated in the present case.
In asystemof heating by steam, a boiler is connected to a line which leads through the various rooms and radiating units to be heated and then returns to the boiler. In various ways air gets into the circulation, and it isimportant that this be eliminated. A part of thie steam is condensed in the line and radiators, and the water so formed is forced back into theboiler and so used again. The steam that returns is also valuable and must not be allowed to escape through the air eliminator. Therefore the problem is to permit ready expulsion of air through a device locked against passage of steam or water. There is a further problem in that air must not be allowed to pass into the system by reverse flow through the air eliminator; and this must be positively guarded against, since a sudden chilling of the radiators causes a large amount of steam to condense and so creates a partial vacuum in the line, which would draw air through done by a Heat the escape port if nomeans of prevention were provided.
All of these functions are-found in the present invention, which comprises a return line 1 having a T-connection to apipe 2 leading downwardto thello tver port of a boiler in the circulating system and apipe 3 leading upward to the air ,eliminating apparatus. This consists of a casing 4 having an opening 5 to thepipe 3, and an opening 6 at its top to a second casing 7. In the easing 4 a large float 8 is.mounted on a lower stem 9 a nd upper stem 10; the lower stem passing through an opening in the lower wall of the casing and so acting as a guide for the vertical movement of the float. A collar is fixed on stem 9 and seats on the lower wall of the casing 4 to limit the downward travel of the float, as will be obvious. The upper stem 10 is similarly guided by an opening in the upper part of the casing, here shown as a rentrant supplementary avalve disk 16 is fixed, adapted when the float is raised to cooperate with seat- 15 to close thepassage 17 between casings 4 and 7.
.Another; beveledvalve seat 18 is provided in the casing 7 at the upper end ofpassage 17. Thechamber 19, formed by easing 7, is closed by a threadedmember 20, having free ports 21 therethrough, and carrying athermostat member 22, insidechamber 19. This thermostat consists of a stem, in two parts, one being fixed to the casing wall, the other carrying avalve disk 23 adapted to cooperate withseat 18 to el'bse'tlgrk5 17, when a volatile liquid con-31drums 24 expands to lengthen the stem of the thermostat member. This thermostat is not itself ne'w; its operation is well known;
-wall 12, forming asmall chamber 13, con- I 'nected to the main chamber 14 by ports 6,
and noextended description is here neeestop ofcasing 26, and in thechamber 28, formed by said casing, carries'a bell-shapedopen terminal 29, ending below thepipe 27. Thecasing 26 is closed by a threaded mem her 30, to make thechamber 28 fluid tight at the bottom, and it is filled with water to the height ofpipe 27. A float 31, in the form of a hollow sphere, of any suitable material, is held in the mouth of bell-shaped terminal 29 by its bouyancy in the water.
The operation is as follows: Steam generated in a boiler (not shown) passes through the heating and radiating system (not shown) and then returns bypipes 1 and 2 to the boiler. A certain amount of Water of condensation and of air aremixed with steam in the return line. The water, of course, flows downpipe 2, and collects in that pipe, which connects by a non-return valve to the feed supply of the boiler. When pressure in the system mounts high enough to equalize (or nearly equalize) the pressure above this water and the boiler pressure, it passes into the feed supply and is used again to make steam.
Air in the return pipe will rise inpipe 3,
pass freely through chamber 14,passage 17,
chamber 19,pipe 25; depress the ball-float 31 and out thepipe 27 to the atmosphere.
Should a large amount of water come through pipe 1 so as to back up into chamher 14, the float 8 will rise,seating valve disk 16 and closingpassage 17 against esca e of Water. Pressure will eventually build up and the waterbe forced out to the boiler. I, I
Should. steam come through the return pipe to the eliminator, it will rise through chamber 14andinto chamber 19, enveloping the theremostat therein. The steam is of course at a temperature above 212 degrees Fahrenheit, and the thermostat is so made that such temperature will expand it sulfieiently to seat thevalve disk 23, and so close I thepassage 17 against escape of steam."
Sometimes a sudden chilling of the radiators condenses a large amount of steam and creates a partial vacuum in the system.
In such case air cannot reenter by the eliminator, even though both valves'16 and 23 be unseated, because the ball float 31 is always in position to close the mouth-piece v 29 against any upward fiow' therein, and the greater the pressure, the tighter this closure.
It will be observed by those familiar with Eli not be displaced or stick, and that the whole 60 apparatus is simple and positive in operation. The thermostat is ordinarily mounted so as to be adjustable with relation to the valve seat, though this is not here shown.
f In a steam heating system comprising a return line, an air eliminator comprising a easing connected to the return line, a float in the casing havinga guiding stem and a valve thereon adapted to close a passage from the casing, a thermostatically controlled valve also controlling the passage from the casing, and a pipe extending downward from the-passage through the casing having a bell-shaped terminal, a.casing surrounding the terminal, a ball float in said casing adapted to seat against the terminal and form a non-return valve, and a lateral V passage 'from the casing above the level of the terminal. Y In testimony whereof, I have hereunto set my hand. v
WILLIAM J. BURKART. Witnesses:
' GLENN H. Lnmesonn, 1J0. BAILY BROWN.