US1721693A - Steam heating system - Google Patents

Description

JMW ffL :ffl FQRD STEA1V1-HEATING SYSTEM Filed March 10, 1923 jrmm@ mmf Claw/23312 Patented .luly 23, 1929..

"PATENT OFFICE.

BRUCE FORD, F PHILADELPHIA, PENNSYLVANIA.

s'rnalvr HEATING sYsrn-M.

Application lerl March 10, 1923. SerialjN'o. 624,294.

The present invention relates to improvements in low pressure steam heating systems in which the Water of condensation is returned to the boiler by gravity, and the principal object .of the present invention is to provide for a supply of steam to the radiators, not only when the `boiler temperature is appropriate :for steam generation at or vabove atmospheric pressure,'but also when 110 the temperature, is below that for steam generation at atmospheric pressure, or in other words, the object is to'provide heat at the lradiators at times, or under conditions, when', without my improvement, they would be cold, thus extending the range of use-y ulness or effectiveness of the system, both in respect to iiring up or starting, and in respect to operation when the fire is low. @ther obects of the invention will appear from the following description:

Generally stated, this invention comprises the combination of; a vacuum pump connected to the return or air-line forinsuring a higher water lever in an air-separating column in the return piping than the water level of the boiler, even at steam pressures at or below atmospheric pressure,whereby steam may be generated and distributed at abnormally low boiler temperature; float means for starting the pump; and float means responsive t'o increase in the difl'erence in these water levels for automatically stopping the pumpv and preventingl the scape otwater from the system. Asa result, there are rovided simple, safe and positive means ot accomplishing the objects, with provision for the return to the boiler by gravity of the water. of condensation.

The invention also comprises the improvement to be presently described and4 finally claimed.

In the following description, reference will be made to theaccompanying drawings,

forming part hereof, and in which bill Figure 1 is a digrammatic andschematicpresent. 4 is a steam generating boiler. 5

is a steam line, and 5a risers therefrom to n' the radiators. 6 is an air and water return line having a Water receiver' at 7, which separates air and Water for the return of the latter by gravity through the vpipe or connection 6a to the boiler and for the controlled escape .of the air from the system. As shown, the water column is contained by a covered tank or vessel 7' and the pipe 6, and

at its base communicates with the water inV the boiler, and the difference in level between the water in the tank 7 and tne Water 1n the boiler is indicated by a. There is a Heat device forlimiting the dierence in said water levels, thereby preventing overflow from the tank 7, and resulting escape -i of water from the system. The float device includes an air take-oli comprising a passage or connection 8 having a oateeuated valve 10, and there may be provided an air relief 9 with an inwardly closing check valve to exclude the atmosphere. 11 is a vacuum (or air exhaust) pump connected to the air take-off 8 by a pipe 12, in which there isa check valve 13. The vacuum pump is shown as driven by an electric motor 14, and there are means responsive to, or directly or indirectly actuated by,the height of the water column at 7 for stopping theump. As shown, the. valve 10 is opened an closed by the float 15b and the circuit of the motor 14 is automatically opened and closed by the float 15". Evidently a snap-switch should be employed for the automatic making and breaking of the motor circuit. One, but by no means Aan essential, form of such switch is shown in Fig. 2, in which 18 is an arm motor control circuit atb. 'llhe device so far described in connection' with Fig. 2 is, assumed to be contained within a casingc, from which the arm 18 projects to be operated upon by the adjustable prongs 26 on the 'Heat shaft. 28 is a wet return that communicates with the water of the boiler,

by Way of a line 29. 30 are bleeder pipes for draining the Water from the air-l1nes parts of the system as may be desirable, or' /lmay be omitted when they are not necessary.

'Itis presupposed that there is appropriate tire'control apparatus for regulating, the draft` or dampers of the boiler lire as is customary.

The mode of operation may be-described as vfollows:

In starting, the lire under the boiler is, of

' course, low and there is no steam in the system. The steam traps 3 are open, and the vacuum pump 11 is in operation.` These `conditions are favorable-for the generation of steam at lower pressure than that of the atmosphere. The vacuum pump will exhaust air from the entire system andtend to raise" l the height of the Water column at 7 by .causing Water of condensation trapped in the .radiators or in-theijreturnfline 6 to be discharged into 'the Water column and also, as

the-traps 3 begin lto close "against steam, by

tendingto suck Waterfup from the Wet returns 28 and the boiler, vuntil the iioat- 15b is' raised suicientlyto open the motor control circuit at b and stop the vacuum pump, which will again be started' when the lioat 15b` reaches a predetermined low level. When *steam passes `through the radiators llthe valves 3 c lose. The radiators are heated well in v advance of the time when they would be'heated if the vacuum pump were absent.

' As ythe fire comes up the pressure-in the boiler rises, causinga tendency to back itswater up the kconnection 6a which together with the water of condensationl coming by way of the air return line 6 raises the water level in the @motor 14V is 'stopped before 'the valve -l() is,

Water column at 7 which 'in turn displaces air above it. The arrangement of the lloat is such that the circuit is opened at?) and the closed.l As theimixtiire of air and Water of kcondensation from the return line reaches the Watery column it is separated, the airescaping by Way of .the valve '10,'and the `water of condensation reaching the boiler by way yof the-connectionv 6a by gravity. If the height of the Water column materially diminishes the pump will be again started, and will restore the level vand the pump will be stopped. As the pressure in the boilencontinues tol rise luntil it exceeds atmospheric pressure by morethan the value represented by the height a, the air will be expelled through. the check valve 9, the pump remaining stopped. As the Water column at 7 continues torise the lloat 15b closes the valvelO before Water escapes into the air take-oit 8. Thus the. difference in level a, is kept substantially constant since Ithe closing by valve 10 of the air takeoff'will prevent any substantial further rise in this direction, and lowering the Water level will permit air to be exhausted through'the'check valve 9 by the opening of valve 10 and thus# permit the level of the Water column at 7 to risc vso long as the pressure at the top .of the' :water column is above thatlotl the atmosphere, and if the fire .cools off and the pressure is reduced below that of the` atmosphere and the float 15b is lowered, the vacuum pump is again started. A supply of steam'atlthe radiators is insured in the manner above described, From the foregoing description it will be evident that the vacuum pump and its connections and automatic control, by maintaining a difference in the pressure inthe air line and that in the boiler (represented bythe heightva) in a direction favorable to the passage of steaml to the radiators and Waterof' condensation and air from the radiators through the traps 3 to the air return line 6, operate to provide heat at the radiators at times when otherwise the boiler pressure would be too low to do so, and the check valves 9 and 13 0ppose the reentry of air into the system.

The circuit of the'motor 14 may be the main motor circuit, as illustrated for simplicity,` or may, as often practiced, be a re= lay circuit for operating a main switch for starting and stopping the motor.

It should be-understood that the rotary type of vacuum pump diagraminatically illustrated. does'not limitthe invention to a pump of thisV type as any suitable means for applying vacuum may bel substituted',`and furthermore, a mechanical pump operated and controlled -by an electric motor and its circuit isv shown for the sake of simplicity and clearness and not as limiting the invention beyond what is covered by the claims.

It Will be obvious yto those skilled in the art to which the invention relates that modifications may be made in details of construction and arrangement without departing from the spirit of the invention which is not limited in respect to those matters or othertors, means for supplying steam from the boiler to the radiators, a water column Whose base communicates with the Water in the boiler, an'air line and its connections from the radiators to the water column,

traps :tor opposing the passage of steam while permitting the passage of air and water and included in tlle'ar line connec-4 tions, an air lake-ofi' from the top of the water column, a vacuum pump operatively connected wiilr the ai1' take-ol' to apply vacuum t0 and raise the water level of the water column above the water level of the boiler, auf] a float. controlled n'lcclluuism for starting (lle pump in response toa low wafer level of the wafer column and stopping the pump in response to a 'high water level of the water column.

2. 1n a steam heating system ille combination of a boiler, a radiator, steam'supply means bet-Ween the' boiler and the radiator, an an' ret-urn lme conneeied to the "radiator,

an air separating column connected to the air return line and boiler', a vacuum pump having valved connection with the top of the eo1umn,fand mechanlsm connected wlth the pump for starting and stopping the 20 pump 'and responsive solely to conditionscolumn.

BRUCE FORD.

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