US1983218A

US1983218A - Heating system

Info

Publication number: US1983218A
Application number: US669363A
Authority: US
Inventors: Clayton A Dunham
Original assignee: C A DUNHAM CO
Current assignee: C A DUNHAM Co
Priority date: 1923-10-18
Filing date: 1923-10-18
Publication date: 1934-12-04
Anticipated expiration: 1951-12-04

Description

C. A. DUNHAM Y HEATING SYSTEM p'neys.

a She ets-Shee t 1 Filed Oct. 18,

Filed on. 1a, 1925 s Sheets-Sheet 2 Hi g C. A. DUNHAM HEATING SYSTEM Filed Oct. 18,

1923 8 Sheets-Sheet 3 vnems.

Dec. 4, 1934. c. A. DUNHAM HEATING 5151-1111 Filed 001. is, 192:5 a Sheets- Sheet 4 2 v 3 y w w y w 4 7% j J 0 wr H W WW \1 W? m i 4 W1 1 C. A. DUNHAM HEATING SYSTEM Filed Oct. 18, 1923 8 Sheets-Shget 6 C. A. DUNHAM HEATINGVSYSTEM Dec. 4, 1934.

Filed Oct. 18; 1923 8 Sheets-Sheet 7 I}! W I C. A. DUNHAM HEATING SYSTEM 1923 8 Sheets-Sheet 8 Filed Oc t. 18

Patented Dec. 4, 1934 HEATING SYSTEM Clayton A. Dunham, -Glencoe, Ill., assignor to C. A. Dunham Company, Marshalltown,'lowa,

a corporation of Iowa Application October 18, '4': .Claims.

My invention relates to steam heating apparatus and its general purpose is to make certain improvements in this art conducive to more economical operation, more uniform distributionof the steam to the places more or less remote from the source of supply where the steam is condensed, better and more accurate automatic control of the apparatus for generating and distributing the steam, together with a wider range ofadjustability for varying conditions of temperature than is possible with the steam heating systems here-' 1 tofore devised, and to accomplish these results by certain devices and mechanisms which are simple and inexpensive in their construction, positive and reliable in operation, and which may be readily adapted for use, if need be, in connection with existing installations.

More specifically, the objects of the invention comprisetheprovision of a heating apparatus with certain new and improved constructions, devices and expedients, preferably used in combination as shown in the drawings but susceptible of employment singly in some cases as will appear hereinafter, whereby-a constant but adjustable, that is a controlled, difierence in pressure may be maintained between the supply and return piping of the apparatus; whereby the condensate and air may be withdrawn from the radiators and the condensate returned to the boiler, either con.-

of water is accumulated; whereby a pumping whereby the quantities of steam received by the several radiators will be proportioned to their requirements regardless of the positions of the radiators with relation to the source of supply; whereby the system will be capable of variable operation so that the pressure in the radiators may be kept either at or above or below atmospheric pressure; and whereby the maximum quantity of steam that may be .introduced into the several radiators or heating units is subject to centralized control independent of conditions existing in the localities of the several radiators.

The invention consists in the new and improved constructions, arrangements and devices to be hereinafter described and claimed for carrying out the above stated objects and such other incidental objects as will be adverted to in the following description of the preferred embodiment of the invention shown in the ac- ,companying drawings.

In the drawings: v i Fig. 1 is adiagrammatic representation of the tinuously or intermittently as a certain volume 1923, Serial No. 669,363 (Cl. 237-9) view of one of the radiator Fig. 3 is a side elevation of the mechanism for V withdrawing water and air from the return pipe of the radiating system.

Fig. 4 is a view, in elevation, of the same apparatus viewed from a plane at right angles to the plane of Fig. 3.

Fig. 5 is a sectional .view on line 5-5 of Fig. 3.

Fig. 6 is a longitudinal sectional view of the jet exhauster forming part of the apparatus shown in Figs. 3 and 4. v r I Fig. "I is a sectional view of the inlet pipe of one of the radiators and the valve associated therewith.

Fig. 8 is a sectional elevation illustrating the difierential controller for maintaining constant difference of the pressure between the supply and returnmains of the radiating system.

Fig. 9 is a sectional view on line 99 of Fig. 8.

Fig. 10 is a fragmentary view of the upper portion of the mechanism shown in Fig. 8 but with the parts in a different position,

Fig. 11 is a longitudinal sectional view of the device for venting the hurling water circuit of air.

Fig. 12 is a sectional view taken on line 1212 of Fig. 11.

Fig. 13 is a sectional view taken on line 1313 of Fig. 8...

Fig. 14 is'a fragmentary side elevation of the controlling mechanism shown in Figs. 8, 9,10 and 13.

Fig. 15 is a wiring diagram of the controller.

Fig. 16 is a fragmentary view, in elevation with parts in section, of a differential gauge by means .ducer arranged in the steam supply main.

Fig. 21 is a sectional view on line 21-21 of. Fig. 20; and I Fig. 22 is a sectional view illustrating a modifled form of radiator inlet valve.

Referring first to Fig. 1, Adesignates a steam generator, B a steam supply pipe leading from the boiler oi the generator for supplying steam to the radiating system consisting of a plurality of radiators', two of which are shown and designated side of the building heated by the apparatus.

is a device subject to pressure in the boiler of the generator for controlling the operation of the generator through the closing and opening of one or more of the dampers. I is'a water tank at the end of the return pipe D and J a strainer arranged in the return pipe in advance of thewater tank I.

The latter is provided with an outwardly opening check valve K. L is a hurling water pipe circuit one leg of which extends through without communicating with the water tank I. In the circuit L is arranged a centrifugal pump M .and a jet exhauster N which latter draws water from the tank I into the hurling circuit through a pipe 0 having a check valve P opening in the direction of the exhauster. The hurl'mg circuit also contains a trap or device Q for ridding the hurling water of air drawn into the same from the radiating system. The term air" is intended to include any incondensable gas and is used in this sense in the appended" claims. R is a controlling device .for governing the motor S (Fig.- 15) which operates the pump M. The controller has a dual function. It operates to' start and stop the motor responsive to pressure fluctuations in the supply and return pipes B and D so as to maintain a constant but adjustable pressure differential as between the medium in these pipes. It also starts and stops the pump in accordance with changes in the water level in the tank 1. Any suitable pumping mechanism might be employed in place of that shown. Referring to Fig. 15, T is-a source of supply of current for the pump motor S. U is a circuit "breaker operated through controlling mechanism R by a float in tank, I, V a circuit breaker operatedthrough controller R. in accordance with changes in the pressure differential in the supply and return mains, and W a hand operated switch for putting the differential control out of operation.

Again referring to Fig. 1, X designates the feed pipe of the boiler which is connected with the hurling circuit by a pipe Y and with the supply pipe B by a pipe Z. V

Before describing in detail the construction of the several lnstrumentalitiesenumerated above, a brief summary will be given of the operation of the system as a whole. -,In comparing the detail views of the apparatus shown in Figs. 3 and 4 with the general view of Fig. 1, it will be observed that for the-purpose of general illustration of the whole apparatus the controller R has been arranged in Fig. 1 to the right of tank I instead of back of it, as shown in Figs. 3 and 4.

Steam from the generator passes into. the supply main B and after passing the pressure reducer F enters radiator C throughpipe 25 and hand operatedvalve 26. interposed between valve 26 and the radiator is a restricted-inlet opening in the form of an-oriflce plate 2'1 (Fig. '7) which restricts the inflow of steam so thatmnd'er normal conditions of operation the maximum quantity so that all of the radiators regardless of their position, receive substantially the same maximum quantity of steam (assuming radiators of equal volumetric contents), which quantity may, of

course, be reduced by operation of the hand operated valves 26. The steam is retained in the radiator C by steam trap E which, however, permits outflow of water of condensation and air through pipe '29 to the common return pipe D.

I 30 designatesthe feed pipe for radiator C and 31 the outlet pipe leading to the common return pipe D. 32 and 33 indicate feed pipes. extending to other radiators, not shown, and 34, 35 the outlet pipes from these other radiators.

The pressure reducer F operates to throttle flow of steam through the supply'pipe B in case of a rise of pressure in the boiler so that the pressure on the radiator side of the pressure reducer cannot exceed a certain maximum for which thepressure reducer is set. f The pressure reducer is also controlled by thermostat G so that if thetemperature in the locality of the thermostat rises above a certain point, the steam supply to the radiators is'throttled regardless of the pressure on the low pressure side of the pressure reducer F. a

Water of condensation and air withdrawn from 'the radiating system passes through pipe D and charged through the venting device Q which is constructed so as to prevent the outflow of water. The excess of water drawn into the hurling circuit is forced from the same through pipe Y into pipe X andthence into the boiler or generator A. Through pipe Z the pump and hurling water circuit are under boiler pressure. Pipe Y is located preferably'at substantially the normal water level of the boiler.

The pump, therefore, serves two diating system which operates to withdraw from functions: It creates a vacuum in the return pipe of the rathe radiating system the condensate and air therein; and it forces the condensate back into the boiler so as to maintain the water therein at a relat vely constant level. v

The pump is subject normally to a dual control. Assuming that switch W is closed any change'in pressure either in the supply main orin the return main which results in an increase in the difference in pressure in said pipes will operate the controller R to stop the pump and thereby bring about a decrease of the suction on the return pipe until the proper balance is restored.

Referring to Fig. 15, with switch W closed by hand and switch V closed through balancing of pressures on the pressure responsive element or controller R, current will flow through the motor over the following circuit: Source of current supply T, wire 36, switch member 37, wire 38.

switch member 39; wire 40, pump motor 8,. wire 41, switch member 42,.wire 43, switch member 44 and wire 45 to the source of current supply.

. By opening the switch W the differential control may be put out of operation but whether the diflerential control is operative or not the pump motor will be set in operation when the water in tanklrisestoacertainlevelsothattheaccumulated condensate is always taken care of. With switch w closed the pump will be in operation either when necessary to maintainproper difference in pressure between the supply andreturn mains or when water has accumulated in tank I. with the float controlled switch U closed the pump motor is supplied over the following circuit: battery T, wire 86, wire 46, switch member 47, wire 40, pump motor S, wire 41, switch member 48 and wire 49 to the battery.

The apparatus, the parts of which have bee enumerated above and their general relationship explained, will now be described in detail.

Steam traps of any suitable construction-may be used at the outlets of the radiators, Apreferred form of trap is shown'in-Fig. 2. 50 designates a corrugated vessel containing an expansible fluid, the vessel being provided with a stud 51'which is screwed into a boss 52 in the upper section 53 of a casing 54 having nipple 55-for attachment to the radiator. The thermostatic vessel 50 is provided on its under side with a valve 56 adapted to seat over a port 57-which leads to the radiator outlet pipe 29.

The radiator valve is shown in Fig. '1 and is preferably constructed as follows: 58 is a valve casing having an inlet port 59- communicating with feed pipe 25 adapted to be closed by a valve 60 arranged on a corrugated structure 61, having 'a stem 62 provided on opposite sides with notches 63 for non-rotatable engagement with a nut 64 which has a threaded engagement with an internal threaded sleeve 65 adapted to be rotated by a handle 66, the sleeve and handle being supported on the bonnet 67 of the valve casing. The stem 62 is non-circular in cross section and extends through .an opening of similar shape in a guide plate 68 which is interposed between the upper edge of the casing-andthe bonnet. Consequently when the handle 66 is-turned nut 64 is forced downwardly so as to seat the valve 60 over port 59. The outlet port of the valve casing is through 'a boss 69 secured by union 70 to a nipple 71 which is screwed into the radiator C. The orifice plate 27 above referred to is arranged in the boss 69 and is held against a shoulder 72 by a split ring 73. The oriflce plate is removable so that the valve for each of the radiators may be fltted with a plate having an oriflce of the propersize to provide for the admission of the proper amountof' steam to the radiator dependent upon the position of the radiator with respect to the source of supply of the other radiators of the system.

The pressure reducer F arranged'on' the supply pipe B is preferably constructed as follows (Figs. 20 and 21) 741sa valve casing interposed between sections of pipe B. Thecasing has an interior web 75 provided with two .

ports

76, 77 which. are adapted to be closed by a pair of valves 78, 79 on a stem 80 which passes'through a stu'fling box 80 in the bonnet 82 of the valve casing. Valve stem '80 is secured to a yoke 81 and the upper end of the yoke to -a stem 82v on a-plate 83 fastened to the under side of a flexible diaphragm 84 arranged in the diaphragm casing 86. The space-under the diaphragm 84 is open to the atmosphere through an opening 86 in the bottom of casing 86. The space above the diaphragm 84 is connected by a pipe 87 with supply pipe B on the low pressln-e side of the that is, the radiator side,-of the pressure reducer.

If the pressure on "this side of. the device exceeds that which is intended to be maintained, diaphragm 84 is deflected downwardly, against the action of the weight, moving valves 78, 79 against or toward their seats so as to shut oil or diminish the inflow of steam through

ports

76, 77 until the balance shall have been restored.

The temperature controlled regulator comprises a motor means in the form of a flexible, corrugated vessel 94 which is secured by means of an upstanding threaded stem 95 and lock nut 96 to a cross piece 97 on the yoke structure 89.. The expansible vessel is provided on its under side with a boss 98 slotted to receive acircuiar pro- ;iection 99 on the end of a lever 100 pivoted to the yoke structure 89 and carrying an adjustable weight 101. The weight, therefore, tends to compress the vessel 94. Interposed between the threaded stem 95 and the flexible portion of-the vessel is a boss 102 formed with a port 103 leading to the interior of the vessel, which'port is connected by a tube 104 with thethermostat G which, as shown,consists of lower and

upper headers

105, 106 connected by tubes 107. Thermostat G contains a fluid which expands and rise of temperature to the point at which the thermostat is designed to act, the pressure of the fluid in' the thermostat G, pipe 104 and 'expansible vessel 94 overcomes the force exerted by weight 101, (which force will, of course, depend upon the position to which the weight has been adjusted on lever 100) and moves the valves 78, 79 against or toward their seats to shut 08 or throttle flow of steam to the sup ply mainB. The arrangement is such, it will 5 be observed, that even though the presure on the radiator side of the pressure reducer is insuflicient to deflect diaphragm 84 to close or throttie the ports of the pressure reducer, if the temperature is reached at which thermostat G is set to operate, the thermostat will, nevertheless, bring about the closing or throttling of the ports. The apparatus for exhausting the return main D of the radiating system and introducing the condensate as feed water into the boiler of generator A is preferably constructed as follows;

The hurling water circuit L (Figs. 3, 4, 5 and 6) is composed of a pipe 108 extending from top to bottom through the water tank I, a T 109 on the top of the tank, a hollow fltting 110 which supports the tank (the latter having a flanged neck 111 which rests upon the fitting 110), a pipe section'll2, preferably provided with a shutoil valve 113, constituting the induction pipe of thecentrifugal pump M, a pipe section 114 leading to the iet exhauster N (Fig. 6), a pipe section 115 leading from the Jet exhauster to the vent trapQ, and a pipe section 116 connecting the vent trap with the T 109. With the pump M in operation water is driven centinuously through the hurling circuit as above described.

Water is drawn into the hurling circuit from 'exhausters.

cured to boss 128 by union 133 and to pipe section preferably constructed as follows: The jet nozzle of the. emustermomprises 'a member 117 secured by iunion ma toethe eduction pipe 114 of'pump M andrtomiedwithav contracted throat at 119 and: with a diverging-passageway 120. A casing 121-=--is"secured to the enlarged end 122 of jet member, 117 by means of a union 123, pipe 0 being. tapped into the side of this casing. Pro-'- jecting. through the casing is a nozzle member 124.having a threaded end 125 screwed into the end of nozzle member 117.- The bore of nozzle member 124 ispreferably of uniform diameter. The receiving tube of the jet exhauster is composed of two

members

126, 127 having a tight fit one with the other, member'126 having a threaded connection with a boss 128- on casing 121.- The throat of member 12615 flared as indicated at 129, the main portion of the bore 130 being of uniform diameter. The passageway 131 through member 127 is of gradually increasing cross sectional area as is common with jet 132'is an enclosing pipe section se- 115 by union 134. The water of the hurling circuit will ordinarily be quite hot and as a result, if a jet exhauster of ordinary construction were used diminution in kinetic energy of the jet would result from the tendency of the warm water to expand in throat 129.

stead of the one shown there would be less contraction of the jet issuing from nozzle member 124 than with cold water. By the construction shown the expansion is controlled in member 117 so that the heat released as a result of the pressure'change within the nozzle is utilized to increase the kinetic energy of the water particles as a result of the expansive action and when the water issues 'from the straight portion of the nozzle, that is member 124, it comes in a coherent stream which passes across the suction space in casing 121 and enters the flared portion of member 126 as a homogeneous jet.

The venting trap Q for ridding the water of the hurling circuit of entrained air is preferably constructed as follows (Figs. 11 and 12): 135 is .a casing provided at one end with, a separately formed closure plate 136 secured to the body of the casing by bolts 137. Secured to the inside of the cover plate is a casting 138 provided with a forked bracket 139 to which is pivoted at 140 the arm 141 of a float 142. Casting 138 is formed with a port 143 in alignment with an opening 144 in the cover plate in which port is arranged a valve 145 having a stem 146 passing through a bushing 147 supported by a web 148 on casting '138. The float arm 141 has a finger 149, with a forked projection 150 straddling the valve stem 146 and bearing upon .the valve 145 on one side and a collar 151 on the other. An accumulation of water in casing 135 will cause float 142 to close the port 143, thereby preventing the outflow of water through the vent. Under ordinary conditions the water level in casing 135 will be held low enough by the air trapped in the upper portion of tank Q so that valve 145 is unseated at intervals to permit the escape of Pipe section 115, as above shown as tapped into a boss 152 on one end of the casing. Preferably the casing is formed with an interior baflle web 153 arranged in front of That is. with warm water and an ordinary nozzle in use inthe was inlet. Pipe 11s leads from the lowe part of the casing to the T 109.

Excess of water in the hurling circuit is forced from the T 109 through pipes Y and X into the boiler below the. normal water level therein. The

hurling circuit operates under' boiler pressurewhich is balanced on opposite sides of pump M so that fluctuations in the pressure of steam in.

the boiler do not affect the operation of the pump. Moreover, the boilerpressure does not tend to backup the water in thevent trap Q.

The motor which intermittently drives pump M is controlled throughchanges in the level of the water accumulated in tank I by the float controlled mechanism preferably constructed as follows (Figs. 4, 5, 8, l3 and 14): 154 is afloat in the tank I arranged on an arm 155 which issecured to a shaft 156 within the tank extension 157 on a'plate 158 secured to the side of the tank I, the lever passing through an opening 159 in the plate 158. The shaft 156 is journaled in a stufilng box 156 in the wall cftank extension 157 and in a bracket arm 156 on plate 158. A crank am 155 on the outer portion of shaft 156 is connected by a link 160 with a trip 161 which latter is pivoted at 162 to the side of a casing 163 which is supported on a shelf 164 projecting outwardly from' plate 158. On

pivot stud 162 is mounted a weight 165 adapted to .be moved back and forth between

stops

166, 167. The weight is provided with a pair of studs 168, 169 adapted to be engaged by the trip 161. The weight 165 is provided with a stud 170 which projects through a slot 171 in the side wall 172 of casing 163 (Fig. 8) and through a slot 173 in a rocking member 174 which is pivoted at 175 to'the side wall 172 of the casing. The rocking member 174 is provided with a cross. bar 176 on which is arranged, with the interposition of suitable insulation 177, a pair of contact shoes 47, 48 (diagrammatically shown in Fig. 15). The

contact shoes 47, 48 are provided with extensions 178 connected by conductors 179 to binding posts 180. The line wires 46, 49 (Fig. 15) are connected with the binding posts 180. The shoes '47,, 48 are adapted to bear against a pair of contacts 181 supported on inclined ledges 182 on the upper ends of standards 183 mounted on an insulating block 184 in the casing. On the standards 183 are binding posts 185' to which are connected the pump motor leads 40 and 41. The

contacts 181 are held in placeon the standards by means of guide studs 186 flxed to the ledges 182 and extending loosely-through the contacts and through an upper pair of contacts 187 (for the diflerential control) and by set screws 188 extending through the upper and lower contacts and into the ledges 182, coiled springs 189 bein interposed between the upper and lower contacts of each pair. .With this arrangement a yielding pressure is exerted between the contact shoes 47, 48 and contacts 181, and also between the coacting pairs of contacts forthe diflerential I control to be hereinafter described.

Operation of the float control-when the level of the water in tank I falls, the float lever 155 is rocked raising link 160 and bringing trip 161 against stud 168 on the tilting weight 165. The weight is thus swung from right toleft (Fig. 4) until it passes center, whereupon it falls to the 'left until stopped by the bumper or stop member 167. This falling movement of the weight brings stud 170 .(Fig. 8) against the right hand end of slot 173 in the rocking switch'member 174 rocking the switch member to the right so as to separate contact shoes 47, 48 from the cooperating pair of contact 181 by a quick snap movement.

With the contact shoes 47, 48 bearing against the contacts 181 the pump leads 40, 41 are con-' nected with the line wires 46,49 as indicated by the diagram (Fig. 15). When this circuit is broken as above described, the pump motor is stopped unless it is receiving current over the circuit controlled by .the pressure differential of the radiating system is preferably constructed as follows (Figs. 4, 8, 9-, 10, 13 and 14): 190 is a diaphragm casing supported on the bracket plate 158 on the side of tank I (Fig. 4). The casing contains a flexible diaphragm 191 under which is arranged a spring 191 to which is secured a rod 192 (Fig. 8) extending through a.

I stumng box 193 and attached to a yoke 194, the

upper end of which carries a rod 195.- A lever 196 is pivoted at 197 to a standard 198 on the diaphragm casing and extends through yoke 194 having a knife edge bearing 199 on which the lever fulcrums. The lever 196 carries a weight, 200. Flxedfto rod 195 is a collar201having a curved arm 202 provided with a forked end 203 connected to a bell crank 206 pivoted at 207 to the casing 163, the bell crank extending into the casing through a slot 208 in the side thereof. A second bell crank 209 is pivoted to a bracket 210 in the casing and to the upper end of the upstanding arm 211 of this bell crank is secured a cross bar 212 carrying contact shoes'39, 42 (diagrammatically shown in Fig. 15) which are adapted to bear against the pair of contacts 187 previously described. The other arm 213 of the bell crank projects out through the slot 208 in the side wall of the casing and has a forked portion 214 with rounded edges engaging a collar 215 slidably arranged on rod 195 between a coiled spring 216 held against a washer 217 positioned by nut 218 6n the upper end of the rod, and a longer coiled spring 219 bearing against a washer 220 positioned against the fixed collar 201. The upstanding arm 221 of bell crank 206 has a hook 222 which is adapted to extend over a lug 223 on the am 213 of bell crank 209. The lower compartment of the diaphragm casing 190 is connected by a pipe 224 with the pressure side of the system at someconvenient point, the pipe being shown as extending into the fitting 110 which forms part of the hurling circuit. The upper compartment of the diaphragm casing 190 is connected with the vacuum'side of the apparatus by a pipe 225 which is shown as tapped into the tank I.

Line wires

38, 43 are connected with binding, posts 226. (Fig. 13.) From these binding posts extend a pair of wires 227to the binding posts 228 on the contact shoes 39, 42, wires 22'! being guided by a cross member 229 on the bell crank 211. In order to insure proper electrical connection between the standards, 183 and the

contacts

181 and 187

wires

230 and 231 are provided which extend to these'contacts respectively, from binding posts 232 on the standards.

Operation of the diflerential controL-The differential control is put into or out of operative connection with the apparatus by closing or opening hand operated switch W (Fig-15). Solon! as the difference in pressure between the supply and return mains is less than that which the apparatus is'inte'nded to maintain the contact shoes controlled switch U is opened or closed. If the balance of pressures on diaphragm 191 is disturbed either by increase of pressure under the same 'to increase the pressurediflerential over that for which the controller is set, the diaphragm is deflected upwardly against the action of weight 200, the-position of which on lever arm 196 determines the pressure diil'erential sought to be maintained. The upward movement of rod '195 rocks the bell crank 208 but without disturbing the position of hell crank 209 so long as the hook 222 bears upon the lug 223 on bell crank 209. During this initial upward movement of'rod 195 spring 219. is compressed. The spring 219 is in fact comdiaphragm or by diminution of pressure above the pressed to a certain extent when the parts are in the intermediate position shown in Fig. 8. As

soon as the upward movement of the rod releases the hook 222 from the lug 223 bell crank 209 is given a sudden' rocking movement by the force of spring 219 which moves the contact shoes 39, p

42 away from contacts 187 with a snapaction preventing arcing. The sprin 219 which is compressed more than spring 218 gives sleeve .215- a movement of greater amplitude than the vertical movement of rod 195 to effect a sumciently wide separation of the contacts as shown in Fig. 10.

"The pump motor circuitgoverned by the differential controlling mechanism is now broken v and the motor stopped, unless there is an excess of water in tank I, in which case the pump will tion of the float controlled switch U. Fig. 15

continue to operate because of the closed posishows the position of the difl'erential controller in the circuit breaking position of its parts.

When the balanceof pressures on diaphragm 191 is restored rod 195 is moved 'back to its normal position. During the flrst part of this movement hook 222 passes under lug 223 keeping the contacts in their separated positions and compressing spring 216.- When the hook clears the lug bell crank 209 is given a quick movement through action of spring 216 which moves the contact shoes 39, 42 against contacts 187 closing the circuit. The pump M and exhauster N are" designed so as to be capable of withdrawing from the radiating-system a larger quantity of condensate than will be formed under any normal conditions. Therefore if the, difference in-pres- I sure between the supply and return mains becomes less than the intended differential, resulting in a downward deflection of diaphragm 191 the pump will continue its operation for a proportionately longer period of time, namely until the diaphragm has been deflected past center and to its upper or circuit breaking positio The apparatus .is preferably provided with a gauge by which the difference in pressure between the supply and return portions of the system my be ascertained. In the preferred arrangement shown (Figs. 4 and 16 to 19 inclusive) the gauge is connected with the pressure side of the differential control diaphragm casing 190 and with the pipe which connects the vacuum sidev of the differential casing with tankI.

The differential gauge is preferably constructed as follows: 233 is a casing connected by pipe 234 with pipe 225. 235 is a casing connected the gauge tubes.

by pipe 236 with the lower side of the diaphragm casing 190. These casings are supported on a plate 237 having ears 238 for attachment to the side of tank 1. Within the casings are a pair of corrugated membranous

flexible structures

239, 240 open at the bottom to

pipes

234 and 236. Supported in stuffing boxes 241,242 on the tops of the casings and in recesses in the cross member 243 on the plate 237 are a pair of

glass gauge tubes

244, 245. The casings are filled with-bodies of liquid which rise to a greater or less extent in The base plate 237 is formed with a groove 246 to receive a sliding member 247 on which is fastened a scale plate 248 provided with graduations indicating pressure units, ounces of pressure, for example, and fractions thereof, beginning at zero atthe bottom of the plate. The liquid column 249 in gauge glass 244 will rise to a level determined by the pressure on the vacuum side of the apparatus while the liquid column 250 in gauge glass 245 will rise to a level determined by the pressure on the pressure side of the apparatus. By setting the gauge plate with the zero graduation in line with the upper surface of the liquid column 249 a reading may be taken of the height of the liquid column 250 which will indicate the difference of pressure maintained by the apparatus. In order to frictionally hold the scale plate at the desired elevation the slide 247 isv provided with elastic clips 251 which bear against ribs 252 on the back of the base plate 227. v The controlling device H for the generator may be of any usual type. It is shown as consisting of a diaphragm casing 253 (Fig. 1) the diaphragm of which operates on a lever 254 pivoted to the diaphragm casing at 255 and connected by achain 256 with the front damper 257 of the generator. There may also be a chain connected to the furnace pipe damper.

In Fig. 22 I have shown a radiator inlet valve which may be used in place of the radiator inlet valve shown in detail in Fig. 7. The purpose of both valves is the same, to provide means whereby the amounts of' steam which the radiators receive will be proportionedto their respective condensing capacities. In the arrangement of Fig. 7 this is accomplished by providing the valves of the severalradiators of the system with barrier or oriflce plates having orifices properly proportioned, with reference to the position of the ra-- diators in the system, to produce the desired results. In the arrangement shown in Fig. 22

the position of the valve body controlling the inlet port is made to depend uponthe difierencev in pressureas between the supply pipe and th interior of the radiator.

Pressure reducing radiator valve'.-Referring to Fig. 22, a pressure reducing valve is connected with the radiator inlet pipe 25 and with radiator C, the: means for making the latter connection being those shown in Fig. 7, namely, a nipple 71 screwed into the radiator and a union 70 connecting this nipple with a boss on the valve casing. The valve casing consists of upper and lower members 256, 259, the boss engaged by union 70 being designated 260. Clamped between casing members 258 and 259 is a flexible diaphragm 281. The lower casing member has an inlet port 262 in which is arranged a valve seat 263, A

provided with a stem 265 secured to a button 266 I to which diaphragm 261 is fastened. A flexible corrugated'structure 267 is secured at its lower end to the valve body 264 and at its upper end against a web 263 by means of a cap 269, A carvupon web 273 above referred to. Steam from the radiator supply pipe 25 can by-pass the valve 263 through duct 278 so as to reach the under side of diaphragm 261. The chamber 279 above the diaphragm is .connected with the interior of the radiator C by a pipe 280. Stem member 271 projects into a bonnet 281 on the valve casing. This bonnet is internally threaded to receive the threaded portion 282 of the end of an operating 'stem 283 which projects through the bonnet and is provided with a hand grip 284. The valve body 264 may be seated on valve seat 263 by turning hand grip 284, but when the valve is not seated in this positive way its position with respect to the valve seat will depend upon the balance of steam pressures on opposite sides of diaphragm 261 and upon the pressure of spring 277 whichv may be varied by adjustment of nut 275. When the pressure builds up in the radiator to a certain point diaphragm 261 will be deflected downwardly so as to close the inlet port into the radiator or throttle it. When the pressure falls in the radiator the'diaphragm will be raised so as to increase the eil'ective sizeof the inlet port of the radiator. j

Summary of operation of the. system as a whole-Steam from the boiler of generator A passes through common supply pipe B and into the several radiators through oriflce plates 27 having openings of different sizes proportioned,

with respect to the locations of the radiators in the system and their condensing capacities, so that the quantity of steam entering each radiator will'be proportioned to the heat demand upon that particular radiator (Fig. 7). A similar result is obtained by providing the radiators with the pressure reducing valves as shown in Fig. 22. The steam is retained in the radiators by steam traps E, E when operating conditions are such that the radiators are completely fllled with steam but air and water of condensation are withdrawn through common return pipeD by the vacuum created in the water tank I through operation of pump M and jet exhauster N. The excess of water drawn'into the hurling circuit L ratus is out of operation, through the opening of switch W, and the system is functioning by gravity at pressuresslightly above atmospheric'pressures. The valve closes inwardly when the tank is under vacuum through operation of the pump. Whenever the water in tank I reaches a certain' level, the float 154 closes a circuit through pressure in the tank when the. exhausting appathe motor whereupon the pump is started and withdraws water from the tank forcing the same into the boiler of the generator. If the water level in the tank I falls below a certain point the pump isstopped provided the motor circuitis not closed by operation of the pressure differential controller. The pressure differential controller may be made effective or ineffective through the closing or opening of circuit break'erW. With the'circuit breaker W closed-the" differential conthe pressure of the hurling water circuit, which is subject to boiler pressure, and the lower pressure existing in tank I which corresponds to that in the return pipe D. These two controls are independent of each other. Eitheronewill keep the pump motor in operation regardlessof the other when conditions require the evacuation of water from tank I or the maintenance of a desired vacuum in the return pipe of the radiating system. Check valve P prevents water from being forced by boiler pressure into tank I when thepump is, stopped. Such back flow of water, un-' less checked, might eventually fill the tank and set the pump in operation.

The maintenance of aconstant, but'adjustable,

difference in pressure between the supply and reapparatus. The condensate from the radiating turn mains of the radiating system has several advantages: The introduction-oi steam. into each of the radiators of the system is assured. The amount of steam introduced into the radiators is made dependent solely upon the pressure of steam in the supply pipe and the size of the orifices leading to the several radiators. By properlyproportioning the inlet orifices of the radiators and by providing the pressure reducer Fin the supply pipe, the maximum amounts of steam received by each radiator (subject to diminution by manual valves 26) will be the same and can be accurately controlled from a central point. Through proper adjustment of the pressurereducer and with properly proportioned radiator orifices, the apparatus can be operated so as to maintain pressures in the radiators either at, above or below atmospheric pressure. This adjustment of pressure in the radiatorsof the system may be eil'ected automatically through operation of the thermostat G. For example, as-

suming thermostat G to be located outside of the building, its operation can be controlled (variably by adjustment of weight 101) so that in warm weather for example, the thermostat will cause

valves

16, 77 to throttle the steam supply tothe radiators to such an extent that with the pumpiri operation under the diilerential control, atmos-' pheric or even sub-atmospheric pressure can be maintained in the radiators. Under mild weather conditions the supply of steam may be so reduced that the radiators will be only partially filled with steam; and this condition will necessarily result. with continued reduction of steam supply, after the maximum vacuum has been obtained. As the outside temperature falls more steam will be admitted to the radiators, and this inay be enough, for example, in very cold weather, to raise the pressure to atmospheric pressure or to a pointabove atmospheric pressure. The automatic control of the pump by the controlling mechanism R. results in a more uniform control of the supply of steam to the radiators. because the pressure diflerential is between the return and supply ends of the system instead of being between the return piping and the atmosphere; and also results in an economy of electric current since the pump motor 8 is in operation only when necessary tomaintain the desired conditions. The diii'erential controller maintains a constant pressure diiferential as between the heating medium in the source of supply of heat, pipe B on the boiler side of the reducing valve 1', and the return pipins. which differential is sulllcient to keep the radiators filled with steam and purged of air differential between and condensate under the severest weather condiq tions. The pressure reducing valve F under con-.

trol of the thermostat (3 reduces. to a greater or less extent, the pressure of steam going to the radiators; the pressure in the supply main 3 on the. radiator side of valve I being regulated by thermostat G so as to supply ,theradlators with the quantity of steam required-by existing. heat demands. The operationof the diil'erential controller in conjunction with that of the pressure reducer F maintains as between radiators andretum piping pressure differentials which are of less magnitude than that between the source of supply and the return piping and which :are 'proportioned to the quantities of heating medium which must be handled-by the system, these diff fe'rentials being less when the amount of steam I circulated is less and greater when the amount of steam circulated -is greater. This results in further economy in the operation of the in full lines in Fig. 15) will ordinarily be open. The diil'erential controller is, therefore, cut out of operation. The. pump is operated under the control of the float controlled operator 154 (Fig. .5) to return water. accumulated in'tank I at suitable intervals to the boiler.

Under these conditions the system will operate at pressures above atmospheric pressure. The

pump operates only at intervals and, therefore; does not maintain a constant vacuum in the re-- turn piping. If for nighttime operation a lower temperature is desired the weight 101 is'shifted to reset the

valves

76, 77 to positions closer to their seats. Thereafter the thermostat G operates as before' to vary the position of these valves according to temperature changes, wherebythe desired lower inside'temperature is maintained.

The traps will function as in daytime operation. But with the system operating at pressures above atmospheric pressure, check valve K on the tank I will open to permit the outflowof non-condensable gases. The radiators'may beeither completely or only partially filled with steam according to the quantity of steam supplied to the radiators through operation of controller F,

This application is a continuation in part of my copending application Serial No. 518,386, filed November 28,1921. 1

I claim: y 1. In heating apparatus, the combination of a generator, a radiating system, supply and return- .pipes, a water tank, a hurling water circuit under boiler pressure comprising a pump and jet ex- .hauster for withdrawi'ng medium from the return pipe and introducing condensate into the generator, and means for starting and stopping the operationof the pump ln'response to a decrease or increase, respectively, inthe pressure the tank and hurling water circuit. A

2. In heating apparatus, the combination of a generator, a radiating system, supply and return pipes, a water tank, a hurling water circuit under boiler pressure comprising a pump and jet ex- 105 For nighttime operation the switch W (as shown 3. In heating apparatus, the combination 01' a generator, a radiating system, supply and return pipes, a water tank, a hurling water circuit under a boiler pressurecomprising a pump and jet exhauster for withdrawing medium Iro'm the return pipe and introducing condensate into the generator, means subject to changes in the water level in the tank for controlling the operation of the pump, means subjected to pressures in the tank and hurling water circuit for controlling the operation of the pump, and means for starting and stopping the operation of the pump in re- 's'ponse to a decrease or increase, respectively, in the pressure differential between the tank and hurling water circuit.

4. In an automatically regulated heating system, the combination of heating units each having a restricted inlet opening so proportioned that the quantity of heat carrying medium admitted to the unit can be regulated by variations in pressure in theheat carrying medium, a pressure regulator for varying the pressure in the heat carrying medium, and a temperature controlled rcgulator'ior automatically controlling said pressure regulator. v

5. In combination in a heating system, a plurality of radiators, a common supply main ,for supplying heating fluid to said radiators, each radiator being connected to the supply main through a regulable but normally fixed orifice to control the rate or flow to the respective radiators for a given pressure in the supplymain, and

' means-responsive to temperature to regulate the pressure of the heating fluid in said mains.

6. In a heating system, the combination oif a supply main for heating fluid, aplurality oi radiators having connection withsaid main through orifices for controlling the relative flow of heating fluid to each radiator, a pressure regulator in the supply main for maintaining a given pressure of the heating fluid supplied to said orifices, and

means responsive to temperature for controlling 'the setting or said regulator. I

7. In a heating system, a radiator having a fixed orifice to control the inlet of heating fluid thereto, a supply main for heating fluid to be supplied to said orifice, a pressure regulator for holding a predetermined pressure upon said ori- I lice, and temperature responsive means for controlling the setting of said regulator so that the rate of flow of heating fluid through the orifice to the radiator is adjusted tothe requirements (or heat to be given ofl by the radiator..

8. In a heating system, the combination or ra-. diators each having a restricted inlet opening so proportioned that the quantity of heat carrying medium admitted thereto can be regulated by variations in the pressure of the heat'carrying medium, an automatic pressure regulator for varying the pressure of the heat carrying medium, adjustment varying means for varying the adjustment of saidautomatic pressure regulator,

and temperature controlled means governing said adjustment varyingv means. I

9. In a steam heating system, the combination of radiators each having a restricted inlet opening so proportioned that the. quantity of steam admitted thereto can be regulated by variations in the pressure of the heat carrying medium, an automatic regulator for varying the pressure oi! the steam, and means for automatically varying the setting of the pressure regulator commensurate with. variations of temperature.

10. In a heating system, the combination of radiators each having a restricted inlet opening so proportioned that the quantity of heat carrying medium admitted thereto can be regulated I by variations in the pressure of the heat carrying medium, an automatic pressure regulator for controlling'the pressure in the heat carrying medium, regulable means for varying the setting of the pressure regulator, and temperature controlled means governing such regulable means whereby it may automatically vary the setting of the pressure regulator commensurate with variations in temperature.

11. In a heating system for a building, the combination of a plurality of radiators therein each having a restricted inlet opening so proportioned that the quantity of heat carrying medium admitted thereto can be regulated by variations in the pressure thereof, an automatic regulator for varying the pressure 01 the heat carrying medium, adjustment varying means for varying the adjustment of said pressure regulator, and thermalh sensitive means exposed to variations in pressure of the heat carrying medium, an automatic pressure regulator for varying the pressure of the heat carrying medium, regulable means for varying the setting of the pressure regulator, and

temperature controlled means governing said re g- I ulable means whereby it may automatically vary the setting of the pressure regulator commensurate with variations in the atmospheric conditions external to the building.

13. In a heating system, the combination of heating units having each a restricted inle't opening so proportioned thatthe quantity of heat v carrying medium admitted thereto can be regulated byvariations in the pressure oi. theheat carrying medium, a pressure regulatorvior varying the pressure of the heat carrying medium,

means for loading said regulator to a variable degree comprising motor means and a temperature controlled device for governing the action oi! said motor means.

14. In -a heating system, the combination of radiators each. having a restricted inlet openingso proportioned that'the quantity of heat carrying medium admitted thereto can be regulated by variations in the pressure of the heat carrying medium, an automatic pressure regulator loaded to a variable degree Ior varying the pressure of the heat carrying medium, means for loading said regulator to a variable degree comprising motor means and a temperature controlled device for governing the action of said motor means.

15. In a heating system for a building, the combination of heating units each having a restricted inlet opening so proportioned that the quantity of heat carrying medium admitted thereto can be regulated by variations in the pressure oi! the heat carrying medium, a loaded diaphragm pressure regulating valve for automatically regulating the pressure oi! the heat'carcharging condensate from said receiver; a ditdensate irom the radiators and return piping ierential controller for the exhausting apparatus for maintaining a controlled diiierential between the pressures in the supply and returnpiping; and a second controller for the exhausting apparatus which operates in response to differences in water level in the receiver, said exhaustingr apparatus being started by operation of either controller but stopped only when both controllers I are in their stopping positions.

17. In a steam heating system, the combination with a source oi steam supply, a plurality of radiators, 'andsupply'and return piping: or a receiver for water of condensation; an exhausting apparatus ior withdrawing air and coriand condensate from said receiver; a diflerential'controller for the exhausting apparatus for maintaining a controlled diilerential between the pressures in the supply and return piping; a second controller for the exhausting apparatus which operates in response to diflerv ences in water level in the receiver,-said exhausting apparatus being started by operation of either controller but stopped only when both controllers are in their stopping positions; and means whereby the diiierential controller may be put out of operation and the second controller put into iullcontrol oi the exhausting apparatus.

18. In a steam heating system, the combination with a source of steam u ply. a plurality oi" radiators, and'supply and return piping; or a receiver i'orwater oicondensation; an exhaust-v in'g apparatus for withdrawing air and condensate irom the radiators and return piping and discharging condensate (mm the receiver;- acontroller. actuated by steam pressures in the system for controlling the exhausting apparatus; and a second controller for the exhausting apparatus operating, in response to changes in 'water' level in said receiver, said exhausting apparatus being started by operation at either controller but stopped only when both controllers are in their stopping positions. I T

19. In a steam heating system, the combination with a source or steam supply, a plurality oi radiators. and supply and return piping; or a receiver for water of condensation: and exhaust-. ing apparatus for withdrawing air and controlleractuatedbysteampree'suresin-the tor-controlling the exhausting apparatus: a sec.- 'ond controller for the exhausting apparatus operinresponseitochangesinwaterlevelinsaid atim receiver, saidexhaustingapparatus beingstarted 'byoperation oieither controller butstoppedonly when both controllers arein their stopping-peeltions; andmeanswherebythepressure actuated controller maybe put out of operation and the and supply and return piping: 01' a receiver for -'condensate connected with the return piping;

both controllers are in their stopping positions.

21. In a steam heating system, the combination with a source of steam supply, a plurality oi radiators, and supply and return piping: of a receiver for condensate; an exhausting apparatus for withdrawing air and condensate from the ra-- diators and return piping and discharging condensate iromthe receiver; controlling means'ior said exhausting apparatu'sresponsive to changes 01' liquid level in the receiver and also to changes in pressure differential between the supply and return piping so that the exhausting apparatus will be set in operation when either the liquid in the receiver reaches a certain level or when said pressure diflerential falls below a predetermined minimum. and will continue to operate until both the desired liquid level and the desired pressure diiierential have been reestablished.

22. In a steam heating system,-the combination with a source of steam supply. a plurality of. radiators. and supply and return piping: ot a receiver for condensate; an exhausting apparatus for withdrawing air and condensate irom the radiators and return piping and discharging condensate from the receiver; controlling means for said exhausting apparatus responsive to changes of liquid level in the. receiver and also to changes in pressure diiferential between the supply and return piping so that the exhausting apparatus will be set in operation when either the liquid in the receiver reaches a certain level or when said pressure difl'erential falls below ,a predetermined minimum, and will continue to operate until both the desired liquid level and the desired pressure diii'erential have been re-established; and means for rendering the pressure control of the exhausting apparatus ineilective and making the exhausting apparatus subject only to control by changes in liquid level. I

23. In a steam heating system, the combinationwith a source of steam supply. a plurality of radiators. and supply and return piping: of: steam traps at the outlets oi said radiators; means comprising an exhausting mechanism for maintain.- ing a controlled diiierentialbetween the'pressures in the supply and return piping, means comprising a valve actuated by pressure in the supply piping for controlling the flow of steam to the radiators, and a thermostat acting on said valve in a man ac; to meet varying heat requirements oi the sys- 24. In a steam heating system, the combination with ssource oi steam supply. a plurality oi radiators, and supply and return piping: 0! means for restricting the flow of steam into the radiators in proportion to their individualheat requirements; means actuated by pressures in the supply and return piping for maintaining a con-' trolled diflerential between the pressures in the supply'and return piping and means for varying saiddiil'crentialinamannertomeettheheat requirementsotthe systemasawhole.

25. In a steam heating system, the combination with a source of steam supply, a plurality oi radiators, and supply and return piping: of orifice plates, theoriflces oi which are proportioned so as to restrict the flow of steam into the radiators .actuated by pressures in the supply and return piping for maintaining a substantially constant pressure differential between the source of steam supply and return pipin and controlling means in the supply piping for maintaining determinable pressure diflerentials, of less magnitude than that between supply and return piping, between the pressures in the radiators and return piping.

27. In a steam heating system, the combination with a source oi steam supply, a-plurality of radiators, and supply and return piping: oi! means actuated by pressures in the supply and return piping for maintaining a substantially constant pressure diiierential between the source of steam supply and the return piping; and thermostatically controlled means in the supply piping for maintaining determinable pressure diflferentials, of less magnitude than that between supply and return piping. between the pressures in the radiators and return piping.

28. In a steam heating system, the combination with a source of steam supply, a plurality oi radiators, and supply and return piping: of means actuated by pressures in the supply and return piping for maintaining a substantially constant pressure difl'erential between the source of steam supply and the return piping and controlling means for determining the pressure of steam supplied to the radiators in response to the heat requirements of the system.

29. In a steam heating system, the combination with a source of steam supply, a plurality of tween the pressures in the radiators and return' radiators, and supply and return piping: of means actuated by pressures in the supply and return piping for maintaining a substantially constant,

pressure diil'erential between the source of steam supply and the return piping and a thermostatically controlled means for maintaining determinable pressure diflerentials, of less magnitude than that between supply and return P pin be- 30. In a steam heating system, the combination with a source or steam supply, a plurality oi radiators, and supply and return piping: of means for maintaining controllable pressures in the source of steam supply; means actuated by pressures in the supply and return piping for maintaining a substantially constant pressure dinerential between the source oi steam supply and the return Piping: and controlling means in the supply piping for maintaining determinable pressure difierentials, of lessmagnltuiie than that between supply and return piping, between the pressures in the radiators and return piping.

31. In a steam heating system, the combination- I with a soin-ce of steam supply, a plurality oi radiators, and supply and return piping; of means for retaining steam in the radiators while permitting the system.

the outflow of air and condensate therefrom; means actuated by pressures in the supply and return piping, comprising an exhausting mechanism, for maintaining a substantially constant pressure difl'erential between the source 01' supply and the return piping; and controlling means in the supply piping for maintaining determinable pressure diil'erentials, 0! less magnitude than that between supply and return piping, between the pressures in the radiators and return piping. I

32. In a steam heating system, the combination with a source of steam supply, a plurality oi radiators, and supply. and return piping: 01' means for retaining steam in the radiators while permitting the outflow of air and condensate therefrom; means actuated by pressures in the supply and return piping comprising an exhausting mechanism, for maintaining a substantially constant pressure difierential between the source of supply andthe return piping; and controlling means for maintaining determinable pressure differentials,

means actuated by pressures in the supply and return piping, comprising an exhausting mechanism, for maintaining a substantially constant pressure'difierenti'al between the source of .supply and the return piping; and thermostatically controlled means in the supply piping for maintaining determinable pressure differentials, of less magnitude than that between supply and return piping, between the pressures in the radiators and return piping.

34. In a steam heating system, the combination with a source of steam supply, a plurality of radiators, and supply and return piping: of means actuated. by supply and return pipe pressures for maintaining a controlled diii'erential between the pressures in the supply and return piping means 0 including a valve between the source oi supply and the radiators influenced by pressure in the supply piping for retarding to a greater or less extent the flow oi steam between the-source of supply and the radiators; and thermostatic means sub- 'iect to temperatures external .to the system, (or additionally controlling the flow of steam to the radiators inaccordance with the heat requirements oi the system. i

35. In a steam heating system, the combination with a source of steam supply, a plurality of radia tors, and supply and return piping: of means for maintaining a substantially constant pressure in the source oi steam supply; means-actuated by supply and return pipe pressures for maintaining a controlled diflerential between the press'ures in the supply and return pipin means including a valve between the source 01 supply and radiators influenced by pressure in the supply piping for retarding, to a greater or less extent-the the radiators, and thermostatic means for additionally controlling the flow 01' steamto the radiators in accordance with the heat requirements of 45 e 1 36. In asteam heating system, the combination with a source of steam supply. a plurality oi radiators, and supply and return piping: of means actuated by supply and return pipe pressures for maintaining a controlled diilerential between the 15 1,oss,21a

pressure'in the supply and return piping; a thermostatically operatedivalve mechanism in the supply piping between the source or steam supply and the radiators and influenced by pressure in the supply pipingwhich is capable of closing to shut of! steam supply to the radiators or being opened to agreater or less extent, for additionally sive means controlling the exhausting apparatus.

to maintain a controlled diflere'ntial between the pressures in the source and return piping; and a pressure reducer in the supply piping for determining the quantities of steam supplied to and the pressures maintainedin the radiate regardless oi fluctuations of pressure in the source of steam supply, in accordance with the heat requirements of the system.

38. In a steam heating system, the combination with a source oi. steam supply, a plurality oi radiators, and supply and return piping: oi means for maintaining steam in the radiators while permitting the outflow of air and condensate; an exhausting apparatus for withdrawing fluids from said radiators and return piping; pressure responsive means controlling the exhaustingapparatus to maintain a controlled difl'erential between the 85 pressures in the source and return piping; a pres-;

tion of a source of steam supply; a plurality of radiators having flxed restricted inlet orifices of such sizes that the radiators. receive quantities of steam proportioned to their individual heat requirements; supply and return pipin thermostatic means for controlling the pressure of steam in the supply piping adjacent the radiator inlets in accordance with the heat'requirements .oi .the system as a whole; and means cooperating with the thermostatic means for maintaining a controlled diirerential between the pressures in the supply and'return piping.

40. In a steam heating system, the combine. tion of a source of steam supply; a plurality o! radiators having flxed restricted inlet oriflces o! m such sises that'the radiators receive quantities of steam proportioned to their individual heat requirements, and being provided at their outlets with steam traps; supply and return piping; thermostatic means i'or controlling the pressure or steam in the supply piping adjacent the. radiator inlets in accordance with the heat requirements of the system as a whole; and means cooperating with the thermostatic means and comprising an exhausting apparatus for maintaining a controlled diflerential between the pre'sj sures in the supply and return piping.

41. he steam heating system-the combina tionofasouroeoi'steamsupplyiaplwalityof radiators having iixed cted inlet oriflces of such'sises that the radiators receive quantities 'provided at their inlets with oriflce plates, the orifices 01' which are proportioned so that the return PM.

of steam proportioned to their individual heat requirements; supply and return piping; thermostatic means, subject to temperatures external to the system, for controlling the pressure oi! steam in the supply piping adjacent the radiator inlets in accordance with the heat requirements of the system as a whole; and means cooperating with' the thermostatic means tor maintaining a con trolled differential between the pressures in the supply and return piping.

42. In a steam heating system, the combination oi a source of steam supply; a plurality of radiators having flxed restricted inlet orifices of .such' sizes that the radiators receive quantities of steam proportioned to their individual heat requirements; supply and return piping; thermostatic means, subject to temperatures external. to the space being heated, for controlling the pressure of steam in the supply piping adjacent the radiator inlets in accordance with the heat requirements 01' the system as a whole; and means cooperating with the thermostatic means .tor maintaining a controlled diiierential between the pressures in the supply and return piping.

, 43. In .a steam heating system, the combination of a source oi! steam supply; a plurality of radiators having flxed restricted inlet oriflces of such sizes that the radiators receive quantities of steam proportioned to their individual heat requirements, and provided at their outlets with steam traps; supply and return piping; thermostatic means subject to temperatures external to the system for controlling the pressure of steam in the supply piping adjacent the radiator inlets in accordance with the heat requirements 0! the system as a whole; and means cooperating with the thermostatic means and comprising an exhausting apparatus, for maintaining a controlled 'diflerential between the pressures in the supply and return piping. 1

44. In a steam heating system, the combination of a steam generator; a plurality of radiators provided at their inlets with orifice plates, the orifices of which are proportioned so that the radiators receive steam in proportion to their individual heat requirements; steam traps at the outlets of said radiators; supply and return piping; an exhausting apparatus for withdrawing air and condensate from the radiators and return piping; a pressure reducer in the supply piping whichmaintains determinate pressures in the radiator inlets regardless oi fluctuations in generator pressure; and a controller for the exhausting apparatus cooperating with the pressure reducer tor maintaining a controlled diiierential between the pressures in the supply and radiators receive steam in proportion to their individual heat requirements: steam traps at the outlets of said radiators; supply and return piping: an exhausting apparatus for withdrawing air and condensate irom the radiators and return piping; a pressure reducer in the supply piping which maintains determinate pressures at the radiator inlets regardless of fluctuations in generator pressure; and a thermostat-to control said pressure reducer. and a controller tor the exhausting apparatus cooperating with the pressure reducer for maintaining a controlled ditferentialbetweenthepressuresinthemppiy and Patent No. 1,983,218.,

pipes, heating units, each having a restricted inlet opening so proportioned that the quantity oi! heat carrying medium admitted to the unit can be regulated by variations'in pressure in the heat carrying medium, a pressure regulator tor varying the pressure in the heat carrying medium, a, temperature controlled regulator for automatically controlling said pressure regulator,

and exhausting means for maintaining a lower pressure in the return pipe than in the supply pipe. 1

47. In an automatically regulated steam heating system, the combination of supply and return pipes, radiators each having a restricted inlet opening so that the quantity of heat carrying medium admittedto the unit can be regulated by variations in pressure in the heat carrying medium, and each provided at its outlet with a steam trap to prevent the escape of steam while permitting the discharge of water of condensation and air, a pressure regulator for varying the pressure in the heat carrying medium, a temperature controlled regulator for automatically controlling said pressure regulator, and an exhausting means for maintaining a lower pressure in the return pipe than in the supply pipe.

ICLAY'IOIN 'A. DUNHAM.

CERTIFICATE or connection.

CLAYTON A. DUNHAM.

is hereby certified that error appearsin the printed specification oi the above numbered patent requiring correction as follows: Page 8, lines 17,, i8 and 19, claim 3, strike out the words and comma "means subjected to pressures in the tank and hurling water circuit for controlling the operation of the pump, and'line 23, of said claim, after "circuit" insert the words and means forpreventing the escape of steam from the radiating system while permitting the outflow of water and air 'therelrom and that the said Letters-Patent shouldbe read with these corrections therein-that the same may conform to the record oi. the

.case in the Patent Oiiice.

Signed and sealed this 12th dayol February, A. D. 1935.

A (S eal) Leslie Frazer Acting Commissioner of Patents.

" December 4, 1934.