US2703074A - Hot-water heating system - Google Patents

Description

March 4l, 1955 H. P. BIRKEMEIER 2,703,074

HOT-WATER HEATING SYSTEM Filed Aug. 8, 1950 2 Sheets-Sheet l March 1, 1955 HP. BIRKEMEIER HOT-WATER HEATING SYSTEM 2 Sheets-Sheet 2 Filed Aug. 8, 1950 United States Patent C) Hor-WATER HEATING SYSTEM Henry Birkemeier, Chicago, lll., assignor to Bell & lGossett Company, Morton Grove, Ill., a corporation Hof-,Illinois Application August s, 195o', serial No. 118,337

s claims.V (ci. 12a-504) My invention relates to hot water heating systems and is -concerned primarily with an arrangement for Aautomatically preventing overheating of the boiler.l

VIn hot water heating systems, overheating of the boiler may result from nthe faillite ofthe electrically operated controls toshut .down the gas or oilburner when the boiler: water attains its maximum, safe working temperature, or in the case` of a stoker or hand fired boiler, overheating may be caused by the fact that sutlicient fuel has been fed to the rebox to sustain continued heating of the -boiler after the hot water, circulating pump has stopped. Under either of the above conditions, heating ofthe boiler continues and if the system is equipped with flow control valves which close when the circulating pump stops, the situation soon becomes critical because the valves confine the boilerwater and prevent its ow through the system where the heat could be dissipated.

'As'the temperature of the boiler water rises, the boiler pressure increases and where, as is usual in systems of this character, a pressure relief valve is associated with theboiler, thisvalve vrelieves the boiler pressure at the setting of the valve, ordinarily thirty pounds gage, although, as a matter of fact, suchV valves begin to open at about twenty-eight pounds'which is evidenced by a slight drip Aat the valve. The valve eases the boiler pressure temporarily, but at the expense of the watercontent of the boiler. heating continues, produces a water line in the boiler,

and the relief valve thereafter discharges steam. A lowering of .the water line is objectionable, particularly if the water loss persists until the crown sheetrof vthe boiler 1s exposed accompanied by continued input of heat, because if .atY that time relatively cold water surges over the crown fsheet, the boiler mayA either explode or at the very least will be subjected to racking strains occasioned by the flashing of the cold water as it flows over the hot crownl sheet. t This cold water may reach the boiler either through a manually or automatically operated valve connected `to a cold water supply main, or the weightof the relatively cold water in the heating system mayioverbalance the weight of steam in the boiler, thus permitting large quantities of this water to ilow through therreturn line and enter the boiler.

I-t is-therefore one object of my invention to 4devise a heating system which incorporates means for preventing overheating. of the boiler by automatically introducing Coldwater ,into the boiler when steamforms atthe top of the boiler. I

r VA further -object is to provide a heating system of the character indicated in which the overheating prevention meansis conditioned -to introduce cold water at pressures below the setting of the relief Valve, and to relieve the boiler pressure in the, event of failure of the cold water supply or of the safety or relief` valve.

A furtherobject is to` provide an apparatus for accomplishing the foregoing results which is capable of separate assembly and installment as a unit ina hot water heating system, s l p fjThese and further objects of the invention will be set forth inthe following specification, reference being had` to the accompanying drawings, and the novel means by which. said objects ,are effectuated will .be definitely pointedout in the claims.

In the drawings:

Fig. '1f a fragmentary-elevation of a hot water heating systemshowing the application of my improved apparatus This intermittent, water loss, sol long as the rice Fig. 2 is an enlargedgsectional elevation of one form of the apparatus showing 'the relation of parts during normal operation of the connected'system;

Fig. 3 is a sectionas viewed along the arrows 3--3 in Fig. 2 showing a bypass which is utilized when the apparatus functions.

Fig. 4 is a view similar to Fig.`2, but showing a modied form of the apparatus.

Figs. 5 and 6 are enlarged Vviews of certain skeleton caps, partly in section, looking in the directions of the arrows 3 and 6 in Figs. 2 and 4,"respectively.

Referring to Fig. l of the drawings, the numeral designates a hot water heating boiler of any convenient type which may be fired in any suitable manner, automatically or manually, and which vmay or may not be equipped with thecustomary controls. A supplyV pipe 11 which may incorporate a ow control valve 12 leads from the top of the boiler to radiators (not shown) and a return pipe 13 which may include a motor driven, circulating pump 14 connects the radiators with the lower part of the boiler. Preferably, the supply pipe 11 is con# nected to the top of the boiler by means of a tting 15 which includes a dip tube 16 that communicates with the pipe 11 and extends a distance into the boiler such that air bubbles released in the boiler above the lower end of the tube will vpass to a pipe 17, one end of which connects with the tting and is in communication with the boiler, while the opposite end connects with an expansion tank 18. A fitting of this type vis disclosed in U. S. Letters Patent No. 2,500,621, dated March 14, 1950.

A pressure relief valve 19 of'standard construction is also connected to the boiler and,for present purposes, it will be assumed that this valve is adjusted to relieve the boiler at a gage pressure of 30 p. s. i. So far as described, the system is of known arrangement and, as a matter of disclosure, it will 4be assumed further that the system is of the closed type.

My improved apparatus is indicated generally by the numeral 20 in Fig. l and it is preferably installed as a unit above the boiler. I-t comprises a oat chamber 21 whose lower end connects with the lower end of the boiler through a pipe 22 that includes a swing check valve 23 which is gravity actuated to close the pipe against flow from the boiler but opens in response to adifferential pressure crea-ted by a mass of water in the chamber 21 under conditionsV presently described. The lower part of the chamber 21 also communicates with. a cold water supply through a pipe 24 which includes a pressure reducing valve 25 of the usual type that may be adjusted to admit cold water at a gage pressure of l0 to l2 p. s. i. A valve casing 26 closes the upper'end of the chamber 21 and the casing inlet is connected by a. pipe 27 with the top of the boiler and its outlet connects to an exhaust pipe 28.v

The apparatus 20 is more particularly illustrated in Fig. 2 to which reference will now be made. The valve casing 26 includes an inlet chamber 29 Vthat communicates with the pipe 27 and a discharge chamber 30 that connects with the pipe 28, the chambers being separated by a wall 31 having a passage 32 therethrough that is normally closed by a primary valve 33 which engages a seat around the upper end of the passage. The stem of the valve 33 extends slidably upward through a plug-34 that is threaded in the top wall of. the casing 26 which also serves as the top wall of the chamber 30. The upper end of the valve .stem is connected to a plate 35 which carries a diaphragm 36 whose periphery is clamped between the top wall of the casing 26 and the llanged end of a cover 37, and the upper side ofthe wall is hollowed to define with the diaphragm a chamber l38 for a purpose presently explained. A loading spring 39 is interposed between the plate 35 and a disk` 40 carried by a ferrule 41 threaded in the upper end of the cover 37. The spring 39 acts tomaintain the valvein 4the. closed position shown and is preferably adjusted 4to. a pressure of; from tiveA to ten pounds p. s. i. higherv than thesetting of the relief valve 19. The usual manual release lever 42 is pivotally connected to the outer end of a stem 43 which extends downwardlythrough the ferrule forattachment to the plate 35.. Y

tling oriiice 44. havinga diameter of about 1A with the float chamber 2,1 in which is arranged for buoyancy a oat 45 having an upwardly extending pilot valve 46 that is guidable for up andl down movements by upper and lower ns 47 provided within a skeleton cap 48 threaded in the under side of the valve casing 26. The cap 48 includes a. passage 49 whose lower end `s closed by the pilot valve 46 when occupying the raised position shown in Fig. 2 and which communicates through an opening 50 in the cap 48k with the chamber 21 when the oat 45 drops sufficiently as hereinafter explained. The upper end of the passage 49 connects with the lower end of a bypass-51 in the casing 26 (see Fig. 3.) which extends around the passage 32 and connects with the chamber 38. Hence, when the passage 49 isVv opened by the pilot valve 46, communication is established between the fioat chamber 21 and the chamber 38.

When the system is first filled, water flows through the reducing valve 25, the primary valve 33 being closed, enters the boiler through the pipe 22V and thence rises to fill the remainder of the system in the usual manner. If, during filling and with the oat 45 unbuoyed, sufiicient total air pressure is built upin the chamber 21, this pressure exerted through the bypass 51 against the diaphragm 36, lifts the primary valve 33 for venting. When the system is completely filled', the valve 25 will close and some air may be trapped in the top of the oat chamber 21 and the fioat. 45 will be buoyed sufficiently to cause the pilot valve 46 to close the passage 49. The system thereafter operates in the usual. manner with the relief valve 19 openingV to discharge water from time to time when the system pressure exceeds the setting of this valve, my improved apparatus begins functioning when the boiler is overheated sufiiciently to create steam which may occur when the boiler is heated to a temperature of from 270 to 275" F. This action is accelerated if a water line is established' in the boiler by repeated openings of the valve 19.

Since the, apparatus 20 is located above the boiler, steam from the latter flows through the pipe 27 into. the chamber 29 and thence through the orifice 44 into the chamber 21. If. steam is. formed without a water line in the boiler as by theformation of a water line in the pipe 27, or if a water line exists. in the boiler, a differential pressure then exists in the chamber. 21 occasioned by the. weight of the water thereinand this water flows downwardly by gravity through thepipe 22 into the lower part of the boiler, the valveu 23 whose controlling element is light in. weight opening during this movement. As the water ows out of the,` chamber 21 under either of the above conditions, thev float 45' drops, thus opening the pilot valve 46 andv connecting the chambers 21 and 38 through the bypass 51' sothat pressure in the chamber 21 is effective against the diaphragm 36.

The primary valve 33 is thereby opened to exhaust the boiler. pressure and the steam to the exhaust pipe 28. as supplied through the pipe 27, the boiler pressure being restrained from passing through the pipe 22 by reason of the one-way action of the valve 23. At this time, the pressure within the chamber is substantially atmospheric or slightly thereabove and in any case is below that at which the reducingvalve opens sothat. cold water enters the chamber 21 and buoysthe iioat 45 upwardly to close the pilot valve 46'. yAssoon asthe pressure in the chamber 2l drops sufficiently,v the spring 39 closes the valve 33 while water is owing into the chamber. This operation proceeds intermittently as long as steaming continues or a water line exists in the boiler until the overheated condition is remedied.

Preferably, the area of the diaphragm 36 is about twenty times that area of the valve 33 which is exposed tothe boiler pressure'in thechamber 29. This relation insures an opening of the` valve 33, when the pilot valve 46 is open, at pressuresof as low as 3 p. s. i. in the chamber 21. As shown in Fig..2, theinlet pipe 27 is sized smaller than the passage 32 and also smaller than the exhaust pipe 28 so that when the valve 33 opens, pressure in the pipe 27 is relieved freely. The purpose of setting the spring 39 tov a higher compression than the spring in the. relief` valve 19 is to prevent directopening of the valve 33 by theboiler pressure. If. the` valve 33 were so opened, thensince the-ow area of the pipe-27 is smaller than that ofthe pipe 282 andthe openinguncoveredby the valve 33,.

the pressure in chamber 21 would at that time notbe the same as that of the boiler so. the water in chamber 21 would either not flow to the boiler or at the best at a very slow rate. When the valve 33 opens in response to a pressure under the diaphragm 36, the pressure in the chamber 21 is exhausted slowly through the orifice 44 to thereby prevent a slamming closure of the check valve 23 by thepressure in the boiler. Downward movement of the float is limited by stops 52 on the valve 46 which engage the lower fins 47.

The modification shown in Fig. 4 differs from that illustrated in Fig. 2 in that the passage, corresponding to the bypass 51' which provides communication between'v the chambers 21 andl 38, is provided in the primary valve. and the pipe 27 connects with the chamber 21 by a non-throttling port. Where parts in Fig. 4 are identical with those shown in Fig. 2, they are designated by like numerals.

The upper end of the chamber 21 is closed by a valve casing 53 having inletl and outlet chambers 54 and 55, respectively, which are separated from each other and from the chamber 21 by an irregular wall 56 which directly closes the latter chamber andy forms the lower wall of the casing 53. The delivery` end of the pipe 27 connects with the chamber, 54 and the latter communicates through a non-throttling port 57 with the chamber 21, while the chamber connects with the exhaust pipe 28.

A fioat 58, positioned within the chamber 21, carries an. upwardly extending, pilot valve 59 which is guidable for up and down movements byY upper and lower fins 60 provided within a skeleton cap 61 that is threaded in thev wall= 56. The upper portion of the cap 61 includes a passage 62 whosev lower end constantly communicates with the chamber 21 and whose upperl end is formed as a valve seat that is normally engaged by a primary valve'V 63, corresponding to the primary valve 33. The stem 64 of the valve 63' extendsl slidably upward through the topv wall of the casing 53, which is also the upper wall of the chamber 55, and is secured to the plate 35. Hence, the spring 39 tends to seat' the valve 63. The valve 63v includes a passage whose lower end is closed by the'. pilot valve 59 when` the float 58 occupies the raised' position shown in Fig. 4. The upper portion of the passage 65'V extends through the stern 64 and is laterallybranched for communication with the chamber 38" beneath the diaphragm. 36. Accordingly, when the oat 58 drops' for reasons noted in connection with the form of the apparatus shown in Fig. 2, the chambers 21 and 38 are'pl'aced in communication. The downward movement ofthe lioat; 58 is limited by stops 66 on the valve 59 which engagel the lower fins 61.

The operation of this modification is identical withV that shown. in Fig. 2, except that, when the fioat 58. drops, chamber pressure is exerted against the diaphragm 36 through the passage 65 in the primary valve 63 and there is not any throttling connection between the pipe' 27 and' chamber 21.

1. Apparatus. for facilitatingy the evacuation to the atmosphere of gases and steam liberated from the water in a hot water heating boiler and for coolingl the boiler by admitting cold water thereto comprising a chamber normally containing a mass ofwater and havingadjacent the' top and bottom thereofrespectively, an inlet-port adapted# for connection to the upper part-of' the boiler; and an outlet port adapted. for connection to the boiler and having means for preventing return fiow to the chamber, an ex'- haust port larger in size than and arranged for communication with the inlet port, a normally closed, primary valve for controlling Isaid communication, means-for opening the primary valve responsive to pressure. in the cham.- ber, means for admitting pressure from the chamber ,tol the responsive means when the depth of'v water in the chamber drops. below a predeterminedV minimum and inL- cluding a bypass around the primary valve for-connecting the chamber to the responsive means, and means operable by the drop in chamber pressure when the primary valve opensv for feeding cold water to theV chamber to at least restore said minimum depth.

2. Apparatus for facilitating the evacuation to theA atmosphere of gases. and steam liberated from the water in` a hot water heating boiler and for cooling the boiler by admitting cold'. water thereto comprising a` chamber normally partially containing a mass of water and: having in the bottom thereof an outlet port including means for preventing returnow to the water chamber, a valve casing closing the topv of the. water chamber. andhaving a discharge chamber, an inlet port adapted for connection.-

ammore to the upper part of the 4boiler and communicating with thewater chamber, a primary valve for controlling flow between the Water and discharge chambers and being exposed in an opening direction to pressure in the water chamber, the discharge capacity of the primary valve when open being greater than the supply capacity of the inlet port, a spring actuated diaphragm mounted on the top of the casing and connected to the primary valve, the diaphragm forming a control chamber with the casing top, a passage through the primary valve for providing communication between the water and control chambers, means for admitting pressure from the water chamber to the passage `for opening the primary valve when the depth of Water in the water chamber drops below a predetermined minimum, and means responsive to the drop in water chamber pressure when the primary valve opens for feeding cold water to the water chamber to at least restore said minimum depth.

3. In a closed hot water heating system, the combination of a boiler having supply and return lines for connection to radiating elements, a chamber normally partially containing a mass of water disposed above the boiler, an outlet pipe connecting the lower part of the water chamber to the boiler and having means for preventing return flow from the boiler, a valve casing closc,ing the top of the water chamber and having a discharge chamber, an inlet pipe connecting the water chamber with the upper part of the boiler, a normally closed, primary valve for controlling llow between the water and discharge chambers, the discharge capacity of the primary valve when open being greater than the supply capacity of the inlet pipe, pressure responsive means mounted on the top of the casing and connected to the primary valve, a pas-- sage through the primary valve for providing communication between the water chamber and responsive means, means for admitting pressure from the water chamber to the passage for opening the primary valve when the depth of water in the water chamber drops below a predetermined minimum, and means responsive to the drop 1n water chamber pressure when the primary valve opens for feeding cold water to the water chamber to at least restore said minimum depth.

4. Apparatus for facilitating the evacuation to the atmosphere of gases and steam liberated from the water in a hot water heating boiler and for cooling the boiler by admitting cold water thereto comprising a chamber normally partially containing a mass of water and having in the bottom thereof an outlet port including means for preventing return flow of the water chamber, a valve casing closing the top of the water chamber and having a discharge chamber, an inlet port adapted for connection to the upper part of the boiler and communicating with the water chamber, a normally closed, primary valve for controlling flow between the water and discharge chambers, the discharge capacity of the primary valve when open being greater than the supply capacity of the inlet port, pressure responsive means mounted on the top of the casing and connected to the primary valve, a passage through the primary valve for providing communication between the water chamber and responsive means, means for admitting pressure from the water chamber to the passage for opening the primary valve when the depth of water in the water chamber drops below a predetermined minimum, and means responsive to the drop in water chamber pressure when the primary valve opens for feeding cold water to the water chamber to at least restore said minimum depth.

5. Apparatus for facilitating the evacuation to the atmosphere of gases and steam liberated from the water in a hot water heating boiler and for cooling the boiler by admitting cold water thereto comprising a iloat chamber normally partially containing a mass of water and having in the bottom thereof an outlet port including means for preventing return flow to the float chamber, a valve casing closing the top of the lloat chamber and having a discharge chamber, an inlet port adapted for connection to the upper part of the boiler and communic atng with the float chamber, a normally closed, primary valve for controlling ow between the float and discharge chambers, the discharge capacity of the primary valve when open being greater than the supply capacity of the inlet port, pressure responsive means mounted on the top of the casing and connected to the primary valve, a passage for opening the primary valve through the primary valve for'providing communication between theI oat chamber and responsive means, a iloat actuated, pilot valve in the lioat chamber for admitting pressure from the float chamber to the passage when the depth of water in the float chamber drops below a predetermined minimum, and means responsive to the drop in oat -chamber pressure when the primary valve opens for feeding cold vat to the oat chamber to at least restore said minimum 6. Apparatus for facilitating the evacuation to the atmosphere of gases and steam liberated from the water in a hot water heating boiler and for cooling the boiler by admitting cold water thereto comprising a chamber normally partially containing a mass of water and having in the bottom thereof an outlet port including means for preventing return ow to the water chambery-,ga valve casing closing the top of the water chamber and having a discharge chamber, an inlet port arranged for communication to the upper part of the boiler and communieating with the water chamber, a primary valve lfor controlling ow between the water and discharge chambers and being exposed in an opening direction to pressure in the water chamber, the discharge capacity of theprimary valve when open being greater than the supply capacity of the inlet port, a spring actuated diaphragm "mounted on the top of the casing and connected to the primary valve, the diaphragm forming a control chamber with the casing top and having a larger area than the vprimary valve, a passage through the primary valve for providing communication between the water and control chambers, means for admitting pressure from the water chamber to the passage for opening the primary valve when the depth of water in the water chamber drops below a predetermined minimum, and means responsive to the 'drop in water chamber pressure when the primary valve opens for feeding cold water to the water chamber to `at least restore said minimum depth.

7. In a closed hot water heating system, the combination of a boiler having supply and return linesvfor connection to radiating elements, a float chamber normally partially containing a mass of water disposed above the boiler, an outlet pipe connecting the lower part" ofthe float chamber to the boiler and having means for preventing return flow from the boiler, a valve casing closing the top of the oat chamber and having a discharge chamber, an inlet pipe connecting the lloat chamber with the upper part of the boiler, a normally closed, primary valve for controlling flow between the float and discharge chambers, the discharge capacity of the primar) valve when open beingA greater than the supply capacity of the inlet pipe, pressure responsive means mounted on the top of the casing and connected to the primary valve, a passage through the primary valve for providing communication between the float chamber and responsive means, a float actuated, pilot valve in the oat chamber for admitting pressure from the float chamber to the passage for opening the primary valve when the depth of water in the float chamber drops below a predetermined minimum, and means responsive to the drop in lioat chamber pressure when the primary valve opens for feeding cold water to the float chamber to at least restore said minimum depth.

8. Apparatus for facilitating the evacuation to the atmosphere of gases and steam liberated from the water in a hot water heating boiler and for cooling the boiler by admitting cold water thereto comprising a chamber normally partially containing a mass of water and having in the bottom thereof an outlet port including means for preventing return flow to the water chamber, a valve casing closing the top of the water chamber and having a discharge chamber, an inlet pipe adapted for connection to the upper part of the boiler and communicating with the water chamber, a normally closed, primary valve for controlling flow between the water and discharge chambers, thezdischarge capacity of the primary valve when open being greater than the supply capacity of the inlet pipe, pressure responsive means mounted on the top of the casing and connected to the primary valve, passage means providing communication between the water chamber and responsive means, means for admitting pressure from the water chamber to the passage means for opening the primary valve when the depth of water in the water chamber drops below a predetermined minimum, and means responsive to the drop in water chamber pressure 7 when the primary valve opens for feeding cold water to 1,856,105 the-water chamber to at least restore said minimumv depth. 1,921,550 2,487,4 8 References Citedin the file of this patent UNITED STATES PATENTS o 655 966 1,839,144 Flagg Dec. 29, 1931 8 Marden May 3, 1932 Carson, Jr. June 5, 193'4 Berkemeier ety al. Nov. 8, 1949 FOREIGN PATENTS France Apr. 25, 1929

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