US2751156A - Hot water heating system - Google Patents

Description

m 1 D. E. MORGAN HOT WATER HEATING SYSTEM 4 Sheets-Sheet 1 Filed May 12, 1955 EM IOQ INVENTOR. DAVID E. MORGAN BY QQuxA,Qzo.9 QMQM OWL (0c momma ATTORNEYS June 19, 1956 MORGAN 2,751,156

HOT WATER HEATING SYSTEM Filed May 12, 1955 4 Sheets-$heet 2 AIR ELIM- INATION CHAMBER AUTOMATIC AIR VENT Fig. la

Fig. 1d

INV

DAVID E. MORGAN ATTORNEYS n 1956 D. E. MORGAN HOT WATER HEATING SYSTEM 4 Sheets-Sheet 3 Filed May 12, 1955 25 1 nPEfiw mo. 5um o N025 mi; N. 9 a o v N c on I. 3 on M 3 w 02 m H 3 cm. m. s n o! a zoFzm z 1:; Mai 122. m M ow.

w. 3 U 2: B J a COM ofl'l] 1i.

INVENTOR. DAVID E. MORGAN ATTORNEYS n 1 D. E. MORGAN HOT WATER HEATING SYSTEM 4 Sheets-Sheet 4 Filed May 12, 1955 o o o m m mm W TM m m W W D 5 m, M 0 F ATTORNEYS HOT WATER HEATING SYSTEM David E. Morgan, Westmont, N. J., assignor to Warren Webster & Company, Camden, N. J., a corporation of New Jersey Application May 12, 1955, Serial No. 507,852 9 Claims. (Ci. 237-8) August 2, 1954, now forfeited, and entitled Hot Water Heating System.

Although such circulating hot water systems have long to circulate hot water through the relatively cold radiating system, the resulting rapid expansion of the piping, radiators and the radiating fins causes annoying snapping, pings and chunk noises. Similar troublesome noises also occur to some extent on each occasion when the the coldest weather. With such widely spaced intervals of heating of the circulating water, its maximum temperature during the on intervals may exceed, for example, 200 P. so that when the thermostat acts'to stop the circulating pump, there will be so much excess heat available in the radiators and the water therein, that the ensuing off period will be prolonged, and while the actual room temperature may remain resonably close to the d sired value during the off intervals, yet the radiators will have time to become so cool that they will not give off radiant energy but will in efiect absorb radiant energy from the atmosphere in the room and from the occupants so that a condition will exist which is sometimes referred to by heating experts as a cold 70 temperature. In short, although the temperature of the room atmosphere may remain reasonably close to the desired level, yet the a range, for example, of more than 125 F which gives rise to a feeling by the occupants of pronounced alternate cooling and heating.

Attempts to secure more uniform heating have included use of well-known forms of so-called anticipating thermostat arrangements such that the thermostat will be actuated to start an off period somewhat prior to the intervals somewhat prior to the lowering of the room temperature to its minimum level. But while such anticipating thermostats tend to regulate the room temperature more closely to a predetermined value, they have no substantial effect upon reducing the widevariaof the temperature in the circulating water itself, and

returned from the radiating system and is mixed with the hot water by way of such by-pass. With such a bypass, each time when the circulating pump is started there will be a slight delay before the water circulating in the lower than the boiler water temperature, these results being due to the fact that the circulated water comprises a mixture of hot boiler water and relatively cool returned water coming through the by-pass. Thus while such a bypass, to some extent, diminishes the problem of niomentarily excessively hot radiators during mild weather, it tends to prevent flow of a suthciently hot stream to in sure most eflicient cold weather heating. And while the use of the conventional by-pa'ss causes a slight delay in bringing the circulating Water up to the desired temperaperature during on and off periods will still vary within such a wide range as to give occupants alternate sensations of overheating and excessive cooling and the diflicul'ty will remain even though the above-described anticipating types of thermostat arrangements are used.

The present invention involves a means and method for avoiding or substantially minimizing the above-noted difiiculties in a relatively'simple', reliable and inexpensive Way, whereby the variations in the circulating water temperature during the on and off periods may be kept within a quite narrow range, thereby avoiding the troublesome noise effects and at the same time giving the room occupants a feeling of quite uniform heating;

According to the present invention, a by-pass as above described is used, preferably one which has a predetermined and relatively small or somewhat restricted passage. At the point where the by-passe'd water mixes with the outcoming hot boiler water, aheat-responsive valve operating device is inserted, this device being connected to operate a valve which controls the flow of the outcoming hot boiler water. (In some cases, but not preferably, this valve alternatively might belocatedat the juncture of the by-pass and the returnline to the boiler.) The valve element has a small aperture or apertures, or an equivalent by-pass, through whichat least asmall quantity of the hot boiler water may flow whenever the pump is operating and even though the" valve may otherwise be closed so far as normally p ssible'. Thus when the circulating pump is initially started, it will cause a small temperature suitable for mild weather heatin and it the weather is mild the circulating pump will be stopped by its thermostat before the radiating system is excessively heated. Furthermore, the radiating system during this period will only gradually become heated and the troublesome noises will be avoided or eliminated. However, if the weather is cold enough to require operation of the pump for a longer interval, then after such period of five or ten minutes, the circulated water in the radiating system will have reached a temperature such as to operate the above-mentioned heat-responsive valve means thereby opening the valve which it controls, to the extent necessary for allowing a larger stream of hot water to come from the boiler and mix with the returned by-pass water thereby bringing the radiating system up to the necessary higher temperature for cold weather heating, But since the heating of the radiating system has been gradual, there will still be no sudden application of hot water to relatively cool metal parts and as a consequence the troublesome noises will be largely avoided or eliminated.

Usually to secure the most satisfactory results from the above-described special heat-responsive valve and by-pass, one should use the above-described anticipating type of thermostat arrangement or the equivalent. While without such special valve and by-pass the anticipating thermostat arrangements have no substantial elfect toward minimizing the fluctuations in the circulating water temperature, yet with such special valve and by-pass means, the anticipating thermostat means will permit the water temperature to be confined to an exceptionally narrow range, for example, from about 8- in a typical case in cold weather up to about 10-20", for example, in warmer weather, the position of such range on the temperature scale shifting automatically according to the heating requirements and the range being high enough to insure that some heat will always be given off by convection as well as radiation.

Preferably, a valve is inserted in the boiler water outlet connection in advance of the connection to the bypass, which valve is of a construction adapted to open only when the circulating pump causes a flow under pressure to occur therethrough, this valve at other times remaining closed to prevent gravity circulation of water through the system at times when the thermostat does not call for operation of the circulating pump.

Other and more specific objects, features, and advantages of the invention will appear from the detailed description given below, taken in connection with the accompanying drawings and forming a part of this specification and illustrating by way of example the presently preferred embodiments of the invention.

In the drawings:

Fig. 1 is a diagram schematically showing a boiler and associated heating system including the combinations of features involving the present invention;

Figs. la-le, inclusive, are schematic diagrams showing various possible alternative arrangements for the connection of the various units of the system;

Fig. 2 is a vertical sectional view through the special device or heat-responsive valve means located at the junction of the hot water outlet conduit coming from the boiler and the by-pass connection;

Fig. 3 is a sectional view taken substantially along line 3-3 of Fig. 2;

Fig. 3a is a side view on a smaller scale of a valve assembly like that of Fig. 2, except having a by-pass permitting a limited flow, past the valve in lieu of utilizing valve apertures as of Fig. 3 for that purpose;

Fig. 4 shows certain time-temperature curves indicating the temperature conditions of the circulating water with and without the present invention; and

Fig. 5 shows portions of a circular type temperature recorder dial or graph and indicating an actual example of the circulating water temperature range secured by the use of the invention over a period starting at 6 o'clock on one evening and ending thirty-six hours later, the con current room temperatures and outdoor temperatures for this period also being indicated.

Referring to Fig. l in further detail, a boiler is indicated at 10 provided with any well-known form of fuel burner as indicated at 11 which operates under the control of a boiler thermostat schematically indicated at 12 whereby generally the boiler water will be maintained at a suitable substantially constant predetermined temperature. The hot water outlet conduit from the boiler is indicated at 13, and to which a conventional expansion tank is connected as indicated at 130. If desired, the expansion tank construction and arrangements may be used as disclosed in the co-pending application of David E. Morgan and James E. Tolan, Serial No. 378,512, filed September 4, 1.953. Conduit 13 includes a valve 14 of a suitable known type having a valve-piece which will normally be closed as by gravity to prevent any gravity flow of water through the system when the circulating pump is not operating. From the valve 14 the hot water next flows into a device or valve 15, such as shown in further detail in Fig. 2. From the device 15 connections are provided, such as shown at 16, 17, 18, etc., for conducting the hot water to the various radiators, as indicated at 17 13', 19, etc., each radiator being provided with a return connection communicating with return lines as at 20, 21, 22, running to an air elimination device at 22 of any suitable known type, thence to an electric motor-driven pump 23. This pump discharges the return water through a conduit 24, partially into a by-pass connection 25 and partially into a return connection 26 into the boiler.

The pump is controlled in a known way by a room thermostat 27 connected by means of a relay 27'- to control the circuit of the pump motor so as to start such motor whenever the room temperature decreases to a predetermined point and to stop the motor when the room temperature rises again to a predetermined degree. As above indicated, this thermostat arrangement is preferably of the type which is herein referred to as an anticipating thermostat. That is, in series with the contacts of the thermostat 27 and with the coil 28 of relay 27', an adjustable heating resistance 29 is connected. Assuming that the thermostat contacts are in closed position during an on interval of operation of the circulating pump, then the resistance 29 will cause sufiicient heating of the bimetallic strip of the thermostat 27 to cause the contacts to open shortly before the maximum desired room temperature is reached, that is, in anticipation of such maximum temperature. Also, the thermostat contacts are so adjusted that during an oil interval of operation of the circulating pump, such contacts will remain open only until the room temperature decreases to a value slightly above the intended minimum room temperature, thus causing the next on interval to start in anticipation of the minimum room temperature. Generally the resistance 2 is so made or adjusted as to have about the same value as the resistance of the remainder of the circuit, viz., largely that of the relay coil 28. But with the present invention, preferably although not necessarily. the resistance 29 is made adjustable whereby, as will be hereinafter made apparent, the range of fluctuations of the circulating water temperature may be varied. That is, simply by moving the adjustable contact on resistance 29 to include in the circuit less resistance, one may with the system of this invention limit and decrease the circulating water temperature rangefor by moving such contact 50 as to include in the circuit more resistance, one may secure a wider water temperature range.

The radiators may be of any suitable known type, for example, some may be of the conventional cast iron type such as at 17', 1?, or some or all may be of the finnedtube type as at 18.

The by-pass connection 25 preferably comprises a pre- -rate of flow will be forced out determined length of tubing, for example, ten feet of relatively flexible copper tubingof a diameter generally boiler, such by-passes may beformed. of tubes of the above-stated length and any availableexcess of the tubing in particular installations maybe coiled as at 250.

Referring now to Fig. 2, the/device a T-shaped coupling, connected at boiler the otherside to the outgoing pipe of the circulating system; the third branch of the T being directed downward and connected to the by-pass 25. Within the mid-portion of. the body of this coupling there is located a heat-responsive valve actuator 39 of some suitable known type, for example, a construction operating according to the to-Vernet, No. 2,115,501, Howthat various other known types of heat-responsive valve operating devices may be used for the purpose, same being connected to the actuated valve element, such as a butterfly type of valvepiece 31, which normally when closed is positioned in a vertical plane and has apertures 32 therethrough tov allow some hot water from the boiler to pass even when the valve otherwise is closed. Alternatively, instead of forming the valve-piece itself with apertures it will be appreciated that an equivalent might be provided by so constructing or adjusting the valve-piece or its actuator that the valve will never entirely close but will allow a small stream to by-pa'ss the valve-piece even when thrust as far as it will move toward closed position. Or, alternatively, a small by-passas at 32' may comprise one side to the hot for controlling or varying the flow through the bypass The heat-responsive element and the piece may be formed as a unitary assembly and msertable into the body of the device shown and then removably clamped in place as by the use of a nipple 33 and a threaded ring or annular clamping nut 34. A gasket 35 is provided between nipple 33 and the peripheral flange 36 on" the valve assembly. Preferably, in order to insure that the valve apertures 32 will be located at a predetermined position at the upper-side remote from the by-pass 25, the assembly flange 36 is provided with a pin, or the like, 37 for. engaging in a corresponding hole formed in the body of the device 15.

The operation of the system according to the invention will now be briefly reviewed. Assuming that theroom temperature falls to a degree such as to soon require heat, then the thermostat 27 will act through relay 27 to close the pump motor circuit and water will. be pumped from the radiator system through the aireliminator 22', thence through the pump 23,. thence partly through the by-pass 25 and partly through the return pipe 26 into the boiler. Then hot water at a limited of the boiler through connection 13, valve 14 and through the valve apertures 32 (or the equivalent) into the mid-portion of the device 15. At this point, this limited amount of hot boiler water will mix with the cool water returned through the by-pass 25 and the resulting mixture of intermediate temperature will be forced out through the radiating system and back to the pump. But after, for example, five or ten minutes the mixture as circulated through the radiating system will have increased in temperature enough, so that when mixed with additional hot boiler water coming through apertures 32, it will cause actuation of the heat-responsive means 36 and opening or" the valve 31. However, if before this happens, the room temperature has risen enough to actuate the ther-- 6 mostat 2-7,. the: pump will..- be stopped with consequent stoppage; of: circulation of hot: water through the radiating system. At the: same time valve 14 will automatically close. to prevent further flow of hot water to or from the boiler. by the action of gravity. the radiating system and'its conduits will the required length of the heating cycle during cool or colder weather. Finally, when the room. temperature reaches a level causing the thermostat temperatures of the degree. required during cool or colder weather.

Fig. 5 shows'the results. of an actual test of the system over a typical period of thirty-six'hours during which the room temperature wasretained substantially constant, that in the pipe running to the radiators) was kept within a R, the: median value gradually increasing by amounts corresponding to the gradual decrease of the. outdoor'temperature and the range graduallydecreasingswith.colderweather. Thus, although the vals, the water temperature varies above and below a At the same time there is no excessive eating. of the radiators when the weather is mild or excessive cooling of the radiators even for momentary intervals when theweather is cold.

The advantages of the invention may be appreciated fromthe following: facts. If the water temperature curve of Fig. 5 were for a conventional circulating hot water heating system of the on and oif type with no boiler bypass, then such curve. would zigzag between points in the neighborhood of 200 F. down to room temperature or possibly less. And if the system were one with a welldesigned boiler by-pass but without the thermostatically controlled valve as at 15 herein disclosed, then this water temperature curve would ordinarily zigzag over an intermediate wide range, say of 100 F. or more, and the result would be the same whether or not an anticipating type of thermostat arrangement were used. The troublesome noisy conditions would occur as would also the cold 70 degree sensations during off intervals. With the bypass 25 accompanied by the special thermostatic valve 15, but without an anticipating type thermostat, the zigzag range of the water temperature would be considerably more limited than with either of the other two abovementioned conditions. But with the anticipating thermostat added, the upper and lower temperatures of the circulating water may be not only brought substantially closer together, but the degree of closeness thereof may be very easily adjusted by simply adjusting the contact on resistance 29. While it is desirable to keep the water temperature range within as narrow limits as possible, yet if the range is made too narrow, then the frequency of starting and stopping of the circulating pump may become excessive or annoying, particularly when the outdoor temperature is colder. With the example of the water temperature curve shown in Fig. 5, there are about six on" periods per hour at the time of the start of the test, whereas during the colder and later periods of the test, the number of such periods per hour increased considerably and with a consequent narrowing of the range of water emperatures. The more abrupt changes in the water temperature range indicated in Fig. occurred as a result of opening doors or windows, yet it will be noted that the room temperature remained substantially constant.

In Fig. 4, the full line curve shows the. results of an actual test and indicates the rate at which the circulating water temperature rises, upon starting the pump, to a maximum with delayed action over a period of about nine minutes, when the boiler water temperature is at the predetermined regulated temperature of about 210 degrees or slightly less. The dash line curve in Fig. 4 on the other hand shows the temperature changes which will occur without the combination of the invention, that its, in a system the same as of Fig. l but without the temperature responsive valve means in the device 15. Here it will be noted that immediately upon starting the circulating pump, the hot boiler water will be forced into the outgoing conduits of the radiating system, thus filling at least portions thereof with water at substantially the maximum temperature almost immediately and causing thermal shocks and consequent noises throughout the radiating system. Then when relatively cold recirculated water has replaced the hot water in the boiler, and also through the by-pass, has become mixed with the out-going boiler water, the temperature of the outgoing circulated water will drop sharply again approximately as indicated by the dash line curve. causing further thermal shock and noises before the boiler water and the circulated water gradually increase again in temperature. These conditions, approximately as shown by the dash line curve of Fig. 4, will thus cause two noisy intervals for each cycle of operation of the pump, when the present invention is not used. It should be further noted that preferably the dimensions of the bypass 25 should be so related to the size of the apertures 32 in the valve 31 that the resistance to how through these passages will have a predetermined relationship. For example, with a preferred embodiment of the invention, the three apertures 32 were made circular with diameters of about 5/ whereas the by-pass 25 as above-mentioned was made of a length of tubing feet long and having an internal diameter of about 0.545" /6" 0. D. copper tubing). With these relative dimensions and with the boiler outlet pipe 13 made of l" or 1% piping (standard iron pipe sizes), it was found that when the valve 31 was closed. about 40% of the fiow to the heating system would pass through the valve apertures 37. and the remaining 60% through the by-pass. These relative percentages of flow may, of course, be varied considerably, as may also the pipe and aperture dimensions above given, while still achieving substantially the above-described advantages.

It should be further noted that preferably all portions of the pipe 13 between the boiler and the valve 15 should, as indicated in Fig. 1, be directed upwardly from the boiler or inclined at least somewhat upwardly toward the valve 15. This will insure that any bubbles of air which may be contained in this pipe will pass on through the valve apertures 32 which are located on the upper side of valve-piece 31. Thus the entrapment of air at any point in advance of the valve 15 will be avoided.

The system of the invention has an additional advantage useful in some instances and which has not been mentioned above. With many household heating systems, provision is made for obtaining domestic hot water by the use of a water heater at the boiler. With such systems, it is sometimes the practice to provide a reverse acting" control for the circulating pump so as to prevent actuation of the pump and the heating of the house when the boiler water temperature falls below a certain point, for instance 160 F. This allows the burner to raise the boiler temperature again quickly and to assure that the necessary supply of domestic hot water can properly be heated for a time by the boiler. During this time, of course, the house will not be heated because the circulating pump is not in operation. However, with the present invention, such a reverse acting control on the circulating pump will not ordinarily be necessary because when the boiler water temperature tends to be rather low, the heat-responsive valve-actuating device 30 will not operate to open the valve 31. Accordingly, the house heating system may be kept in operation to at least provide some degree of heat without allowing enough hot water to be taken from the boiler to prevent the latter from heating the domestic hot water supply at times when necessary, and then to permit the boiler temperature to rise to normal.

In difierent installations, the heat-responsive devices 30 may be selected or adjusted so as to start opening valves 31 at different predetermined temperatures depending upon the normal predetermined regulated temperature level in the boiler. Usually, the device 30 may be adjusted or selected to actuate at or F., corresponding respectively to the three common ranges of boiler water temperatures customarily used.

Although the locations of the various units of the system are preferably as per Fig. 1, satisfactory operation or at least improved results may be secured with the various other arrangements as shown in Figs. 1a to la, inclusive, wherein corresponding parts are identified by the same reference numerals as in Fig. 1. For example, in Fig. la the circulating pump 23 is indicated as being located either in the boiler water outlet or as at 23a in the outcoming conduit running to the radiators. That is, either one of the pumps as at 23 or 23a may be used while the other one is inactive with the Water passing therethrough without being pumped, or either one of these pumps may be omitted. In Fig. lb the special thermostatic valve 15 is located at the juncture of the pipe returning from the radiators with the lower end of the bypass 25, the circulating pump being located as in Fig. in. Fig. lc is the same as Fig. 1b except that the circulating pump is located as in Fig. 1. Fig. 1d shows a system like that of Fig. l, but with separate outgoing and return connections for five different heating zones, as may be necessary or desirable, for example, in a large building. Fig. 1e shows another arrangement with separate devices and circulating pipes in outgoing conduits for five heating zones from which a single return connection 24 is provided.

Although certain preferred embodiments of the invention are herein disclosed for purposes of explanation, various modifications thereof, after study of this specification, will be apparent to those skilled in the art to which s ght, the

the invention pertains. Reference should accordingly be had to the appended claims in determining the scope of the invention.

What is claimed and desired to be secured by Letters Patent is:

1. In a circulating hot water heating system, the com a radiating system and including a return connection back into the boiler, said conduit means including therein a motor-driven circulating pump, thermostatic means for starting and stopping said motor-driven pump responsive to temperature changes, a relatively restricted boiler bypass having one of its ends connected into said return connection and having its other end connected into a device through which the outgoing hot boiler water passes to the radiating system, said device having therein a heat-responsive valve-actuating means located in a position to be responsive to a predetermined temperature of the boiler into said device but being arranged with a restricted passage means permitting at least a limited flow of hot boiler Water to normally pass when the pump is operating, for admixture with the returning by-passed water, and whereby after a period of delay following the starting of the pump, the resulting mixture will rise to said predetermined temperature and cause said heat-responsive device to open said valve to allow a greater proportion of hot boiler water to be circulated through the heating system during the remainder of the interval of operation of the pump, such delay aifording time for the radiating system to be gradually heated by a relatively low temperature water mixture before the valve is opened widely for providing higher temperature heating, rapid thermal expansion and consequent noises in the heating system being thereby substantially reduced.

2. In a circulating hot water heating system, the combination comprising a boiler, conduit means for conducting hot water from the boiler through a radiating system and including a return connection back into the boiler, said conduit means including therein a motor-driven circulating pump, thermostatic means for starting and stopping said motor-driven pump responsive to temperature changes, a boiler by-pass having one of its ends connected into said return connection and having its other end connected into a device through which the outgoing hot boiler water passes to the radiating system, said device having therein a heat-responsive valve-actuating means located in a position to be responsive to a predetermined temperature of the mixture of hot water coming from the boiler and cooler return water from the by-pass, and a valve operatively connected to said actuating means, said valve being positioned normally to check the flow of hot water from the boiler into said device but being arranged with a restricted passage means permitting at least a limited flow of hot boiler water to normally pass when the pump is operating, for admixture with the returning by-passed water, whereby after a period of delay following the starting of the pump, the resulting mixture will rise to said predetermined temperature and cause said heat-responsive device to open said valve to allow a greater proportion of hot boiler water to be circulated through the heating system during the remainder of the interval of operation of the pump, such delay affording time for the radiating system to be gradually heated before said valve is Widely opened.

3. In a circulating hot water heating system, the combination comprising a boiler, conduit means for conducting hot water from the boiler through a radiating system and including a return connection back into the boiler, said conduit means including therein a motor-driven circulating pump, thermostatic means for controlling said motor-driven pump at intervals responsive to temperature changes in a space to be heated, a boiler by-p'ass having its ends connected respectively into the outgoing and return cohnecti'ons'of the system, one of said ends being water passes, said device having therein a heat-responsive valve-actuating means located in a position to be responsive to a predetermined temperature of the mixture of circulated water and by-passwater, and a valve operatively connected to said actuating means, said valve being positioned normally to check the flow of circulating boiler water but being arranged with arestricted passage means permitting at least a limited flow of circulating water normally to pass whenever the pump is operating, whereby after a period of delay following the starting of the pump the said mixture will rise to said predetermined temperature and cause said heat-responsive device to open said valve to allow a greater proportion of hot water to be circulated through the heating system while the pump remains in operation.

4. Apparatus accordingto claim 1 and in which an additional valve is located in the hot water outlet conduit from the boiler, which additional valve is constructed and arranged to be normally closed when the pump is not operating, topreve'nt circulation of water through the system by the action of gravity, but to be automatically opened by the flow of water when the pump is operating.

5. In a circulating hot water heating system, the combination comprising a boiler, conduit means for conducting hot water from the boiler through a radiating system and including a return connection back into the boiler, said conduit means including therein a motor-driven circulating pump, an anticipating thermostatic arrangement for controlling said motor-driven pump to start and stop the same at intervals responsive to temperature changes in the spaces to be heated, a boiler by-pass having its ends connected respectively into the outgoing and return connections of the system, one of said ends being connected into a device through which the circulating water passes, said device having therein a heat-responsive valve-actuating means located in a position to be responsive to a predetermined temperature of the mixture of circulated Water and by-pass water, and a valve operatively conand cause said heat-responsive device to open said valve to allow a greater proportion of hot Water to be circuthrough which the circulating water passes, said device having therein a heat-responsive valve-actuating means located in a position to be responsive to a predetermined temperature of the mixture of circulated water and bypass water, and a valve operatively connected to said actuating means, said valve being positioned normally to check the flow of circulating, boiler Water but being arranged with a restricted passage means permitting at least a limited flow of circulating water normally to pass whenever the pump is operating, whereby after a period of delay following the starting of the pump the said mixture will rise to said predetermined temperature and cause said heat-responsive device to open said valve to allow a greater proportion of hot Water to be circulated through the heating system while the pump remains in operation.

7. A circulating hot water heating system embodying the combination specified in the foregoing claim 5 and in which the anticipating thermostatic arrangement includes an electrical heating element for applying heat to cause actuation of the thermostatic means and consequent stopping of the pump in anticipation of the desired maximum temperature in the space being heated, said heating element being adjustable to thereby permit adjustment of the range within which the temperature of the circulating water varies during the intervals of starting and stopping of the pump.

8. A circulating hot water heating system embodying the combination specified in the foregoing claim 5 and in which the thermostatic arrangement includes a thermostatic contact actuating element, an electrical heating element adjacent said operating element, a relay for controlling the pump motor circuit, said relay having a winding in series with said heating element and the thermostat contacts.

9. A device for controlling the flow of water in a circulating hot water heating system having a boiler by-pass, said device comprising a valve chamber with a main inlet and a main outlet for the circulating water and also means for connecting into same one end of the boiler by-pass, a heat-responsive valve actuating means in said chamber and located in a position to be responsive to a predetermined temperature of the mixture of circulated water and by-pass water, and a valve in the chamber operatively connected to said actuating means, said valve being positioned normally to check the flow of boiler water but being arranged with a restricted passage means permitting at least a limited flow of circulating water normally to pass when said actuating means is inactive.

References Cited in the file of this patent UNITED STATES PATENTS

Images