US376830A - prill - Google Patents

Description

(No Model.) 2 Shets-Sheet '1 'W. E. PRAL'L.

I v METHOD OF SUPPLYING HEAT AND POWER. I 8 No. 376,830. PatentedJan. 24; 1888.

. Attorney L v I IIIIIIIIIIIIIIIIIIIIII. 0.3 diam/m 2' Sheets -She'et 2.

(No Model.)

W. E. PRALL. METHOD OF SUPPLYING HEAT AND POWER.

No. 376,830.' Patented Jan. 24, 1 888;"

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WITNESSES ,5 6. Km imw w N. PETERS Phulmulhcgrnphsr. Wnhinglon. DcQ

- UNITED STATES WILLIAM E. PRALL, OF WASHINGTON, DISTRICT OFOOLUMBIA, AssIGNoR TO THE PRALL UNION HEATING OOMPANY, OF NEW YORK,1N. Y.

'MeTHoo'o F SUPPLYING HEAT ANDVPOWER.

SPECIFICATION forming part of Letters Patent NO. 376,830, dated January 24,1888. I I Application filed December 20, 1861- Serial No. 258,464. (No modelJ Patented in England July 23,1879, No. 2,987. 7

To all whom it may concern.-

Be it known that I, WILLIAM E. PRALL, a citizen of the United States, and a resident of Washington, in the District' of Columbia,

have invented a certain new and useful Method for Supplying Heat and Power to large Districts of Buildings in Cities and Towns, .of which the following is a specification.

' This invention relates toa-novel method of 13 conveying heat for the purpose of warming large districts of buildingsin cities and towns, and to the manner of utilizing and distributing the same from onecommon source of sup-- ply, and embodies a safe, economical, conven- I 5 ient, and healthful system of delivering and controlling the heat in each and every building and compartment therein, and of supplying motive power for propelling street-cars, stationary engines, and for other purposes.

Figure 1 is a part sectional view of a heating tank or boiler and preheater or water heater; also, of a hot-water circulating main and a building fitted up with radiators connected with an apparatus for converting the hot water when taken from the main pipe into steam, and traps for returning the water of condensation to the circulating main. Fig. 2

shows a plan view of the heaters and circulating pumps, together with a view of the I pipes conveying hot water through different streets, and pipes for returning the water of condensation, and a pump for forcing the same into a preheater, and thence directly into the heater from which it was previously taken. Fig. 3 shows three modifications of the apparatus for taking the hot water from the main and utilizing the same for heating buildings, 'as well as arrangements for metering the'same. Figs. 4:, 5, 6, 7, 8,'aud 9 are de- 40 tail drawings of a pressure-regulating valve, temperature and balance valve for controlling the exhaust-water from the radiators, and means for draining the circulating-pipes and an apparatus for measuring steam.

5 In Fig. 1, A represents a hot-water tank or heater, and should be of sufficient capacity to furnish all the hot water that would be required for supplying heat to the district reached by the circulating pipe or main 0,- said pipe being connected thereto at or near the bottom, certainly below the water-line.

able building convenientto the district to be being also connected with G, which is,;iu

The heater is provided with a constant 'supply of water by means of a pumping-engine from any convenient source in such quantities as is needed to keep up the wasteffrom 5,5 the main pipe, which may be drawn from it for any purpose whatever. The power for driving the pumping-engine may be taken from the steam generated in the Water-heater, or it may, be taken from any other boiler erected for that purpose. It is evident that there may be several of the water-.heaters-employed for the purpose of supplying water for circulation, and they may all be conuected,or they may be separated, by means ofcocks V placed in the connecting-pipes, so that one'or more of them may be used independent of, the others; A

In the practical operation of this invention the water-heaters should belocated in a suitsupplied with heat, and the circulatingpipe 0 connected with-the force-pump B, said pump fact,the same from its connectionwith the 7 5 heater A, extending through the force or cit culating pump B, and from thence through 1 one street and returning through another, as:- represented, and terminating again in the.

heater, the purpose of the force-pump B being only that of circulating the hot water, taking it fromthe heater under pressure and returningit again for the purpose of reheating, and t the pump will be kept operating with suflicient rapidity to cause the flow of water to 8.5 be rapidenough to convey heat without much reduction of temperature along the entire length of the pipe. Other means maybe employed to circulate the water through the pipesrs, for instance, the two ends maybe] connected with difierent heaters having a'dif ferent-pressure, and thus the hot water may be forced from the one having the greater pressure through the pipe connecting it with the i V heater of lesspressurew Itis evident that various means maybe employed for circulating water; hence I do not confine myself to any particular manner,and T in some places where theamount drawn from the pipe was sufficiently greatthe flow might 'be enough to keep the temperature high atthe farthest end without the necessity of returning too it to the heater, and in that case no return pipe or force-pump would be required; but the evident advantage of circulating the water is so apparent as to make the adoption of a single pipe only a possibility. The street-mai n is to be covered with some non-conducting substance to prevent as much as possible the radiation of the heat therefrom, and is also provided with expansion and contraction joints to allow for the movement of the main pipe longitudinally. The manifold advantages of thus conveying heat great distances will be easily comprehended, because, as the weight or body of a cubic foot of water (or any given quantity) is at the boiling or steamgenerating point seventeen hundred (1,700)

times as great as the steam thrown off at that temperature, it follows that it contains a far greater number of units of heat. Thus it will be seen that a much larger amount of heat may be delivered through a pipe of great distance without loss from condensation than could be effected by means of steam; and the hot water may by this process be converted into steam or otherwise used for the purpose of heating buildings at the point where required and overcome the great difficulty which has heretofore prevented the heating of buildings located at a distance from the generator, at the same time affording a much more convenient and economical means of heating than by separate fires and generators located in each building, and also avoiding much risk from danger by fire.

In Fig. 1, A represents a hot-water tank or heater, which should be of sufficient capacity to furnish all the hot water that would be required for supplying heat to the district reached by the circulating pipe or main 0, said pipe being connected thereto at or near the bottom either directly or indirectly via the preheater A, as shown by the pipeconnect-ions and the arrows. B represents a circulating-pump, which is connected with the pipe 0 at some point between the connections of the two ends of the same with the heater A, the purpose of which is to cause the hot water to move through the said pipe and be returned to the heater again, and it may be placed at eitherend of the circulating-pipe. The power for running it may be derived from any source whatever. The pump B may be placed in the pipe connecting the preheating-tank with the main heater, and as it would take the water from the preheater the hot water would be forced from the heater In the illustration, D represents a tank connected with the hot-water pipe 0 by means of branch pipes D and D", said pipes being arranged to unite the tank D with the circulating-pipe O at the same point, either very near together, as shown by pipes D and D", or a greater distance apart,by attaching one to the outfiowing end of the pipe 0 and the other to the infiowing end of the same, as shown by pipes D and D.

X represents another tank placed within the tank D, leaving a space between the two.

F is the pressureregulating valve in the pipe connecting the tanks D and X. 7

E- is a pipe connecting with the interior tank, X, and extends to the radiators F in the different parts of the house.

F is the condensed-water pipe, extending from the bottom of the radiators to the discharge-valve E and thence to the circulating pipe 0.

E represents a meter of any kind connected with the discharge F 0 represents a cock or valve, which may be i used to increase or diminish the size of the pipe 0, for the purpose of controlling the pressure and the rapidity of the circulation in said. pipe. I

If the heater A be now filled with water, and by means of the fire in the furnace is heated to a high degree-for example, say 332 Fahrenheit, which would give a pressure of about one hundred pounds to the square inch, and be kept at that point, which would be120 abovethe steamgenerating pointand ifthe connections at both ends ofthe circulating water-mains be opened,the pressure upon them and the water therein will be the same as upon the water in the heater and preheater, and if the force-pumpbe put in motion it will cause the water to be forced through the pipe by taking it from the heater and by discharging it again into the same through the return-pipe and through the preheater. The result will be to soon establish a temperature of about the same degree to the water in the main pipe its entire length as that in the heater. If, now,the cocksin the pipes Dand D be opened, the hot water under pressure will flow from the main pipe 0 into the outside tank, D, and surround the inner tank, X; and if the regulating-valve F be constructed to establish a ratio of difference in pressure that may be desirable the water from between the tanks D and X will flow into X through the valve and connecting-pipe F; but as soon as a small quantity has entered the tank X the reduction of pressure established by the differential valve will cause the hot water so admitted to be converted into steam, as it contains many degrees of heat above the steam-generating point, as before mentioned. As soon as the quantity of water thus admitted, however, has been evaporated into steam, the space in the tank-X will be filled under pressure, which will act upon the differential valve F and close it and prevent the further admission of ators connected thereto andheat the'same; but

the cold air surrounding them conveys away theheat, and the steam therein will be condensed, and thus the amount of water admitted into tank X will be converted into steam and conducted to the radiators. The condensed water, therefore, will be conducted through the pipe F 'an'd the temperature-discharge valve E to the meter E and thence to the pipeO again-" As soon as .condensation has reduced the steam-pressure sufficientlyin tank X and connecting-pipes and radiators, more hot water will beadmitted through the differential valve F into tank X, and thus the supply will be kept constant. The hot water admitted into tank X will not be converted into steam by means of its own specific heat, and hence the purpose of surrounding the converting-chamber X with the hot water in tank;

D, the heat of which will cause all the water admitted into tank X to be evaporated. The

purpose of connecting pipes D and D is to unite tank I) with th'emain'pipe O,fand thus produce circulation, for it will be seen that as the water in said tank transmits itsheat into the water which is admited into the interior tank, X, its temperature thereby will be proportionately lowered, and hence heavier, and

circulation will thus be established between the hot-water pipe 0 and the tank I) through pipes D and D, and by means of this circulation a temperature will be maintained in said tank nearly the same as in the pipe 0.

If the cock in the circulating-pipe G be partially closed and the pump Bis keptin operation with sufiicient rapidity to remove the water fromthe 'endot'pipe G faster than it is permitted to flow through the contracted opening in the pipe at the cock 0, the result would be to make the pressu'r'e'less in there.

turn end of the circulating pipe C, and'thus increase the rapidity of circulation through the pipes D and D as well as 'from the condense-water pipe; or if the circulating-pump is placed at the outflowing end of the circulating' -pipe O the effect would be to increase the pressure in that end'above that of the in- ,fiowing end, which would have the same effect to increase the circulation through the branch pipes connected thereto.

The manner of utilizingto the best possible advantage all the heat in the coal in preheating the water'before it is admitted into the main heater is accomplished, as shown in Fig. 1, by placing the preheater above the main heater in such a manner that the heat will pass through the preheater after passing through the main heater. In this mannerall the Water from the return-pipe, which is of a lower temperature than that in the heater A, will be caused to pass through the preheater. In Fig. 2 I have shown a plan for. circulating hotwater around several blocks of buildings and means for controlling the How in each and every section, and also a system of returnpipes connected with the main hot-water pipes by the connectingpipes from the radiators,

and connections between the hot-wateror sup-v plypipes and the return-pipes maybe made at the connections K at the junction of the streets, if desired. I have alsoshown in this figure a doublc-cylindered pump, one used for v circulating the hot water and the other for taking the return water from the pipes and forcing it into the heater or preheater. In this figure, H designates the supply-pipe, and K.

the return pipe, and the circulation isas indicated by the arrows. It is evident that by the circulation in any ofthe cross-pipes may be cut off or controlled. L is the pipe which 'means'of cocks or valves. at the connections K connects the supply-pipe of the street with the building, and M the pipe which. returns the water to the return-pipe of the street, by which it is reconveyed to the heater. It is evident the pipes except that drawnoff fordomestic purposes, as all the condensed water would be returned for reheating, and to supply the amount so drawn from the pipes the pumpH will supply fromany convenient source. It is evident that a force-pu mp may be employed to cause circulation in the return-pipe, and

'that the pumpB may be placed at eitherend ofthe supply-pipe. F

In Fig.3 I have shown several other modesof arranging the pipes and connections for thrown off by the reduction of pressure by" 7 means of this valve is conveyed to, the radiatorsconnected thereto by meansof pipes. The

' water admitted to the evaporator through the too I the firstbuilding, wateri's adregulating valve which; is not converted into steam is conveyed through the hot-water'coil connected therewith, and thence through the discharge valve or trap 0 into thereturnpipe N, which may beone continuous circulating-main, as shown in Fig. 1; or it may be a separate pipe connected with the supplymain' only by means of the branch pipes, as shown in Fig. 2, these branch pipes being also connected with the radiators, and the return water maybe'taken therefrom by the s'nction-.

pump and forced into the preheater and thence, into the main heater, as shown in Fig. 2. The meter 0" will register the amount'of water forced through the pipe 0, and as the trap O is made to prevent the discharge of the con:

dens'ed water only after it has had its temperature reduced to a certain degree, it becomes an easy matter of calculation to determine the amount of heat consumed. I have'also shown I in this figure means for extinguishing fires in I I,

85 that very little Water would be wasted from buildings provided with this system, which consists of a suitable hose or flexible pipe, which is connected with the supply-pipe, as shown, and atall times when the system is in operation any fire within reach of the hose may be easily extinguished. In the second building of this figure the apparatus is the same, except the air conveyed into the rooms is admitted to the cabinet containing the coil, and after being heated is delivered through the dues extending therefrom into the various apartments. In the third building of this figure is shown an arrangement of the pipes and radiators in a manner to utilize the hot water under full pressure. This plan has some advantages over that of steam for heating purposes, in that it can be controlled by means of cocks or valves in such a manner as to keep the temperature of the radiators at any desired degree,while with steam it must either be at its full heat or entirely out off. All who have used steam have been inconvenienced by this lack of control of the heat. Then, again, the noise occasioned by the condensation of steam is entirely avoided when hot water is used directlyin radiators. I have also shown in the figure an engine which can be run for power directly with hot water, and by exhausting into the return-pipe be quite as economical and operative as when run by steam,

as all condensed water will be conveyed back to the heater. There is no ditiiculty in working water at a high temperature in an engine properly constructed and arranged to exhaust in this manner, provided the cut-off is arranged to work very expansively and at a low pressure and finely wire-drawn or dissipated.

The meter will determine the amount of water consumed as in any other operation.

In some of the illustrations I haveshown the meter in position to measure the condensed water from the radiators. This plan, however, is not considered very practical as a means of determining with any degree of accuracy the amount of heat consumed, as the many accidental leaks, to say nothing of those purposely left in that condition, would easily allow of a very great discrepancy, as one cubic foot of condensed water would represent nearly a thousand cubic feet of steam; hence great opportunity would beafl'orded to practice imposition by means of the many cocks, valves, andjoints in and about the house. The only accurate way when steam is used in a building is to meter the water first before it has entered any of the pipes and radiators connected therewith.

'Fig. 4 represents a pressure regulating valve. It is constructed by fitting a movable plug, B, into the cylinder or barrel R", the plug having a recess turned or cut in it about the center, which communicates, by means of openings, with the tank R to which the case It is fastened. The plug has a stem extending outward through the cap of the cylinder R, which carries a weight, It. In the practical operation of this valve, the pressure-pipe B being opened, the hot water is admitted from the main pipe through the branch pipe and meter connected therewith, as shown in the first and second buildings of Fig. 3 The communication being opened, the hot water will pass freely into the tank or converting-chant ber R but upon entering the said-tank the pressure will be immediately relieved and steam will be generated, the pressure of which will act upon the plug R, and as soon as the pressure has exceeded that of the weight R the plug will be thrown up. and the inlet-port from the pipe R will be cut off and the further admission of hot water will be prevented; but as condensation is constantly going on in the radiators which connect with the convert ing-chamber R", the pressure will soon be so far reduced therein that the weight R will be greater than the sustaining force of the steam on the face of the plug It, and it will begin to descend again. This movement will expose the inlet-port,and a further admission of hot water will be permitted, which will again be converted into steam, and in this manner a constant and nearly equal pressure will be maintained in the tank or converting-chamber R and radiators connected therewith, irrespective of the pressure in the main or hot water pipe.

' In Fig. 9 I have shown a detached view of an apparatus to be used in converting the hot water into steam for running engines, which is designed for use at such times and places where steam only is required for power. V represents aconvertingtankflnto which thehot water is admitted directly from the main pipe V through the meter Vand red ucing-valve'V Said converting-tank is constructed with partitions V, extending perpendicularly or otherwise in such a manner as to cause the water to pass through a considerable distance before it is finally discharged into the trap U and into the return-pipe U, said partitions being of no unequal height and left open at their tops for the escape of steam, as shown in the drawings, the object being to retain the water for a sufficient length oftime to enable the steam which is evaporated by the specific heat of the water to be thrown off before the condensed water is discharged into the return-pipe, and in that manner to enable a near approximation of the amount of heat or steam consumed to be made, for it will be seen that ifa given amount ofwater is admitted into the apparatus at a given temperature and discharged only after it has been reduced to a very much lower temperature nearly all the steam thrown off and used could be determined.

In this apparatus the hot-water inductionport would be controlled by the governor of the engine, and in that way the power would be regulated. The trap shown in Fig. 7 would be the proper kind of thing to use with this apparatus, as it would carry away all the water as fast as it was allowed to pass through the converting-tank, but would not permit the I escape of any steam, whereas an expansion or through the valve T.

temperature trap could hardly be regulated so satisfactorily in such cases as where the water would be required to be discharged above the steam-generating point, as required for power purposes.

In Fig. 5 is shown one form of a temperature steam-trap. It consists of a 1ong copper(or other soft-metal) tube, S, which is arranged to convey the water of condensation from the radiators. There are two bars or rods, S extending the full length of the tube S, which are attached to the same base. These rods carry on their opposite ends a fixed valve, T, which communicates with the valve-seat, constructed on the end of the expansion-tube S. Adischarge-pipe, T, is attached to the expansiontube, to convey away'the water which passes In the operation of this trap the water of condensation will pass into the tube S, and will by its heat expand the same and cause it to close the opening or valve T; but as soon as it has become sufficiently cooled the contraction of the pipe or tube will permit the water to pass out. As soon as the water begins to run hot through the tube, it will again expand and close the valve. By this means the water of condensation can be discharged at almost any temperature from the radiators, and thus the entire heat of the water admitted may be utilized in warming the building. In Fig. 6 I have shown one manner of protecting the pipes under ground from radiation by covering them by some well-known non-conductor and inclosing them in a wooden box, W, arranged with a space, W, to carry off thewater that otherwise might come in contact with the pipes and covering. The space or channel W is in communication'with the street-sewer W 'by means of a pipe, 10.

In Fig. 7 I have shown a trap for discharging the water from the radiators. It is connected with the branch pipe B, leading to the street return-pipe. It is constructed by place 'ing a movable diaphragm, B between two concave cases, B andthen bolted together,

thus holding the diaphragm firmly in its posi-.

tion. To this diaphragmis fastened a stem, B, carrying a valve, B which opens and closes a port constructed in the barrel B", said barrel being rigidly attached to the lower side of the case B. 7 The pipe B, which extends to the return-main, is connected below the valve, as shown. The barrel B is also connected, by

means of a pipe, B wit-h the bottom of the radiator or drip-pipe B", this latterconnection being made with the barrel above the discharge-valve.- A pipe, B,textends from the drip-pipe to the upper side of the diaphragmcases. There is also a "pipe, B, extending from the lower side of the diaphragm-cases and connected to the upper end of the radiator or to a pipe extending upward from the drippipe.

B and B arranged, as shown, to extend above and below the diaphragm, and when In the operation of this trap it should be placed at the position where the water of condensation will flowinto it, and the pipes full of water said pipes will regulate the movements of the same, and thereby control the discharge-valve. v 7

It is evident that if thewatcr should be drawn off from the radiators or from the connecting-pipe B", and the column of water in B were retained by reason of the connections with the lower side of the case B the pressure of the column upon the increased area of thediaphragm would cause it to move in an upwardidirectiou and'carry with it the valve 13?, and thus prevent further discharge of water from the pipe B". So soon, however. as the accumulation of water in the pipeiB. and connecting-pipe B has brought about an equilibrium of pressure inthe pipes B and B,

the diaphragm will drop by the weight con- 3 nected thereto, and the valve B will again be opened and the water permitted to fiow-out,

and thus the operation will continue alternately.

In Fig. 8 1 a valve for regulating the pressure. system for conveying heat and power thepipes are to be provided with cocks or valves, as shown in Fig. 2, so that any section may be closed for repairs without interfering in any way with the constant supply which ca'n'be furnished through. other pipes connected thereto at the junctions of the streets. This system will not only furnish power for running all kinds of engines, elevators, and heat for warming buildings, but it may also be employed through the agency of a steam or hotwater stove for all kinds of cooking and other culinary purposes, and thus a. convenient,

have shown one construction of In thisv root.

heathful, and economicalsupply of heat and power may be delivered and utilized at a great distance fromthe generator without any appreciable loss from condensation orwaste of The return water may be admitted to water. the heater by means of automatic gravity-traps or feed-water apparatus in place of pumps,-if

desired. V

- It is evident that ,many more modifications of the various features and parts of this invention maybe employed, which it is notideeme'd Y necessary here to enumerate. g 7

My invention is not limited to the specific form of pressure-reducer or means for converting the hot water into steam shown and described; but any construction which will operate'to reduce the pressure and convert the hot water into steam maybe employed without departing from the spirit of the invention.

The word superheated throughout this specification and the following claims is used to denote water heated to over2l2.

Some of the parts which are herein shown and described are shown and more fully de- 2 scribedin Patent No. 208,633, granted to me October 1, 1878, and form no part of the invention claimed herein, but .are included in order to more fully andclearly illustrate the said' invention.

Having now described the-nature of the said invention and explained the manner of carrying it into practical effect, I hereby declare that what I consider to be novel and original,

and therefore claim, and desire to secure by Letters Patent of the United States, is

5 1. The herein-described method of furnishing steam for heat and power purposes to large districts of buildings in cities and towns, which consists in superheating water at a central station, conveying the water to the buildings to be heated, converting the superheated wa ter into steam, which is employed for heating purposes, and returning the water of condensation to the heater at the station, substantially as shown and described.

2. The herein-described method of furnishing heat and power for large districts of build ings in cities and towns, which consists in heating water at a central station, conveying it throughout the district to be heated and re 20 turning it to the heat-er, extracting a portion of the hot water at the points where heat or power is required, and returning the same or a portion thereof directly to the heater after it has been used for heat or power purposes, substantially as shown and described.

3. Theherein-described method offurnishing steam for heati ng or power purposes to large districts of buildings in cities and towns, which consists in superheating water at a central station, conveying the water to the buildi ngs where heat or power is required, converting the superheated water into steam, and returning the water of condensation to the heater,where it is reheated and again circulated, substantially as shown and described.

\VILLIAM E. PRA LL.

Witnesses:

NATHAN GUILFORD, THEO. A. VAIL.

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