US1621853A - Water-heating system - Google Patents

Description

March 227 1,621,853 J. A. POWELL WATER HEATING SYSTEM Filed June 27. 1922 2 Sheets-Sheet 1 Hy.: z

March 22, 1927.l 1,621,853

J. A. POWELL WATER HEATING SYSTEM Filed June 27, 1922 2 Sheecs--SheeiI 2 Patented Mar. 22, i927.

narranu JAMES A. PONELL, OF READNG, PENNSYLVANIA.

WATER-I-ATNG SYSTEM.

Application ied June 27,

This invention relates to Water heaters and particularly to jet type heaters in which ithe Water to be heated is subjected to the heating action of Jfh'e steam or other heating fluid in the form of spray.

An object of the invention is to produce a jet type Water heater which v. 'll operate effectively and efliciently under 1widely varying conditions of steam and er flow.

A further and more specrnL obgect is to produce a jet type heater in which means are employed for insuring effective interminglingl of the water and heat .ig fluid, hereinafter termed steam under widely varying conditions of Water flow.

A. further object of the invention is to produce a system of heating and nieteingafeed Water in which means are employed for )ffcctively removingl air from the Yer and for tllerel climihating` corroson in 'he steam boilers and economizers.

This and other obiects which will be made more apparent throughout the further description of the invention, are attained by means of a heater embodying,v the features herein described and illustrated.

in the drawings accompanying and forminga part hereof, Figure l is a diagraim matic sectional view of a heater emboeying my invention and Fig. 2 is an elevation of a feed Water heating` and metering system embodying my invention.

lt is vieil establieihed tiiat the over-all efficiency of a power plant is increased by heating the feed Wat-er before delivering it to the boilers. To accomplish this economically7 it is necessary to avoid a Waste of heat in the operation of withdrawing air or other non-condensible fluids from the heater. It is also essential to avoid the loss of steam particularly on ship-boardv or in localities Where Water suitable for feed Water purposes is scarce.

An object of my invention, therefore, is the production of a jet type Water heater which operates economically under Widely varying conditions of steam and Water fionT and which avoids Waste of heat or steam in the operation of withdrawing the non-condensible fluids from the heater.

It is usual power house practice to heat the feed Water with steam exhausted from one or more steam driven auxiliaries.

The feed Water is made up in part of condensate received from the condensers serving the prime movers and Where jet con* 1322. Serial N0. 571,26*?.

densers are employed it is made up in part of raw Water, consequently, the quantity of Water delivered to the feed Water heater varies with variations in the load on the prime movers, While the flow of steam from the auxiliaries is more constant. lt is, therefore, considered best practice to so propor tion the number of auxiliaries exhausting into each heater that the heaters will oper-l ate economically under conditions occasioned by the most normal load on the prime movers. With heaters now in use, a variation above and below such conditions Will occasion a loss in the efficiency of the heater, Under super-normal load conditions the in creased volume of Water is not heated to the most economical temperature and under subnormal load conditions, a loss is occasioned by the delivery of excess steam to the heater. l/Vith feed Water heaters such as are now in use the permissible range of temperature fluctuations is extremely limited, and in addition, heaters are so constructed that they not only Waste steam under conditions of low Water flow, but actually accentuate the Waste by occasioning an increase in the delivery of heating; steam to the heater under such conditions. rlhis increase in the amount of heating steam delivered is occasioned by the fact that a decrease in the amount of Water decreases the capacity of the heater to absorb heat and to condense the steam delivered to it. The surplus steam in the heater, therefore, increases the back pressure on the auxiliaries and this in turn reduces the efficiency of the auxiliaries and causes them to demand more steam in order to accomplish the Work required of them. Under such conditions the surplus steam must be discharged from the heater and it is ordinarily vented to the atmosphere With a resultant Waste of both heat and water.

`While the jet type of heater is .superior to other types both from the standpoint of operation, first cost and maintenance, the di'iculties encountered in other heaters are accentuated in the jet type and particularly under conditions of low Water supply. This is due-to the fact that a jet type of heater, such as now employed When designed for normal load conditions on the main generating units is incapable of occasioning the necessary intimate intermingling of the Water and steam under subnormal load conditions. As a result, much of the steam delivered to the heater is not subjected to;

the cooling effect of such water as is present in the heater and is, therefore, vented to the atmosphere at substantially its incoming temperature. i

In carrying out my invention, I provide a heater in which a number of groups of spraynozzles are employed and l also se locate and arrange the different groups of nozzles that an eective barrier of water spray is interposed between the steam inlet of the heater and the air outlet, even under extreme conditions of low 'water flow. With this arrangement, the heater operates economically under low water dow conditions and is also capable of operating with high efficiency under conditions of maximum water flow since as the water flow increases, one or more groups of spray nozzles are rendered elfective in delivering water spray to the heater.

Referring to Figs. 1 and 2 of the drawings, the heater a illustrated is associated:

with piping for delivering feed water to the spray nozzles thereof from the usual sources of supply. Various piping arrangements may be employed in carrying out my invention, and it is contemplated that the piping may be varied tosuit conditions encountered.

The heater preferably consists of a cylindrical casing 4a located in a vertical position and provided with a non-condensablc fluid discharge port hereinafter termed an .air oi'ftake port 5, which is located near the bottom of the casing, but somewhat above Y the water discharge port 6. This may communicate with a tail pipe or the inlet of a discharge pump, but in Fig. 2 l have shown a system of piping whereby it may communicate with a V notchV meter 7 or a storage tank 8. As` illustrated, the casing d is provided with two steam inletports 9 and 10 which with the air odtake port 5 are spaced along the casing so that the steam ports are above the port 5. A series of spray nozzles 11 are located-between the inlet port 9 and the air oiltake port 5 and a second series of spray nozzles 12 are located between the steam inlet ports 9 andlO and consequently' between the air offtake port 5 and the steam inlet port- 10. Both the ports 9 and 10 communicate with a steam pipe 13 which receives exhaust steam from one or more auxiliaries, not shown. The pipe 13 is preferably provided with an atmosphericgrelief valve la located on the far side of the connection with the inlet port 10. The relief valve communicates with a vent pipe 15 for carrying away the steam discharged by the relief valve.

The series of nozzles 11 communicate with a source of water supply through a pipe 16. This pipe preferably communicates with a condensate storage tank or som-e similar source of feed water supply. vThe nozzles of the series 11 receive water from an annuthe series l2 through a branch lar chamber 11a and are so proportioned that they are capable of delivering a barrier of spray across the interior of the casing d even under conditions of minimum water supply. With this arrangement, such water as is delivered to the heater, even under conditions of extremely low water flow, is broken up into a mass of separate drops of spray so that it is effectively subjected to the incoming steam. The additional series l2 of spray nozzles is provided for the purpose of delivering excess water to the heater during normal and overload conditions on the prime mover or main power generating unit. rihe discharge area or' these nozzles is preferably greater than the nozzles oi the group l1 so that they are capable oi' delivering a larger quantity of water.

ln Fig'. 2, l have shown one means for controlling the Supply of water to the nozzles of the series 12 so as to insure a full supply to the nozzles of the series 11 at all time As shown, water is delivered to the nozzles of pipe 17 which communicates with the supply pipe 16 but is so located and arranged that no wat-ei' will be delivered to scries12 until after the supply traversing the pipe 16 is in excess of that which can be delivered through the nozzles of the series 11. ln the illustrated embodiment this is accomplished by so forming the branch pipe 17 that no water is delivered to the series 12 unt-il a predetermined head has been established in the pipe 16. In other words, the branch pipe 17 extends upwardly from its point of connection with the pipe 16 and then is looped downwardly so as to communicate with the annular supply passage 12EL of the nozzles of the series 12. lfhe 'height of the upwardly extending leg, or of the loop above the pipe 16 determines the hydraulic head which must be attained before water is the series 12. ln order to prevent a siphonic action, l connect the apex of the loop with the interior of the heater through a pipe or passage 10. lt will, of course, be understood that any well-known mechanism may be employed in place of the upwardly extending branch pipe 15 for controllinow the delivery of Water to the nozzles of the series 12 in respense to variations in the quantity of water flow through the supply pipe 16. It will also be understood that two or more secondary series of nozzles may be employed and that the piping communicating with them may be so arranged that 'they will successively deliver water to the heater as the available supply increases.

In the drawings I have illustrated an annular converging' baille 19 located between the series of nozzles 11 and the air olftake sort 5. As shown, this baffle projects downwardly into the lower portion of the heater and prevents steam or other gases from passdelivered through nozzles of Y ing out through the ofl'take port without first having been intermingled with, and subject-- ed to the cooling action of water traversing the heater. I have also shown a vent pipe 20 which communicates with the heater at a point below the baflle 19 and which is proe vided kwith an atmospheric relief valve 21 of usual construction.

An air pump or air ejector (not shown) is preferably employed for withdrawing air or other non-condensable vapors from the heater through the port 5. An air cooler (not shown) is also preferably employed for cooling and thereby reducing the volume of the air and vapors delivered to the pump or ejector. It will, of course, be appare-nt that the port 5 may communicate directly with the atmosphere if the conditions of operation are such that the normal pressure in the heater is above atmospheric pressure.

Under conditions of low wat n supply, the water delivered to the heater enters through the nozzles of series 11 and previously stated, they are so formed and arranged as to spray the water delivered through them and therefore insure a complete intermingling of the water with the steam in the heater even under conditions of extremely low flow. is the supply of water increases, water rises in the inlet leg of the branch pipe 17 and after a predetermined head is established, water is delivered through the, nozzles of the series 12. lilith this arrangement, the nozzies of the series 11 are always supplied with an adequate flow of water to insure the for-V mation of a spray barrier between the steam inlets and the air ofitake port 5, and even though the quantity of water supplied through the nozzles of series 12 is not sufficient to cause those nozzles to break it up into spray, it is intimately mixed with the steam in the heater in falling through the heater and the converging battle 19.

The form of the baille 19 is such that it in effect forms a. combining chamber and occasions an entrainment by the water of the air or other non-condensibie gases. Consequently, the greatest air pressure within the heater is at a point below the baille 19 and the air or non-condensible gases are therefore withdrawn from the heater at the point of greatest air pressure. This is advantageous not only because it prevents a waste of steam but also because the air and vapor discharged through the port 5 are heavier than would be the case if they were withdrawn from a portion of the heater subjected to the heat of the incoming steam. This last mentioned advantage is important where means such as an air ejector or air pump is employed for withdrawing the air or non-condensible vapors from the heater. I preferably employ a conical member 22, immediately below the series of nozzles 12, which functions as a combining passage in connection with the water delivered by those nozzles and the steam delivered through the inlet port 10.

The ports 9 and 10 are preferably so proportioned as to area with relation to the caf pacity of the pipe 13 as to insure the delivery of steam through both of them under normal conditions of steam supply. It will of course be understood that any suitable means such as a branch pipe not shown may be employed for delivering make-upV water to the heater.

In the drawings, I have shOWn the heater associated with a V-notch meter of a wellknown type.. As illustrated, the meter `'Z' is located immediately above the storage tank V8 and is so arrangedV that water traversing the meter may be delivered directly to the storage tank. As shown, the water discharge port 6 of the heater communicates with the storage tank through a pipe 23 and with the meter 7 through a branch pipe 2li. Valves 25 and 26 are so arranged that water issuing from the heater may be delivered directly to the meter 'l' or the storage tank 8,

One of the features of my invention is that the entire water system may be maintained under vacuum for the purpose of pre4 venting air trapping and air absorption which is the ordinary objection raised in connection with meters of the V-notch type. As shown, I vent the meter through piping 22' which communicates with the air discharge chamber of the heater. I also vent the storage tank through a branch pipe 28 which also communicates with the air discharge chamber of the heater. Under such circumstances, the non-condensable vapors, such as air, are withdrawn from the meter and from the storage tank by means of the air pump or ejector associated with the air ofltake port 5,.

It will be apparent that with this arrangement, air and non-condensable vapors are not only abstracted from the heater but are also abstracted from the storage tank and from the meter. This prevents the reabsorption or retrapping of air; consequently, insures the maintenance of at least a partial vacuum throughout the feed water system and prevents the difficulties ordinarily encountered in boilers and economizers where air is delivered in substantial quantities with the feed water.

llVhile I have described an embodiment of my invention, it will be apparent to those skilled in the art that various changes, modilications, substitutions, additions and omissions may be made in the apparatus illustrated, without departing from the spirit and scope of the invention, as set forth by the appended claims.

I claim:

1. A jet type water heater including a casing provided with a steam inlet port, an air oftake port, separate series of spray nozzles arranged to deliver a water spray between said ports and separate inlets for said series of nozzles arranged so as to deliver water to one series under all conditions of water flow and to deliver water in eXcess of the capacity of said series of nozzles to the other series.

' 2. A jet type water heater including a casin provided with a steam inlet port, an air oiiiliake port, separate series of spray nozzles arranged to deliver a water spray between said ports, separate inlets for said series of nozzles and means associated with said inlets for delivering water to one series under all conditions of water flow and for delivering water in excess of the capacity of said series of nozzles to the other series.

3. A jet type water-heater including a casing provided with a steam inlet port, an air otl'take port7 separate series of spray nozzles arranged to deliver a water spray between said ports7 separate inlets for said series of nozzles and connections associated with said inlets to deli-ver water to one series under all conditions of water How and to deliver water in excess of the capacity Vof said series of nozzles to the other series.

4. A jet type water heater including a casing provided with a steam inlet port, an air olintake port,V two series of spray nozzles arranged to deliver a water spray between said ports, separate inlets for said series of nozzles, an inlet pipe connected to one of said inlets for delivering water to the associated series of nozzles under all conditions of 'waterflow and a` branch pipe connected to the other of said inlets for delivering water in excess of the capacity of said irst series of nozzles to the other series.

5. A jet type waterheater comprising a casing provided with .an air olitake port, and at least two steam inlet ports, at least two series of spray nozzles for delivering water into said casing each so located as to deliver ya barrier of water spray between said airotftake port and at least one of said steam inlet ports, and means for delivering water to one series of nozzles under all conditions of water flow tothe heater, and for delivering water in excess of the capacity of said series of nozzles to the other series of nozzles.

6. A jet type water heater comprising a substantially cylindrical heater, having an air olitake ort, two steam inlet ports and two water inlet ports, a separate series of water delivery nozzles communicating with each water inlet port and each so located as to deliver water jets into the heater between one of the steam inlet ports and the air Yolitalre port, one of said series having a larger Water delivery capacity than the other and means for controlling the supply of water to sai-d larger nozzles in response to variation in the flow of water to the heater.

7. In combination in a jet type water heater, a cylindrical casing having at least two steam inlet ports, and an air offtake port,ra converging cone between each inlet port and said oltake port, a separate series of nozzles associated with each inlet port, and adapted to deliver water through the associated cone, one of said series having a smaller water delivery capacity than the other, and means for controlling the delivery of water to vthe series of larger capacity in response to variations in the quantity of water flow to the heater.

`8. A jet type heater comprising a shell having .an air otltake port and a steam inlet port, two water inlet ports, a separate series of water-delivery nozzles communieating with each water inlet port and each so located as to deliver jets of water into the heater between the air oitake port and the steam inlet port, and means for controlling the delivery of water to one series of nozzles in response to variations in the amount of water delivered to the heater.

In testimony whereof, I have hereunto subscribed my name this 24th day of June, 1922.

JAMES A. POWELL. Y

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