US1894437A

US1894437A - Heater control

Info

Publication number: US1894437A
Application number: US159619A
Authority: US
Inventors: Joseph M Barrett
Original assignee: SWARTWOUT CO
Current assignee: SWARTWOUT CO
Priority date: 1927-01-07
Filing date: 1927-01-07
Publication date: 1933-01-17
Anticipated expiration: 1950-01-17

Description

Jan. 17, 1933. B R T 1,894,437

HEATER CONTROL Filed Jan. 7, 1927 FROM TURBINE JOSEPH M. BARRETT, or .ros'roRm; oiiro, ASSIGNOR To THE SWARTWOUT COMPANY, 1

Patented Jan. 17, 1933 UITED STAT S PATENT OFFICE or cLEvELANn'oHIo, A oonrona'rron on 01nd EAT R. CONTROL- Application filed January 7, 1927; I Serial No. 159,619.

heater asto force water back into the turbine.

To effectively heat the feed water, the condensate from theexhaust steam must be car ried away from the body of the heater and kept out of contact with the heating coils.

The condensate from the; exhaust steam being pure water must be conserved and keptin the water cycle to the best advantage. The pressure of the steam bled from the turbine will vary according to the load on the turbine which in turn determines the boiler rating and it is thus necessary to distribute the condensate with regard to this varying pressure. l/Vhatever happens to the heater, the supply of feed water must be maintained for the boilers. I

It is therefore among the objects of my invention to provide a heater control system which will insure a continuous supply of feed water, even if the heater coils leak or break.

Another object is to regulate and control the outflow of all water from the heating chamber. Another object is to control the flow of feed water, through the heater both with re gard to the presence of heating steam and'to the amount of condensate and leakage collected.

Another object is to control the distribution of condensate according to the pressure of exhaust steam, .which in turn depends upon the load on the turbine. Other objects include the provision of simple positive appara tus in the construction of my invention, which will give an ample and reliable factorof safety.

Further objects will appear from the fol;- lowing detailed 'descriptionof the apparatus, a preferred form of which isshown in the accompanying drawing. The essential characteristics are summarized in the claims.

The drawing includes a layout of a portion of the piping of the feed water line, the heater proper, parts of the condensate distributing lines and the control apparatus in cluding the valves and valve actuating mechanism therefor.

Referring to the drawing, I show a heater shell H having the feed water header 1, to which are connected heating coils, C, but disposed-within the body of the heater H. Thefeed water line2 leads from thefeed water pump, not shown, through a diaphragm actuated valve 3 into the header 1 through the heater coils, mentioned above, through the check valve 4, thence in the direction indie cated to the boilers, not shown. I show. a by pass 12 in the feed water line having a valve 13 which is adapted to normally close the by pass, but which may be forced open when the pressure on the pump side of the valve eX ceeds the pressure on the boiler side by a predetermined amount which may ordinarily be ten or twenty pounds.

The pipe 20 leads from a low pressure stage of the turbine, not shown, to the heater shell H and supplies the heating steam at varying pressures to heat the feed water. An outlet forsteam and condensate from the heater H is provided at 21 through an enlarged portion 22 into the pipe 23 and through the T connection 24'and thence through the valves 30 and 40 which are shown to control the flow.

through pipes 31 and 41 respectively. A check valve42 is disposed in the pipe 41, as Shown.

I show the pipe 31 leading to water storage which in usual practice is located in the lowermost part of the plant and at an elevation lower than the feed water pump. I show the pipe 41 leading upwardly and for the purpose of illustration, I indicate that the pipe 41 leads to an open condenser or dearea tor, which may be at an elevation of possibly one hundred feet, and in which pipe a similar head of Water exists. By apparatus presently to be described, I control the flow through these pipes with regard to the exhaust steam pressure so that if the pressure 'be great enough to raise the water of condensation in the: pipe 41, all of the flow, except/in an emergency, will pass through the valve 40. When however, the steam pressure falls, the flow of condensate is directed through the valve 30 to water storage so that in all events,

condensate is drained from the heater and the water is distributed to its most eificient purpose. p

Tocontrol the valves 30 and 4O aswell as the valve 3, I provide the following appara tus. Connected in parallel with the drain pipe 23, I show the receiver or surge tank having an upper connection 60 leading to the conduit 61 and lower connection 62 leading to the conduit 63. The conduit 64 connects the conduits 61 and 63, so that the water level in the pipe 23, the receiver R and the conduit 64 is substantially the same except .for the velocityeffect in the pipe 23. The conduit 65 extends from the junction 66 of theconduit 64 and 63'to the point 67 where it connects with the steam pipe 20. By connecting the conduit 65 with the steam pipe 20, one ismore certain of obtaining dry steam than if the connection were made for instance, with the body of the heater. The

valves

68 and 69 control the flow of fiuidthrough the conduit 65.

Disposed at anangle to the horizontal and connecting the conduit 64 with the conduit 65, I show three conduits 70, and re spectively.

pressure generators

72, 82 ly. The generators may be of the general type shown in the patent to Copley, No. 1,193,125, issued August 1, 1916. The generators are inclined to the horizontal, and are positioned to intercept the varying planes of water level of the receiver B. Each ofthe generators comprises a closed cylindrical chamber surrounding the conduit on which it is mounted. The chamber contains an expansible fluid which is expanded and put under pressure when the conduit on which and .92 respective:

the generator is mounted, contains steam and which is chilled and contracted when the conduit contains water.

Pressure conduits

73, 83 and 93 lead from the respective generators to the valves 40, 30' and 3respectively. Also mounted on the

conduits

70, 80 and 90 are radiators or coolers 74, 84 and 94 respectively. These coolers may be of the type shown in connection with my copendingapplication. Serial No. 144,815 filed October 28th, 1926. By means of the cooler I am able to obtain a sharp temperature diiierential betweenthe water and steam in the

conduits

70, 80 and 90 so that when the water level in the conduit rises, the water will pass through the cooler and be chilled, thereby causing a more rapid and eifectual definition of the generator action. Theporti'on of the conduit 65 from the point 66 aroundthrough and in-.

-Valvcs 71, 81 and 91 control the fluid flow through these separatev conduits. Mounted on each of the conduits, I show the eluding thevalve 68 constitutes a Icy-pass, in

which any condensate forming in the vertical 2 whereby a sharp difference in heat content between the liquid and gaseous fluid is maintained.

The valves 30 and40 are of the pressure 7 V actuated type having

diaphragm chambers

34 and 44 respectively, which are connected ever one of the pressure generators is chilled in response toa rising water level 1n the re-' with the conduits 83 and 73 respectively. 8

ceiver R, the respective valve isopened. Con- J versely as long as the

generators

72 and 82 are heated by reason of a low water level in the receiver R or an absence of all water, the

valves are forced toclosed position. Thus, for instance when the steam supply through the pipe 20 iscut ofi, the pressure generators cool, the valves 30 and 40 open, and all of the water drains from the system, The check valve 42 maintainsa water column in the pipe 41; Whenever steam :is supplied through the pipe 20, the genera-torsare heated, the valves 30 and 40 closed, and maintained'closed until water accumulates to the level or the generator or gen'erators.

Referring back to the feed water line- 2 and the by-pass 12, I show the pressure actuated diaphragm valve'3, mentioned above,

controlling the flow of feed water through the heater coils. The valve 3, being positioned in a line which maycarry pressures up to a thousand pounds or more, is provided with a double seat, as shown. The valve is urged to closed position by the spring 5. A

6 is provided to which diaphragm chamber the pressure conduit 93 leads, so that a pressure generated by the generator 92 forces the valve 3 to'open position. The pressure is created in the generator 92 by reason of the presence or steam in the conduit 90, and this in turn depends on the conditions of the

valves

69, 9,1 and 68, but primarily 'onthe presence of steam in the heater and in the steam pipe 20; It will be seen therefore, that if the supply of heating steam is arbitrarily cut ofi", that the generator 92' will be chilled the valve 3 will be closed so that the feed water will not pass through the heater. If at any time the water level in the receiver R rises so that the conduit90is substantially full of water, the generator 92 will be chilled and the valve 3 closed. It will be seen therefore, that if for any reason the ieedjwater coils in the heater should leak so that an excess of water accumulates in the receiver, the

valve 3 will be closed before the water level rises into the heater shell; This accomplishes the double purpose of conserving the feed water for the boilers and of protecting the turbine from water which might be forced backwards in the steam pipe 20, if the heater were flooded. The generator 92 will of course only be chilled after the generators 72 p and 82 have been chilled so that the valves 30 and will be wide open and handling as much water, mainly condensate, as the steam pressure in the heater permits.

To insure a continuous supply of boiler feed water, the bypass 12 is provided, having the differential valve 12. A check valve 4 prevents backing up of feed water in the heater, in the event the valve 3 is closed. The valve 13 may advantageously be of the double seat type because of the high. pressure fluid. The valve members are actuated by a dia phragm 14 which is subjected to inlet pres sure on the lower side and outlet pressure on the upper side. The outlet pressure is transmitted through the conduit 15 and controlled by the valve 16. It is augmented by spring or other means not shown, within the casing 17. The spring may be adjusted so that a suitable pressure drop across the valve is nec essary to effect the opening,.which need only be a little greater than the friction through the heater coils.

In operation, steam flows into the heater through the pipe 20. Steam also flows down through the pipe fills the receiver and drain pipe and the whole control system for a moment, and at the same time, heats the

generators

72, 82 and 92. The heated generators exert fluid pressures which open the v valve 3 permitting feed water to flow through the heatingcoils and close the valves 30 and.

40 to prevent the loss of steam and to hold steam in'the heater system untila water seal is formed of the condensate which collects by reason of contact with the heating coils. As the valve 3 opens the valve 13 closes so that all of the feed water is directed through the heater." After the valves 30 and 40 have been closed, the condensate collects in the system and rises in the pipes 23 and 6-4 and in the receiver B. As the condensate level continues to rise, the generator 72 is chilled so that the valve 40 is allowed to open by reason of the-pressure of the spring 43, then if the load on the turbine be great enough so that steam pressure in the heater is sutliciently high, the condensate will be forced through the pipe 40 against a substantial head to either the open condenser or deareator or similar apparatus mentioned above. Supposing that the steam pressure remains constant, and that for any reason the accumulation of condensate becomes greater than the capacity of the valve 40, the condensate level will rise, chill the generator 82, and open the valve 30-. If however, the steam pressure drop through the valve 30 and the check valve 42 would maintainthe water column in the pipe 41. In the event of leakage in the heater coils, the effect would be toraise the water level in the receiver R so that the generator 92 would also be chilled andthe flow of feed water through the heater would either be restricted or cut off so that the water level in all events would never rise higher than that level which would completely chill the generator 92. thevariation in steam pressure in the heater depends on the load on the turbine. It ought also be pointed out that the flow of feed water and the boiler rating also vary with a load on the turbine so that the lesser heat input from the exhaust steam will be adequate for the amount of feed water to be heated. In this same period, the quantity of-water in the water storage normally increases slightly and it will be seen that the diversion of water through the pipe 31 is in harmony with the operation of the whole water cycle. It will also be seen that the heater automatically comes into-or is cut out of operation according to the supplying of steam to the heater. In other words, if the heating steam is cut off, the heater drains itself of all condensate and bypasses the feed water away from the heating coils. Being thus empty and idle, one has only to pass steam through the pipe 20, to bring about the complete and continuous operation of the -apparatus which needs no further attention.

" I claim:

1. The combination of a feed Water line,

heating coils in said line, a valve in said line,

a container for heating fluid surrounding said coils, and means responsive to the tem' perature of the heating fluid and to the level of condensate for positioning said valve to control the flow of feed Water through said heating coils.

2. The combination of a feed water line,

heating coils in said line, a feed water by-' pass around said coils, a container for heating fluid surrounding said coils, and means responsive to the temperature variations of the heating fluid for lay-passing the feed water around said heater coils.

3. In a closed feed water heater having heating coils for feed water disposed Within a container for steam, the combination of means for draining the container and means for by-passing the feed water when the supply of steam fails.

4. The combination of afeed water heater, means for controllmg the flow offeed water through the heater and pressure generator means responsive to the temperature of the heating fluid and to the level of condensate for controlling said first named It has been mentioned that means, whereby the flow of 'feed water through the heater depends uponthe temperature of the-heater. 1

' 5. In a feed'waterheater having feed water coils disposed within a container for steam for heating the coils, the combination of 7 means forv collecting the condensate from the directing the flow of feed water'through said by-pass when the accumulation of water exceeds a predetermined amount.

7 In a closed feed water heater having a feed water heating coil, a container for the heating fluid surrounding said coil, and valve means for controlling the outflow of liquid from the container, the combination of thermal means actuated by the heating flui d for maintaining' a water seal over said valve means, and means dependent upon the elevation of said water seal for controlling the flow of feed water through the heating coil, whereby the seal is maintained and the feed water directed throughthe coils in response to the heat input of the heating fluid.

8. The combination of a closed feed water heater having a feed water heating coil, a container for the heating fluid surrounding said coil, valve means for controlling the outflow of water from said container, and means dependent upon the heat content of said fluid for maintaining a water seal over said valve means and for controlling the flow offeed water through the heating coils, whereby the water seal is maintained and the feed water directed into the coils when the coils are heated by the heating fluid.

9. The combination of a closed heater having feed water heating coils disposed therein, a feed water line leading through said heating coils, a by-pass in said feed water line around said heating coils, a steam inlet to the heater, a discharge outlet from the heater, a discharge pipe, valves in said pipe controlling the fluid outflow from the heater, a reservoir associated with said pipe, and means dependent upon the relative level of water and steam in the reservoir for controlling the outflow of water from the discharge pipe, and for controlling the flow of feed water through the heating coils.

10. The combination of a closed heater having feed water heating coils disposed therein, a feed water line leading to said coils, a valve in said line, a steam inlet to the heater, a Water discharge outlet fromthe heater, a discharge pipe, valve means in said means for controlling the discharge.

level of water and'presence'of steam in the reservoir for controlling the outflow of water from the discharge pipe, and for controlling the flow of feed water .through the heating coils. v p r. T

11. In a heater control system, thecombination of a closed ,heater'having'heating coils therein, a feed water line including said coils, a by-pass around said coils, means for leading steam to the heater, an outlet from the heater'for carrying away both condensate and leakage, a discharge pipe leading from said outlet, means controlling the outflow through said discharge pipe, thermo-respon 'sive means for actuating said last-named means and disposed at an elevation between the heater outlet and said discharge controlling means, means aflording communication between the discharge pipe andthe steam inlet pipe and associated with said thermo-responsive means so that the thermoresponsive means are heated by steam above the water level maintained in said discharge pipe and actuated thereby, and means dependent upon said thermo-responsive means for controlling the flow of feed Water through the heater coils. V

12. The combination of a closed heater having feed water heating coils therein, a feed water line includingsaid coils, a by-pass in said line around said coils, a by-pass valve,

a steam line leading to the heater, an outlet from the heater for taking away condensate and leakage, a discharge pipe, a valve inisaid pipe, fluid conducting means leading from the steam pipe to the discharge pipe, pressure generator means responsive to the heat content of fluid adjacent thereto and associated with the fluid conducting means at the elevation of the surface. of water in the discharge pipe, means dependent upon said pressure generator means controlling said valves, said pressure generator means being actuated by the presence of steam in said conduit whereby the water outflow from the heater and the flow of feed water through the heater are controlled according to the variation in water level in said discharge pipe and the tempera' from said outlet, valves controlling the dis-' tribution of flow from said pipe, a conduit leading from said discharge pipe below the normal water levelmaintained therein and leading to a portion of the heater system containing steam, a plurality of branches for 14c. In a heater control system the combinaa tion of a closed heater having feed water heating coils therein, a by-pass for the feed water without the coils, 'a'steam inlet, a Water discharge line from the heater in which water may be maintained between certain operating levels, valve means in the line for maintaining said water level and for controlling the distribution of outflow therefrom, fluid conducting means spanning the water level and communicating with the steam and water spaces of the system, pressure generator means responsive to change in heat content of the fluid in said conducting means, and associated therewith, and means including said pressure generator means dependent upon the variation in water level and the steam pressure in the heater for controlling the distribution and flow through said valve means and for lay-passing the feed water when the water level rises above a given height.

15. In a heater control system the combination of a closed heater having feed water heating coils therein, a steam inlet, a water discharge line from the heater in which water is maintained between certain operating levels, valve means in a plurality of branch lines for maintaining said water level, and for controlling the distribution of the outflow therefrom, fluid conducting means spanning the water level and communicating with the steam and water spaces of the system, and pressure generator means disposed within said operating levels and responsive to change in heat content of the fluid in said conducting means and associated therewith and connected to said valve means, whereby variation in water level and steam pressure in the heater control the distribution of water through said valve means. I

16. The combination of a closed feed water heater, a steam inlet therefor, a water outlet, a plurality of valves controlling the water outflow, one of said valves controlling the flow of water against a substantial static head, a water reservoir disposed below the heater and above said valves and connected therebetween, means responsive to variation in water level of said reservoir for controlling said valves and first opening the valve against said static head whereby all of the water is'directedagainst the static head as long as the pressure in the heater exceeds the-head and the outflow is less than the capacity of said valve.

17. The combination of a closed feed water heater, a steam inlet therefor, an outlet for condensate and leakage, a plurality of valves controlling the. outflow of water, one of said valves controlling the flow against a substantial static head, a water seal maintained below the heater and above said valves, thermo-responsive means disposed at the level-of the water seal forjcontrolling said valves and directing all of the condensate and leakage against the static head as long as the steam pressure in the heater 'exceeds 'the head and the outflow is less than thecapacity of said valve.

18. The combination of a closed heater having feed water heating coils therein, a

the out-flow of condensed heating fluid and feed water leakage from the heaterto different points, means for maintaining a water seal' above said valves but below the heater outlet dependent upon the temperature of heating fluid and means for directing the distribution of water discharge from the heater depending on the-pressure of the heating fluid. 19. The combination of a closed heater having feed water heating coils therein, a steam inlet for the heater, a plurality of discharge pipes for the heater, valves in said pipes-controlling 'thewater outflow from the heater, means for maintaining a water seal abovesaid valves dependentupon the temperature of heating fluid and means for di-' recting the distribution of waterdiseharge from the heater depending on thepressure of the heating fluid and the level of the surface of said water seal. a r

v 20. In combination a closed heater, a passage for feed water extending therethrough, means for leading heating steam to the heater, an outlet for'eondensate and leakage from the heater, means for controlling the outflow therefrom, means for maintaining a water seal over said last named means and meansresponsive to the elevation of and fluid pressure on said water seal for varying the rate of outflow therefrom. I w

21. The combination of a feed water heater wherein steam is used for the heating medium, means for'controlling the outflow of condensate therefrom, and means for maintaininga water seal over said first named means and for distributing the outflow of condensate to different points depending on the pressure of the steam.

i 22. The combination of a feed water heater wherein steam bled from a turbine is used for the heating medium, means for'controlling the outflow of condensate from the heatsteam inlet for the heater, valves controlling over said first named means and for controlling-the distribution of the outflow of con densate to different points dependent upon the load on the turbine.

23. The, combination of a feed water heater y'vher-ein steam is used for the heating me.- dium, means for controlling the outflow of condensate from the heater, means for controlling the distribution of the outflow of condensate to different points dependent upon the steam pressure, and means for controlling the flow of feed Water through the heater.

24.- The combination of a feed water heater wherein steam bled from a turbine is used for the heating medium, means for controlling the outflow of condensate from the heater, means for controlling the distribution of the outflow of condensate to diflerent points dependent upon the rate of flow of feed water to be transformed for the turbiiiie.

25. The method of controlling a feed water heater including introducing steam to the heater, directing the flow of feed water through the heater in response to the presence of steam inthe heater system, and restraining the outflow of steam independently of the flow of feed water.

- 26. The method of controlling a feed water heater including introducing heating fluid to the heater and directing the flow of feed water through the heater but out of contact with the heating fluid in response to the pres ence ofheating fluid inthe heater system, and by-passing the feed water around the heater when cut off.

27. The method of controlling a feed water heater including passing heating fluid into the heater system, directing thefeed water into the heater in response to the heat of the the'supply of heating fluid is quantityof water collected below the heater. 30. In a feed water heater wherein steam comprisesthe heatingimediumflhe combination of means for controlling the flow of feed water through the heater dependent upon the heatcontent of the steam consumed therein, and means, for restricting the outflow of steam independently of the flow of feed water.

31. The method of regulating a feed water I heater including introducing steam intothe heater, sealing the steam outlet by condensate,

discharging condensate accordingto the rate of accumulation thereof, and restricting'the flow of feed' water through the. heater when rate of accumulation of condensate exceeds a predeterminedamount. a

32. The method of regulatinga feed water heater includingintroducingsteam into the heater and collecting the condensate thereof,

controlling the flow of feed Water through the heater according to the rate of deliveryof heat to the feed water, and supplementing the 7 control of flow of feed water according to the rate of accumulation of condensate.

signature. 1 c l r JOSEPH M. BARRETT.

heating fluid therein, sealing the outlet for the heating medium by the condensate and draining the condensate according tothe rate of accumulation thereof while maintaining a substantially constant level of condensate. .28. The method of controlling a feed water heater including introducing steam to the heating part of the system, sealing the outlet from this part of the system by condensate, maintaining the seal as'long as steam is present in the system, directing feed water to the heater when the steam is in the system, diverting the feed water from the heater and breaking the condensate seal when the steam is cut off.

29. A method heating system including introducing steam to the system for the heating of feed water, collecting water of condensation and any other Water below the heater, controlling the discharge of the water so'collected according to the quantity thereof, supplementing thiscontrol by the pressure of steam in the heater and controlling the, passage of feed water through the heater according to the of controlling a feed water In testimonywhereolf, I hereunto aflix my