US1975519A

US1975519A - Steam plant

Info

Publication number: US1975519A
Application number: US565009A
Authority: US
Inventors: Dagobert W Rudorff
Original assignee: Superheater Co Ltd
Current assignee: Superheater Co Ltd; Superheater Co
Priority date: 1931-09-25
Filing date: 1931-09-25
Publication date: 1934-10-02
Anticipated expiration: 1951-10-02

Description

Oct. 2, 1934. D, W RUDORFF 1,975,519

STEAM PLANT BY /TZQM ATTORN EY OC- 2, 1934. D, w. RUDORFF STEAM PLANT Filed sept. 25, 1951 V2 sheets-sheenu www dNNV

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ATTORNEY Patented Oct. 2, 19.34

UNITED STATES PATENT OFFICE y toy The Superheater Company,

New York,

Application September 25, 1931, Serial No. 565,009 g 4 Claims.

The present invention relates to steam generators and aims to provide an arrangement having high eiiiciency and flexibility of operation.

In operating steam generating plants it is often desired to regulate closely the temperature of some stream of fluid, such as steam or water, in the plant. Owing to the variations in steam output and in the heat generated in the furnace from time to time, difficulty has been experienced in maintaining the desired regulation of the temperature of the selected fluid or uids.

It is an object of myinvention to provide an arrangement whereby this diiliculty may be overcome.

In accordance with my invention, a portion of the heat generated in the boiler furnace is abed out in the appended claims.

sorbed in steam generating tubes in the usual manner, but another proportion of such heatis absorbed by a circulating fluid, preferably one` way of example from a number of possible embodiments thereof and such a description will now be given in connection with the accompanying drawings in which Fig. l is a sectional elevation, somewhat diagrammatic in character, of a steam generating system in accordance with my invention.

Fig. 2 is a sectional elevation, somewhat diagrammatic in character, of an arrangement in accordance with my invention, but including features in addition to those shown in Fig. 1.

'I'he steam generating system illustrated in Fig. 1 includes a boiler l0 having a furnace 12, generating tubes 14 and 16 and a superheater 18, all of conventional type. 20 is a vertical ue connected to receive combustion gases from the boiler 10 and assumed to have a downward flow of gases therein. In flue 20, I have shown a plurality of

groups

22 and 22a of heat absorbing tubes connected for ow of fluid through the two groups in series and forming a portion of a circulating system 24 for absorbing heat from the gases flowing through ue 20 and transferring it to vfluids having a utility in connection with the boiler 10,. Preferably the fluid in such circuit or system is one having a high boiling point such as diphen'yl, mercury, or diphenyl-oxide. However, I do not limit Amyself to this. In the arrangement of Fig. 1, the circulating fluid is forced around a circuit by a pump 26.l Connected'to the outlet of pump 26 by a pipe 28 is a .heat delivering coil 30 forming part of a water preheating apparatus 32 connected to receive water from a source not shown by means of pipe 34 and connected to pipe 36 to deliver to the feed pump 38 for the boiler 10. The coil 30 has avalved by-pass 40 therearound so that, when desired, some of the heat transferring liquid in system 24 can be shunted around coil 30 and the liquid delivered to the pipe 42 on the outlet side of such coil. at a higher temperature than would otherwise be the' case. The reason for such by-pass will appear presently. 'I'he pipe 42 is arranged to deliver through a storage tank 43 for the circulating liquid into the lower one of the heat absorbing coils 22. From the lower coil 22 the circulating liquid passes to the, upper-coil 22a through a junction box 44 at which point a branch delivery pipe 46 is taken olf to a heat absorbing apparatus. At the upper or delivery end of the upper coil 22a a second deliveryl pipe 48 is taken oil. Pipe 48 connects with a heat delivering coil 50 shown as the heating element of an economizer 52 which receives water from said boiler feed pump 38. The pipe 46 connects with a heat delivering coil 54 which is shown as the heating element of an air heater 56 for heating air for the furnace 12. 'Ihe outlet pipes 58 and 60 of the

coils

50 and 54 respectively connect at point 62 and are connected to the circulating pump 26 by a pipe 64. Valves are provided at 66 and 68 in pipes 46 and 58 lrespectively so that the relative amount of heating uid flowing through

coils

50 and 54 respectively may be varied to the extent necessary to regulate the temperatures of the fluid delivered by heater 52 as desired. In the arrangement shown, the heater 52 being an economizer, its advantageous use is to maintain the temperature of the water delivered therefrom to the boiler as nearly as possible at the given temperature equal to the boiling point of the water in boiler 10. The economizer 52 therefore will preferably be operated as a constant temperature apparatus and the air heater 56 `as a variable temperature device. However, the temperature of the uid delivered by the

heating coils

22 and 22a not necessarily being in proportion to the quantity of water passing through economizer 52, it is desirable to have means for regulating the amount of heat delivered to ooI economizer 52 other than the valves 66 and 68. The by-pass 40 in connection with the water heater 32 previously mentioned affords such means. By opening the valve in by-pass 40 more or less, the circulating fluid in system 24 is delivered tothe coil 22 at somewhat higher temperature than' would otherwise be the case and the temperature available for use in the heating coil 50 is therefore increased.

In the arrangement shown in Fig. 2, I have incorporated three

heating coils

22, 22a, and 22h. The boiler 10a. shown in Fig. 2 is of somewhat different type from that shown in Fig. 1, but this fact does not affect the operation of the system as such. In the system 24a illustrated in Fig. 2, however, as distinguishing from the system of Fig. l, I utilize the liquid circulating in the heat transferring system 24a to supply a portion of the heat required for heating the steam delivered by the superheater 18a. The feature of heating the outgoing steam partly by the circulating fluid makes it preferable that an additional heat absorbing coil 22h be included in system 24a. However, I do not limit myself to this. The heat transferring system 24a shown in Fig. 2 includes a pump 26 delivering through suitable connections to the lower heat absorbing coil 22, the three such coils being connected in pairs at junction points 44 and 44a. 'I'he two

lower coils

22 and 22a supply an economizer 52 and an air heater 56 in substantially the same manner as previously described in connection with the economizer and air heaterdn Fig. l. The upper heat absorbing coil 22D, however, delivers to a discharge pipe which connects to a heat delivering coil 72 in heat exchanger 74 for partially superheating the steam from boiler 10a. The steam to be heated in device 74 is taken from the steam drum 76 of boiler 10a through pipe 78 to the heat exchanger '74 and delivered from exchanger 74 through pipe 80 to the superheater 18a which is arranged to receive heat directly from the gases from the furnace 12a of boiler 10a. Preferably, a steam reheater 82 is included in the system illustrated in Fig. 2. As shown, heating fluid for the reheater 82 is taken from the pipe '70 by pipe 84 which branches from pipe 70 at point 86 and connects to the heat delivering coil 88 in the reheater 82. In Fig. 2, the heat delivering coils of

devices

52, 56, '74 and 82 are co-nnected by suitable outlet pipes into the common main 90 which connects with the heat delivering coil 30a in the water heater 32a. From coil 30a, circulating liquid in system 24a is delivered to the storage tank 43a from which it may return to the pump 26 through the pipe 92. It will be seen that the piping connections in Fig. 2 are slightly different from those in Fig. l but the operation of the system is not altered by this fact. It will be seen also that no by-pass is shown in Fig. 2 around the heating coil of the water. heater 32a since it is considered that the system shown in Fig. 2 has sufcient flexibility so that such by-passing is not necessary. It will be understood, however, that in Fig. 2 it is desired to maintain the temperature of the steam vat the outlet of the superheater 18a. substantially constant and that the valves in the lines 84, 48 and 46 are manipulated in use so that the steam delivered from heat exchanger 74 will have the proper temperatures to compensate for the varying rates of heat absorption in the superheater 18a. In respects not mentioned, the system 24a of Fig. 2 is the same as the system 24 of Fig. 1.

A feature of the systems shown in both Figs. l and 2 is that water heaters 32 and 32a have considerable storage capacity so that heat contained in the circulating liquid in systems 24 and 24a, but not absorbed in

devices

52, 56, 74 and 82, or by the amount of feed water flowing to devices 32 or 32a to satisfy the requirements of the boilers at the time, may be absorbed by additional feed water admitted to heaters 32 or 32a by speeding the feed pumps 38 somewhat more than necessary to supply the water going to the boilers at the time. The flnal temperature of the circulating fluid returned to coils 22 is thereby kept low and the overall efliciency kept high.

When the heat transferring liquid circulated in systems 24 and/or 24a has a relatively high boiling point compared to water, the pressure in such system is relatively low compared to the .boiler pressure provided the circulating liquid is permitted to vaporize in the sections 22 and the like and is condensed in the

heat delivering coils

52, 56, 74 and 82. I do not limit myself to this, however, as it is often desirable to prevent vaporization in systems such as 24 and 24a to thereby increase the temperature of the circulating liquid and the maximum possible temperature delivered thereby. When vaporization of the circulating liquid is prevented, it is especially desirable to use a high boiling point circulating liquid to keep down the pressure within the system such as 24 or 24a and thereby to keep down the material and cost of the system.

It will be seen that the system in accordance with my invention operates at a high over-all heat eiciency since the heat transferring liquid in the systems 24 and 24a or the like pass through the heating coils 22, 22a and 22h in the opposite direction from the flow of furnace gases in the iiues 20 in which the heat absorbing coils are placed, and that the heat transferring liquid can be introduced into the heat absorbing coil farthest from the boiler furnace at a comparatively low temperature, thus minimizing the heat carried away in the stack gases. In each of Figs. l. and 2, l' have illustrated the

heat delivering coils

50 and 54 and the like as connected in parallel. However, I do not limit myself to this, since somewhat analogous results may be obtained by connecting the heat delivering coils in the superheater 74, the economizer 52 and air heater 56 in series and providing Valved bypasses around such coils. It will be seen also that a system in accordance with my invention is very flexible and can be operated very conveniently to maintain the temperature of fluid delivered by a given device very close to that predetermined for it.

What I claim is:

1. The combination of a boiler, a furnace therefor, a circuit containing a heat transferring fluid and having a portion arranged to absorb heat developed in said furnace, said heat absorbing portion being so arranged with respect to combustion gases in said furnace as to produce in said heat absorbing portion zones containing fluid of different temperature, and a plurality of heat delivering portions, connections whereby each of said heat delivering portions receives fluid of different temperatures from said heat absorbing portion, and means whereby different fluids having normallydierent initial temperatures absorb heat from different ones of said heat delivering portions, said connections so arranged that the cooler heating fluid flows to the lill@ heat delivering portion acting to heat the cooler one of said heat absorbing uids.

2. The combination of a boiler, a furnace therefor, said boiler having a bank of generating tubes receiving gases from said furnace. a ilue arranged to receive said furnace gases which have passed said bank, a circuit containing a heat transferring uid and having a portion arranged in said flue to absorb heat from gases therein and having a plurality of heat delivering portions, Ian economizervhaving a heating coil arranged in said circuit to be heated bysaid iuid, an air heateralso having a heating coil arranged in said circuit to be heated by -said uid, and a steam superheating means having a heating coil arranged in said circuit to receive said uid.

3. The combination of a boiler, a furnace therefor, a circuit containing a heat transferring fluid and having a portion arranged to absorb heat from the gases from said furnace at a point following the boiler and a plurality of heat delivering portions, said heat absorbing .portion being arranged for iiow of duid therein in a direction counter to the i'iow of the gases, means whereby different fluids having normally different initial temperatures absorb heat from dinerent ones of said heat delivering portions, a connection leading to one of said heat delivering portions from the hotter end of said absorbing portion and a connection leading to another of said heat delivering portions from a point of intermediate temperature of said heat absorbing portion,

'and a means whereby the output of one of said bustion. Y

DAGOBERT W. RUDORFF.