US3704693A

US3704693A - Combined steam and high temperature water generating system

Info

Publication number: US3704693A
Application number: US106472A
Authority: US
Inventors: Erwin Hansen
Original assignee: INTERN BOILER WORKS CO
Current assignee: INTERN BOILER WORKS CO
Priority date: 1971-01-14
Filing date: 1971-01-14
Publication date: 1972-12-05
Anticipated expiration: 1989-12-05

Abstract

A combined steam-high temperature water generating system includes a heated water generating vessel for delivering both steam and high temperature water to delivery circuits therefor. A portion of the heated water is continuously supplied to one or several forced circulation steam boilers which evaporate part, and only part of the throughput water flow. The return flow from the boiler or boilers to the vessel thus comprises a steam-high temperature water mixture. The system accommodates varying relative consumption demands for steam vis.-a-vis. high temperature water. Also, a chemical balance is maintained between the steam and heated water subsystem components by reason of the continuous water recirculation between the boiler or boilers and vessel. Further, the multifunctional use of the common heated water generating vessel renders the system amenable to ready fabrication.

Description

United States Patent Hansen 1 Dec. 5, 1972 I54] COMBINED STEAM AND HIGH TEMPERATURE WATER GENERATING SYSTEM [72] Inventor: Erwin Hansen, New York, N.Y.

[73] Assignee: The International Boiler Works Co.,

East Stroudsburg, Pa.

[22] Filed: Jan. 14, 1971 [21] App]. No.: 106,472

[52] US. Cl. ..122/406 R, 122/491 [51] Int. Cl ..F22d 7/00 [58] Field of Search ..l22/406 R, 488, 491

[56] References Cited UNITED STATES PATENTS 1 2,743,709 5/1956 Armacost ..l22/488 2,994,308 8/1961 Stabenow ..l22/406 3,020,895 2/1962 Durham ..122/406 X OTHER PUBLICATIONS Owen S. Lieberg, High Temperature Water Systems The Industrial Press, N.Y., 1958, pg. 26 & I65, TH7530L5.

WATER MIXTURE STEAM I BO/LER Primary Examiner-Kenneth W. Sprague AttorneySandoe, Hopgood & Calimafde [5 7 ABSTRACT A combined steam-high temperature water generating system includes a heated water generating vessel for delivering both steam and high temperature water to delivery circuits therefor. A portion of the heated water is continuously supplied to one or several forced circulation steam boilers which evaporate part, and only part of the throughput water flow. The return flow from the boiler or boilers to the vessel thus comprises a steam-high temperature water mixture.

The system accommodates varying relative consumption demands for steam vis.-a-vis. high temperature water. Also, a chemical balance is maintained between the steam and heated water subsystem components by reason of the continuous water recirculation between the boiler or boilers and vessel. Further, the multifunctional use of the common heated water generating vessel renders the system amenable to ready fabrication.

9 Claims, 1 Drawing Figure LOAD HEATfD M4751 COMBINED STEAM AND HIGH TEMPERATURE WATER GENERATING SYSTEM DISCLOSURE OF INVENTION Combined steam-high temperature systems have 0 been employed in applications requiring both energy source, e.g., steam to drive a steam turbine or the like, and heated water as for environmental or industrial process heating, among other uses. Illustrative of such prior art systems, a steam boiler is employed to convert water from a drum thereof into steam, the steam being employed for the double purposes of heating water in a suitable heat exchange vessel to generate the requisite high temperature water (HTW), and also as comprising the steam source directly.

As a principal deleterious characteristic, such prior art combined systems have exhibited a chemical imbalance between the steam boiler and the heated water generator which becomes increasingly more severe with time. More specifically, salts and other solid materials initially contained in the water charge and feedwater remain behind in the system boiler where they may break down chemically under the prolonged influence of high temperature while the contents of the hot water system eventually becomes condensed steam. As a consequence, unless countermeasures are taken, the alkalinity in the boiler increases to the point of causing failures by reason of the high causticity. Correspondingly, the gaseous effluents carried into the heated water system with the steam render the water system markedly and progressively more acidic, and thereby corrosive.

Accordingly, the system boiler (or each of them, if more than one) must be periodically purged to reduce alkalinity and solids concentration, while sophisticated chemical treatment is required for the heated water system.

In addition, prior art systems, essentially formed of separate steam and heated water apparatus subsystems, have employed plural distinct system components. For example, each individual steam boiler is fitted with a boiler drum incorporating water separators and steam dryers to achieve the steam quality desired for the steam subsystem, and with water level control and water feed devices while the HTW subsystem requires heat exchange and expansion and pressurizing apparatus. Hence such systems are of inherent complexity, with attendant expense and maintenance difficulties.

lt is therefore an object of the present invention to provide an improved steam and high temperature water generating system.

More specifically, it is an object of the present invention to provide steam-high temperature water generating apparatus wherein chemical balance is maintained between the steam and HTW subsystems.

It is another object of the present invention to provide an improved steam-HTW generating system which may be fabricated in a relatively simple and inexpensive manner, employing multipurpose apparatus.

The above and other objects of the present invention are realized in a specific, illustrative steam-high temperature water generating system which includes a vessel having therein a heated water storage portion, and a steam containing portion. Water is withdrawn from the vessel and urged, as by pumping action, through a forced circulation steam boiler (or plural boilers in series or in parallel depending upon the desired system capacity). The water throughput rate relative to evaporative boiler capacity is adapted such that the boiler output comprises a pressurized mixture of steam and heated water. Otherwise stated, the heat added to the system in the boiler evaporates only a part of the water withdrawn from the vessel.

The mixture of steam and high temperature water is returned to, and separated within the vessel. The steam collected within the vessel may be withdrawn in whole or in part to satisfy external steam load requirements after passing through a dryer section to achieve the desired steam quality. Also, the steam may be condensed in whole or in part, the heat liberated during steam condensation being supplied to the water present within the vessel (comprising a mixture of the water initially present, and that returned from the HTW and steam delivery systems). The water within the vessel is thereby maintained at a temperature approaching the saturated steam temperature.

A part of the heated water within the vessel is Withdrawn as required to satisfy HTW load requirements. In addition, a portion of the water is forced through the boiler or boilers as above described to continue the operative boiler cycle. Thus, chemical balance is maintained between the steam boiler and the HTW generating vessel and the entire HTW subsystem by reason of the continuous water recirculation. Also. the apparatus may be readily easily fabricated by reason of the several system functions effected by and within the vessel apparatus.

The above and other features and advantages of the present invention are realized in a specific illustrative embodiment thereof, presented in detail hereinbclow in conjunction with the accompanying drawing, which depicts a combined steam-high temperature water generating system in schematic form.

Referring now to the combined steam-HTW system shown in the drawing, there is included a HTW gencrator vessel 10 containing a reservoir of water 22 heated to approach the steam saturated temperature, as more fully discussed hereinbelow, and a steam containing volume 24. A part of the heated water is withdrawn from the vessel 10 via a port 52, and conveyed by a line 44 to a forced circulation steam boiler 56 under urging of a pump 46 disposed intermediate the vessel and boiler. The forced circulation boiler may be of any of the well known constructions thereof, such as that available from the International Boiler Works Company of East Stroudsburg, Pa. The line 44 thus supplies only liquid phase material at a temperature approximating the system steam saturation temperature.

The boiler 56 evaporates a part, and only a part of the input heated water flow supplied thereto. This system functioning may be effected by suitably regulating the heat generated within the boiler, for example, under regulation of commercially available boiler control apparatus to maintain a constant pressure in steam space 24. The output of the boiler 56 in a system conduit line 48 thus comprises a pressurized mixture of saturated steam and heated-high temperature water. A typical operational state for the boiler output may comprise, for example, five parts of heated water to one part steam by weight.

The steam-heated water mixture, supplied under pressure by the line 48 and a vessel input port 26, exits at an appreciable velocity into the interior of the vessel. The relatively heavier heated water is propelled downward, and enters, mixes with and becomes part of the liquid mass 22 present in the vessel. Correspondingly, the incoming steam is either inhibited from entering the water 22 by the surface properties thereof, or escapes from the water mass once having penetrated therein.

Baffle plates

28 and 30 may advantageously be transversely disposed within the vessel 10 to aid in steam-heated water separation.

As system outputs, steam is withdrawn as required from the vessel 10 portion 24 via a steam dryer 62, an exit port 12 and a steam line 32, and delivered to a steam load such as a steam turbine. The steam subsystem may be operated open ended. Alternatively, the steam condensate is applied by a conduit 50 to a water return line 36. Correspondingly, high temperature water is furnished from the heated water mass 22 to'a thermal load 60 via a vessel port 54, a conduit 34 and a water circulation urging pump 38. The circulating water flow returns to the vessel 10 for reheating by way of the return line 36. Make-up feed water to offset system losses is supplied to the line 36 via a source 42 thereof and a valve 40.

The temperature of the heated water 22 is maintained at almost that of the saturated steam by several physical mechanisms. First, the circulating water, maintaining its liquid phase while passing through the boiler 56, exhibits such a temperature as it enters the water mass 22. Also, the relatively cooler return water in conduit 36 flows via a pipe 14 and distribution means element 16 downward over and through a series of water trays 18. The turn water flow is broken up by the distribution means element and the trays to present a large surface area for exposure to and interaction with the steam. The energy liberated by steam which condenses upon engagement with the return water heats this water flow which thus approaches the steam saturation temperature.

Finally, by way of maintaining the above described operative steam-HTW generating cycle, a part of the heated water is recirculated through the boiler 56 via the line 44, such that a steam-heated water mixture is continuously supplied to the vessel 10 input port 26.

The system arrangement, considered hereinabove has thus been shown by the foregoing discussion to continuously supply steam and heated water on a demand basis. Moreover, the system is flexible, and can accommodate varying demands for steam vis.-a-vis. heated water. System demands variations are automatically accommodated by steam generated in the boiler variously finding an end use by being withdrawn per se from the vessel port 12 to satisfy steam demands, or by condensing within the vessel 10 to generate heated water.

, 'Also, it is observed that chemical balance is maintained between the high temperature water and steam subsystem apparatus since system water continuously recirculates through all system components and, in particular, between the steam boiler 56 and the hot water generating vessel l0. Further, the system shown in the drawing and discussed above is subject to ready fabrication in requiring relatively few system components, plural system functions being performed within the vessel 10.

The above described arrangement is merely descriptive of the principles of the present invention. Numerous modifications and adaptations thereof will be readily apparent to those skilled in the art without departing from the spirit and scope of the present invention. For example, the vessel 10 may be formed of plural communicating vessels rather than the single such structure as shown in the drawing. Also various return flows, or parts thereof, may be directed through the boiler 56. Furthermore, several boilers may supply simultaneously to the vessel 10 through individual inlet port 26.

What is claimed is:

1. in combination in a combined steam and high temperature water generating system, vessel means for including therein high temperature water and steam, steam boiler means, means for supplying heated water from said vessel means to said boiler means, said boiler means including means for evaporating only a part of the input heated water flow supplied thereto and for supplying as a boiler output flow a mixture of steam and high temperature water, conduit means for supplying said boiler output steam and high temperature water mixture to said vessel means, steam delivery means communicating with said vessel means for supplying steam therefrom, and high temperature water delivery means communicating with said vessel means for supplying water therefrom.

2. A combination as in claim 1 wherein said boiler means is of the forced circulation type, and further comprising pump means for urging water through said boiler means. 4

3. A combination as in claim I wherein said vessel means includes means for separating the steam-high temperature water mixture into its two constituents, high temperature water storage means, and steam storage means.

4. A combination as in claim 1, wherein said steam boiler means includes plural steam boilers.

S. A combination as in claim 3 further comprising water reaction surface means disposed within said vessel steam storage means, and means for supplying return water supplied by said water delivery means to said reaction surface means.

6. A combination as in claim 3 further comprising steam drying means disposed within said vessel steam storage means.

7. A combination as in claim 1 further comprising means for supplying make-up feedwater to said vessel means.

8. In combination in a combined steam and high temperature water generating system; vessel means including a steam-high temperature water input port, means for separating said steam and high temperature water, steam storage means, and water storage means, said vessel means thereby effecting high temperature water generation, and high temperature water subsystem expansion and pressurizing functions; steam boiler means including means for withdrawing high temperature water from said vessel means and for supplying said steam-high temperature water mixture to said vessel means.

9. A combination as in claim 8 further comprising steam delivery means communicating with said vessel means, and high temperature water delivery means communicating with said vessel means.

Claims

2. A combination as in claim 1 wherein said boiler means is of the forced circulation type, and further comprising pump means for urging water through said boiler means.

3. A combination as in claim 1 wherein said vessel means includes means for separating the steam-high temperature water mixture into its two constituents, high temperature water storage means, and steam storage means.

5. A combination as in claim 3 further comprising water reaction surface means disposed within said vessel steam storage means, and means for supplying return water supplied by said water delivery means to said reaction surface means.