US1737075A - Plant for economically using caloric energy - Google Patents

Description

Nov. 26, 192

o. F. K. BRANDT 1,737,075 PLANT FOR ECONOMICALLY USING CALORIC ENERGY 5 Sheets-Sheet nvmwroe orro FB/FZ M7184 Bari/V0 NOV. 26, 1929. o BRANDT 1,737,075

PLANT FOR ECONOMICALLY USING CALORIC ENERGY Filed Jul '7, 1927 s Sheets-Sheet 2 (IVI/ENTOI? 07'7'0 FIE/Z12 107/21. HEW/V07;

9Q yra/MK Patented Nov. 26, 1929 NITED- STATES OTTO FRITZ KARL BRANDT, OF HAMBURG, GERMANY PLANE. FOR ECONOMICALLY USING CALORIC ENERGY Application filed July 7, 1927, Serial No.

The invention relates to the utilization of high pressure hot water'by means of a feed line or main connected with the same boiler, and a number of appliances for using the calorific energy of the high pressure hot water, theseappliances being interposed between the feed and the return line. The calorific energy of the high pressure hot water may be used for many different purposes, es-

]0 pecially heating, generating steam and gencrating kinetic energy. In some cases the nature of what may be called the consuming apparatus renders it undesirable to bringlthe hot water into contact therewith at the igh pressure and high temperature which it has in the feed line, and according to the invention provision is made to have at the intake-end of each consuming apparatus water or steam at the pressure and temperature appropriate to such apparatus, and to prevent any substantial loss of energy arising from the change of pressure and temperature between the feed line and the intake of the consuming ap aratus. v

nother object of the invention is to return the water discharged at an intermediate pressure from the consuming apparatus to the high pressure boiler without substantial loss ofener I Another bject of the invention is to attain the above mentioned purposes in such a way that the mains, which may be of very considerable length, contain always only hot or' warm water, that is to say that they do not-contain steam, as notwithstanding the higher velocity attainable with steam the very much greater volume of steam would necessitate the use of much larger and more expensive pipes with moreexpensive insula- 40 tion for retaining heat. Y

All these advantages are attained according to the invention in an installation wherein between the common feed line coming from the high pressure boiler and the common re- 4 turn li'ne leading back to the high pressure 203,954, and in Germany March 23, 1928.

boiler various appliances for consuming calorific energy are interposed, as for example (1) Apparatus within whiohthe high ressure hot water from the feed line is ma e to expand to an intermediate pressure in a chamber, and the steam generated during the expansion is separated from the remaining water whereupon the-steam and the water, both atintermediate pressures, are used sepa rately;

(2) 7 Apparatus having, in addition to an ex pansion chamber for reducing high pressure water to intermediate pressure steam and intermediate pressure water, means whereby highpressure hot water is caused to heat the intermediate pressure water and vaporize the same.

\Vith the above mentioned objects in view, and to the end of realizing other advantages hereinafter appearin this invention consists in certain features 0 construction, combinations of parts and arrangements of apparatus, devices and pipe lines hereinafter to be described and pointed out in the appended claims, and illustrated in the. accompanying drawings. a v

Figure 1' is a diagram illustrating a. system for the employment of. high pressure, hot water for purposes of heating and steam generation, with apparatus for utilizing the steam, and regulating means for maintaining a water level in the steam enerator.

Figure 2 is a modification of Figure 1, the steam generator and regulatin means of Figure l'bein replaced by a jaciieted steam generator and regulating means therefor to cause the generator to contain steam only.

Figure 3 is a sectional view of the injector .numn ormixing'device shown in Figure 2 for returning the low temperature water from a set of heat utilizing apparatus to the hot water generator.

Figure 4 discloses a hot water system some what similar to those shown in Figures 1- and 2, but having regulating and throttling means 99 for permitting low pressure apparatus to be operated from a high pressure line.

Fig. 5 is a diagrammatical view of a hot water system as applied to an electric or other train.

Referring first to Figure 1; the high pressure hot water generator 1 may be of any suitable type, for instance, it may be a multitubular or fire tube boiler completely filled with water and provided with a. furnace 2. It is to be borne in mind that the generator 1 does not contain a steam space. -The hot water is taken out of the water space of the enerator or boiler'l at any suitable point,

'for instance at 3. A safety valve 4 prevents a predetermined pressure from being exceeded but this valve is only intended to act inexceptional circumstances tending to produce excessive pressure. The feed line 5 comprises an expansion vessel 6, as is usual and necessary in hot water pipe lines. In the return pipe line 7. there is a feed pump 8. The spent water delivered by the pump enters the water space of the boiler 1 at 9.

Any appropriate apparatus may be heated in well known manner directly from the high pressure feed line 5. For instance the heatmg jacket 11 of the a paratus 10 is traversed by water as indicate by arrows, and heated by the wafer, whereupon the hlgh pressure water, having given oflt calorific energy and therefore lowered its temperature, but preserved its pressure, passes into the return pi e line 7.

etween the ends of the feed line 5 and the return line 7 a small valve 12 is arranged, by means of which provision is made for the direct passage of hot water through both main lines in case all the consuming appliances are put out of action at the same time. Other appliances are fed indirectly from the feed line 5, for instance a steaming vessel or receptacle 13, wherein some substance is to be treated with steam which must not exceed a certain pressure or temperature, as is frequently the case in the chemical industry. An expansion or pressure reducin chamber 14 is arranged in front of the sai steaming vessel 13, and is connected with the same by means of a pipe 15 for the steam and a return pipe 16 for the. water of condensation. A hot water pipe 17 leads from the feed line 5 to the expansion chamber 14.

and terminates in a distributing tube-18 arranged within the steam space of the vessel (that is to say above the water level 19), this tube being provided with numerous openings or outlet nozzles. A pipe 20 comin from the chamber 14 close to, but below, the water level 19 connects the expansion chamber 14 with a pump 21, whose delivery pipe leads to the return line 7. Devices for throttling, regulating and shutting off, such as valves 23, 24, are provided in'thepipes 17 and 20, the operating arms23, 24 thereof being connected with each other by means of a link a serving as a common handle for the two valves.

The method of operation of the arrangement just described is as follows.

The temperature of. the hot water in the feed-line may, for example be 204 C. or 400 Fahrenheit, so that the pressure in the feed line is about 12 atmospheres or 171 pounds per square inch. Within the steammg vessel 13 steam at 157 C. or 315 Fahrenheit, at 3 atmospheres or 43 pounds per square inch ma be required. The capacity of the cham er orexpander 14 is appropriate to the requirements of the steaming vessel 13. steaming process the'valve 23 (with the valve 24) is opened, so that hot water of high temperature passes through the pipe into the ex pander l4, and is distributed by the openlngs or nozzles of the tube 18. At the momentof issuing from the tube a portion of the water expands to form steam. The heat becoming latent by the evaporation is taken from the water whicha'emains in the liquid state, whereby the temperature thereof is lowered in proportion to the pressure drop.

The quantity of steam necessary for the steaming process is either definitely known or may be estimated aplproximately. Accordin to the calorific t eory it is possible to ca culate how much steam is formed, in the iven instance, out of water at 400 degrees ahrenheit and 171 pounds pressure in the case of expansion to 315 degrees F. and 43 pounds pressure. With the given data it is calculated,v or ascertained empirically, how much hot water must be deliveredinto the expander for tit of low pressure steam.

en a state of balance has been attained the Water level in the expander is kept: at 'the level 19 to compensate for small pressure providing the necessary quan- V At the beginning of the variations which are caused within the expander by varying steam consumption within the steaming vessel. For this purpose the pipe terminal at 24 is disposed on the expander at the level 19, which is to be the water level. The capacity of the pump 21 is also-calculated according to the calorific theory.

Calculations have been made for various 7 pressures and expansion rates, and it is found that for enerating a useful quantity of steam at t e rate of 1:. pounds per hour a quantity of heating water ranging approximately from 8n to 20a is necessary.

Should the steam consumption in the steaming vessel 13 vary at different times,

evaporation and by the delivery of calorificenergy within the steaming vessel 13, and at the pressure existing in the return line. The water passes through the pipe 22 into the return line 7, where it is mixed with the spentwater coming from other consuming appa-T ratus. Consequently the whole of the water returns at a low average temperature to the heating boiler l, to be heatedto the required high temperature for' return tothefeed line- Sometimes it is not necessaryito separate the chamber wherein the steam is generated from the chamber wherein it is used. For instance the vertical tubes of anv evaporator 25 such as is commonly used in-the chemi-, cal industry, are exposed'outside tosteam, whereby} liquor within the tubes is heated or boiled. -Inthis case the heating chamber ,of the evaporator serves also as an expansion chamber. The high. pressure hot water, ad: mitted through the-pipe 26 passes from the distributing tube 28-into the heating cham- V CI ber 25', from which the water remaining in the liquid state after the expansiomtogether with the, steam developed during the expansion and then condensed 'outsideof the heating'tubes=,-is discharged throuthe pipe 27. Devices 29 and 30 serving for closing, regus lating, and throttling, are provided-in the pipes 26,-and 27.. The operating arms 29, 30 oftheosaid devices are connected by means of alink a as in the case of the valvesl3, 14.

In the case of the evaporator 25*? no separate return pipe forthe water ofcondensation is necessary. The great loss of heat and other disadvantages connected with the return p1pe otherwise usual in steam heating systems are thus avoided. For this and other IGiiIISOHS the evaporator 'works very economica y,

safety valve 31 prevents the proper pressure within the heating chamber 25" from being exceeded. 1

Ditierent temperatures are generally used for diiierent processes in chemical manufaetures, and some ofthe appliances are designed for low pressures. The heating plant according to the invention is adapted to these requirements in a very perfect manner. v For each process of" manufacture the advantage of the comparatively cheap hot water system is available, without expensive alterations of the plant. For example when the temperature of 315 degrees Fahrenheit, corresponding to a pressure of 43 pounds per square inch, is necessary for the heating chamber 25 of the evaporator 25*, then the water flowing into the pipe 27 has approxi mately the same pressure and temperature. The sensible heat of the spent water is used preferably for heating other apparatus, such as a kettle 32 and heating plate 32". For this purpose the pipe 27 is branched, the branches 27 27* leading respectively to the apparatus 32 and 32 to be heated. The pipes 34, 34 into which these appliances discharge are joined to the pipe 34 of the pump 33, whose delivery pipe 35 is joined to the main return line 7.

There may be several heating steps in series ifthe available temperature difference is sufficient. Furthermore several appliances such as the steaming vessel 13 may be suppliedwith steam from a single expander 14, or several expanders such asthe apparatus 14 and 25 may fbe connected with a single pump such'as 21 or Consequently M cordingtothe invention it is possible to 'pro'} vide a large number of appliances with steam or hot water of difit'eren't temperatures and pressures from a single main feedline, with 1mportant ;improvement over the know-n steam heating. installations requiring sep- 9,5 a single main return line, and this isa very arate-supply pipes for steam of different p es 3 sures, and separate return pipes for the water of condensation. A large saving of costand simplification of working are attained there,

The heating plant may be employed, apart from the chemical industry, for house heating from a distance, andalso for heating railway trains,.in which case, it istrue, the'usual singlestea-m, pipe would be replaced by a feed line and a return line for hotwater, but two hot water pipes are not as expensive asa single steam pipe. Such a hot water heating system for railway trainswould have special advantages if adopted generally for electrical railways, in which case a small high-pressure boiler B (Fig. 5) for producing hot water .would be placedin the middle part of the train, so that the feed and return pipes F and R for the two halves of the train (consisting of a locomotive L and a plurality of cars C) would be relatively short, and the spent water passes directly from the feed pipe into the return pipe, without first going to one end of the train.----

It frequently happens in the chemical industry that the steam used for steaming, and then condensed, receives from the substances treated some detrimental admixture, such as an acid, which would destroy the pipes, and the boiler. In such cases the water of condensation is not retained in the system, but is discharged for .which purpose no pump is required. owever, with the system shown in Figure 1 the return pump would not be dis-.

' jacket of the expander contains water of mo erate temperature but high pressure, so that no pressure increase by a return pum is required, and the used water is returne to the boiler with little expenditure of energy. This rocedure, which is extremely economical, is illustrated in Fi ure 2.

In the system s own in Fi re 2 the water condensed within the steaming vessel 13 is charged with detrimental substances such as acids, and is let out in the usual manner through a pi 16 and a steamseparator 37. It is not retained in circulation- The expander 14 islifrovided with an outer wall or jacket 14. ighressure hot water coming from the main eed line 5 is led through a pipe 17 into the space 14" between the two walls, and after having given ofi a rtion of its calorific ener through the mar wall to the interior o the expansion chamber, it is led through a ipe 22 into the main return line 7. ccorgingly there is high-pressure also in the Pipe 22.

At the end of the tube 18 within the receptacle 14 there is a sprayer nozzle 18. Part of the water sprayed out of this nozzle is, by expansion, immediately transformed into steam,

' and the remaining water strikes the hot inner surface of the container 14 in the form of minute drops, which are'evaporated immediately, the calories necessary for the evaporation being taken from hot water circulating within the jacket. If for instance the hot water entering the jacket has a temperature of approximately 400 de rees Fahrenheit, and steam at a pressure 0 43 pounds per square inch (corresponding to a temperature of 315 degrees Fahrenheit) is required within the vessel 13, then the temperature drop through the inner wall of the expander 14 is s'uflicient to evaporate instantaneously the spray thrown against the inner wall surface.

The whole of the steam developed within the container 14 is led into the steaming vessel 13. Where steam of a definite temperature and pressure is required for the steaming procedure, and neither must be exceeded, a regulating device 36 of well known construction for controlling the temperature and pressure This regulator operates a throttling device 23* in the supply ,pipe'17 in such away that at all times only so much water flows into the expander 14 as is necessary for generating the required quantity of steam at the required pressure. I

Of course the pressure for which the safety valve is set is above the pressure normally maintained by the regulator 36.

As also seen in Figure 2, an eva orator 25' and several heaters 32, 32 are isposed in series, and the quantity of the water which has given off the greater portion of its heat, and is to be returned, is relatively small so that the employment of the single pump 33 shown in Figure 1 would be uneconomical. The case is complicated by the fact that in certain circumstances several such small pumps with different pressures at the suction side would be necessary at different stations, increasing the cost of the plant.

A device for returnin small uantities of water partly or complete y expan ed is shown at 39 in Figure 2, and in greater detail in Figure 3. A housing 39 with a central nozzle 40 similar to an injector is provided in the main return line 7 at the oint where the lowpressure water enters. y means of the nozzle 40 the high-pressure water returning in the line 7 is brought to a lower pressure, and thereby acquires a higher velocity. The lowpressure water to be added enters laterally through a branch 41 and is drawn by the ac celerated water in the well known manner, as in an injector. Accordingly the injector 39 shown in Figure 2 has the same function as the return pump 33 shown in Figure 1.

The principle of using high-pressure hot water in such a manner that itundergoes only relatively small reduction of pressure drop leads also to a more eflicient use of existing steam boilers. Many steam-boilers designed for a high pressure are in fact used ata lower pressure, and consequentl with poor efiiciency, the reason being t at the apparatus to be fed with the steam from these boilers are suitable only for low pressure. The ar rangement shown in Figure 4 enables highpressure hot water to be used instead of steam with full benefit of the maximum pressure for' which the boiler is rated, the proper conditions for apparatus requiring lower pressure being nevertheless obtained. For instance it is possible to work a boiler rated for a pressure of 171 pounds per square inch, correspondin to a saturation temperature of 400 degrees Fahrenheit, and to heat therewith apparatus adapted for. a pressure of not more than 43 pounds, corresponding to a temperature of 315 degrees F.

.In the system shown in Figure 4 the main feed line 5 is run at high pressure, and the main return line 7 at low or intermediate.

pressure. It is assumed that the apparatus 86 is preferably connected with the pipe 15. 42. 43, 44, 45 is to be heated only with throttling members 48 and 49, and the regu-' a pressure substantially lower than 'the'pres-' sure in the main feed line 5 and the boiler. A first throttling member 48 is arranged 1n the pipe in front of the inlet, and a second throttling member 49 is placed behind the outlet of each apparatus. The throttling members are adjusted by hand in the case of the apparatus 42, and by automatic regulators 50 in the case of the apparatus 43, 44 and 45. Each regulator is itself controlled by the pressure prevailing within the respective apparatus 43, 44 or 45. In each vessel the heating chamber is filled completely with water. The high pressure water reaching the throttling member 48' is prevented from expanding and evolving steam. The throttlmg at the inlet has the effect that only'a predetermlned small quantity of high-pressure water, depending on the regulator, enters the apparatus, and is mixed therein with the cooler water already within the'heating chamber, and givingoff its surplus heat to this cooler water, whereby its 'ressure is lowered to the pressure desired or the apparatus. The

throttling members 49 at the outlet have the effect of, adapting the outlet-section in 'each case to the inlet section regulated by thethrottling member 48 in such a way that no expansion and steam development within the heating chamber or the connecting pipes will take place, Between the main return line 7" and the boiler 1 a return pump 8 is 1nterposed for the purpose of bringing the water in the main return line 7 a to the pressure within the boiler 1. The combination of the lator 50, prevents the production of steam, under the suctional effect of the'pump 8 in the heating chamber of any of the appliances.

Provided that the pressure in the main return line 7 is lower than in the main feed line 5, which will be attained by the arrangement and combination specified, the injector device 39, shown in Figure 2 as being placed at the outlet-pipe of consuming apparatus, lea ding to the main return line, may be omitted. For in this case the whole return pipe system contains only low-pressure water. Accordingly the main pump 8 has the function of bringing the whole of the spent water back to the pressure of the boiler 1. For this purpose a first throttling member 8 is pro vided in front of the pump, and a second throttling member 8 is provided behind the pump. The members 8 and 8 are either operated by hand or by an automatic regulator 51 controlled by the pressure in the return line 7. The regulation is efi'ected in such a way that the pressure in the main return line 7 a in front of the pump 8 is slightly lower than the pressure in the outlet pipes of each consuming apparatus.

What I claim is:

1. In an installation for utilizing the calorific energy of highpressure hot water,

the combination with a high pressure hot water generator of a hot water main leading from said generator, a main return hne, an

intermediate pressure container connected with the hot water main, means for regulating the quantity of hot Water which flashes into steam in said container, steam utiliz-' ing apparatus connected to the steam space of said container, a drain pipe from said between the steam generator and main re- 1 turn line, and means coupling the two throttling members together in a predetermined manner.

3. A method of heat generation and trans fer, comprising the steps of converting water of relatively low temperature into water of high temperature and pressure, conducting it to a container and there permitting a portion of it to flash into steam of intermediate pressure, withdrawing theisteam so formed and condensing it during a heating process, passing the condensate back into the container, and then transferring the intermediate pressure water from the container back to its original. source of conversion.

4. In an installation for utilizing the calorific energy of high pressure hot water,

the combination with a high pressure hot water generator of a main hot water line leading from said enerator, a main return line, and a branc across the two lines, steam generating apparatus in said branch, and a pump in said branch between said T team generating apparatus and the return 5. In an installation for utilizing the calorific energy of high pressure hot water, the combinationv with a high pressure hot water from said generator, a main return line, a steam generator connected with the main line, means interposed in the connection for regulating the amount of hot water supplied to the steam generator, a connection between the steam generator and main return line, a pump in the main return line, and a pump in said last-named connection.

6. In-an installation for utilizing the calorific energy of high pressure hot water, the combination with a high pressure hot water generator, of a main hotwater line leading from said generator, a mainreturn line, a branch across said lines, steam generating apparatus in said branch, regulating members in said branch on each side of said apgenerator of a main hot water line leading 7. In an ap aratus for utilizing the calorific energy f high pressure hot water, the combination with a high pressure hot water generator, of a main hot water line leading 5 from said generator, a main return line, a branch across said lines, steam generating apparatus in said branch, regulating members in said branch on each side of said apparatus, means coupling the regulating members toi gether in a predetermined relation, a pump in said main return line, and a pump in said branch between said apparatus and the main return line.

In testimony whereof I have signed this specification.

- OTTO FRITZ KARL BRANDT.

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