US1289182A - Steam-boiler economizer plant. - Google Patents

Description

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" STEAMBOILER ECONOMiZER PLANT APPLICATION FILED DEC-8.19M.

Patented Dec. 31, 1918.

3 5HEETS-S HEET l.

I l/VVE/VTOR WITNESSES:

IIIL I I I I III I I I I I I I III zlllllg ZIIIIIQWIIIIU/IIII I -i h :I I I I l I I I I I I I I I 1 I l I I I I I I APPLICATION FILED DEC. 8. I914.

Patented Dec. 31, 1918.

3 SHEETS-SHEET 2.

WI T/VESSES:

144/964 TTOR/VE D. S. JACOBUS.

STEAM BAOILER ECONOMIZER PLANT.

APPLl CATl0N FILED nacfe. I914.

Patent-ed Dec. 51, 1918.

3 SHEETS-SHEET 3.

' WITNESSES: Q -//w//vr0/-2 M14 TTORIVEJ Df Us; .iLi-LQLJU ore-tac DAVID S. JACOBUS,OF JERSEY CITY, NEW JERSEY, ASSIGNOB TO THE RAB COCK & WILOOX COMPANY, OF BAYONNE, NEW JERSEY, A CORPORATION OF NEW JERSEY.

STEAM-BOILER ECONOMIZER PLANT.

matinee.

Specification of Letters Patent.

Patented Deco til, 11918.

Application filed December 8, 191%. Serial No. 876,011.

State of New Jersey, haveinvented certain new and useful Improvements in Steam- Boiler Economizer Plants, of which the following s a specification.

In my application Serial No..78i,315, filed August 12, 1915 liability of corros'on of an economizer is prevented or mini ized by first heating the feed water, then withdrawing it from the heating apparatus andpermitting the greater part of the air or gases to escape before this water is fed to the economizer or a part thereof. In that application the feed water is heated by passing it through the low pressure stage of a plural stage economizer and then deliveredto a tank in which the greater part of the air or gases is permitted to escape. From this tank the water is forced through the high pressure stage of the economizer against the boiler pressure, the high pressure stage being subjected to th hottest gases. To meet.

tion of the air and gases from the water before it is delivered to the high pressure stage. My inventlon also enables me to use cast iron for the low pressure stage of the economizer, and thereby obtain the advantage of the less liability of cast iron, over wrought iron or steel, to corrosion.

The present invention relates to a special arrangement of an economizer, and to a special form and arrangement of a two stage economizer. The entire economizcr, or at least th high pressure part of a two stage economizer, is arranged for a down pass of the gases over the economizer tubes and an upward pass of the feed water through the tubes. This prevents laning of the gases as well as of the feed water. This down pass of the gases also allows long economizer to be used with a single straight pass for thesection and partly in elevation, of a plant embodying the invention; Fig. 2 a rear view of the high pressure stage of the economizer of F ig. 1; Fig. 3 a detail showing the vent connection between the boxes of Fig. 2; Fig. 4 a diagrammatic view to illustrate the use of a common air releasing tank for two or more boilers; and Fig. 5 a diagrammatic .view to illustrate the use of two or more boilers with high pressure economizer stages in connection with 'a single low pressure stage. Similar reference numerals indicate similar parts in the several views.

Referring to Figs. 1, 2 and 3, the numeral. 1 designates a portion of a boiler of any usual or standard design having a steam and water drum 2 to which the feed water is delivered from the high pressure stage of the economizer, said stage being designated generallyvby the letter A. Thereaiof the latter is illustrated in Fig. 2, and in Fig. 1 said stage is shown aslocated in the vertical parto'f the flue 3, and as sub jected to the hottest gases. The gasesare made to travel in a downward direction over the tubes of the high pressure stage,

and the flow of thewater through said stage I is, in general, in the reverse direction of the flow of the gases. The low pressure stage of the economi'zer, designated generally by the letter B, isarranged in separated banks of vertical tubes in the horizontal part of the flue 3, and is subjected to the coldest gases. Tie gases finally enter a fan 4: and are delivered to the uptake 5. The fan maintains the necessary draft suction. By setting the economizer partly above and partly below the boiler floor 6, improved results are secured as to head room and in locating the induced draft apparatus in the basement instead of at a high level above the boiler. The feed water whichmay come from the hot well, or any other source, enters the pipe 7 through a valve 7, and is delivered to the low pressure stage of the ecouomizer, shown as consisting f three banks, 8, 9 and 10, each having five rows of tubes, preferably of cast iron, fitted into cast iron horizontal boxes or headers to form transverse sections. It is to be understood, of course, that the invention is not limited to the exact number of tubes in a section or the exact number of sections shown. The spaces between the banks of tubes provide for access to the low pressure stage of the economizer through doors 11, Beneath each ofthesebanks is a-pit, having access doors 1-2, for collecting soot deposited from the gases, and that removed from the exterior ofthe tubes by scrapers 13 hung by chains over wheels ,14; The latter are geared-to a shaft 15 adapted to be rotated in both directions to raise'andlower the scrapers along the tubes. To secure an increasein economy and efficiency the temperature. of the water. fed to the low pressure stageof the economizer should be such that fumes and moisture in'the gases will be condensed on the' obtain access for coating the tubes with paint, or ther material, to prevent or minimize external corrosion. Even where scrapers are used the low pressure stage should be arranged for access, as a pasty material may cling to the lower ends ,of the tubes and above the lower headers, and by providing access between the banks, and making the banks of a proper width, this material may be removed by hand when the boiler is shut down. Should any of the fumes or vapor condensed from the 'gases run down the tubes to the lowermost headers, it will fall into the pit below. the' economizer sections, which space is utilized for collecting ,the dust and soot scraped from the tubes.

The tubes of the several banks of the low pressure stage are so connected that the Water entering through pipe 7 is distributed through the lower connected headers of bank 8, and flows upward through all of the tubes of said bank to the upper headers thereof, and passes therefrom to the header of the right hand section or row of tubes of bank 9, then down said row of tubes, and is distributed through the remaining four connected lower headers of bank 9, then upward through the four rows of tubes of 9,.to the upper headers of said bank, and downward through tubes 9' to the. lower headers of bank 10 and'then upwari through all of the rows of tubes of bank 10 through pipe 16' to a tank 17, in which tank'are preferably perforated plates over which the water is made to flow, and" bywhich it is broken up, to facilitate the disengagement and escape of the air and gases. The disengagement of the air and ases from the water is assisted by the heat? mg of the water in the low pressure stage of the economizer and by maintaining a partial vacuum in the tank 17 by the vacuum pump 18 connected to said tank by pipe 19. 17' is a relief valve for limiting the pressure in'the tank 17. The tank 17 is therein.

How of the water. This causes any air or rovided with the blow-off connection 17 .or theremoval of any sediment deposited From the tank 17 the water is conducted by the pipe 20, leading from a. point-above the bottomof the tank, to a feed pump 21 which forces it through pipe 22 to the bottom. of the high pressure stage -of the economizer. Steam for operating the'pumps 18 and21 is supplied from a pipe 23, and in the connection for pump 21 is a valve 23' controlled by a float 24, so as to maintain a substantially uniform level of the water in tank 17. This regulating device varies the amount of steam supplied through the branch connection from pipe 23 to pump 21', and in that way regulates the speedof, the -pump 21. 'The high pressure stage of the economizer is shown as consisting of a series'of rows of tubes 25 expanded into horizontal boxes or headers 26, and as having a slight inclination upward in the direction of flow of the water. The tubes and boxes are preferably of wrought iron or wrought steel to withstand thehigh boiler pressure to which this stage of the economizer is subjected. The inlet pipe 22, from pump 21, enters the lowermost of the headers 26, as shown in Fig. 2, and by said header is distributed to the tubes of the lowermost row. The water then flows through the successive rows of tubes, from side to side, as indicated by the arrows, until it leaves through'pipe 27 by which it is delivered to the steam and water drum 2. The described flow of the water through the high pressure stage of the economizer provides for a positive circulation, and the passage through tubes all'of which are inclined upward with reference to the direction of non-condensable gases which may not have beenremoved from the water in the tank 17 to be carried along with the general current and out of the economizer. It also allows of a. construction which can be readily relieved of air on being filled with water from an empty state. The positive circulation of water through the high pressure sta e is also of great advantage in causing a maximum amount of heat absorption from the gases. The horizontal boxes or headers 26 of each row are spaced apart so that the tubes may be replaced by passing them between two of theboxes and into the hole in the box on the opposite side of the economizer. The

tube is slipped in some distance through the boX on the opposite side, then brought opposite the hole in the other box to which it is to be connected, and then drawn back to the proper position. Another advantage of the construction is that the hand-hole fittings oppo'sit'e to .the tube ends for use in expanding 'the tubes may be made smaller than where the tubes are passed through 30 boxes and introduced at an angle.

near the top of .th v 50 As so arrangedpthe air'or gases must flow the hand-hole fittings, thus making it possible to construct a stronger box from the same thickness of material. Again, a single hand-hole fitting may be employed for expanding two or more of the tubes, the

expander being introduced through such hand'hole fitting. Where the hand-hole fittings do notadmit the use of an expander with a straight shank, a jointedexpander may be employed. Another way of expanding the tubes is to use a jointed expander passed through hand-hole fittings in the ends of 'the boxes, in which case only as many handhole fittings need be provided 1n the sides of the boxes as are desired for assisting in the manipulation of the jointed expander and for inspecting the tube ends. Replacing the tubes in the way described is advantageous also in making it possible to -set the boilersand economizers nearer toget'her, that is, with less aisle room, than where the tubes are replaced through the Should the tubes be -re-- hand-hole fittings. placed through the ordinary form of hand- 25. hole fittings, the aisle width would have to. be such that the full length'of a tube could be introduced at right-angles to the boxes, whereas with the arrangement descrlbed the tubes may be moved sidewlse between the Still another advantage of this arrange ment relates to cleaningv the-tubes. Owing to the boxes being spaced apart from each other in the rows and a space being left in the (separating bricks or material which may be used between the boxes, a steam or air-lance may be inserted. between the boxes either through'special openings or through the doors 27 show'n'on Fig. '2. Such steam 40 or air lance will'serve' to blow ofl the soot and collection on the economizer tubes.

In Fig. 3 I ha've shown, on anenlarged scale, the manner of connecting the boxes 26 to prevent the pocketing of air in the upper part of thebo'xes andto permit its escape to the uppermost'b'ox. As, there shown, the

26".extending from: top of one box to yboxdlrectly' above it.

- connection consists ofia relatively small pipe all the way along each one'of the boxes be fore can enter theone directly above it,

thus preventing short circuiting of the water without the removal of the air and causing theair from the lowennost boxes to sweep through the full length of all of the .upper boxes,which lead'sto the removal of any air 3 bubbles which might otherwise lodge at certain points in the upper sides :of the boxes. In Fig. 31 have also indicated haird-hole fittings 26 in the sides'of the boxes for exanding the tube ends to make a tight joint. each hand-hole fitting'serves for. the expansion of three tube ends, a jointed expander- I being used. I havealso shown hand-hole fittings 26 in theends of the boxes through which a jointed expander may be introduced for expanding the tubes.

Thehigh pressure stage ofthe eo'onomi'zer is especially applicable to conditions where steam may be generated in the economizer.

This feature will be useful in connection with waste heat work where the ratio of the work done in the economizer and the boiler varies a considerably greater amount than in coal fired boiler furnaces. In a waste heat boiler the initial temperature of the gases may for a time be over 2000? F. The temperature of the gases may then fall to, say,

approximately 1000 F., 'with'the same, or

even a greater, Weight or gas flowing" give the best results with the high temperature gases, steam will be formed in the economizer with the low temperature gases. With the arrangement shown of the high pressure stage of the economizer, any steam formed therein will not have a tendency to carry over slugs of water aswould be the tendency in some other forms of econo mixers, such for example, as the form shown in the low pressure stage B. Should steam beformed in the middle bankof tubes in an economizer of the form used for the low pressure stage it would betrapped in this.

bank, and to obtain an outlet would force the water downward through the tubes 9 leading from the top of the middle bank 9 to the bottom of the' third bank 10. The

steam would then haveto" force its way,

through the water in the tubes of bank 10, and, in doing so, would be apt to carryover slugs of water.

- In Fig. 4 Ihave shown, diagrammatically,

a plant in which the water from'the low pressurestages of plurality of boilers isrun to a common tank 17. The feed water enters the low pressure stages of the economlzers through pipes 7, and after passing through the banks 8, 9 and' lO flows through I branch pipes 16 to a common pipe 16 by which it is delivered to tank 17. The pipes 316 are provided with valves 16 and ther; fmometer s 16 flters pipe 20 and is'fedby the pump 21,

From tank l7 the water en through" the pipe 22, into the high pressure "stages of the economizers, entering these stages through the branch pipes 22" and leaving through the pipes 27, passing through the'feed valves in said pipes into the steam andwater drums of-the, respective boilers. The amount of water fed to each high pressure stage may be regulated by ad lusting the valves i h Pipes 22". -flhe amount of Water fed to the low-pressure stages may be estimated by noting the exit temperatures indicated by the thermometers 16 The pipes 16 and 22 are shown as openended to indicate that more than two boilers and economizers may be connected to the plant. The dry vacuum pump is shown at 18, the air and non-condensible gases withdrawn from tank 17 being discharged from the pump through pipe 18.

In Fig. 5 I have shown, diagrammatically, a plant in which is employed a single low pressure stage of a two-stage economizer in connection with two or more boilers each having a high pressure stage. The water enters through pipe 7, and flowing through the banks 8, 9 and 10 of the low pressure stage B passes by the pipe 16, having a valve 16 into pipe 16 and tank 17 From the latter the water is delivered through pipe 20 to pump 21 and by the latter is I the pipes 22.

forced to the several high pressure stages,

entering the same from pipe 22 through the branchconnections 22 the amount of water being regulated by'means of the valves in From the high pressure stages the water enters the steam and Water drums of the respective boilers through valves in the pipes 27. The amount of water fed to the low pressure stage may be estimated by noting the exit temperature indicated by the thermometer 16 in connection with the temperature of the Water supplied to the low pressure stage.

The gases leaving the high pressure stages of the-eeonomizers pass through the lower dampers. 28 and enter the common flue 29 from whence they either pass to the low pressure stage of the economizer through the dampers. 30, or are by-passed around the economizer through the connection 31. When the low'pressure stage of the economizer is in action the dampers 30 are open and the damper 32 is closed. When the economizer is out of action, and the flue gases are by-passe'd, the damper 32 is opened and the dampers 30 and 33 are closed. The gases finally enter the fan 4 from whence they are forced into the uptake 5. A by-pass connection may be ovided for conveying the gases from the ue 31 directly to the stack when so desired without passing them through the fan. As in Fig. 4 the pipes 16 and 22 are shown as open-endedto indicate that other units-may be connected to theplant. The common flue 29 is also shown as open-ended to indicate that it may serve more than the 1 two boilers shown.

The economlzer may be of a one stage form in which case the vertical arrangement which has been described for the high pressure stage will give the advantages already described for such arrangement.

I As has-been stated, the drawings are diagrammatic. Certain common and wellknown features such, for example, as safety valves for the economizers, have not been shown, in order to emphasize the features which-apply more particularly to the invention.

1V hat I claim and desire to secure by Letters Patent of the United States is 1. A steam boiler havin an ofl'take flue with 'a vertically dispose portion and a horizontally disposed portion, an economizer in said flueeomprising a high pressure part or section in the vertically disposed portion thereof and having a series of horizontally extending tubes inclined upwardly to the horizontal in the direction of the flow of the water, horizontal headers to which said tubes are connected, a low pressure part or section in the horizontally disposed portion of said fl-ue and havinga series of separated banks of vertical tubes, and means for maintaining the water in said economizer sections under different pressures.

2. A steam boiler having an ofitake flue with a vertically disposed portion and a horizontally disposed portion, an economizer in said flue comprising a high pressure part or section in the vertically disposed portion thereof and having a series of horizontally extending tubes inclined upwardly to the horizontal in the direction of the flow of the water, horizontal headers to which said tubes are connected, connections arranged to prevent pocketing of air in said headers, a low pressure part or section in the horizontally disposed portion of said flue and having a in said flue comprising a high pressure part or section in the vertically disposed portionv thereof and having a series of horizontally extending tubes inclined upwardly to the horizontal in the direction of the flow of the water, horizontal headers to which said tubes are connected, a low pressure part or section in the horizontally disposed portion of said flue and havin a series of separated banks 3 of vertical tu es, means intermediate the economizer sections arranged to allow air or v gases to escape from the water heated in the low pressure part or section, and means for maintaining the water in said economizer sect-ions under. difi'erent pressures.

4. A steam boiler economizer comprising a series of horizontal headers and-horizontally extending tubes connecting the headers, said vtubes being inclined from one h'eaderto the opposite header in the direcback and forth passes, means for admitting water to the lower set of tubes, and air connections on alternate ends from the upper I low pressure economizer part or sectionv common to all the boilers and feeding to the high pressure parts or sections, means for maintaining the water in said parts or sections under different pressures, and a by-pass to direct the gases either through or around said low pressure art or section.

6. The herein-described system comprising a plurality of boilers each having a high pressure economizer part or section, a low pressure econolnizer part or section common to all the boilers and feeding to the high pressure parts or sections, means for maintaining the water in said parts or sections under different pressures, at by-pass to direct the gases either through or around said low pressure part or section, and means intermediate the econoinizer sections arranged to allow air or gases to escape from the Water heatedin the cooler low pressure economizer part or section.

In testimony whereof I have hereunto signed my name in the presence of two subscribing Witnesses.

DAVID S. JACOBUS. Witnesses M. E. MGNINCH, CHARLES S.' JoNEs.

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