Патент USA US2132093код для вставки
Oct. 4, 1938. c. K. BENNETT 7 LIQUID ' HEATER ‘ Filed Jan. 14; 1937 7 84 2;132,9% 3 Sheets-Sheet l 30 36 2, 526 Oct. 4, 1938. c. K. BENNETT 2,132,093 LIQUID HEATER Filed Jan. 14, 1937 3 Sheets-Sheet 2 //VJ/E/V70/F W/7#551617” cy/mm/igpmgzal Oct. 4, 1938. ‘ c. K. BENNETT LIQUID ' HEATER‘ Filed Jan. 14, 1937 ‘WIT/V558.’ ' 60 - ' (Zr/226225 2,132,093 _ ‘ I is SheetSI-ISheeIt s Patented 4, 193a ' 2,132,093 ‘v , UNITED STATES PATENT oFFlcE 2,132,093 ' ' noun) HEATER Clement K. Bennett, Philadelphia, Pa., assignor I to C. H. -Wheeler Manufacturing Company, Philadelphia, Pa, a corporation of Pennsyli vania ' Application January 14, 1937, serial Nc. 120.533 ' ' 8 Claims. .ol. 251-225) This invention relates to a liquid heater and particularly to a water heater to which steam is I applied during the blow down of wood ?ber di gesters. - 5 sions being made for free expansion and con traction of the tubes which it contains. ' Heretofore it has been generally customary to use substantially an ordinary surface condenser " In normal operation digesters are operated at . as a blow down heater with some additional pro about 100 lbs. per square inch pressure and are arranged to cook wood ?ber for extended .pe riods of time, normally around two or more hours. At the end of the cooking period the pressure is 10 reduced to about 75 lbs. per square inch and the blowing takes place at such pressure. The contents of the digester during'the blowing op eration are discharged into a tank having ap proximately one and one-half times the capacity 15 of the digester, the blowing taking from eight to ?fteen minutes time. In general the blow'down may occur approximately every six hours from a single digester. . ' _ - ' From the blow down tank the steam which is formed is generally passed through a separator into a blow down heater wherein the latent heat content is recovered and used for heating proc ess water or other liquid. s It sometimes happens that operators are care 25 less about the liquid level in the blow tank or in the manner of blowing and the liquid level may then reach too high a level in the blow tank, in which case liquor is blown over into thelheater. When this occurs the paper ‘pulp contained in vision forv the insertion of a hose to wash on‘ the tubes. The arrangement of tubes in the con ventional surface condenser is by no means 's'at isfactory in such cases since inv general it is found that while high pressure water may remove the 10 wood ?ber from the tubes nearest its inlet, it may serve to compact the wood fiber even more into remoter locations. Furthermore, the conven-' tional surface condenser must be specially made to provide for uneven expansion'necessitated by 15 the very rapid impingement of steam upon cold surfaces. The multiple passes of the cold water v which is being heated. are also generally arranged in a fashion which contributes in'causing asym metrical 'It is a stresses general to object be setofupthe in present the heater. invention to provide an improved'liquid heater (generally for‘ heating water) designed for use in conjunc tion with the blowing down of wood ?ber di gesters. In the attainment “of this object provi 25 sion is made ?rst for the reduction of the strains incidental to the very rapid heating of a cold apparatus by insuring that the heating takes place in a symmetrical fashion with respect to the mechanical structure. This is accomplished 30 theliquor quickly foulsand plugs the heat ex change surfaces and the e?iciency of the heater ‘by providingradial symmetry for the multiple is very much reduced. Even if the liquor is not ‘liquid passes together with a single passage of blown over due tortoo high a liquor level, the the steam in such fashion that substantially all ?ashing of water into steam takes place almost ' of Ythesteam is caused to ?rst impinge uponv the - 35 explosively and the repidity of flow causes a car 40 hottest'tubes from which the~ water flows out rying over into the heater of very considerable quantities of the wood ?ber which will be de-' of the heater. Ample provision is also made for permitting the expansion which will result with posited upon the heat exchange surfaces of the out thevimposition of :gre'at strains upon, the, heater. - structure. . . Secondly, provision is made for the complete 40 and easily accomplished cleaning of the surfaces ample provision must be made in properly de signed blow down heaters to permit periodicv of the tubes. This end is?accom'plished by reason washing down of the surfaces, this wash down of the radial symmetry ‘of the arrangement in conjunction with the provision of suitable pas 45 preferably occurring between blows by means of sages for high pressure liquid introduced from 45 water under pressure. Means must also be pro the outside of the shell and also by the strategic vided for sluicing the surfaces with a high pres location of wash down nozzles for causing wash sure hose inserted through the shell, this latter ing water to ?ow downwardly along the vertical operation taking place when results indicate that tubes in such fashion as to reach and wash all ' 50 the surfaces are badly fouled. As a result of ."the fouling which thus occurs ' ‘of them. ‘ Due to the fact that the heater is cold for ex tended periods and then receives a certain rush ‘of steam the construction must be such as to cause it to stand severe temperature changes without distortion or weakening, ample provi-_ - ‘ ~ ' Other objects of the invention relate primarily to details of 'construction'which will‘ be apparent from the accompanying drawings in which Fig ure 1 is an elevation of a heater constructed in accordance with the invention. certain parts vbe-. 55 2,182,098 ing broken away and shown in section to clarify the internal construction. I ' Figure 2 is a section taken as indicated at 2-2 inFigure 1; , . ' Y ’ Figure 3 is a plan view or the heater showing the manifolding of the wash down nozzles; ' Figure 4 is a vertical section showing the ar rangement and construction of a ' wash down ' ‘ nozzle; Figure 5 is a fragmentary vertical section ‘taken on the plane indicated at 5—5 in Figure 1; and 10 Figure 6 is a fragmentary section showing _ speci?cally the mode of connecting the ?oating tube plate and its cover. The heater comprises a shell 2 extended at its lower end, as indicated at 4, into a non-conden 15 sible gas belt 6 provided witha gas outlet 1. ' The _ extensions 52 threaded to receive nuts 60. The heads 58 are provided with hook elements 6! designed to be received in an annular groove 62 formed adjacent the periphery of the upper sur-1 face of the plate 40. By. turning the hook mem bers ii to an outer position the cover 42- may be aligned with the plate 40 ‘with the interposition of a~ gasket indicated at 64'. ‘The heads 56 may then be turned to cause the hook members ii to enter the groove 62, whereupon the bolts 60 may be tightened to secure the cover 42 tothe vplate. It will be noted that wherever tight connections are required annular gaskets are set into grooves to prevent blowout. Besides the connection by means of the hook bolts, there are providedstay 15 bolts between the cover 42 and tube plate 40. . Nozzles 66 'are provided inproper locations rel .ative to the tubes to introduce the necessary 'water for washing down-the outside of the, tubes. prevents to a considerable extent the carrying out . These nozzles 66 are shown in Figure 4 and_com 20 20 with non-condensible gases of steam condensate. prise vertically extending pipes carrying distribu The lower wall of the belt 6 may be made square provision of the skirt provided by the extension 4 so asto provide corners extending beyond the cir tion nozzles 68. Each of the pipes is threaded into a coupling ‘I0 secured by a member 12 to the upper end of a tube 14 welded to the cover 30 and on which the apparatus may be supported. 25 A lower outside shell cover In is provided hav ' drawn down by means of stay bolts 18 in contact with the upper ?xed tube sheet 28 with the inter ing a condensate outlet l2. This is secured to position of suitable gaskets such as indicated at the under?de of the plate 8. The upper end of the shell 2 is continued as ‘I6 to prevent leakage. Distribution, of wash cular portions of, the apparatus to provide feet ' indicated at I4 and IS. The first continuation ll provides a steam impingement baille cut away at its lower corners, as indicated at Hi, to permit the reaching of the tubes by the stream from a washing ‘nozzle. Surrounding the upper end of the shell and extending somewhat below the‘ex water to the nozzles is provided through a mani folding arrangement. indicated at 8, receiving the 30 water from a common inlet 82. The pipes of this manifolding arrangement are graduated, as indi cated in Figure 3, to insure that all the nozzles receive an adequate supply of water under pres sure to insure proper cleaning of all of the tubes. point of maximum diversion from the shell with It will be noted from ‘Figure 2 that the tubes 38 a steam inlet indicated at 20. The ba?ie ll is ‘ are so arranged as to provide a series of eight .35 tension II is an, eccentric belt l8 provided at its . opposite this steam inlet and causes the steam’ . radial passages which are substantially clear to ?ow laterally within the eccentric belt it so into the innermost pass of ‘tubes throughout the entire vertical’ extent of the heater. Opposite 40, ‘40 that it is distributed substantially‘uniformly to j these passages there are provided openings 84 the periphery of the tube bundle. The belt II is . normally closed by covers 86 against which press provided with a bottom plate 22 shaped to .?ll the space between the outer wall of-the belt and adjustable screws 88 threaded into levers 90 piv the shell 2. Drain openings 24 are provided in oted at 92 and arranged to be held in their ‘closing positions by means of loop members 94. _ , this plate 22, these openings being normally cov , ered by suitable cover plates bolted thereto. " 50 The top 20 of the belt It serves to support the‘ fixed tube plate 20, which in turn is surmounted by the water distributing head 20. This head is provided with a water inlet passage 32 feeding water into a central pass of tubes, an annular connecting passage 24 and an outer annular water ' discharge passage 38. The construction shown is designed to provide four water passes, the water The covering arrangement just described is read ily opened and closed by manipulation of the loop members 84 and screws 88. ‘Through the openings 84 there may be manipulated high pres sure water streams for'the purpose of reaching 550 and cleaning the tubes when the accumulation takes place to such extent that the nozzles at the uppermost portion of the apparatus may be ine?'ective to provide complete cleaning. The or other liquid being led ?rst to the innermost passages, it will be noted, have between them only relatively small numbers of the tubes, with the pass and then successively through the intermedi ate passes to the outermost one, from which it is ‘result that streams of washing water introduced discharged into the passage 26. The symmetrical into any passage will readily effect the washing » arrangement of the successive passes is indik out into an adjacent passage of accumulated ?ber. cated in Figure 2. The tube bundle at its lower However, the nozzles 66 are primarily depended 760' end-supports the ?oating tube plate ".which is upon for washing down purposes. These nozzles are located withinv the groups of tubesbetween > provided with a cover 42 containing suitable par titioning means to provide connections‘ between the passages and serve to wash out the accumu the ?rst and second and the third and fourth lated material into the passages. whence it will ?ow down and out theonening 44. > ~ ‘passes, as indicated at 48 and 50. A central open A considerable accumulation of ?ber and other L, ing 46, through the cover, is aligned with a cen tral opening 44 through the tube plate 40 to pro sediment will occur in the channel formed be? vide for the passage of condensate into the tween the extension ll of the shell 2 and the cover l0. . The connection between the ?oating cover 42 Wand the tube plate 40 is worthy of note and is indicated on- an enlarged scale‘in Figure 6. The connection is made by means of- a series of hook outer wall of the belt 18. Such accumulation may be readily washed out through the openings ' “by the insertion of a hose into the various openings 84 formed inthe belt. .I . The construction has been speci?cally described as applied to a four pass liquid ‘arrangement. It bolts generally indicated at 52 and comprisini . will be obvious that a similar construction will 75 upper hook ends it forwarded integral with bol) ‘2,182,098 > be applicable to single mother multiple pass ar rangements, suitable changes being made in the headers to secure the proper ?ow. The fact that the cold liquid enters the center Cl and ?ows to the outside through the successive passes and that the passes are arranged annu larly around the center insures a symmetrical distribution of stresses when expansion and con traction take place to prevent any tendency to 10 ward lateral buckling of the structure. The sym metry of the stresses is also promoted by the dis-_ tribution of the steam in the eccentric belt II, which, together with the baille ll, produces a ?ow oi’ the steam so as to substantially equally distribute it to all of the outer tubes of the last liquid pass. It will be noted that a counter?ow _ 3 . each other throughout the lengths of the 4. A heat exchange apparatus comprising an outer shell, a passage for the introduction of gas into the shell, a series vof tubes extending longi— tudinally within the shell, and connections be tween groupsof tubes to provide a multiple pass arrangement, the groups 0! tubes iorming the passes being concentrically arranged longitu— dinally within the shell, said tubes being ar ranged in groups with passages between the 10 groups, and washing nomles arranged to direct liquid along the tubes within the groups to wash material therefrom into said passages. > . 5. A heat exchange apparatus comprising an outer shell, a passage for the introduction of gas. into the shell, a series of tubes extending ver arrangement is substantially provided to further tically within the shell, and connections between minimize the stresses and promote e?iciency. ' groups oi tubes to provide a multiple pass ar While an arrangement having a steam inlet at. rangement, ‘the groups of tubes forming the 20 the top has been speci?cally described and is pref passes being concentrically arranged vertically erable because there is no counter?ow of con within the shell, said tubes being arranged in densate and steam, it is also feasible to cause groups with vertically clear passages between the the steam to enter at the bottom and ?ow up groups, and washing nozzles arranged to direct wardly. In both cases condensate will run down liquid downwardly within the groups to wash ma Ni M the tubes and aid to some extent in preventing terial therefrom into said passages. ‘ i the deposition of ?ber or other sediment. 6. A heat exchange apparatus comprising an It may be remembered that the steam carries outer shell, a passage for the introduction of gas over with it both volatile and non-volatile ma-' into the shell, a series of tubes extending longi- terials, which may be‘of a corrosive nature, and tudinally within the shell, and connections be 30 depend upon the particular digestion process tween groups of tubes to provide a multiple pass which is used. Consequently, the tubes and the arrangement, the groups of tubes forming the other parts which come into contactwith such passes being concentrically arranged longitudi corrosive materials should be made of suitable nally within the shell, said tubes being arranged metal to withstand the corrosive action. in groups with radial passages between the 36 What I claim and desire to protect by Letters groups, and openings in said shell aligned with Patent is: . the passages for the, introduction of washing l. A heat exchange apparatus comprising an liquid to force accumulated material from the outer shell, a passage for the introduction of gas tubes into said passages. I into the shell, a series of tubes extending longi 7. A heat exchange apparatus comprising an tudinally within the shell, and connections be outer shell, a passage for the introduction of gas 4 tween groupsci tubes to provide a multiple pass into the shell, a series of tubes extending longi arrangement providing at least three passes, the - tudinally within the shell, and connections be groups of. tubes forming the successive passes-be tween groups of tubes to provide a multiple pass ing circularly and concentrically arranged, the 45 gas spaces‘ about the various groups being in free communication with each other throughout the lengths of the tubes. 2. A heat exchange apparatus comprising an outer shell,'a passage for the introduction‘ of gas into the shell, a series of tubes extending'longi arrangement, the groups of. tubes forming the passes being concentrically arranged vertically' within the shell, said tubes being arranged in groups with vertically clear radial passages be tween the groups, and openings in said shell aligned with the passages for the introduction of washing liquid to force accumulated material 50 from the tubes into said passages. tween groups oi.‘ tubes to provide a multiple pass 8. A heat exchange apparatus comprising an arrangement providing at least three passes, the ‘_ outer shell, a. passage for the introduction of gas tudinally within the shell, and connections be-v groups of tubes forming the successive passes be ing circularly and concentrically arranged with the ?nal pass outermost, the gas spaces about the various groups being in tree communication with each other throughout the lengths oi’ the tubes. 69 ' - . 3. A heat exchange apparatlm comprising an outer shell, a passage for the introduction of gas into the shell, a series of tubes extending longi tudinally within the shell, connections between groups of tubes to‘ provide a multiple pass-ar rangement providing at least three passes, the groups of tubes forming the successive passes being circularly and concentrically arranged and means for distributing the introduced gas mainly to the outermost group, the gas spaces about the 70 various groups being in free communication with into the shell, a series of tubes extending longi tudinally within the shell, and connections be tween groups of tubes to provide a multiple pass arrangement, said connections including means joining the lower ends of the tubes provided with 9. ~ central wash-out port, the groups of tubes ‘forming the passes being concentrically arranged so vertically within the shell, said tubes being ar ranged in groups with vertically clear radial pas sages between the groups of the outer passes, and , ' openings in said shell aligned with the passages for the introduction .of washing liquid to force accumulated material from the tubes into said 65 passages, the group of tubes forming the'inner most pass surrounding a vertical space, clear of tubes, aligned with said wash-out port. CLEMENT K. BENNETT. 70 '