Патент USA US2128469код для вставки
Aug. 30, 1938. E, NlBBs 2,128,469 'EVAPORATOR Original Filed Aug. 8, 1934 5 Sheets-Sheet 1 _ 47 ‘ '_ ' f/zz/eniiow: 54/2651" #62655 I wag/.2 Aug. 30, 1938. ‘ ' E. NIBBS 2,128,469 EVAPORATOR Original Filed Aug. 8, 1934 s Sheets-Sheet 2 *W I Aug. 30, 1938. E. NIBBS 27,128,469 EVAPORATOR'v Original Filed Aug.. 8, 19:4 3 Sheets-Sheet 3 2,128,469 Patented Aug. 30, 1938 PATENT OFFlCE‘ UNITED STATES 2,128,469 EVAPORATOR ' _ Ernest Nibbs, New London, Conn,- assignor to Electric Boat Company, Groton, Conn, a cor poration of New Jersey Original application August 8, 1934, Serial No. 738,922. ‘ Divided and this application No vember 27, 1935, Serial No. 51,771 10 Claims. This invention relates to evaporators for sub marine boats, and has to do with means for evap~ crating sea water or water of ?otation so as to produce steam useful within the hull for various 5 purposes, including the obtaining of drinking water for the personnel of the boat. It is known, in submarine boats, to evaporate sea water and condense the resulting steam and fresh water vapor so as to obtain water suitable for drinking purposes. This may be accom plished by electrical heating means deriving energy from the boat storage battery, by inde pendent boilers within the hull, or by boilers heated by the exhaust gases from the main 15 and/or auxiliary internal combustion engines within the hull. In all of these cases, accord ing to present practice, the boiler or evaporator is installed within the hull, which is objection able as taking up valuable space. A further ob 20 jection to having the boiler within the hull is that it radiates considerable heat resulting in greatdiscomfort to the crew, even when the evap orator is insulated, and providing thick and ei ?cient insulation upon the evaporator with a 25 view to avoiding radiation of heat therefrom fur ther increases the bulk of the evaporator, so that it occupies additional space within the hull. It is an object of my invention to provide a boiler or evaporator of simple and efficient con; struction disposed exterior of the hull and capa ble of being operated from the interior thereof, thereby conserving valuable space within the hull ’ while avoiding the above noted objections to hav ing the boiler or evaporator in the interior of the boat. It is also an object to provide a boiler of the character stated of light weight, which can be readily disassembled for cleaning and repairs, and which has associated therewith means for quick ?ooding of the various spaces of the boiler .40 or evaporator and associated parts. A further object is to provide a boiler of this character adapted to be heated from a source of heat with in the hull, conveniently the main and/or aux iliary internal combustion engines, this boiler be ing suitable for disposition between the deck of the superstructure and the top of the hull while avoiding objectionable heating of the superstrucé ture deck. Further objects and advantages of my invention will appear from the detail description In the drawings:-' 50 Figure 1 is a central longitudinal sectional view through an evaporator embodying my invention, certain parts being shown in elevation, this view being taken substantially in the plane of line 55 |--l of Figure 2; (Cl. 114—16) Figure~2 is a sectional View taken substantially ‘ in the plane of line 2-2 of Figure 1; Figure 3 is an end view of the boiler, looking at the inlet end thereof for the exhaust gases from the internal combustion engine within the hull of the submarine boat; Figure 4 is a side view of a boiler embodying my invention as applied to a submarine boat, the latter being shown fragmentarily and in sec tion, parts being broken away and shown in sec 10 tion with certain parts shown in elevation, this view being semi-diagrammatic. In my co-pending application for evaporator for submarines, Serial No. 738,922, ?led August 8, 1934, which matured into Patent No. 2,025,524 15 I have disclosed an evaporator as applied to a submarine boat. The evaporator of my present invention is similar to that disclosed in my co pending application and the instant application, which is a continuation in part of said co-pend ing application, has to do more particularly with the evaporator per se. The boiler or evaporator includes an inner muf ?er unit M and an outer water jacket unit W, the latter, though preferred, not being essential 25 in all cases, as will hereinafter appear. The muf?er unit comprises a mu?ler tube 5 conveniently of rectangular cross-section and open at both ends. This tube is welded or other wise suitably secured, at its outer end, to an outer closure plate or head 6. The inner end of tube 5 is welded to a relatively thick ?ange l bolted or otherwise suitably secured to an inner closure plate or head 8, the latter being detachable from flange 1. The plates 6 and 8 are of circular shape and the latter plate is welded or otherwise suit ably secured in the inner end of a cylindrical shell 9 which extends about tube 5 and de?nes therewith a water space and a steam space thereabove. The outer end of shell 9 is welded or otherwise suitably secured to a relatively thick annular ?ange 8a bolted to plate 6. Circular swash plates 10 are secured upon tube 5 and fit snugly within shell 9. These plates H] are pro vided with suitable openings for flow of the water therethrough and serve to prevent objectionable surge of the water within shell 9, incident to sudden or abrupt movements of the evaporator caused by pitching and rolling of the submarine boat, with which the evaporator is associated, when traveling on the surface in rough weather. The normal water level within shell 9 is indi cated by the line a:,—:z: in Figures 1 and 2. Tube 5 is provided with a plurality of thimble-shaped hollow projections or tubes ll extending there 2 2,128,469 into from opposite sides thereof and disposed in staggered relation, these tubes or projections ll constituting baffles for the hot exhaust gases discharged into tube 5. It will be noted that the thimble-shaped tubes I! are closed at their inner ends and open at their outer ends into shell 9 below the normal water level therein, that is, 39 to which is welded a frusto-conical element 40 into the water space within this shell. de?ning an outlet opening for the exhaust gases from muf?er tube 5. Plate 39 is spaced away from plate 8 of shell 9 and de?nes with the latter a gas receiving space All. The other end of cyl inder 36 is welded to a relatively thick annular ?ange 42 the inside diameter of which is slightly Prefer greater than the outside diameter of cylinder‘ 35. ably, vertical ba?le plates I? are suitably sup ported between the swash plates It a short dis Flange 52 is bolted to a head or plate 43 spaced tance from the outer ends of the thimble tubes outlet opening 44% which registers with the outlet opening of element 439. Plate 43 is shaped, about opening lid, to provide a seat which snugly re ceives the outer portion of element 49, the latter being Welded to plate 93. Adjacent the lower 15 ll, these ba?ies l2 promoting circulation and quick heating of the water within shell 9. A steam take-off pipe I5 is disposed within 15 shell 9 adjacent the top thereof, in steam space 16 above the normal water level. The pipe 55 is closed at its inner end, extends through plate 6, and has its outer end welded in a ?tting ll bolted to the outer face of plate 6, this ?tting providing means for connecting a steam con ducting pipe to the steam take-off pipe. Pipe I5 is slotted at its upper portion for reception of steam and exclusion of water, in a known man ner. Preferably, the steam take-01f pipe is dis 25 posed within a housing I8 extending from plate 6, the inner end of this housing being closed and the upper wall of shell 9 constituting the top of the housing. Housing l8 has its upper portion slotted as shown for admission of steam and is 30 provided, at its lower portion, with suitable open ings for drainage therefrom of water into the shell 9. As clearly shown in Figure 1, the slots of housing I8 are staggered relative to the slots of pipe l5, better to prevent entry of water into 35 the latter. Conveniently, pipe l5 seats in curved supports l9 of angle cross-section suitably se cured in housing l8, though any other suitable means may be provided for supporting the steam take-01f pipe. The swash plates H] are, of course, 40 suitably notched out at their upper portions to accommodate the housing III, as shown in Fig ure 2. Each of these plates is also preferably provided, at its lower portion, with a notch 20 to facilitate blowing of sediment out of the shell 45 9, as will hereinafter appear. Plate 6 is provided with an opening 2! into shell 9 at the bottom of the latter. A ?tting 22 is bolted to the outer face of plate 6 and provides means for connecting a blow-off pipe 23 to open ing 2|. A ?tting 24 is bolted to the outer face of plate 6 adjacent one side thereof and below the water level within shell 9, this ?tting 24 pro viding means for connecting a water supply pipe 25 to the interior of shell 9. Two additional fit 55 tings 26 and 2‘! are bolted to the outer face of plate 6 below and above the water level in shell 9, respectively, and provide means for connect~ ing tubes 28 and 29, respectively, to the interior of shell 9. Preferably, plate 6 is suitably bored and threaded for reception of a plurality of zinc plugs 39 which project beyond the inner face of this plate into the interior of shell 9. These plugs, being susceptible to corrosion, localize the corrosive effect of the sea water within the shell 65 9, which reduces corrosion of the latter. The water jacket comprises two concentric cylinders 35 and 36 spaced apart and de?ning therebetween a water space 37. The cylinder 35 is welded at one end to a flange 35a, which seats 70 against the inner fact of flange 8a, and the adja cent end of cylinder 36 is welded to a. relatively outwardly from plate 39 and provided with an 10 portion of element 99, an inwardly projecting de ?ecting element 615 is welded to plate 39 and is disposed to direct a. portion of the gases flowing from tube 5 downward into space M and thence into gas circulating space 45 between shell 9 and cylinder 35, the latter being spaced from the former, as shown, to permit of flow of a portion of the exhaust gases about shell 9 in contact therewith. An outlet nipple M is secured through plates 39 and 43, conveniently by weld ing to these plates, and opens into the top thereof. An arcuate baffle from the inner face of plate 39 and low and to either side of nipple 47. space 4| at 48 projects extends be This ba?le serves to direct the gases from the upper por 30 tion of space 46 into nipple 41, and thence to atmosphere. This promotes circulation of the gases about shell 9. A drainage nipple 49 is suitably secured through plates 43 and 39, con veniently by welding to these plates, and opens into the cylinder 35 adjacent the bottom thereof for draining water from this cylinder, as will hereinafter appear. A. ?anged water inlet ?tting 59 opens into water space 31 between cylinders 35 and 36 for 4-0 normally supplying water to this space, this tting being welded to the latter cylinder. Fit ting 50 is provided with a ?anged neck 5! in tended for connection to supplementary water supply means for assuring ?ooding of the water jacket when the boat dives or is submerged. Cylinder 39 is further provided, at the top there of, with a ?anged outlet ?tting 52 welded to cyl inder 36 about a suitable opening through the latter. The boiler or evaporator so far described com prises the water jacket unit and the mu?‘ler unit previously referred to. The muffler unit is car ried by plate 6 and may be inserted into and withdrawn from the water jacket unit by re moval of the bolts which secure ring 38 to plate 6. The inner end of the mu?ler unit is spaced from plate 39 of the water jacket unit, as above, it also being noted that plate 8 is spaced from baflies 45 and 48, as shown in Figure 1. This 60 accommodates independent expansion and con traction of the two units lengthwise thereof and relieves the structure, as a whole, of objection able stresses from this cause. Preferably, suit able blocks 53 are welded or otherwise suitably 65 secured to the inner face of cylinder 35 and pro vide means for supporting and centering shell 9 therein. Preferably, the ends of the blocks to ward plate 6 are beveled at 54, as shown, to facilitate insertion of the muf?er unit. I also 70 prefer to provide suitably spaced blocks 55 welded thick ring 38, the latter seating against the inner or otherwise suitably secured in cylinder 36 and face of plate 9 and being bolted or otherwise re aligned with blocks 53, to assist in supporting the muffler unit within the water jacket unit. The mu?ier unit and the water jacket unit 75 movably secured thereto. The inner cylinder 35 75 is provided, at its otherend, with a closure plate 3 2,128,469 may be assembled and disassembled in the man ner above stated. Access may be had to the in terior of the mu?ler unit, for cleaning, repairs, or other purposes, by removing the‘ bolts se curing plate 8 to ?ange 1, after which the bolts securing ?ange 8a to plate 6 may be removed, and the muffler tube, together with swash plates l0 and the steam take-oil‘ pipe I5, may be with drawn as a unit from shell 9. This gives ready access to all parts of the mu?ier unit structure. Access may be had to the interior of the water jacket, after removal of the mu?ier unit, as above, by removing the bolts securing head or plate 43 to ?ange 4-2 of cylinder 36, the latter being then moved endwise away from plate 43 and from about cylinder 35. It will be understood that, in the structure of the boiler or evaporator, suit able gaskets and packings may be provided where desired or necessary. These have been omitted, for clearness of illustration, and as be ing obvious. . ' In Figure 4 I have illustrated an evaporator in accordance with my invention applied to a submarine boat B comprising a hull a and a superstructure b having a deck 0 above the top of the pressure hull a. The boat itself is of known construction and need not be illustrated nor described in detail. One or more internal combustion engines are suitably disposed within hull a and each of these engines is provided with a cylinder water jacket, in a known manner. Cooling water, commonly water of ?otation, is supplied under pressure to the cylinder jacket of the engine in a suitable 35 manner, as by means of a pump driven by the engine and having its intake connected to a sea valve opening to the sea through the hull, the dis charge of the pump being connected to the water jacket of the engine. An axhaust pipe 69 is con 40 nected to the exhaust manifold of the engine for conducting the hot exhaust gases therefrom. This pipe is provided with a water jacket 6! which ‘communicates with the water ‘jacket of the en gine in a known manner for receiving water there 45 from. The engine and the means for supplying cooling water thereto and to the water jacket of the exhaust .pipe are of known construction and need not be illustrated nor further described here. The general arrangement is disclosed more upper end, with a ?anged outlet neck 68 to which is bolted one end of an exhaust horn 69. This horn is of rectangular cross-section and ?ares toward plate 6 of the evaporator, to which the other end of the horn is bolted about the rectan gular opening through this plate corresponding to the adjacent end of exhaust tube 5. Water jacket 6| of exhaust pipe 60 is connected to water jacket ‘63 of ?tting 62 in a suitable man ner, as by means of short passages 19 and ‘ll '10 formed in pipe 60 and neck 62a of ?tting 62, re spectively, and disposed in register one with the other, it being understood that any suitable num ber of these passages may be provided. Valve 66 has associated therewith a water jacket 12. This 115 water jacket 72 and water jacket 63 of ?tting 62 are connected by pipes 13 and '14, respectively, to a Y member ‘F5 from thestem of which extends a pipe 1'6 provided with valves TI and 18 disposed inboard of the hull. A branch pipe 19, provided with a valve Bil disposed outboard of the hull, but operated from within the latter, connects pipe 16 to water jacket 65 of ?tting 64. It will be noted that valve 6? has associated therewith a water jacket 8! in direct communication with water 25 jacket 65 of ?tting 64. Pipe 16 is further pro vided with a valve 82 exterior of the hull, but op erable from within the latter, and a branch pipe 83, connected to pipe T6 at opposite sides of valve 82, provides a shunt around the latter. Branch 30 pipe 83 is provided with a valve 84 exterior of, but operable from within, the hull. Pipe 16 is connected, by means of pipe 25 and ?tting 24, to the interior of the boiler or evaporator for sup plying water thereto. Water jacket 65 of ?tting 35 G4 is connected, by a tube 86, to an elbow 81 se cured to the lower end of ?tting 50. Tube 86 serves normally to supply water to the water jacket. In the normal use of the evaporator, when the boat is on the surface, valves 66 and ‘6'! are open, as shown, and valves ll, 18, Bl] and 84 are opened, valve 82 being closed. By adjusting valve 80, to restrict more or less the pipe 19, the desired pres sure within pipe 16, for delivering water into the 45 evaporator, may be obtained. The valve 80 is normally open to a su?‘icient extent to permit ?ow of water through pipe “#9 into water jacket 65 while also assuring ?ow of waterthrough pipe TB. Fitting ‘62 accommodates an inboard valve 66 for By adjusting valve 84, the rate of feed of water 50 to the evaporator may be regulated as desired. Opening valve 82 permits free flow of water into the evaporator, which may be desirable for wash ing out the latter or for other purposes. While water is being thus delivered into the evaporator, 55 water is also being delivered to the water jacket, by means of tube 86, and is discharged from the opening and closing the passage from exhaust pipe 60 into this ?tting. Valve 66 is of known type water jacket through ?tting 52 and a discharge conduit 99 attached to this ?tting and disposed to and is operated, in a known manner, by means discharge the water overboard. The hot exhaust 60 gases are delivered into the muffler tube and ?ow therethroughinto space 4!, a portion of these gases being de?ected into space 46 so as to cir culate about the shell 9, as above described, and the remainder of the gases being discharged 65 through a conduit 9! bolted to the outer face of 50 fully in my above identi?ed copending application. Exhaust pipe ‘60 is connected, at its upper end, to a valve ?tting 62 disposed at the inner face of the top of the hull, this ?tting being provided with a water jacket 63. Fitting 62 is aligned with a ?tting 64 disposed at the outer face of the top of the hull and provided with a water jacket 65. (not shown) disposed within the hull. An out board valve 61, of known type, is mounted in ?tting 64for controlling the passage therethrough, and is operated, by known means (not shown), from within the hull, in a known manner. The , ?ttings 6?! and 64 are disposed in register with an opening through the hull and are suitably se cured, by means of bolts passing through ?anges at the adjacent ends of these ?ttings and through 70 the hull, suitable gaskets being provided between the ?tting ?anges and the hull so as to provide watertight and pressure resistant closures at these points. The upper end of pipe '60 is ?anged and may be bolted to the lower end of ?tting 52, in 75 a known manner. Fitting 64 is provided, at its plate 43, this conduit being open to the atmos phere. The heat from the hot exhaust gases is, to a large extent, absorbed by the water within the evaporator, by means of tube 5 and the baffle 70 elements l I thereof, so that this water is quickly heated to boiling temperature and generates steam and water vapor which collects within space l'6 above the normal water level. . A steam conducting pipe 92 is connected, at 4 2,128,469 its upper end, by means of a T 93, and ?ttingr II, to the outer end of steam take-off pipe I5. The lower end of pipe 92 is connected to a cruci form pipe ?tting 90, to the lower end of which is connected a steam conducting tube 95 which extends into hull a and is there provided with two valves 96 and 91. The other end of tube 95 is connected to the inlet of a condenser 98 of known type disposed within the hull, from which 10 the condensate is withdrawn through a take-off pipe 99. This condenser 98 is cooled in a suitable manner, conveniently by the water of ?otation, for which purpose the condenser may be pro vided with water inlet and outlet pipes I00 and 15 IOI, respectively. Conveniently, the cooling wa ter may be supplied to the condenser from the pump which supplies water to the water jacket of the engine, or in any other suitable manner. The steam generated within the evaporator is 20 led to the condenser where it is condensed to provide pure water suitable for drinking pur poses and other uses by the personnel of the boat. During normal use of the evaporator, the valves 96 and 9‘! are, of course, open. A safety or pressure relief valve I02, of known 25 type, is mounted at the upper end of T 93. Neck 5| of ?tting 50 is connected, by a pipe I03, to one side of ?tting 94. A valve 88, oper able from within the hull, is interposed in pipe An in tation ?ows through pipe I03, neck EI and ?tting 50 into the interior of the water jacket and wa ter may also enter the water jacket through ?tting 52 and the associated conduit 90. In this man ner, all of the spaces of the evaporator, includ ing the evaporator unit and the water jacket unit, are quickly ?ooded so as to be completely ?lled with the water of ?otation, when the boat dives or submerges. This renders it unnecessary to construct the evaporator sufficiently strongly to withstand submergence pressure and, accord ingly, the evaporator, including the water jacket, may be of relatively light weight, which is an im portant consideration. Since the tube 86 com municates with the interior of the water jacket, through the ?tting 50, the pressure within. water jacket 65 of ?tting 64, and within the pipes and tubes exterior. of the pressure hull a, and the pressure exterior of these parts, when the boat is submerged, are equalized. Accordingly, none of 20 these parts need be of exceptionally heavy con struction, which is advantageous as rendering the structure, as a whole, of relatively light weight. If desired, known means may be provided for venting air from the Water jacket when submerg ing. This means may be of any suitable or pre ferred type. It is also contemplated to provide the water jacket with suitable areas of zinc to localize the corrosive action of the salt water 30 I03, this valve normally being closed. ?owing therethrough. of known type, is connected to the other side of ?tting 94. This latter valve is to assure quick ?ooding of the water jacket, when diving or sub merging, as will be explained presently. Blow 35 out pipe 23 is provided with a valve I05 oper able from within the hull, which valve is nor mally closed. If desired, however, valve I05 may be kept slightly open for drainage from shell 9 of salt and other sediment which may collect at the lower portion thereof, it being understood that in this case valve 89 is kept open sui?ciently to supply water to the evaporator at a rate suf ?cient to compensate for the continual slight dis charge of water through pipe 23. Tubes 28 and 45 29 pass into the hull and are connected, through valves I06 and I07 and I08 and I09, respectively, to tubes 28a and 29*‘, respectively, the latter tubes drains from spaces 4| and 46 through the con- - wardly opening pressure responsive valve I04, When the boat emerges after diving, water duit M and nipple 49, ?tting 64, above the closed valve Bl, horn 69 and muffler tube 5 draining into space II. The boiler or evaporator drains through the blow-out pipe 23 until the desired normal water level is reached, at which time valve I05 is closed. Valves 66 and 61 may then be opened, as may valves TI, ‘I8, 96, 91, I09, I01, I08 and I09, valve 88 being ?rst closed. The engine may then be set into operation and the evap orator again used in the manner previously de scribed. It will be noted that the lower portion of ?tting 92 is of bowl-shape and is provided with a screw plug I I I. This provides convenient means for draining from ?tting 62 any slight amount of water which may collect therein, such as water which may ?ow into this ?tting from being connected to a water level indicator or the upper portion thereof when valve 6‘! is opened gauge ill] of known type disposed within the after the boat emerges at the surface from a dive. What I claim is:— hull. This provides convenient means for ob serving the water level within the evaporator. Preparatory to submerging or diving, the en gine is stopped and the exhaust stack valves I56 and 61 are closed, it being understood that pipe 60 may lead from the exhaust manifold of a single engine or may be connected to the exhaust manifolds of a plurality of engines. Shortly thereafter, as soon as the engine water supply stops, valves ‘II and ‘I8 are closed and valves I05, 60 I01, I08 and I09 are also closed, either at this time or earlier, valve 88 is opened, and valve I95 is fully opened. During submergence of the boat, water of ?otation ?ows freely through pipe 23 into the evaporator so as to ?ll completely shell 65 9, the space at the upper portion of this shell being vented through pipe 92 and tube 95 into the condenser 98. As soon as the evaporator has thus been completely ?lled with water, the valves 99 and 91 areclosed. Water also enters freely vI70 through the exhaust conduit 9| and nipples 4? and 49 into spaces M and 56, tube 5, horn 99 and the upper portion of ?tting 64 above valve 61, in the closed position of the latter; Also, valve I04 opens under the influence of the water pres sure, when submerged, so that the water of ?o 1. In an evaporator for use with submarine boats, a horizontal muf?er tube open at its ends for reception and outlet of hot exhaust gases from an internal combustion engine, a. horizon- " tal shell enclosing said muffler tube and de?n ing therewith a water space and a steam space thereabove, a steam take-off pipe communicat ing with said steam space, a cooling water jacket enclosing said shell in spaced relation. thereto and de?ning therewith a gas receiving space‘, and means establishing communication between the outlet end of said tube and said space. 2. In an evaporator for use with submarine boats, a horizontal muffler tube open at one end for reception of hot exhaust gases from an in ternal combustion engine and open at its other end for escape of said gases, 2. horizontal shell enclosing said muf?er tube and de?ning therewith 70 a water space and a steam space thereabove, a steam take-off pipe communicating with said steam space, and a water jacket enclosing said shell, the latter and said tube being spaced at said other end of said tube from the adjacent 5 2,128,469 end of said water jacket and free therefrom for connected to said inlet member, a valve con expansion and contraction independently of said water jacket. trolled ?ood pipe connecting said water inlet 3. In an evaporator for submarine boats, a mu?ler unit comprising a mu?ier tube and a shell surrounding said tube and provided with end closure plates attached to said tube and hav ing openings aligned with the ends thereof, and a water jacket enclosing said unit and having 10 one end attached thereto and its other end free from and spaced outwardly beyond said unit to accommodate independent expansion and con traction of the latter, said other end of said wa ter jacket having an exhaust gas outlet open 15 8. In» an evaporator for use with submarine boats, a mu?ler tube, a shell enclosing said tube and de?ning therewith a water space and a steam space thereabove, a valve controlled water sup ply pipe communicating With said shell, a valve 10 controlled steam take-01f pipe communicating with said steam space, a valve controlled blow ing. off pipe communicating with said shell, a water jacket enclosing said shell and spaced therefrom with its end adjacent the inner end of said shell 15 4. In an evaporator for submarine boats, a muiller unit comprising a mu?ler tube: and a haust gas‘ outlet opening, said water jacket and shell surrounding said tube and provided with end closure plates attached to said tube and 20 having openings‘ aligned with the ends thereof, and a water jacket enclosing said unit and hav ing one end secured to one end of said unit and its other end free from and spaced outwardly beyond the other end of said unit to accommo 25 date independent expansion and contraction of the latter, said other end of said water jacket having an exhaust gas outlet opening, said one end of said water jacket being detachably- se cured to the closure plate at said one end of 30 said unit. 5. In an evaporator for submarine boats, a muffler unit comprising a muffler tube and a shell surrounding said tube and provided with end closure plates attached to said tube and having openings aligned with the ends thereof, and a water jacket enclosing said unit in spaced rela tion thereto and having one end secured to said unit and its other end adjacent and spaced from the other end of said unit, said other end of said water jacket having an exhaust gas outlet opening, said one end of said water jacket be ing detachably secured to the closure plate at said one end of said unit. 6. In an evaporator for use with submarine 45 boats, a muffler tube, a shell extending about said tube in spaced relation thereto, swash plates mounted on said tube and ?tting within said shell, a closure plate for one end of said shell removably secured to one end of said tube and 50 having an opening into the latter, a water jacket enclosing said shell and having one end spaced from said closure plate and provided with an opening communicating with the opening of said plate, and a closure plate secured to the other end of said tube and shell, said second closure 55 plate being removably secured to the other end of said water jacket and provided with an open ing to the other end of said tube. 7. In an evaporator for use with submarine boats, a muffler tube, a shell enclosing said tube and de?ning therewith a water space and a steam space thereabove, a valve controlled water sup ply pipe communicating with said shell, a valve controlled steam take-off pipe communicating with said steam space, a valve controlled blow o-? pipe communicating with said shell, a water 70 member and said steam take-off pipe, and an in wardly opening pressure responsive valve con trolling said ?ood pipe. jacket enclosing said shell and having an ex haust gas outlet opening communicating with the outlet of said tube, said jacket being pro vided with a water outlet open to the atmosphere and a Water inlet member, a water supply tube spaced from the latter and provided with an ex said shell de?ning a gas circulating passage ex tending about said shell and opening freely into the space between the inner end of the latter 20 and the adjacent end of said jacket, the latter being provided with a water outlet open to the atmosphere and a water inlet member, a water supply tube connected to said inlet member, a valve controlled ?ood pipe connecting said wa 25 ter inlet member and said steam take-off pipe, and an inwardly opening pressure responsive valve controlling said ?ood pipe. 9. In an evaporator for use with submarine boats, a muffler tube, a shell extending about 30 said tube in spaced relation thereto, a closure plate for one end of said shell removably se cured to one end of said tube and having an opening into the latter, a Water jacket enclosing said shell and having one end spaced from said 35 closure plate and provided with an opening‘ com municating with the opening of said plate, and a closure plate secured to the other end of said tube and said shell, said second closure plate being removably secured to the other end of said 40 water jacket and provided with an opening to said other end of said tube. 10. In an an evaporator for use with submarine boats, a muffler tube, a cylindrical shell extend ing about said tube in spaced eccentric relation 45 thereto, two concentric cylinders extending about said shell concentrically therewith, said cylin ders being spaced apart and de?ning a water jacket extending at one end beyond one end of said shell, inner and outer closure plates secured 50 in said inner and outer cylinders at said end of said jacket, said plates being secured together in spaced relation and de?ning an outlet open ing into said inner cylinder, said outer closure plate being removably secured to said outer cyl 55 inder and the adjacent end thereof de?ning an opening of a size to accommodate said inner cylinder, said inner plate being spaced from one end of said shell, a closure plate for said one end of said shell removably secured to the 60 adjacent end of said tube and having an open ing thereinto, and a closure plate for the other end of said shell secured to the other end of said tube and having an opening thereinto, the last mentioned closure plate being removably secured 65 to said other end of said shell and to the other end of said outer cylinder, the other end of said inner cylinder being free from said last men tioned closure plate. ERNEST NIBBS.