US2388599A

US2388599A - Distillation unit

Info

Publication number: US2388599A
Application number: US446482A
Authority: US
Inventors: John C Cleaver; Resek Jules Verne
Original assignee: Cleaver Brooks Co
Current assignee: Cleaver Brooks Co
Priority date: 1942-06-10
Filing date: 1942-06-10
Publication date: 1945-11-06
Anticipated expiration: 1962-11-06

Description

Nov. 6, 1945. J. c. cs EAvl-:R ET AL DISTILLATXON UNIT Filed'aune 1o, 1942 4 sheets-sheet 1 Il; l i

HQ III lll-n1 w Nov 6, 1945.( J. c. CLEAVER ET A1.

DISTILLATION UNIT Filed June lO, 1942 4 Sheets-Sheet 2 INVENTORA L/JL@ C @leader (fe Z/efzzejee,

Nov. 6, 1945- J. c. CLE/WER ET A1. 2,388,599

DISTILLATION UNIT FilPd June 10, 1942 4 Sheets-Sheet 4 ll E i kn C. Cleaver, JL//es Z/efyz ejeev, 1

Patented Nov. 6, 1945 DISTILLATION UNIT John C. Cleaver and Jules Verne Resek, Whitefish Bay, Wis., asslgnors to Cleaver-Brooks Company, Milwaukee, Wis., a corporation of Wisconsln Application June 10, 1942, Serial N0. 446,482

Claims.

This invention relates to a water distillation unit and has as a general object to provide a new and improved, highly emcient distillation unit.

A more particular object of the invention is to provide a new and improved distlllationunit having a plurality oi' effects or evaporators, with the evaporators after the iirst having a heat exchanger constituting the heating means for the evaporator and the condensing means for the steam of the previous evaporator.

Another object is to provide a new and improved distillation unit for operation on salt water and embodying means for driving oii gases from the water before it is vaporized. Y

Another object is to provide a distillation unit having an aerator for aerating water ultimately to become distillate. at a temperature near boillng where odors and gases are readily given off.

Yet another object is to provide a distillation unit having evaporating means and means permitting a continuous blow-down from the evaporating means to prevent the water in the evaporating means from obtaining an excessively high salt content.

A further object is to provide a distillation unit having a plurality oi effects or evaporators with a pump for supplying water to the first effect at a rate in excess of the evaporation in the unit, a continuous blow-down from the first evaporator to the vother evaporators at a rate in excess of the evaporation of said other evaporators and blow-downs from the other evaporators.

Yet another object is to provide a distillation unit, having an evaporator, a condenser and an aerator, means connected to the condenser at a point spaced from the end thereof to conduct to Waste a portion of the coolant water flowing therethrough, a means connected to conduct the coolant Water flowing completely through the condenser to the aerator.

Still a further object is to provide in a distillation unit a first elTect evaporator or boiler with a multiple pass, large diameter lire tube withdrawable through the end of the boiler for cleanins.

Other objects and advantages will become apparent from the following detailed description, taken in connection with the accompanying drawings, in which:

Fig. 1 is a perspective view of a device embodying the features of our invention. Casing portions are cut away in the view in order to reveal certain interior constructions.

Fig. 2 is an enlarged plan view of one element of the distillation unit, namely. the aerator.

Fig. 3 is a sectional view taken approximately along the line 3 3 of Fig. 2.

Fig. 4 is a sectional view taken approximately along the line 4 6 of Fig. 2.

Fig. 5 is a diagrammatic view showing the circuit arrangement of the distillation unit, with dotted, broken and solid arrows indicating the presence and direction of flow of vapor, condensate and coolant, respectively.

Fig. 6 is a plan View, again with certain casing portions broken away to reveal the interior, of the right haii of the distillation unit shown in Fig. 1.

Fig.' 7 is a side elevational view of the construction shown in Fig. 6, again with a portion of the casing broken away to reveal the interior.

Fig. 8 is a side elevational view showing the heating tubes partially withdrawn for purposes of cleaning.

While the invention is susceptible of various modifications and alternative constructions, it is here shown in the drawings and will hereinafter be described in the preferred embodiment showing a two effect distillation unit. It is not intended, however, that the invention is to be limited thereby to the two effect units since features thereof are readily applicable to units having more than two effects. The scope of the invention is dened in the appended claims.

In the embodiment disclosed herein, the invention comprises generally a iirst eiIect evaporating means, generally designated l0, a second effect evaporating means, generally designated II, an aerator, generally designated I2, a condenser, generally d .signated i3, and a cooler, generally designated I4. These various subassemblies are combined into a unit assembly mounted upon an elongated frame I5 with the first and second evaporating means supported directly on the frame i5 in end to end relationship, and with the remaining subassemblies disposed at the remaining end of the second evaporatingmeans and supported either by the evaporating means or directly by the frame I5. As disclosed in Fig. l, for exemplary purposes, the frame I5 is in turn supported upon a Wheeled undercarriage structure, generally designated I6, shown in broken lines. While the distillation unit is admirably adapted, and is in fact intended, to be employed as a portable unit for use in the field, it is to be understood, of course, that it might equally Well be stationarily mounted.

For a more ready understanding of the invention, as the structures making up the distillation unit are described in detail, the operation of the unit will be set forth generally. Heat is supplied to the rst effect evaporating means Ill from a primary heat source and causes the Water in the first evaporating means to form steam and vapor. It is a feature of this invention that 4this steam or vapor is herein utilized to provide the heat for evaporating the water in the second effect evaporating means. To that end, it is conducted to a heat exchanger, located in the second evaporating means. which functions both as a heat source for the second evaporating means and as a condenser for the steam and vapor obtained from the first evaporating means. The condensate resulting is conducted to the condenser Il and from there to the cooler I4 to ilow from the latter as cooled distillate. The vapor of the second effect evaporating means is conducted to the top of the condenser I3 to be thereby condensed into condensate, which, like the condensate from the heat exchanger, flows through the cooler I4 to issue therefrom as cooled distillate. Coolant water is initially supplied to the coolei I4 and, after flowing through the cooler I4 is conducted to the condenser I3 from whence a large portion of the coolant water is-discharged to waste. A portion of the coolant which, as a result of its passage through the cooler and the condenser. has been heated to near the boiling point is discharged to the aerator I2 where it has an opportunity to give off undesirable fumes and odors. From the aerated water there is drawn the water supplied to the evaporating means to be by the process just described converted into pure, cooled distillate.

The subassemblies will now be described in greater particularity, an 'i the first effect evaporating means IIi will be first considered. This first effect evapora/ting means is in reality a boiler composed of a cylindrical casing or shell i1 and suitable heat exchange means IB. The inner end I9 of the boiler, as viewed in Fig. l, is integrally and permanently attached to the cylindrical side walls of the boiler, while the opposite or outer end of the boiler is formed by a removable, circular head 20. The head 2li is removably secured by means of a plurality of bolts 2| extending through the head at its periphery and through an external, annular flange 22 formed on the shell I1. The head 20 in turn is formed with a man hole 23 (see Figs. 6 to 8) through which access may be had to the interior of the boiler for inspection and minor repair or cleaning without necessity df removing the entire head.

The heat exchange means I8 herein employed is of unique construction and comprises a. fire tube 25 of comparatively large and uniform diameter throughout its length. The fire tube 25 at one end is rigid with the head 20 at a. point adjacent the periphery and just below the horizontal diameter of the head, at which point the head is formed with an opening 26 for the discharge into the tube of a combustible mixture. From this point, the fire tube extends longitudinally toward the opposite end of the boiler and is then bent upon itself numerous times to form four passes disposed in the same horizontal plane. From the last pass, the tube extends first laterally of the boiler toward the rst pass, then downwardly and again laterally, to commence a second horizontal layer of four passes lying beneath the first layer. The remaining end of the fire tube is, like the first end, rigid with the head 20 and opens to a flue 21 formed on the exterior of the head 2U. Aithougiy the rire tube 25 is herein illustrated as of the same diameter throughout its length, the first portion or pass may be in some instances larger in diameter to form a larger combustion chamber. In either event the entire tube 25 is withdrawable from the shell I1 as an incident to removal of the head 20 giving complete access to the re tube for cleaning scale therefrom or for inspection or repair.

The boiler herein is firedV by means of an oil burner of conventional type. Suffice it to say, therefore, that the burner comprises a nozzle 39 (see Fig. 1) a fuel oil pump 3l (see Figs. 6 and 7) supplying fuel oil to the nozzle, and a blower 32 supplying both primary air for atomization oi.' the fuel as it is discharged from the nozzle 30 and secondary air for supporting combustion. The blower and nozzle are supported directly on the head 2Il with the nozzle 3|! projecting into the opening 26, while the fuel oil pump 3| is supported on a plate 33 removably secured by bolts 34 on the frame I5. Driving the blower and the fuel oil pump 3i is a power unit 35, preferably a gasoline engine, also mounted on the plate 33. Projecting from the power unit is a shaft 36 having non-rotatably secured thereon a plurality of pulleys 31 and a single smaller diameter pulley 38. The smaller pulley 3l, through a belt 38, drives the fuel oil pump 3l, while one of the larger pulleys 31, through a belt 40, drives the blower 32. Removal of the head 2U and withdrawal of the fire tube 25 for cleaning or repair, as previously described, is, of course. impossible without removal of the power unit 35. the fuel oil pump 3|, and other structures, which will hereinafter be described. 4`It is therefore of importance in this invention that the plate 33 is removably secured, enabling the plate 33 and the parts mounted thereon to be removed. if desired, simultaneously with the removal of the head 20.

The secondary effect 4evaporating means is distinctly an evaporator and comprises a casing 42. generally rectangular in horizontal cross section. and having a rounded top. Each side wall of the casing 42 is composed in part oi' a door 43 hingedly supported at 44 and adapted to be tightly closed to prevent leakage-of the water in the evaporator. Supported internally on each of the doors 43 is a heat exchanger. generally` designated 45, and herein shown as composed of a plurality of coils 46. Physically one of the` heat exchangers 45 is shown in the drawings. but in the diagrammatic view of the circuit the other heat exchanger and the coils composing the same is diagrammatically shown at 41.

Disposed above the normal water level in the casing 42 are a. plurality of baffles 4B and 49 projecting inwardly and partially across the evaporator from opposite end walls. At the very top 0f the second evaporating means is an enlarged tube 5I! open at one end to the interior of the evaporating means and discharging at the other end through a conduit 5I of somewhat smaller diameter to the top of a. downwardly extending and diverging header 52 opening at its lower end to the top of the condenser I3. It is believed apparent from the foregoing that improvedieiiiciency of operation is obtained by the employment of a heat exchanger in the second effect which serves to condense the steam or vapor from the first effect and thereby utilize the heat which is present in such steam or vapor.

Herein the condenser I3 is shown as supported from the end of the casing 42 of the second effect.

heads il. The tubes are in weil known manner arranged in groups and discharge to chambers formed Aby bailles 55 interposed between each head Il and a recessed closure plate B. The arrangement of the bailles is such that coolant hows through one set of tubes, thence laterally to another set o! tubes, thence through the tubes and upwardly to the set of tubes above, and thence through the tubes and again laterally to another set of tubes longitudinally and upwardly as be- 1 oi' tubes 61 terminating in heads 58. Interposed between the heads 58 and end closures I9 are bailles 80 to direct coolant water supplied to the cooler-from end to end successively through Vdif-- ferent groups of tubes. The condensate to'be cooled ilows over and around the tubes YEl'y to issue as cool, clear distillate. y y

Referring now particularly to Figs. 2 to 4, the aerator I2 shown therein comprises a generally rectangular container having a bottom wallf! resting upon or even formed by the top wallyof' the' condenser I3, and end and side walls 68, i1,A

and 69. Extending downwardly through the container and interrupting the continuity ot the inner surface of the side wall 69 is the header 62. No top wall is provided for the container in order that it may be open to atmosphere for the discharge to atmosphere of any odors in the water discharged to the aerator. The side walls 8B and El maybe formed as ccntinuations of theV corre spending walls of the condenser I3. Y

The container is divided into numerous chaine bers or compartments by means of a plurality of partitions. One such partition 10 extends from end wail 68 to end wall 61, and at its upper edge is ush with the upper edges of the end walls. y

Over more than hal! its length. however, the partition is cut away near the bottom wall Bl so as tgprovide at the bottom of the partition an elongated opening 1l. Extending transversely of the containerbetween the side wall 88 and the fuel portion of the partition 10 is a second partition 12 spaced a short distance from the end wall lli. This partition extends to the bottom wall BIA, but is only about half as high as the peripheral walls 0i.' the container. A third Apartition 13 alsoextends transversely of the container between side wall 6! and the partition 1li. This partition extenck tothe bottom wall of the container and is flush with the topledge of the peripheral walls. It is spaced from the end wall 00 a distance approximately twice the spacing of the partition 12. Division of the container into chambers is com longit ally of the container between the end wall 61 and the partition 13. This partition is comparatively close to the partition 10 and extends to the bottom wall 65. but terminates somewhat short of the upper edge of the peripheral walls and hence of the upper edge of the

partitions

10 and 13. It is believed apparent that the four partitions divideV the container into ilve chambers or compartments designated in the order of their formation in the above description, respectively, 1B, 11, 18, 19` and 80.

The vapor passes over the exterior of the4 eted by a fourth partition 1l which extends Formed in the partition 1li adjacent the end wall B8 isla V-shaped notch 82, the apex of which is disposed Just slightly below the upper edge of the partition 14. The purpose o! this notch so located with its apex below the level of the upper edge of the partition 14 is to permit any scum that may form on the surface of the water in the compartment 16 to dow oil into compartment 11 which is the waste flow-oil` compartment, being formed with a discharge opening Il in the bottom of the side wall I9. A V-shaped notch BI similar to the notch I2 is also formed in the partition 13. The apex of this notch is below the top edge oi the partition 1l, permitting excess water in the compartment 19 to now into oompartment 18 and thence `over partition 12 into compartment 11. Near its lower edge. the partition 13 ls formed with an opening, and inserted in this opening to control the ow of water therethrough is a check valve B5. This valve is disposed to prevent flow of water from the compartment 18 to the compartment 18, but to permit flow in the reverse direction; It is for the purpcselof` constantly maintaining in the compartment 1B a reserve supply of water that may iiow into the compartment I9, should the water therein fall below a desired level, that the partltion 12 is provided. This partition extends well above the check valve controlled opening in the partition 13 and thus maintains a reserve of water with a head suilicient to open the check valve and discharge to the compartment 18 should the water in that compartment drop below a desired level.

It is to be understood that the aerator is constantly supplied with lan excess quantity of water. As a matter of fact, it is a feature o! this invention that excess quantities of water are supplied to all of the parts of the distillation unit. This will best be understood from a. consideration oi the fluid system of the distillation unit which will now be described. This system is best understood from the diagrammatic showing thereof in Fig. 5, and reference will primarily be made to that figure. However, for the most part, that system is also shown as it actually is constructed in some one or other of the remaining figures, and where possible the actual construction thus shown will be identified by the same reference character applied Vto the diagrammatic showing of Fig. 5. For convenience, the system will be described in the order of the flow of water from its source, which may be a creek, a lake, or any other natural accumulation, to its discharge from the unit as potable, clear, and germ-free distillate.

Initiating such la system is an intake conduit 9|! leading to a pump 8|, which will hereinafter be termed the cold water pump. This pump, as clearly seen in Figs. 1, and 6 to 8, is mounted on the plate 33 so as to be removable therewith, and is driven from the engine 35 by a belt 82 running over one ofthe pulleys 3.1. In Figs. 1 and 6 to 8. the conduit, is shown short and capped. It is understood, of course. the distillation unit will carry adequate conduit means, usually hosing, which will be attached to the conduit S0 to form an extension thereof. In fact it may in some instances even prove desirable to carry a booster pump to lift the water from the source to approximately the level of the pump 9|. Leading from the discharge side of the pump 9i is a conduit 93 opening through the closure 58 of the cooler Il to discharge to an appropriate chamber formed by the baille B0 between the closure and the head 50. Interposed in this conduit 93 to control the now of water therethrough is a valve Sl. The water thus supplied through the conduit 93 acting as a coolant flows through the tubes 51 and thence through a conduit 95 leading from the closure S to the closure plate 56 of the condenser |3, and to the lowermost of the chambers formed by the bailles 55 between the head 54 and the closure plate 56. The water or coolant, thus partially heated by the heat subtracted from the condensate in the cooler, flows through the tubes 53 of the condenser i3, as previously described.

Tapped into the condenser at a point short of the upper terminus thereof, as best seen in Fig. 5, is a conduit 90 designed and proportioned to take off and discharge directly to waste a portion of the water flowing through the cooler and condenser, and serving as a coolant. This conduit 06, clearly shown in Fig. 3, extends from the condenser upwardly and partially over the aerator I2 to terminate approximately over the compartment 18. The conduit 96 is closed at its end by a cap 01 but is cut away at 9B on its underneath side to discharge downwardly into the compartment of the aerator. Leading from the upper and final terminus of the condenser is a conduit 99. This conduit, as best seen in Figs. 2 and 3, also extends upwardly and laterally to project over the aerator I2. This conduit is disposed over the compartment 16 and extends over substantially the full length of the compartment and throughout its horizontal portion has its top half cut away to form a trough |00. It will be noted that the water discharged to the compartment 16 passes through the final. uppermost tubes of the condenser not reached by the water discharged through the conduit 05. This water is thus raised to a higher temperature and preferably the distillation unit should be so operated that the temperature of this Water is raised approximately to the boiling point, while the water discharged through the conduit 96 has a temperature of from 180 to 200 Fahrenheit.

The Water discharged through the conduit 80 to the compartment 18 will overow the compartment and discharge over the top of the partition 12 to the compartment 11. From there it will flow through the opening 83 through a Waste conduit |03 threaded into the opening 83. The water discharged through conduit 99 to compartment 10 will in the main now underneath the partition 10 into the compartment 00 and thence over the upper edge of the partition 1I to the compartment 19. A smaller quantity will, as previously described, flow through the notch 02 so as to skim off any scum that may form on the top of the compartment 10. With proper operation, an excess quantity oi' water will be supplied to the compartment 19 and will flow oi through the notch 04. However, should this excess temporarily be absent, a certain level of water will be maintained in the compartment 19 by reason of the constant and excessive supply of lwater discharged through conduit 98 to the compartment 11.

The heated and aerated water in the compartment is utilized as the feed water for the lrst effect evaporating means l0. To that end, a conduit |04 opens at one end through the side wall B9 of the aerator (see Fig. 2) and connects with the intake of a pump |05 which, to differentiate from the pump 9|, will hereinafter be called the hot water pump. This pump (see Figs. 6 to 8) is mounted on the plate 33 to be removable therewith, and is driven by a belt |06 running Cab over the remaining one of the pulleys 31. Leading from the discharge port of the pump |05 is a conduit |01 discharging at the other end to the first effect evaporating means l0. interposed in this conduit |01 is a valve |08 to control the quantity of water discharged to the rst eil'ect evaporating means. In order that the water in the first eiect evaporating means, especially if sea water is being distilled, may not attain too high a salt concentration, or for that matter a concentration of any other substance that is not evaporated, means is provided for effecting a continuous change in the water in the iirst effect evaporating means. To that end, feed water is supplied to the rst evaporating means in quantities substantially in excess of the amounts evaporated. The amount of excess varies with the condition of the Water being distilled, but for average conditions the excess supplied is from seventy-five per cent to one hundred per cent of the amount of the distillate.

With provision made to supply feed water in excess of the rate of evaporation, means is also provided for a discharge from the rst effect evaporating means of the excess feed water supplied. Herein this supply and exhaust of excessive feed water is utilized not only to provide for continuous change in the water of the first effect evaporatlng means, but to supply and, in fact, again continuously change the feed water for the second effect evaporating means. To that end, provision is made to have the nrst effect evaporating means blown-down to the second effect evaporating means. Consequently, there is cony nected between the boiler of the first effect evaporating means and the second eiect evaporating means a conduit |09 having interposed therein a valve for controlling the rate or quantity of blow-down. This rate of blow-down should, of course, be enough to keep the water in the rlrst effect evaporating means at a constant, proper level, and at the same time supply to the second effect evaporating means feed water at a. rate in excess of the evaporation from the second eect evaporating means. The excess is discharged from the second effect evaporating means through a conduit leading to waste. This conduit contains no valve and for proper operation there should be a continuous discharge from this conduit. Conduit |09 is, of course, connected to boiler |1 at a point below the normal water level so as to always be covered with water, while conduit is connected just at the normal water level of the second evaporating means.

The steam that is generated in the rst eiect evaporating means is, by a pair of conduits ||2 and ||3 opening to the boiler |1 near the top thereof through the end |0, led to the heat exchangers 41 and 45, respectively. In passing through the plurality of coils forming each of the heat exchangers I5 and 41, the steam is condensed and the condensate is by the steam pressure in the coils forced through the conduits Il and IIE, connected respectively to the heat exchangers 41 and 45, to the bottom of the condenser |3. To regulate the ow of condensate there is interposed in the conduit ||4 a valve IIB, and in the conduit ||5 a valve ||1. These should be so adjusted that only condensate ows through the conduits, and not uncondensed, live steam. The heat given off by the steam in condensing operates through the heat exchangers 45 and I1 to evaporate the water in the second effect evaporating means. This vapor then flows through the tube 50 and conduit 5| to the header 52 and thence downwardly through the header and over the tubes 53 of the condenser I3, where the vapor is condensed into condensate. This condesate joins with the condensate received from the heat exchangers I and 41 and flows from the condenser through a conduit H8 that leads from the bottom of the condenser to the top side of the cooler I4 where the condensate is further cooled by contact with the tubes 51. Finally there leads from the cooler a conduit H8, suitably capped or valved, through which the final distillate may be withdrawn for use.

Provision is, of course, made for the initial filling of the boiler and the casing 42 to the proper level, as well as for the draining of the boiler, the casing 42, the heat exchangers d1 and l5, the condenser, and the cooler. All or parts of the conduits or valves for those purposes are shown in Fig. l, but have not been incorporated in the diagrammatic showing of Fig. 5, inasmuch as they are more or less conventional and form no part of this invention. No detailed description thereof has therefore been made.

Where the distillation unit is mounted upon a wheeled undercarriage structure, so as to be portable, one or more tanks |20 may be supported beneath the frame I 5 for carrying the fuel oil and the gasoline necessary to operate the oil burner and the motor 35.

It is believed apparent from the foregoing that we have perfected a unique and vastly improved distillation unit, and especially one that is particularly well adapted for use in the field where it is called upon to distill the Worst types of water, and many times sea water with its initial high salt content. With our distillation unit, an

excessively high salt content in either evaporating means is prevented by the continuous change of the water in the evaporating means. Moreover, not only does this feature contribute to an ultimately potable distillate, but an odor-free distillate is further assured by the provision for aerating all of the water that is ultimately con`- verted into distillate. This aeration as herein effected is performed with the Water at a high temperature where the odors are most easily taken off.

In the past great diiiiculty has been experienced when distilling salt water because of the foaming which occurs when the water is heated in the first effect of the still. In our apparatus the gases which are formed or liberated in impure or salt Water when it is heated, are driven off in the aerator with the result that foaming is substantially eliminated in the evaporators.

Our construction also provides for ready access to the heating means or heat exchangers of both evaporating means. Any scale which accumulates may thus be easily and thoroughly removed. assuring the most efficient operation of the evaporating means at all times. Increased efficiency is also assured by the employment, first, of the heated coolant water of the cooler and the condenser for feed water of the first evaporating means, secondly, of the heated water of the first evaporating means as the feed water for the second evaporating means, and, thirdly, of the steam of the rst evaporating means as the heat for evaporating the water of the second evaporating means. Other features and advantages, it is believed, are clearly apparent from the objects and the detailed description of the invention.

We claim as our invention:

i. A distillation unit comprising, in combination, a first evaporator comprising a casing and fire tubes within the casing, a second evaporator comprising a casing and heat exchanger means within the casing, a first conduit leading from a point hear the top of the casing of the first evaporator to the heat exchanger means of the second evaporator, a second conduit leading from the casing of the first evaporator at a point be low the normal water level thereof to the casing of the second evaporator, a valve means interposed in said second conduit open during the operation of the distillation unit to permit a continuous flow of water from the first evaporator to the second evaporator at a rate in excess of the rate of evaporation therefrom, a conduit discharging to waste opening to said second evaporator at about the normal water level therein, a condenser, means for conducting the vapor of said second evaporator to said condenser, a cooler, means for conducting the condensate from the condenser and the condensate from said heat exchanger to said cooler, an aerator, means for supplying coolant water to said cooler and to said condenser, means discharging a portion of the coolant water to the aerator, and means for drawing water from said aerator and discharging the same continuously to said first evaporator at a rate in excess of the rate of evaporation of both evaporators.

2. A distillation unit comprising a first evaporator, a second evaporator, means for continuously supplying water to the first evaporator at a rate of from 75% to 100% ln excess of the rate of distillate production from both evaporators, a conduit connected at one end to the first evaporator at a point below the normal water level thereof and at the other end to the second evaporator, a valve in said conduit normally adjusted to permit a continuous flow of water from the first evaporator to the second evaporator at a rate in excess of the rate of evaporation from the second evaporator and to maintain a predetermined water level in said first evaporator, and a normally open conduit connected to the second Aevaporator at about the normal'water level thereof fory the continuous discharge therethrough of the excess water supplied to the second evap orator.

3. A distillation unit comprising, in combination, evaporating means. an upright condenser having a plurality of horizontally disposed tubes interconnected for the passage o coolant water laterally and progressively upwardly, a cooler having a plurality of tubes for the passage or coolant water laterally and progressively upwardly, a conduit drawing vapor from the cranorating means and discharging the same to th topyof the condenser for downward flow of the vir and distillate over the tubes of the condenser, and means for supplying aerated and heated water to the evaporating means including a pump operable to draw water from a source and discharge the same to the cooler at a rate greatly in excess of the feed water requirements of the evaporating means, a conduit leading from the cooler and discharging to the lowermost tubes of the condenser for now of the coolant water progressively upwardly through the tubes of the condenser counter to the direction of flow of vapor and distillate in the condenser, a conduit tapped into the coolant water circuit of the condenser at a point in advance of the end thereof for the discharge to waste of a major portion oi the coolant permitting a reduced quantity of coolant to pass through the remaining tubes of the condenser to be heated to a temperature just short of boiling, a conduit tapped into the coolant water circuit of the condenser at the end thereof, an aerator to which the last named conduit discharges at a rate in excess of the feed wate`r requirements of the evaporating means, a conduit leading from the aerator to the evaporating means, a pump interposed therein and operable continuously to supply heated and aerated feed water to the evaporating means at a rate of '75% to 100% in excess of the evaporation requirements of the evaporating means, and means for permitting a continuous blow-down of the evap-Y orating means.

4. A distillation unit comprising, in combination, evaporating means, a water cooled condenser to which vapor from the evaporating means is conducted to be condensed into distillate, a water-operated cooler connected to said condenser to receive the distillate therefrom, and means for supplying aerated and heated water to said evaporating means including a pump operable to draw Water from a source and discharge the same to said cooler at a rate greatly in excess of the feed water requirements of said evaporating means, a conduit leading from said cooler to said condenser for conducting the partially heated water to said condenser for further absorption of heat while reducing the vapor in the condenser to distillate, an aerator having a first, a second and a third compartment, with the second and` third compartments operable to maintain a reserve of liquid, a conduit tapped into the coolant water circuit of said condenser at a point in advance of the end thereof and discharging to the second compartment of said aerator and designed to take oi the major part of the coolant flowing through said condenser, a conduit tapped into the coolant water circuit of said condenser at the end thereof and discharging to the third compartment of said aerator, the rate of discharge being in excess of the feed water requirements of said evaporating means, said third compartment overowing into the first compartment and said second compartment providing a reserve operable to flow into said first compartment if the overflow from said second compartment is insufficient to maintain the water in the first compartment at a predetermined level, a feed water conduit leading from the bottom of said first compartment to said evaporating means, a pump in said conduit continuously supplying feed water to said evaporating means at a rate in excess of the evaporation thereof, and means for permitting a continuous blow-down from said evaporating means.

5. A distillation unit comprising, in combinaaseaseo tion, a first evaporator comprising a casing and nre tubes within the casing, a second evaporator comprising a casing and heat exchanger means in the form of upright coils within the casing, a first conduit leading from a point near the top of the casing of the first evaporator to the top of the heat exchanger means of the second evaporator, a second conduit leading from the casing of the first evaporator at a point below the normal water level thereof to the casing of the second evaporator, valve means interposed in said second conduit open during the operation of the distillation unit to permit a continuous flow of water from the first evaporator to the second evaporator, a conduit discharging to waste opening to the casing of the second evaporator at about the normal water level of the casing, an upright condenser having a plurality of horizontally disposed tubes interconnected for the passage of coolant water laterally and progressively upwardly, a cooler having a plurality of tubes for the passage of coolant water laterally and progressively upwardly, a conduit leading from the top of the casing of the second evaporator and discharging vapor to the top of the condenser for downward flow over the tubes of the condenser, a conduit leading from the bottom oi' the heat exchanger coils of the second evaporator to the bottom of the condenser, a. common conduit leading from the bottom of the condenser to the cooler for iiow of the distillate over the tubes of the cooler, and means for supplying aerated and preheated feed water to the first evaporator comprising a coolant pump operable to draw water from a source and discharge the same to the tubes of the cooler at a rate many times in excess of the feed water requirements of the evaporators, a conduit leading from the cooler and discharging to the lowermost tubes of the condenser for flow of the coolant water progressively upwardly through the tubes of the condenser counter to the direction of flow of vapor and distillate in the condenser, a conduit tapped into the coolant water circuit of the condenser at a point in advance of the end thereof.r a 1second conduit tapped into the coolant wateri'ircuit of the condenser at the end thereof with the ow of Water through the last named first and second conduits being proportioned so that the water flowing through said last named second conduit is raised to a temperature just short of boiling, an aerator to which said last named second conduit discharges, and

means including a pump for drawing water from said aerator and continuously supplying the same to the first evaporator at a rate of '75% to 100% in excess of the evaporation requirements of both evaporators.

JOHN C. CLEAVER. JULES VERNE RESEK.

DISCLAIMER 2,388,599.-John C. Cleaver and Jules Verne Resek, Whitefish Bay, Wis.

Patent dated Nov. 6, i945,

LATION UNIT.

Dls'rIL- Disclaimer filed Aug. 28,

1946, by the assignee, Cleaver-Brooks (Tompfmy. Hereby enters this disclaimer to claim l of said Letters Patent.

[Ojcal Gazette October l, 1.946.]

coolant permitting a reduced quantity of coolant to pass through the remaining tubes of the condenser to be heated to a temperature just short of boiling, a conduit tapped into the coolant water circuit of the condenser at the end thereof, an aerator to which the last named conduit discharges at a rate in excess of the feed wate`r requirements of the evaporating means, a conduit leading from the aerator to the evaporating means, a pump interposed therein and operable continuously to supply heated and aerated feed water to the evaporating means at a rate of '75% to 100% in excess of the evaporation requirements of the evaporating means, and means for permitting a continuous blow-down of the evap-Y orating means.

JOHN C. CLEAVER. JULES VERNE RESEK.

Patent dated Nov. 6, i945,

LATION UNIT.

Dls'rIL- Disclaimer filed Aug. 28,

[Ojcal Gazette October l, 1.946.]