US3699006A

US3699006A - Vacuum still having heat exchange coils and particle means therewith

Info

Publication number: US3699006A
Application number: US63863A
Authority: US
Inventors: James G Hasslacher
Original assignee: JAMES G HASSLACHER
Current assignee: JAMES G HASSLACHER
Priority date: 1970-08-14
Filing date: 1970-08-14
Publication date: 1972-10-17
Anticipated expiration: 1989-10-17
Also published as: FR2101951A5; CH544560A; ES394223A1; DE2135442A1; NL7111175A; AU3151171A; GB1347545A; IL37262A0; ZA714603B; BE770891A

Abstract

A METHOD AND APPARATUS FOR DISTILLING LIQUIDS INCLUDING A CLOSED HOUSING VERTICALLY DIVIDED INTO FEED AND DISTILLATE COMPARTMENTS HAVING RESPECTIVELY INTERCOMMUNICATING EVAPORATION AND CONDENSATION CHAMBERS THEREABOVE. A VACUUM IS INDUCED IN THE CHAMBERS BY INTRODUCING A PRIMING CHARGE TO FILL THE HOUSING AND EXPEL THE FREE GASES FROM A VENT IN THE TOP, FOLLOWED BY CLOSING THE VENT AND DISCHARGING A PORTION OF THE PRIMING CHARGE. DISTILLATION IS ACCOMPLISHED BY HEATING THE LIQUID IN THE FEED COMPARTMENT TO PRODUCE VAPOR IN THE EVAPORATION CHAMBER AND BY COOLING THE VAPOR TRANSMITTED TO THE CONDENSATION CHAMBER TO PRODUCE DISTILLATE WHICH DRIPS INTO THE BOTTOM OF THE DISTILLATE COMPARTMENT. AN IRREVRSIBLE HEAT PUMP MAY BE THE MAIN SOURCE OF BOTH HEAT AND COLD. THE TRANSMISSION OF VAPOR FROM EVAPORATION TO CONDENSATION CHAMBERS MAY BE INCREASED BY USING A DUCTED FAN, WHICH WOULD ALSO SERVE BOTH TO DECREASE THE VAPOR PRESSURE IN THE EVAPORATION CHAMBER AND TO INCREASE THE VAPOR PRESSURE IN THE CONDENSATION CHAMBER. TO PREVENT THE SUDDEN FORMATION OF LARGE AMOUNTS OF VAPOR ON THE HEATING COILS IN THE FEED COMPARTMENT, NONBUOYANT SPHERES MAY BE USED ON TOP OF THE COILS AND BUOYANT SPHERES MAY BE USED BELOW THE COILS.

TO INCREASE THE SURFACE OF THE WATER IN THE EVAPORATION CHAMBER, JETS OPERATING BY THE SUCTION OF THE VACUUM MAY BE USED TO INJECT THE LIQUID INTO THE CHAMBER OR INTO THE FEED COMPARTMENT.

Description

Oct. 17, 1972 J. G. HASSLACHER ,6

VACUUM STILL HAVING HEAT EXCHANGE COILS AND ARTICLE MEANS THEREWITH Filed Aug. 14, 1970 5 Sheets-Sheet 1 x 2 z u; vo- 2 M c C! II 5- (I) S :5 i 5 w m 8 m 5 2 e 2 VALVE-PUMP SYSTEM l2l us T0 RESIDUE STORAGE AREA FROM unmsmuso uo. SUPPLY ATTOIN BY Oct. 17, 1972 J. G. HASSLACHER 3,

VACUUM STILL HAVING HEAT EXCHANGE COILS AND ARTICLE MEANS THEREWITH 5 Sheets-Sheet 2 Filed Aug. 14, 1970 FIG. 2

ATTORNEY Oct. 7, 1972 J. G. HASSLACHER 3,699,006

VACUUM STILL HAVING HEAT EXCHANGE COILS AND ARTICLE MEANS THEREWITH Filed Aug. 14, 1970 5 Sheets-Sheet 15 VALVE PUMP SYSTEM FIG. 4

ATTOIN BY Oct 1972 J. G. HASSLACHER 3,699,006

VACUUM STILL HAVING HEAT EXCHANGE COILS AND ARTICLE MEANS THEREWITH Filed Aug. 14, 1970 5 Sheets-Sheet 4 5|? 539 540 A SIQW g I IV I J u 534 L JV l l :3

b 52l I Oct. 17,

J. G. SSLACHER 3,699,006 VACUUM LL NG T EXCH E COILS A AR LE ME THERE H Filed Aug. 14, 1970 5 Sheets-Sheet 5 Anon United States Patent 3,699,006 VACUUM STILL HAVING HEAT EXCHANGE COILS AND PARTICLE MEANS THEREWITH James G. Hasslacher, 7010 University Drive, Richmond, Va. 23229 Filed Aug. 14, 1970, Ser. No. 63,863 Int. Cl. B01d 3/10 US. Cl. 2034 6 Claims ABSTRACT OF THE DISCLOSURE A method and apparatus for distilling liquids including a closed housing vertically divided into feed and distillate compartments having respectively intercommunicating evaporation and condensation chambers thereabove. A vacuum is induced in the chambers by introducing a priming charge to fill the housing and expel the free gases from a vent in the top, followed by closing the vent and discharging a portion of the priming charge. Distillation is accomplished by heating the liquid in the feed compartment to produce vapor in the evaporation chamber and by cooling the vapor transmitted to the condensation chamber to produce distillate which drips into the bottom of the distillate compartment. An irreversible heat pump may be the main source of both heat and cold. The transmission of vapor from evaporation to condensation chambers may be increased by using a ducted fan, which would also serve both to decrease the vapor pressure in the evaporation chamber and to increase the vapor pressure in the condensation chamber. To prevent the sudden formation of large amounts of vapor on the heating coils in the feed compartment, nonbuoyant spheres may be used on top of the coils and buoyant spheres may be used below the coils. To increase the surface of the water in the evaporation chamber, jets operating by the suction of the vacuum may be used to inject the liquid into the chamber or into the feed compartment.

BACKGROUND OF THE INVENTION This invention relates generally to distillation apparatus and more particularly to an apparatus for purifying polluted, brackish or salt water.

Mankind has been increasingly polluting fresh water and, thereby disturbing the ecology. An economic means must be found to separate water from liquid or dissolved pollutants.

Nature has for a long time been polluting fresh water with salt. In arid places near oceans or salt seas, such as Southern California or Northern Africa, and Islands, such as Bermuda, where excessive population, increasing per capita consumption, and agriculture have strained the use of naturally pure water, and inexpensive source of pure water is also needed.

There have been attempts, in the prior art, to provide stills which are adapted to provide fresh water from brackish or sea water in areas such as those described above. Examples are taught in the US. patent to Walford 3,248,307, issued Apr. 26, 1966, and the patent to Kimmerle 3,232,846, issued Feb. 1, 1966, which teaches the use of solar heat.

SUMMARY OF THE INVENTION This invention provides a distillation apparatus which is ideally suited to purify water in economically developed 3,699,006 Patented Oct. 17, 1972 "ice areas where pollution is a problem or in arid, economically underprivileged areas by furnishing a device which has inexpensive construction costs, which is simple in operation, and which operates with a low power requirement.

This invention also provides water of the greatest purity which can be used in such other devices as steam boilers.

This invention further provides a means of salvaging chemicals which in the past have been discarded because of too great a dilution but which after distillation would be concentrated in the residue.

This invention also provides an apparatus which can be employed to reduce such factors as thermal pollution from nuclear reactors by providing a still which is adapted to utilize waste heat from reactors as a source.

This invention further provides a use for natural gas in regions where it has had to be discarded because the region was remote from the area in which the natural gas could be utilized.

This invention also provides a distillation device which is ideally suited for operation at low power requirements by furnishing an apparatus which utilizes, to a maximum degree, the ambient resources such as gravity, solar heat, and atmospheric pressure.

This invention further provides an apparatus which has a minimum of moving parts whereby it is simple and rugged in construction, relatively maintenance-free, and, therefore, suited for operation in remote and/or technically backward areas.

In a preferred embodiment, the invention provides a distillation device having a housing; a wall vertically dividing the housing into a feed compartment and a distillation compartment; the feed and distillation compartments each having an inlet and outlet at its base; the feed and distillate compartments including respectively evaporation and condensation chambers in the upper ends thereof; means for establishing a vacuum in the chambers; means for transmitting vapor between the chambers; thermal means supplying heat to the feed compartment and cold to the condensation chamber; means to prevent the sudden formation of vapor on the heating coils; and means to increase the liquid surface in the feed compartment.

These and other attendant objects and advantages of the invention will become better understood by those skilled in the art by reference to the following detailed description when viewed in light of the accompanying drawings wherein each figure number is used as the hundreds digit, wherein like components throughout the figures thereof are indicated by like numerals of tens and units digits (unless there are two or more additional like components, in which case letters are added to the numerals) wherein:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view of a distillation device in accordance with the invention;

FIG. 2 is a fragmentary view similar to FIG. 1 showing the use of a ducted fan, a variation in accordance with the invention;

FIG. 3 is a fragmentary view similar to FIG. 1 showing the use of buoyant and nonbuoyant spheres, variations in accordance with the invention;

FIG. 4 is a fragmentary view similar to FIG. 1 showing the use of jets, a variation in accordance with the invention;

FIG. 5 is a fragmentary view similar to FIG. 1 showing a valve-pump system in detail in accordance with the invention;

FIG. 6 is a fragmentary view similar to FIGS. 1 and 4, combined, showing a more sophisticated valve-pump system in detail in accordance with the invention; and

FIG. 7 is a view of the device of FIG. 1 showing a preferred installation of a desalinization device in an arid area near a large body of salty water and near a supply of natural gas,

And wherein the following index gives the tens and units digits and the nomenclature for all the items used in the figures:

INDEX still 01 housing 02 top wall 03 side wall 04 bottom wall 05 feed compartment 06 distillate compartment 07 dividing wall 08 evaporation chamber 09 condensation chamber 10 vent 11 vent valve 12 heat pump heating coil 13 heat pump heat conduits 14 heat pump 15 heat pump cooling coils 16 heat pump cold conduits 17 feed conduit 18 valve-pump system 19 distillate conduit 20 residue conduit 21 intake conduit 22 output conduit 23 tank conduit 24 fan structure 25 augmenting heating coil 26 augmenting heat conduits 27 buoyant spheres 28 nonbuoyant spheres 29 jet nozzles 30 float 31 upstanding jet conduits 32 jet conduit 33 base conduit 34 flow conduit 35 pump inlet conduit 36 pump 37 pump outlet conduit 38 priming conduit 39 connector conduit 40 separation conduit 41 intake valve 42 flow valve 43 residue valve 44 priming valve 45 separation valve 46 output valve 47 controlled feed conduit 48 reversible connector conduit 49 reversible conduit 50 first alternate priming conduit 51 feed operational conduit 52 feed pump inlet conduit 53 feed pump 54 feed pump outlet conduit 55 second alternate priming conduit 56 irreversible connector conduit 57 distillate operational conduit 58 first preferred priming conduit 59 distillate pump inlet conduit 4 60 distillate pump 61 distillate pump outlet conduit 62 storage filling conduit 63 second preferred priming conduit :64 reversible valve 65 first alternate priming valve 66 feed operational valve 67. second alternate priming valve 68 controlled feed valve 69 distillate operational valve 70- first preferred priming valve 71 storage filling valve 72 second preferred priming valve 73 priming storage tank 74 supports 75 residue storage area 76 intake storage area 77 body of salty water 78 dam 79 dam conduit 80 dam valve DESCRIPTION OF THE PREFERRED EMBODIMENTS On FIG. 1 a still, generally indicated at 100, comprises a housing 101 which is in the form of a frustoconical enclosure having top, side, and

bottom walls

102, 103, and 104 thereto. For economy and durability the housing may be fabricated, as illustrated, from precast or cast in situ concrete or may be fabricated from steel or any other material as desired. The structure may also comprise combinations of materials and/or structural techniques as may be found appropriate from the location and environment at the site. Although the configuration illustrated is generally preferred for construction and maintenance purposes (e.g., lack of corners), the housing may be cylindrical, square, triangular, or any other shape found desirable within the limits of practicality. The generally tapering walls illustrated structurally compensate for the change in local pressure on the walls due to static head as is common in the design of water-containing structures. The walls may have parallel surfaces or be otherwise conformed as design requirements dictate.

The housing 101 includes bottom, side, and top wall means and is vertically divided into a feed compartment 105 and a distillate compartment 106 by a dividing wall or partition means 107 which extends upwardly within the housing 101 to a point spaced from the top wall 102. The dividing wall 107 could also extend to the top of the housing 101 and be provided with openings for the purposes of providing communication between the compartments. If a barometric leg is used, the minimum height of the dividing wall 107 or any opening therein is dictated by the liquid to be distilled and is a function of the head or external height of liquid to be distilled and the external pressure, and the density of the liquid. The minimum height above the outside liquid height, for example, can be ascertained by dividing the external, ambient pressure by the liquid density. In case of water at atmospheric pressure, for example, the minimum height is 33.9 feet above the outside water level. If a barometric leg is not used, the dividing wall 107 or any opening therein must be sufficiently high to keep the liquid in the feed compartment 105 separate from the liquid in the distillate compartment 106.

The areas above the levels of the liquids in the feed and distillate compartments 105 and 106 comprise evaporation and

condensation chambers

108 and 109 respectively. A vent 110, controlled by an on-oif valve 111, is disposed at the uppermost point in the still through the top wall 102 to provide venting of the

chambers

108 and 109.

The feed compartment is provided with a heat exchange means comprising a heating coil 112 which connects through insulated conduits 113 to the heat output side of a heat pump .114. The coil 112 is preferably disposed to be totally immersed in the liquid in the feed compartment 105 and is preferably coated with a deposit and corrosion resistant material such, for example, as polytetrailuoroethylene or the like. Other portions of the still which may be subject to deposit or attack may be similarly coated if so desired.

The condensation chamber 109 is provided with a heat exchange means comprising a cooling coil 115 which is connected to the cold producing side of the heat pump .114 through insulated conduits 116. Care should be taken that, due to low temperatures, condensate does not solidify or accumulate on the coil 115, thereby reducing the efiiciency thereof. Such conditions may be avoided, if encountered, by providing temperature sensing means (not shown) which will signal controls to adjust the pressures of the refrigerant in the heat pump.

Although the reverse cycling thereof is not required for this invention, heat pumps suitable for use with this invention are well known in the art as is evidenced by Encyclopedia of Chemical Technology (1953), Kirk- Othmer, vol. 11, page 642, and the operation thereof is understood to those skilled in the art. In areas where natural gas is abundant, it should probably be used as fuel for the heat pump, which would be similarly constructed to those used in a gas refrigerator.

Means other than the heat pump 114 may be utilized in place of or to augment heating and/or cooling if so desired. Such means would be particularly appropriate where waste heat or cold is produced as a by-product of some other operation, and such means would be even more desirable where use of waste heat from a nuclear reactor, for example, would preclude or reduce thermal pollution of the environment while, at the same time, reducing or eliminating the heat requirements of the still. Solar heaters and other similar devices may also be incorporated to similarly reduce heat input requirements.

The housing 101 is provided with a feed conduit 117 which is communicative with both a lower portion of the feed compartment 105 and a valve-pump system 118. The housing is also provided with a distillate conduit 119 which is communicative with both a lower portion of the distillate compartment 106 and the valve-pump system 118. The valve-pump system 118 is also communicative with and controls the flow in: a residue conduit 120', which goes to the residue storage area; an intake conduit 121, which comes from the supply of the liquid to be distilled; an output conduit 122, from which the pure distillate leaves the still 100; and a tank conduit 123, which goes to the priming storage tank. A more detailed description of the valve-pump system 118 appears post.

In operation, the vent valve 111 is opened, and a priming charge is introduced into the housing 101. Where rapid start-up is desired, the priming charge comprises distilled liquid, preferably from a previous cycle. When there is no priming storage tank because of the expense involved in its construction or when there has been no previous cycle, the priming charge must comprise undistilled liquid, and the liquid in the distillate compartment 106 must be routed to the feed compartment 105 until the liquid in the distillate compartment 106 is pure. This routing takes place through the distillate conduit 11 9, the valve-pump system 118, and the feed conduit 117.

The housing 101 is filled at least to the top of sloped top wall 102 to eliminate all of the free gases from the interior, whereupon the vent valve 111 is closed. Then the priming charge is allowed to drain or is pumped out of the housing 101 until the liquid level in the compartments 105 and 106 is below the top of the dividing wall 107 or any openings therein. Next, the heat pump 114 is turned on, and after the distillate has become pure, the distillate is removed from the still 100. The operation of the still is continuous, until, in some cases, the residue has to be removed.

In the embodiment of FIG. 2, components thereof corresponding to like components in the preceding embodiments are indicated by like numerals, only of the next higher order. In this embodiment, the primary distinction over the embodiment in FIG. 1 is the fan structure 224. The fan in this embodiment is ducted because it sits in a round opening in the dividing wall 207. There may be more than one fan, and the fans may not be ducted, although ducting greatly increases the efiiciency of the fan operation, as is known in the art. With a ducted structure, however, gas can be trapped on either side of the uppermost part of the dividing wall 207 during the abovedescribed priming operation, and it is, therefore, required that vents 210a and 21% be provided at the uppermost parts of the top wall 202 on opposite sides of the dividing wall 207. The vents 210a and 21% are valved by means of on-otf valves 211a and 211b, respectively. The fan or fans are turned on at the same time as the heat pumps. Other than the above-described changes, the remainder of the device of FIG. 2 is identical to and operates in the same manner as the above-described embodiment.

The fans serve a quintuple purpose, as is known in the art. They decrease the pressure in the evaporation chamber and increase the circulation over the surface of the undistilled liquid, thereby causing increased evaporation of the undistilled liquid. They increase the flow between the evaporation and condensation chambers. They increase the pressure in the condensation chamber and increase the circulation over the cooling coils, thereby causing increased condensation of the distillate.

To prevent the sudden formation of large quantities of vapor, commonly called thumping or bumping, chem ists use glass beads or bits of broken crockery in test tubes and flasks, which are heated externally. A similar problem arises in an internally heated device. If thumping occurs, large quantities of undistilled liquid will mix with pure vapor and pass over to the condensation chamber, thereby polluting the distillate.

FIG. 3, which is also a fragmentary view similar to FIG. 1, illustrates a solution to this problem. The heat pump heating coil, generally indicated at 312, which is supplied heat by insulated heat pump heat conduits 313, is disposed in horizontal grids. The augmenting heating coil, generally indicated at 325, which is supplied heat by insulated augmenting heat conduits 326, is also disposed in horizontal grids. (N.B. only part of the augmenting heating system is shown. Crosses and dots in the heating coils are used to indicate the direction of internal flow.) Buoyant particles or spheres 327a, 327b, and 327a are placed below each layer of horizontal grid. Nonbuoyant particles or spheres 328a, 328b, 9280, and 328d are placed above each layer of horizontal grid.

Both types of spheres may be made of the same material if buoyancy is controlled by using heavier cores or by using hollow centers. The spheres will not pass through a horizontal grid if the transverse dimension or width of every particle or diameter of every sphere is greater or larger than the horizontal gap between each part of the heating coils or between the coils and the side wall 303 or between the coils and the dividing wall 307. Care should be taken that the spheres do not bend the coils, which may be strengthened by fins or transverse rods anchored to the adjacent walls.

The use of buoyant (low density) and non buoyant (high density) particles, spheres, and the like in gasliquid contacting systems is known in the art, as exemplified in US. Pats. No. 3,122,594 to Kielback; No. 3,302,372 to Hynson et al.; No. 3,348,825 to McIlvaine; and No. 3,- 409,279 to Metrailer. Applicant has adapted the theories expressed in such disclosures in the present vacuum still and the above patents are incorporated by reference in this application.

In FIG. 4, which is also a fragmentary view similar to FIG. 1, jets which operate on the principle that a vacuum Will suck in a liquid are illustrated. In a still using the barometric leg, the jet nozzles 429 must be below the minimum height of the dividing wall 407 or any opening therein. In a vacuum still not using a barometric leg, a float 430 may be used to sense the level of the liquid in the feed compartment 405. The float 430 may not be too close to the nozzles 429, because it might be pushed up by the action of the jet and, thereby, lose its elfectiveness. The nozzles 429 must also not be too near a fan, because the fan might transport spray with vapor. The lower the nozzles 429 are from the surface of the liquid in the compartment 405, the lower will be the height of the fountain, and, hence, the less will be the increase in the surface area of the liquid in feed compartment 405. As is known in the art, more surface area in the feed compartment 405 means that more evaporation takes place in the evaporation chamber 408 and, thereby, that the efficiency of the still is increased.

The jet nozzles 429 are part of upstanding jet conduits 431, which branch from a jet conduit 432. The jet conduit 432 comes from a valve-pump system 418. A base conduit 433 also comes from the valve-pump system 418 and goes to the feed compartment 405. The base conduit 433 and the jet conduit 432 together take the place of the feed conduit 117.

There are many types of valve-pump systems which can be used in the still. FIG. is a fragmentary view of FIG. 1, except that the tank conduit 123 is omitted, and illustrates a valve-pump system 518 which is used in a less expensive variation of the still where the distillate is of primary importance. The intake conduit 521 communicates with a first T member, which further consists of a flow conduit 534 and a pump inlet conduit 535. [Each small circle with a V indicates a valve which will be described below. The pump inlet conduit 535 leads to a unidirectional pump 536, from which comes a pump outlet conduit 537. The pump outlet conduit 537, in turn, communicates with a second T member, which also consists of the residue conduit 520 and a priming conduit 538. The priming conduit 538 next leads to a third T member, which further is composed of the feed conduit 517 and a connector conduit 539. The connector conduit 539 then forms a fourth T member, the other parts of which are the flow conduit 534 and a separation conduit 540. The separation conduit 540 also communicates with a last T member, which also consists of the distillate conduit 519 and the output conduit 522. This valve-pump system 518 also consists of the following on-ofl? valves: an intake valve 541 on the intake conduit 521, a flow valve 542 on the flow conduit 534, a residue valve 543 on the residue conduit 520, a priming valve 544 on the priming conduit 538, a separation valve 545 on the separation conduit 540, and an output valve 546 on the output conduit 522. Pump 536 is controlled by an on-otf switch.

In the below description of the valve-pump system 518 in operation, the pump and all valves are considered to be oif unless they are specified as being on. The still operates without jets and on a barometric leg. To prime the still the pump 536 is turned on, and the vent valve 111 (FIG. 1) and

valves

541 and 544 are opened. In forming the vacuum only

valves

541, 542, and 545 are opened. If recycling is needed to purify the distillate after priming or at any other time, only valve 545 is opened. Normal operation of the still takes place when

only valves

541, 542, and 546 are opened. The residue is removed by turning on the pump 536 and opening

valves

542 and 543, during which time valve 546 may be left open. The housing may be emptied by opening the vent valve 111, valve 546 and either

valves

543 and 544 if the residue is to be saved, or

valves

541 and 542 if the residue is not concentrated enough to be saved. The heat pump and/or the fan or fans are turned on only during recycling and normal operation.

A more sophisticated valve-pum system 618, used where the residue is of primary importance, is shown in FIG. 6, which has the embodiments of FIG. 1 as modified by the embodiments of FIG. 4. The still, in this case, does not operate by using a barometric leg, nor would its priming storage tank return flow be operated mainly by the force of gravity. This variation of the still has jets and probably fan or fans. Valves are controlled by electric power. There must be a device, such as a float so rigged as to put out electrical signals, in the priming storage tank and in both the feed and the distillate compartments to determine the height of the liquid in each. Both feed and distillate compartments have individual monitors capable of putting out electric signals to determine the purity of the liquid. Such devices, as is known by those skilled in the art, usually work on electrical conductivity. Electrically signaling monitors capable of distinguishing between air and liquid are required on the base conduit 633, on the distillate conduit 619, and on the vent above the vent valve 111. Two

unidirectional pumps

653 and 660 are also used. The still operates both continuously and automatically.

An intake conduit 621 communicates with a first T member, which also consists of a controlled feed conduit 647 and a reversible connector conduit 648. The reversible connector conduit 648 goes to a second T member, from which also comes a reversible conduit 649 and a first alternate priming conduit 650. The first alternate priming conduit 650 leads to a third T member, which further consists of a feed operational conduit 651 and a feed pump inlet conduit 652. After a feed pump 653, comes a feed pump outlet conduit 654. The feed pump outlet conduit 654 communicates with a first cross member, which also communicates with the reversible conduit 649, a residue conduit 620, and a second alternate priming conduit 655. The second alternate priming conduit 655 then goes to a fourth T member, which also connects with a base conduit 633 and with the feed operational conduit 651.

The controlled feed conduit 647 leads to a fifth T memher, to which also comes a jet conduit 632 and a separation conduit 640. The separation conduit 640 communicates with a sixth T member, which further communicates with an irreversible connector conduit 656 and a distillate operational conduit 657. The distillate operational conduit 657 goes to a seventh T member, from which comes a first preferred priming conduit 658 and a distillate pump inlet conduit 659. The distillate pump 660 communicates with a distillate pump outlet conduit 661. The distillate pump outlet conduit 661 leads to a second member, which also connects with an output conduit 622, a storage filling conduit 662, and a second preferred priming conduit 663. The storoge filling conduit 662 goes into an eighth T member, from which comes the first preferred priming conduit 658 and a tank conduit 623, and the second preferred priming conduit 663 goes into a ninth T member, from which comes the irreversible connector conduit 656 and a distillate conduit 619.

The valve-pump system 618 also consists of the following electrically controlled on-off valves, each of which is designated by a small circle with a V: a reversible valve 664 on the reversible conduit 649, a first alternate priming valve 665 on the first alternate priming conduit 650, a feed operational valve 666 on the feed operational conduit 651, a residue valve 643 on the residue conduit 620, a second alternate priming valve 667 on the second alternate priming conduit 655, a controlled feed valve 668 on the controlled feed conduit 647, a separation valve 645 on the separation conduit 640, a distillate operational valve 669 on the distillate operational conduit 657, a first preferred priming valve 670 on the firs-t preferred priming conduit 658, an output valve 646 on the output conduit 622, a storage filling valve 671 on the storage filling conduit 662, and a second preferred priming valve 672 on the second preferred priming conduit 663.

Before operation, all pumps, heat pumps, fans, and valves are off or closed. To begin operation the automatic control switch is turned on. If there is sufiicient liquid to fill the housing as determined by the fioat inside the priming storage tank, pump 660 is turned on and vent valve 111 and valves 670 and 672 are opened. If there is insufiicient liquid, pump 653 is turned on and vent valve 111 and

valves

665 and 667 are opened. After the housing has been primed as determined by liquid being above the vent valve 111, all valves including the vent valve 111 are closed, and if it is on, pump 660 is turned off. A vacuum is formed by opening

valves

664, 666 and 645, and if it is not already on, by turning on pump 653. The termination of vacuum formation occurs when the {float in the distillate compartment indicates that the level of the liquid is lower than the top of or the holes in the dividing wall. After the vacuum has been formed, recycling begins and all valves except valve 645 are closed. The pump 653 is turned off, and the heat pump and fan or fans, if they are used, are turned on. Recycling continues until the monitor determining the purity of the liquid in the distillate compartment indicates the liquid is pure. It is then stopped by closing valve 645. Recycling begins again anytime the distillate becomes impure as determined by the monitor in the distillate compartment. New, unprocessed liquid enters the still by opening valve 668 whenever the liquid level in the feed compartment becomes too low, as indicated by the float in the feed compartment. The float in the distillate compartment determines when the distillate should be removed. When it should be removed, valve 669 is opened, pump 660 is turned on, and either valve 671 is opened if the priming storage tank needs filling as determined by the float in the tank or valve 646 is opened. The monitor which measures the impurity of the residue in the feed compartment determines when the residue should be removed. When it should be removed,

valves

666 and 643 are opened and pump 653 is turned on.

To cease operation the automatic control switch is turned off. The heat pump and the fan or fans, if they areused, are turned off by the automatic control switch, which also turns on

pump

653 and 660 and opens the vent valve 111 and

valves

666, 669 and 646. If the residue is concentrated enough to send to the residue storage area as determined by the purity monitor in the feed compartment, valve 643 is opened. If the residue is not concentrated enough, valve 664 is opened. All other valves are closed. Pump 653 runs until air begins coming into the base conduit 633, and pump 660 runs until air begins coming into the distillate conduit 619. When both pumps 653 and 660 stop, all valves including the vent valve 111 are closed, and the still is ready to begin operation again.

FIG. 7 shows a preferred installation of the still 700 already shown in FIG. 1. It is the type built in an arid area, preferably near a large supply of natural gas, since the heat pump 714 can use natural gas as fuel and the electricity for the pump or pumps can be generated by also using natural gas as fuel. The still would not only make pure water but would allow salt to be recovered as a by-product. The housing 701 would be so constructed that the feed chamber would face into the sun and the distillate chamber would face away from the sun (i.e., in the northern hemisphere the feed chamber would be southward, and in the southern hemisphere the feed chamher would be northward). The housing 701 would also be built on a hill so that it would not have to be so high and its walls would not have to be so thick. Internal rinsing of the housing 701 would also be lessened since the volume of the distillate compartment would be made smaller. Incidentally, evaporation in the distillate compartment would be even less if surface area of the distillate were reduced. A priming storage tank 773 is located above the housing 701 on supports 774 so that the preferable priming can be done by gravity. A residue storage area 775 would be shallow, would be open and would have its bottom coated black in order to increase final evaporation. In wetter areas, of course, the residue area would be covered, and the shape of the tank would be engineered so as to hold the residue better. An intake storage area 776 would also have its bottom coated black for preheating purposes, but it would be deeper to slow evaporation. The intake storage area 776 would be separated from a nearby body of salty water 777 by a dam 778 having a dam conduit 779 with a dam valve 780. The whole dam structure prevents fluctuation of the barometric leg caused by tides and waves if the dam valve 780 is opened only at high tides. Operation of the still 700 would occur as described above.

I claim:

1. A liquid distillation device comprising wall means including bottom, side, and top wall means defining a housing, vertically extending partition means projecting upwardly from said bottom and dividing the interior of said housing into side by side feed and distillate compartments, conduit means communicating with the lower portion of each of said compartments, vent means at the top of said housing, valve means for controlling said vent means, said partition means having at least one opening therein beneath the top wall means of said housing to provide vapor intercommunication between said compartments, means for controlling liquid flow through both said conduit means, means for establishing a vacuum in the upper portion of said compartments so as to constitute the same as evaporation and condensation chambers comprising priming means communicating with one of said conduit means for introducing a priming charge of liquid into the lower portion of at least one of said compartments with said valve means for said vent means open to completely fill said compartments to exclude noncondensable gases from within said housing, the closing of said valve means and the discharge of a portion of said liquid from the other of said compartments establishing a vacuum in said chambers above the level of the lower part of said opening in said partition means, a heat exchanger within said feed compartment below the level of said opening in said partition means and thus below the liquid level therein for applying heat to such liquid to produce vapor in the evaporation chamber to flow through said opening in said partition means into said condensation chamber, cold producing coil means arranged in said condensation chamber above the level of said opening in said partition means for cooling the vapor transmitted to the condensation chamber to establish a distillate in said distillate compartment, said heat exchanger including heat transfer medium receiving conduit means arranged in at least one horizontally extending layer, buoyant particles disposed beneath the conduit means of said layer to curtail sudden formation of vapor during distillation, and said particles having a transverse dimension greater than any horizontal gap between the conduit means in such layer and between the end conduit means of such layer and the adjacent side wall means and partition means.

2. A liquid distillation device comprising wall means including bottom, side, and top wall means defining a housing, vertically extending partition means projecting upwardly from said bottom and dividing the interior of said housing into side by side feed and distillate compartments, conduit means communicating with the lower portion of each of said compartments, vent means at the top of said housing, valve means for controlling said vent means, said partition means having at least one opening therein beneath the top wall means of said housing to provide vapor intercommunication between said compartments, means for controlling liquid flow through both said conduit means, means for establishing a vacuum in the upper portion of said compartments so as to constitute the same as evaporation and condensation chambers comprising priming means communicating with one of said conduit means for introducing a priming charge of liquid into the lower portion of at least one of said compartments with said valve means for said vent means open to completely fill said compartments to exclude non-condensable gases from within said housing, the closing of said valve means and the discharge of a portion of said liquid from the other of said compartments establishing a vacuum in said chambers above the level of the lower part of said opening in said partition means, a heat exchanger within said feed compartment below the level of said opening in said partition means and thus below the liquid level therein for applying heat to such liquid to produce vapor in the evaporation chamber to flow through said opening in said partition means into said condensation chamber, cold producing coil means arranged in said condensation chamber above the level of said opening in said partition means for cooling the vapor transmitted to the condensation chamber to establish a distillate in said distillate compartment, said heat exchanger including heat transfer medium receiving conduit means arranged in at least one horizontally extending layer, nonbuoyant particles disposed on top of the conduit means of said layer to curtail sudden formation of vapor during distillation, and said particles having a transverse dimension greater than any horizontal gap between the conduit means in such layer and between the end conduit means of such layer and the adjacent side wall means and partition means.

3. A liquid distillation device comprising wall means including bottom, side, and top wall means defining a housing, vertically extending partition means projecting upwardly from said bottom and dividing the interior of said housing into side by side feed and distillate compartments, conduit means communicating with the lower portion of each of said compartments, vent means at the top of said housing, valve means for controlling said vent means, said partition means having at least one opening therein beneath the top wall means of said housing to provide vapor intercommunication between said compartments, means for controlling liquid flow through both said conduit means, means for establishing a vacuum in the upper portion of said compartments so as to constitute the same as evaporation and condensation chambers comprising priming means communicating with one of said conduit means for introducing a priming charge of liquid into the lower portion of at least one of said compartments with said valve means for said vent means open to completely fill said compartments to exclude non-condensable gases from within said housing, the closing of said valve means and the discharge of a portion of said liquid from the other of said compartments establishing a vacuum in said chambers above the level of the lower part of said opening in said partition means, a heat exchanger within said feed compartment below the level of said opening in said partition means and thus below the liquid level therein for applying heat to such liquid to produce vapor in the evaporation chamber to flow through said opening in said partition means into said condensation chamber, cold producing coil means arranged in said condensation chamber above the level of said opening in said partition means for cooling the vapor transmitted to the condensation chamber to establish a distillate in said distillate compartment, said heat exchanger including heat transfer medium receiving conduit means arranged in at least one horizontally extending layer, buoyant and non-buoyant particles disposed respectively beneath and on top of the conduit means of said layer to curtail sudden formation of vapor during distillation, and said particles having transverse dimen sion greater than any horizontal gap between the conduit means in such layer and between the end conduit means of such layer and the adjacent side wall means and partition means.

4. A method of distilling liquid comprising providing an enclosure around side by side feed and distillate compartments, providing inter communication between the upper portions of said compartments, opening a vent at the top of at least one of said compartments, introducing a priming charge of liquid into the lower portion of at least one of said compartments sufficient to fill both compartments with liquid so as to exclude all noncondensable gases therefrom, closing said vent, discharging a portion of said introduced liquid from the lower portion of at least one of said compartments to induce a vacuum in the upper portion of both of said compartments, applying heat directly to the liquid in one compartment through at least one layer of a heat exchanging coil disposed beneath the level of the liquid in said one compartment to evaporate liquid therein to produce vapor in the upper portion thereof to flow into the upper portion of the other compartment, preventing too rapid a formation of vapor by providing buoyant particles beneath the coil of the layer with such particles having a transverse dimension greater than any gap formed between and relative to the coil of such layer, condensing said vapor in said other compartment by contacting the same with at least one cold producing coil in the upper portion of said other compartment to form a distillate and withdrawing such distillate from the lower portion of said other compartment.

5. A method of distilling liquid comprising providing an enclosure around side by side feed and distillate compartments, providing intercommunication between the upper portions of said compartments, opening a vent at the top of at least one of said compartments, introducing a priming charge of liquid into the lower portion of at least one of said compartments sufiicient to till both compartments with liquid so as to exclude all noncondensable gases therefrom, closing said vent, discharging a portion of said introduced liquid from the lower portion of at least one of said compartments to induce a vacuum in the upper portion of both of said compartments, applying heat directly to the liquid in one compartment through at least one layer of a heat exchanging coil disposed beneath the level of the liquid in said one compartment to evaporate liquid therein to produce vapor in the upper portion thereof to flow into the upper portion of the other compartment, preventing too rapid a formation of vapor by providing non-buoyant particles on top of the coil of the layer with such particles having a transverse dimension greater than any gap formed between and relative to the coil of such layer, condensing said vapor in said other compartment by contacting the same with at least one cold producing coil in the upper portion of said other compartment to form a distillate and withdrawing such distillate from the lower portion of said other compartment.

6. A method of distilling liquid comprising providing an enclosure around side by side feed and distillate compartments, providing intercommunication between the upper portions of said compartments, opening a vent at the top of at least one of said compartments, introducing a priming charge of liquid into the lower portion of at least one of said compartments suflicient to fill both compartments with liquid so as to exclude all noncondensable gases therefrom, closing said vent, discharging a portion of said introduced liquid from the lower portion of at least one of said compartments to induce a vacuum in the upper portion of both of said compartments, applying heat directly to the liquid in one compartment through at least one layer of a heat exchanging coil disposed beneath the level of the liquid in said one compartment to evaporate liquid therein to produce vapor in the upper portion thereof to flow into the upper portion of the other compartment, preventing too rapid a formation of vapor by providing buoyant and non-buoyant particles respectively beneath and on top of the coil of the layer with such particles having a transverse dimension greater than any gap formed between and relative to the coil of such layer, condensing said vapor in said other compartment by contacting the same with at least one cold producing coil in the upper portion of said other compartment to form a distillate and withdrawing such distillate from the lower portion of said other compartment.

References Cited UNITED STATES PATENTS Stone 203-26 Ross 203-DIG 17 Lusknader 203-11 Cummings 20'3-11 Harper 203-11 Adrassy 159-1 S Day 203-26 14 Grow 203-11 Creskoif 203-11 Hardy 159-1 S Bie 203-11 Brown 202-205 Schenk 202-205 Bimpson et a1. 202-205 WILBUR L. BASCOMB, JR., Primary Examiner US. Cl. X.R.

159-1 S; 202-205, 234, 236; 203-11, 26, 90, 91, DIG 1, DIG 4, DIG 7, DIG 17; 261-94 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. B699QOO6 Dated fI 17, 197

Inve James G. Hasslacher It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column l line 50, "Islands" should read islands Column 6', line 32, "chem" should read chem- Column 6 1ine 51, "928 should read 52a Column 8, line #7, between "second" and "member" cross should be inserted.

Column 8, line 50, "storoge" should read storage Column 13, line '9, "Lusknader" should read Lustenader Column 13, line 12, "Adrassy" should read Andrassy IN THE DRAWING: I

The drawing should be corrected as follows:

-- In Fig. 7, the heat pump cold conduits connected to the top of heat pump 71 and now bearing the numeral "71 should read 716 Signed and sealed this 20th day of August 197 ERE S i McCOY GIBSON, JR. C. MARSHALL DANN 1 I Attesting Officer Commissioner of Patents FORM P0-1 0 Y uscoMM-Dc 6O376-P69 fi' U.S, GOVERNMENT PRINTING OFFICE I 9'9 0-366-33I.