Multiple-effect vapor chamber distillation system and methods of use

A distillation system having a plurality of chambers, an input conduit connected to each chamber to deliver an aqueous fluid to each chamber; a pressure reducing valve connected to the input conduit; a waste output conduit connected to a waste collection compartment of each chamber; and condensate output conduit connected to a condensate collection compartment of each chamber. An evaporation wall of each chamber is constructed to maintain an evaporation surface temperature that is greater than a condensation surface temperature of a condensation wall of each chamber. The aqueous fluid forms a fluid coating, which moves down the evaporation wall. A saturation pressure differential is created as water from the aqueous fluid evaporates from the evaporation wall and condenses on the condensation wall forming an aqueous condensate, which moves down the condensation wall and is collected as an aqueous distillate in the condensate collecting compartment.

BACKGROUND

In 2012, 20×109barrels (bbl) of produced water (referred to herein as production or aqueous fluid) were produced in the oil and gas industry in the United States. Handling produced waste water presents a major challenge for the extraction and production companies. In addition, several states with the highest waste water output suffer from increasingly scarce fresh water resources—aggravating the competition between oil and gas companies and local farmers. Treatment of the waste water produced by oil and gas operations could benefit the agriculture and food production industries in at least two ways: (1) the water requirement of the oil and gas companies could be satisfied without exerting pressure on fresh water sources, and (2) treated produced water could be used for irrigation and livestock use, reuse in oil and gas operations, or other uses.

One factor that hampers treatment of waste water from oil and gas operations is that most production sites are located in remote areas with limited access to electricity. Further, some of the natural gas produced from certain wells might not be economic to refine and transport and thus is burned into the atmosphere. Due to the above considerations, a thermal desalination system that can use waste heat has advantages over current membrane-based systems.

Constructing a desalination plant near a production site might not be economically justified due to the inherently transient quantity of produced water generated by wells. Thus, there is a need for a portable modular thermal desalination system that may be transported for on-site treatment of the produced waste water at an oil and gas operation site. It is to this end that the water distillation/purification/desalinization system of the present disclosure is directed.

DETAILED DESCRIPTION

The present disclosure is directed to a novel compact and portable vapor chamber distillation (desalination) system for thermal treatment of production fluid, such as waste water, or other types of water which are desired to be desalinated or otherwise purified. The system offers performance ratios comparable to state-of-the-art commercial desalination plants in a compact, modular, and portable design—which may significantly reduce costs of purification. The vapor chamber distillation system may work with a variety of low grade heat sources available at a production site—such as waste heat and solar energy, for example—to treat the waste water produced at oil and gas operations for beneficial reuse.

Before further describing various embodiments the multiple-effect vapor chamber distillation system of the present disclosure in more detail by way of exemplary description, examples, and results, it is to be understood that the embodiments of the present disclosure are not limited in application to the details as set forth in the following description. The embodiments of the present disclosure are capable of being practiced or carried out in various ways not explicitly described herein. As such, the language used herein is intended to be given the broadest possible scope and meaning; and the embodiments are meant to be exemplary, not exhaustive. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting unless otherwise indicated as so. Moreover, in the following detailed description, numerous specific details are set forth in order to provide a more thorough understanding of the disclosure. However, it will be apparent to a person having ordinary skill in the art that the embodiments of the present disclosure may be practiced without these specific details. In other instances, features which are well known to persons of ordinary skill in the art have not been described in detail to avoid unnecessary complication of the description. While the present disclosure has been described in terms of particular embodiments, it will be apparent to those of skill in the art that variations may be applied to the apparatus and/or methods and in the steps or in the sequence of steps of the methods described herein without departing from the concept, spirit, and scope of the inventive concepts as described herein. All such similar substitutes and modifications apparent to those having ordinary skill in the art are deemed to be within the spirit and scope of the inventive concepts as disclosed herein.

All patents, published patent applications, and non-patent publications referenced or mentioned in any portion of the present specification are indicative of the level of skill of those skilled in the art to which the present disclosure pertains, and are hereby expressly incorporated by reference in their entirety to the same extent as if the contents of each individual patent or publication was specifically and individually incorporated herein.

As utilized in accordance with the apparatus, methods and compositions of the present disclosure, the following terms, unless otherwise indicated, shall be understood to have the following meanings:

Throughout this application, the terms “about” and “approximately” are used to indicate that a value includes the inherent variation of error in a parameter. As used herein the qualifiers “about” or “approximately” are intended to include not only the exact value, amount, degree, orientation, or other qualified characteristic or value, but are intended to include some slight variations due to measuring error, manufacturing tolerances, stress exerted on various parts or components, observer error, wear and tear, and combinations thereof, for example. The terms “about” or “approximately”, where used herein when referring to a measurable value is also meant to encompass, for example, variations of ±20% or ±10%, or ±5%, or ±1%, or ±0.1% from the specified value. As used herein, the term “substantially” means that the subsequently described event, circumstance or parameter completely occurs or that the subsequently described event, circumstance, or parameter occurs to a great extent or degree. For example, the term “substantially” means that the subsequently described event, circumstance, or parameter occurs at least 90% of the time, or at least 95% of the time, or at least 98% of the time.

As used herein, all numerical values or ranges include fractions of the values and integers within such ranges and fractions of the integers within such ranges unless the context clearly indicates otherwise. Thus, to illustrate, reference to a numerical range, such as 1-10 includes 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, as well as 1.1, 1.2, 1.3, 1.4, 1.5, etc., and so forth. Reference to a range of 1-50 therefore includes 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, etc., up to and including 50, as well as 1.1, 1.2, 1.3, 1.4, 1.5, etc., 2.1, 2.2, 2.3, 2.4, 2.5, etc., and so forth. Reference to a series of ranges includes ranges which combine the values of the boundaries of different ranges within the series. Thus, to illustrate reference to a series of ranges, for example, a range of 1-1,000 includes, for example, 1-10, 10-20, 20-30, 30-40, 40-50, 50-60, 60-75, 75-100, 100-150, 150-200, 200-250, 250-300, 300-400, 400-500, 500-750, 750-1,000, and includes ranges of 1-20, 10-50, 50-100, 100-500, and 500-1,000. The range 100 units to 2000 units (for example where units are Pa) therefore refers to and includes all values or ranges of values of the units, and fractions of the values of the units and integers within said range, including for example, but not limited to 100 units to 1000 units, 100 units to 500 units, 200 units to 1000 units, 300 units to 1500 units, 400 units to 2000 units, 500 units to 2000 units, 500 units to 1000 units, 250 units to 1750 units, 250 units to 1200 units, 750 units to 2000 units, 150 units to 1500 units, 100 units to 1250 units, and 800 units to 1200 units. Any two values within the range of about 100 units to about 2000 units therefore can be used to set the lower and upper boundaries of a range in accordance with the embodiments of the present disclosure.

Where used herein, the term “waste water” is intended to refer to all types of water that contains solutes that are desired to be removed from the water source, including but not limited to saltwater, wellwater, industrial water, contaminated freshwater, and water produced from oil and gas operations. The terms “waste water” and “produced water” and “production fluid” may be used interchangeably herein.

Where used herein, the term “facial surface” in intended to refer to a surface that faces another surface.

The inventive concepts of the present disclosure will be more readily understood by reference to the following examples and embodiments, which are included merely for purposes of illustration of certain aspects and embodiments thereof, and are not intended to be limitations of the disclosure in any way whatsoever. Those skilled in the art will promptly recognize appropriate variations of the apparatus, compositions, components, procedures and method shown below.

Referring now toFIG. 1, shown therein is a vapor chamber distillation system10constructed in accordance with the present disclosure. The vapor chamber distillation system10will be referred to hereinafter as the distillation system10. The distillation system10may be used for thermal treatment of a production fluid (e.g., an aqueous fluid), such as waste water, or other types of water which are desired to be desalinated or otherwise purified. For example, but not by way of limitation, the distillation systems of the present disclosure may be used for treating waste water at an oil and gas production site. The distillation system10generally includes a chamber12, an input conduit14fluidly connected to the chamber12, a pressure reducing valve16connected to the input conduit14, a waste output conduit18connected to the chamber12, and a condensate output conduit20connected to the chamber12.

As will be explained in further detail below, a production fluid22(an aqueous fluid) may be conveyed through the input conduit14and delivered to the chamber12where the production fluid22is distilled, desalinated, or otherwise purified. An amount of the production fluid22exits the waste output conduit18and an amount of an aqueous distillate24exits the condensate output conduit20. The distillation system10may further include a first heat exchanger26located at an intersection between the input conduit14and the waste output conduit18and a second heat exchanger27located between the input conduit14and the condensate output conduit20for transferring heat from the waste output conduit18and aqueous distillate24, respectively, to the input conduit14. The distillation system10may further include a first pump28positioned on the condensate output conduit20for discharging the aqueous distillate24from the chamber12and a second pump29positioned on the waste output conduit18for discharging an aqueous waste fluid51(e.g., brine) from the chamber12.

The chamber12includes a top end30, a bottom end32, an evaporation wall34having an inner surface36and an outer surface38, and condensation wall40positioned opposite (facing) the evaporation wall34and having an inner surface42and an outer surface44. The chamber12has an internal pressure. The inner surface36of the evaporation wall34may be referred to as an evaporation surface. The inner surface42of the condensation wall40may be referred to as a condensation surface. The inner surface42of the condensation wall40faces the inner surface36of the evaporation wall43.

The chamber12further includes an inlet46positioned at the top end30and a baffle48to direct the production fluid22from the inlet46to the inner surface36of the evaporation wall34to form a liquid coating50on the inner surface36of the evaporation wall34. The chamber12also includes a waste collection compartment52positioned at the bottom end32adjacent to the evaporation wall34to receive the aqueous waste fluid50formed from the unevaporated production fluid22that drains from the evaporation wall34, and a condensate collection compartment54positioned at the bottom end32adjacent to the condensation wall40to receive the aqueous distillate24from the condensation wall40. The waste collection compartment52has a waste outlet56at a lower end thereof, and the condensate collecting compartment has a condensate outlet58at a lower end thereof.

The input conduit14is fluidly connected to the baffle48to deliver the production fluid22to the chamber12. The pressure reducing valve16is connected to the input conduit14and configured to adjust the internal pressure of the chamber12proportional to the saturation pressure corresponding to the vapor temperature inside the chamber12. The waste output conduit18is connected to the waste outlet56of the waste collection compartment52of the chamber12, and the condensate output conduit20is connected to the condensate outlet58of the condensate collection compartment54of the chamber12. The pumps28and29function to isolate the internal pressure of the chamber12from the external atmosphere if the internal pressure of the chamber12is less than the external atmosphere. If the internal pressure of the chamber12is greater than the external atmosphere the pumps28and29may be replaced with pressure reducing valves. As the skilled artisan will understand, the pumps28and29have a low pressure side and a high pressure side. When the internal pressure of chamber12is less than the external atmosphere the pumps28and29raise the pressure of the fluid passing through the pumps28and29such that a first pressure at the discharge side is higher than a second pressure at the suction side.

The inner surface36of the evaporation wall34is constructed to maintain an evaporation temperature that is greater than a condensation surface temperature of the inner surface42of the condensation wall40such that when the production fluid22is delivered from the input conduit14into the chamber12and the production fluid22forms the liquid coating50, which moves down and coats the inner surface42of the evaporation wall34towards the waste collection compartment52, a saturation pressure differential is created as water from the production fluid22evaporates from the inner surface36of the evaporation wall34and condenses on the inner surface42of the condensation wall40to form an aqueous condensate53, which moves down the inner surface42of the condensation wall40and is collected as the aqueous distillate24in the condensation collecting compartment54. This process may be referred to herein as “filmwise” evaporation.

When the distillation system10is in use, air and any other non-condensable gases may be initially purged from within the chamber12. The production fluid22(or aqueous fluid, e.g., waste water) is introduced to the chamber12at inlet46and is directed by the baffle48to form the liquid coating50trickling down the inner surface36of the evaporation wall34of the chamber12. Simultaneously, a thermal energy source, such as thermal energy64“q”, may be supplied to the external surface38of evaporation wall34. Due to reduced pressure inside the chamber12, the liquid coating50evaporates by absorbing the supplied heat64“q” as the liquid coating50trickles down the evaporation wall34. The heat source64may be any heat source known in the art such as, but not limited to, natural gas, low pressure steam from a cogeneration power plant, or solar energy. As a result, a saturated water vapor60fills an inner space62of the chamber12and the internal pressure of the chamber12rises. As the pressure increases, the corresponding saturation temperature of the saturated water vapor60also increases. As indicated above, the condensation wall40opposite to the evaporation wall34is maintained at a slightly lower temperature than that of evaporation wall34. Adjacent to the condensation wall40, a temperature gradient is formed within the vapor60that equals the temperature of the condensation wall40, on one end, and the saturation vapor temperature corresponding to the internal pressure of the chamber12, on the other end. As long as the vapor saturation temperature is less than the temperature of the condensation wall40, the vapor60adjacent to the condensation wall40may be in a superheated state and will not condense. However, once the saturation vapor temperature surpasses the temperature of condensation wall40, the vapor60adjacent to the condensation wall40will become subcooled and condense on the inner surface42of the condensation wall40forming the aqueous condensate53, which trickles down the inner surface42of the condensation wall40forming the aqueous distillate24.

The portion of the liquid coating50, which does not evaporate, trickles down the inner surface36of the evaporation wall34and is collected as an aqueous waste fluid51by the waste collection compartment52. From the waste collection compartment52, the aqueous waste fluid51passes though the waste output conduit18, which passes through the heat exchanger26, thereby transferring heat from the waste output conduit18to the input conduit14and preheating newly supplied production fluid22in the input conduit14. In this way, the distillation system10is able to use a “recycled” heat source to heat the newly supplied production fluid22, in addition to the heat source64. The aqueous waste fluid51then passes from the heat exchanger26and is output from the chamber12through the waste output conduit18(which may transport the waste to a disposal mechanism or may transport the waste to a subsequent chamber for further processing, as described below with reference toFIG. 2).

After the formation of the aqueous condensate53on the inner surface42of the condensation wall40, a temperature gradient is established across the thickness of the aqueous condensate53with the liquid-vapor interface at the vapor saturation temperature and the wall-liquid interface at a condensation wall temperature. The latent heat released during the condensation of the vapor60on the condensation wall40leaves the chamber12at a temperature equal to that of the condensation wall40. The aqueous condensate53trickles down the inner surface42of the condensation wall40forming the aqueous distillate24which is collected in the condensate collection compartment54. From the condensate collection compartment54, the collected aqueous distillate24is removed from the distillation system10via the condensate output conduit20for or another use such as, but not limited to, reuse in the oil and gas extraction or irrigation.

The evaporation wall34and the condensation wall40may be constructed from any suitable metal or other material which functions in accordance with the requirements of the present disclosure. In general, any high thermal conductivity solid material with an operating temperature range greater than 0° C., has sufficient mechanical strength may be used to construct the evaporation wall34and/or the condensation wall40. Candidate materials include, but are not limited to, metals such as aluminum and aluminum alloys, stainless steel, nickel, and coated iron, and high thermal conductivity ceramics such as alumina and Shapal™ Hi-M Soft, and high thermal conductivity plastics and polymers. In non-limiting embodiments, the evaporation wall34and condensation wall40thickness may be in a range from about 0.1 mm to about 5 mm. In one embodiment the thickness ranges from about 0.1 mm to about 3 mm, depending on the mechanical strength of the material. A thinner wall may be made from a high thermal coactivity material for beneficial heat transfer.

In non-limiting embodiments, a special coating (e.g., a Teflon material) may be applied to the inner surface36of the evaporation wall34and/or the inner surface42of the condensation wall40for reducing deposit formation on the inner surface36by creating a non-stick surface. The special coating may also be applied to the inner surface42of the condensation wall40to promote a special regime of condensation, e.g. dropwise condensation, which may promote heat transfer.

The input conduit14, the waste output conduit18, and the condensate output conduit20may be comprised of any pipe known in the art for transferring production fluids (e.g., waste water produced by oil and gas operations) and waste fluids and distilled fluids therefrom. The conduits14,18, and20may be made of any material suitable for conveying a production fluid such as, but not limited to, polymer, rubber, plastic, cast iron, ductile iron, aluminum, copper, brass and silicon and other materials known for corrosion resistant properties. The input conduit14may have a diameter between 1 mm and 1000 mm inches (or millimeters). In one embodiment, the diameter of the input conduit14is about 20 mm. The waste output conduit18may have a diameter between 1 mm and 1000 mm. In one embodiment, the diameter of the waste output conduit18is about 20 mm. The condensate input output20may have a diameter between 1 mm and 1000 mm. In one embodiment, the diameter of the condensate output conduit is about 20 mm.

The pressure reducing valve16connected to the input conduit14may be any known pressure reducing valve known in the art suitable for controlling the pressure of fluid flowing through a pipe such as but not limited to pilot-operated or direct-acting pressure reducing valves. One having ordinary skill in the art will appreciate that pressure reducing valves are configured to reduce a higher inlet pressure to a lower downstream pressure, regardless of changing flow rate and/or varying inlet pressure. Such pressure reducing valves are generally formed of a corrosion resistant material such as, but not limited to, brass, plastic, aluminum, and various grades of stainless steel. The preferred material may depend on the operating temperature and the corrosiveness of the fluid being conveyed through the input conduit14.

The heat exchangers26and27may be any heat exchanger known in the art for transferring heat from one location to another by transmitting the heat between fluids such as, but not by way of limitation, a plate heat exchanger or shell-and-tube heat exchanger. The heat exchange26may be formed from a variety of materials known in the art such as, but not limited to copper, stainless steel, and copper/nickel allow. Other materials may be used in the heat exchanger's device fittings, end bonnets, and heads.

The pump28and the pump29may be any pump known in the art such as, but not limited to, centrifugal pumps and positive displacement pumps for aiding in the discharge of a fluid from a chamber. The pump28is used to equalize the pressure of the aqueous distillate24with ambient pressure and discharge the fluid from the chamber12if the internal pressure of the chamber is smaller than the external atmosphere. The pump29is used to equalize the production or waste fluid (e.g., brine) with ambient pressure and discharge the fluid from the chamber12if the internal pressure of the chamber is less than the external atmosphere.

Referring now toFIG. 2, shown therein is another embodiment of a distillation system10ashown with a plurality of chambers12connected in a series. The chambers12are labeled inFIG. 2with the notations12a,12b,12c, and12dfor purposes of clarity. The distillation system10aincludes an input conduit14aconnected to a first chamber12a, a first transfer conduit18aextending from the first chamber12aand connecting to a second chamber12b, a second transfer conduit18bextending from the second chamber12band connecting to a third chamber12c, a third transfer conduit18cextending from the third chamber12cand connecting to fourth chamber12d, and a condensate output conduit18dextending from the fourth chamber12d. The distillation system also includes a first condensate output conduit20aextending from the first chamber12a, a second condensate output conduit20bextending from the second chamber12band connecting to the first condensate output conduit20a, a third condensate output conduit20cextending from the third chamber12cand connecting to the first condensate output conduit20a, and a fourth condensate output conduit20dextending from the fourth chamber12dand connecting to the first condensate output conduit20a.

As will be explained in further detail below, a production fluid22amay be conveyed through the input conduit14aand delivered to the chamber12awhere the production fluid22ais distilled. An amount of the production fluid22aexits the transfer conduit18aand an amount of an aqueous distillate24aexits the condensate output conduit20a. The distillation system10amay further include a plurality of heat exchangers26a/26b/26c/26dlocated at a plurality of respective intersections between the input conduit14aand the transfer output conduits18a/18b/18c(respectively) and between the input conduit14aand the waste output conduit18dfor transferring heat from either the transfer conduit18a/18b/18cor the waste output conduit18dto the input conduit14a. The distillation system10amay also include a plurality of heat exchangers27a/27b/27c/27dlocated at a plurality of intersections between the input conduit14aand the condensate output conduits20a/20b/20c/20d(respectively) for transferring heat from the distillate flow to the input stream. The distillation system10may further include a plurality of pumps28a/28b/28c/28dpositioned on the condensate output conduit20for discharging the aqueous distillate24a(e.g., distilled water) from the chambers12a/12b/12c/12d. The distillation system may also include a pump29apositioned on the waste output conduit18dfor expelling an aqueous waste fluid from the fourth chamber12d.

As will be explained below, each of the first, second, third, and fourth chambers12a/12b/12c/12dof the distillation system10acomprise an evaporation wall34a/34b/34c/34d(respectively) and a condensation wall34a/34b/34c/34d(respectively). The distillation system10amay be referred to as a “forward feed” system. In certain embodiments, the opposite side of the condensation wall34aof one chamber (e.g., chamber12a) serves as the heat source and evaporation wall34bof the downstream chamber (i.e., chamber12b). In certain embodiments, the condensation wall and evaporation wall of adjacent chambers about each other and are connected but do not form a single integral wall between the two chambers. In the high temperature and pressure (input) end (i.e., first chamber12a) of the cascade of the chambers12a/12b/12c/12d, the production fluid22awithin chamber12ais vaporized by a heat source64a“Q” supplied to the evaporation wall34a. The temperature at which evaporation occurs depends on the available heat source, such as natural gas, low pressure steam from a cogeneration power plant, electrical heater, or solar energy. An amount of saturated vapor60aformed by evaporation from the evaporation wall34atravels across the chamber12ato the condensation wall40aof the chamber12a, where the water vapor is condensed to an aqueous condensate53aand flows to and out of a bottom end32aof the chamber12aas the aqueous distillate24a. This process also occurs in each of the consecutive chambers12b,12c, and12d.

Now referring to each chamber in more detail, the first chamber12ahas a first internal pressure, a first top end30a, a first bottom end32a, a first evaporation wall34ahaving an inner surface36a(or evaporation surface) and an outer surface38a, a first condensation wall40apositioned opposite the first evaporation wall34aand having an inner surface36a(or condensation surface) and an outer surface38a, a first inlet46apositioned at the first top end30a, a first baffle48ato direct the production fluid22afrom the first inlet46ato the inner surface36aof the first evaporation wall34ato form a first fluid coating50a(or liquid coating) on the inner surface42aof the first evaporation wall34a, a first waste collection compartment52apositioned at the first bottom end32aadjacent to the first evaporation wall34ato receive the production fluid22afrom the evaporation wall34a, and a first condensate collection compartment54apositioned at the first bottom end32aadjacent to the condensation wall40ato receive the aqueous distillate24afrom the first condensation wall40a. The first waste collection compartment52ahas a first waste outlet56a, and the first condensate collecting compartment54ahas a first condensate outlet58a.

The inner surface36aof the evaporation wall34ais constructed to maintain an evaporation surface temperature that is greater than a condensation surface temperature of the inner surface42aof the condensation wall40a. When the production fluid22ais delivered from the input conduit14ainto the first chamber12aand the production fluid22aforms the liquid coating50a, which moves down the inner surface42bof the first evaporation wall34aas a first waste fluid towards the first waste collection compartment52a, a saturation pressure differential is created as water from the production fluid22aevaporates from the inner surface36aof the first evaporation wall34aand condenses on the inner surface42aof the first condensation wall40ato form a first aqueous condensate53a, which moves down the inner surface42aof the first condensation wall40aand is collected as the aqueous distillate24ain the first condensation collecting compartment54a.

The second chamber12bhas a second internal pressure, a second top end30b, a second bottom end32b, a second evaporation wall34bhaving an inner surface36b(or evaporation surface) and an outer surface38b, and a second condensation wall40bpositioned opposite the second evaporation wall34band having an inner surface36band an outer surface38b. The second evaporation wall34bis positioned adjacent or integral the first condensation wall40aof the first chamber12a. The first condensation surface42aof the first chamber12aand the second evaporation surface36bof the second chamber12bmay comprise (1) facial surfaces of a first common wall shared by the first chamber and the second chamber, or (2) facial surfaces of separate but abutting walls of the first chamber and the second chamber, respectively. For example, as shown inFIG. 2A(for illustrative purposes), a condensation surface42cof the third chamber12cand an evaporation surface36dof the fourth chamber12dmay comprise of separate but abutting walls of the third chamber12cand the fourth chamber12d. In this configuration, the two adjacent chambers12cand12dmay be modular and placed next to each other—allowing the heat form the condensation surface42cto transfer to the evaporation surface36d. It should be appreciated that the configuration shown inFIG. 2Amay be used for each of the chambers12a-d. It should also be appreciated that the configuration of the chamber walls is not limited to being shared common walls or abutting walls, but may be configured in any known means suitable in the art for heat transfer.

The second chamber12balso has a second inlet46bpositioned at the second top end30band a second baffle48bto direct a production fluid22b(i.e., the first aqueous waste fluid from the first chamber) from the second inlet46bto the inner surface36bof the second evaporation wall34bto form a second fluid coating50b(or liquid coating) on the inner surface42bof the second evaporation wall34b. The second chamber12bfurther includes a second waste collection compartment52bpositioned at the second bottom end32badjacent to the second evaporation wall34bto receive a second waste fluid from the second evaporation wall34b, and a second condensate collection compartment54bpositioned at the second bottom end32badjacent to the second condensation wall40ato receive a second aqueous distillate24bfrom the second condensation wall40b. The second waste collection compartment52bhas a second waste outlet56b, and the second condensate collecting compartment54bhas a second condensate outlet58b.

The inner surface36bof the second evaporation wall34bis constructed to maintain an evaporation surface temperature that is greater than a condensation surface temperature of the inner surface42bof the second condensation wall40b. When the production fluid22bis delivered from the transfer conduit18ainto the second chamber12band the production fluid22bforms the liquid coating50b, which moves down the inner surface42bof the second evaporation wall34btowards the second waste collection compartment52b, a saturation pressure differential is created as water from the production fluid22bevaporates from the inner surface36bof the second evaporation wall34band condenses on the inner surface42bof the second condensation wall40bto form a second aqueous condensate53b, which moves down the inner surface42bof the second condensation wall40band is collected as the aqueous distillate24bin the second condensation collecting compartment54b.

The second internal pressure of the second chamber12bis less than the first internal pressure of the first chamber12asuch that the temperature required for the water to evaporate from the inner surface36bof the second evaporation wall34bof the second chamber12bis less than the temperature required for the water to evaporate from the inner surface36aof the first evaporation wall34aof the first chamber12a.

The third chamber12chas a third internal pressure, a third top end30c, a third bottom end32c, a third evaporation wall34chaving an inner surface (or evaporation surface)36cand an outer surface38c, and a third condensation wall40cpositioned opposite the third evaporation wall34cand having an inner surface (or condensation surface)36cand an outer surface38c. The third evaporation wall34cis positioned adjacent or integral the second condensation wall40bof the second chamber12b. The second condensation surface42bof the second chamber12band the third evaporation surface36cof the third chamber12cmay comprise (1) facial surfaces of a second common wall shared by the second chamber and the third chamber, or (2) facial surfaces of separate but abutting walls of the second chamber and the third chamber, respectively.

The third chamber12calso has a third inlet46cpositioned at the third top end30cand a third baffle48cto direct the production fluid22c(i.e., the second aqueous waste fluid from the second chamber) from the third inlet46cto the inner surface36cof the third evaporation wall34cto form a third aqueous coating50c(or liquid coating) on the inner surface42cof the third evaporation wall34c. The third chamber12cfurther includes a third waste collection compartment52cpositioned at the third bottom end32cadjacent to the third evaporation wall34cto receive the production fluid22c(i.e., a third aqueous waste fluid) from the third evaporation wall34c, and a third condensate collection compartment54cpositioned at the third bottom end32cadjacent to the third condensation wall40cto receive a third aqueous distillate24cfrom the third condensation wall40c. The third waste collection compartment52chas a third waste outlet56c, and the third condensate collecting compartment54chas a third condensate outlet58c.

The inner surface36cof the evaporation wall34cis constructed to maintain an evaporation surface temperature that is greater than a condensation surface temperature of the inner surface42cof the condensation wall40c. When the production fluid22c(i.e., the second aqueous waste fluid from the second chamber) is delivered from the transfer conduit18binto the third chamber12cand the production fluid22cforms the liquid coating50c, which moves down the inner surface42cof the evaporation wall34ctowards the waste collection compartment52c, a saturation pressure differential is created as water from the production fluid22cevaporates from the inner surface36cof the third evaporation wall34cand condenses on the inner surface42cof the third condensation wall40cto form a third aqueous condensate53c, which moves down the inner surface42cof the third condensation wall40cand is collected as the aqueous distillate24cin the third condensation collecting compartment54c.

The third internal pressure of the third chamber12cis less than the second internal pressure of the second chamber12bsuch that the temperature required for the water to evaporate from the inner surface36cof the third evaporation wall34cof the third chamber12cis less than the temperature required for the water to evaporate from the inner surface36bof the second evaporation wall34bof the second chamber12b.

The fourth chamber12dhas a fourth internal pressure, a fourth top end30d, a fourth bottom end32d, a fourth evaporation wall34dhaving an inner surface (or evaporation surface)36dand an outer surface38d, and a fourth condensation wall40dpositioned opposite the fourth evaporation wall34dand having an inner surface (or condensation surface)36dand an outer surface38d. The fourth evaporation wall34dis positioned adjacent or integral the third condensation wall40cof the third chamber12c. The third condensation surface42cof the third chamber12cand the fourth evaporation surface36dof the fourth chamber12dmay comprise (1) facial surfaces of a third common wall shared by the third chamber and the second chamber, or (2) facial surfaces of separate but abutting walls of the third chamber and the fourth chamber, respectively.

The fourth chamber12dalso has a fourth inlet46dpositioned at the fourth top end30dand a fourth baffle48dto direct the production fluid22d(i.e., the third aqueous waste fluid from the third chamber) from the fourth inlet46dto the inner surface36dof the fourth evaporation wall34dto form a fourth aqueous coating50d(or liquid coating) on the inner surface42dof the fourth evaporation wall34d. The fourth chamber12dfurther includes a fourth waste collection compartment52dpositioned at the fourth bottom end32dadjacent to the fourth evaporation wall34dto receive the production fluid22d(a fourth aqueous waste fluid) from the fourth evaporation wall34d, and a fourth condensate collection compartment54dpositioned at the fourth bottom end32dadjacent to the condensation wall40dto receive a fourth aqueous distillate24dfrom the fourth condensation wall40d. The fourth waste collection compartment52dhas a fourth waste outlet56d, and the fourth condensate collecting compartment54dhas a fourth condensate outlet58d.

The inner surface36dof the fourth evaporation wall34dis constructed to maintain an evaporation surface temperature that is greater than condensation surface temperature of the inner surface42dof the fourth condensation wall40d. When the production fluid22d(i.e., the third aqueous waste fluid) is delivered from the transfer conduit18cinto the fourth chamber12dand the production fluid22dforms the liquid coating50d, which moves down the inner surface42dof the fourth evaporation wall34dtowards the waste collection compartment52d, a saturation pressure differential is created as water from the production fluid22devaporates from the inner surface36dof the fourth evaporation wall34dand condenses on the inner surface42dof the condensation wall40dto form a fourth aqueous condensate53d, which moves down the inner surface42dof the fourth condensation wall40das the fourth aqueous distillate24dand is collected as the aqueous distillate24din the fourth condensation collecting compartment54d.

The fourth internal pressure of the fourth chamber12dis less than the third internal pressure of the third chamber12csuch that the temperature required for the water to evaporate from the inner surface36dof the fourth evaporation wall34dof the fourth chamber12dis less than the temperature required for the water to evaporate from the inner surface36cof the third evaporation wall34cof the third chamber12c.

As mentioned above, the first, second, third, and fourth chambers12a/12b/12c/12dmay be formed substantially the same as the chamber12described above with reference toFIG. 1. Likewise, the conduits14a,18a,18b,18c,18d, and20amay be made of substantially the same materials as the conduits14,18, and20described above in reference toFIG. 1. The pressure reducing valves16a/16b/16c/16dmay also be constructed substantially the same as the pressure reducing valve16described with reference toFIG. 1. Further, the heat exchangers26a/26b/26c/26dand27a/27b/27c/27dmay be constructed substantially similar to the heat exchangers26and37described with reference toFIG. 1. Finally, the pumps28a/28b/28c/28dand29amay be constructed substantially similar to the pumps28and29described above with reference toFIG. 1.

The non-evaporated portion of the input production fluid22a-d(e.g., aqueous fluids) is introduced to the next downstream vapor chamber (e.g., from the chamber12ato the chamber12b). As noted, each of the evaporation walls34a/34/b/34c/34dforms a corresponding evaporating film sections (aqueous coatings50a/50b/50c/50d, respectively), and each of the condensation walls40a/40b/40c/40dform corresponding condensing film sections (aqueous condensates53a/53b/53c/53d, respectively).

Before entering the second chamber12b, the temperature of the saturated production fluid22bmay be reduced, for example by about 2° C., by heat transfer from the transfer conduit18ato the main input conduit14athrough the heat exchanger26a. The temperature reduction of the production fluid22bentering the second chamber12bcreates a temperature differential necessary for heat transfer between the condensing steam on the inner surface42aof the condensation wall40aof the upstream first chamber12aand the liquid coating50bon the inner surface36bof the evaporation wall34bin the downstream second chamber12b. The pressure of the production fluid22bentering the chamber12bmay also be reduced using the valve16b. This may allow for evaporation at a lower temperature inside the second chamber12brelative to the previous first chamber12a. The process may repeat as the production fluid22b-dmoves throughout each consecutive chamber12b/12c/12d.

Inside the chamber12b, the falling liquid coating50bon the inner surface36bof the evaporation wall34b(the common wall separating chambers12aand12b) absorbs the heat of condensation generated by the condensing vapor in chamber12a. As a result, condensation and evaporation occur simultaneously on the two surfaces (i.e., condensation on the inner surface42aof the condensation wall40aand evaporation on the inner surface36aof the evaporation wall34a) of the wall separating chambers12aand12bat slightly different temperatures and pressures. The aqueous distillate24afrom chamber12ais discharged via the condensate output20aafter its pressure is equalized with the ambient via the pump28aand the saturated vapor created in the second chamber12bmoves to the condenser section (the inner surface42bof the second condensation wall40b). The sensible heat content of the aqueous distillate24bformed therein may also be recovered before discharging by heat transfer via the heat exchanger26bto the main input conduit14a. Similar to the first stage described above, the non-vaporized liquid waste water or production fluid24bfrom the second chamber12bflows through the transfer conduit18bbefore entering the third chamber12cand trickling down the inner surface36cof the evaporation wall34cof the third chamber12c.

For each of the chambers12a/12b/12c/12d, the lower temperature at the inner surface42a/42b/42c/42dof the condensation wall40a/40b/40c/40dcompared to the higher temperature at the inner surface36a/36b/36c/36dof the evaporation wall34a/34b/34c/34dcreates a saturation pressure differential that drives the vapor from the inner surface36a/36b/36c/36dof the evaporation wall34a/34b/34c/34dto the inner surface42a/42b/42c/42dof the condensation wall40a/40b/40c/40d. The same evaporation/condensation configuration is repeated in the distillation system10auntil the generated saturated vapor temperature reaches a temperature relatively close to a cooling medium, i.e. ambient air or the waste water. The concentration of waste retained in the production fluid (e.g., brine) being transferred downstream chamber to chamber increases as the production fluid22moves from one chamber to another chamber. The high concentration waste (or brine) from the last and fourth chamber12dis discharged after its pressure is raised to the atmospheric pressure using the pump29a. Although the distillation system10ais described as having four chambers12a-d, it should be understood that the distillation system10amay have more or less of the chambers.

FIGS. 3, 4A, and 4Bshow another embodiment of a distillation system, referred to as distillation system10b. Distillation system10bis constructed substantially similar to distillation system10a, except that each of a first, second, third, and fourth chambers12f/12g/12h/12iincludes a plurality of input portals and baffles (described below) on each of the walls of the chambers for shortening the flow length of the fluid films on the evaporation walls34f/34g/34h/34iand condensation walls40f/40g/40h/40i. The distillation system10bshown inFIGS. 4A and 4Bis also provided with edge walls45f1-2/45g2/45h1-2. The edge walls45f1and45f2connect the evaporation wall34fto the condensation wall40f. The edge walls45g1and45g2connect the evaporation wall34gto the condensation wall40g. The edge walls45h1and45h2connect the evaporation wall34hto the condensation wall40h. As shown inFIGS. 4A and 4B, the evaporation walls34f/34g/34hhave an evaporation wall width47, the condensation walls40f/40g/40hhave a condensation wall width49, and the edge walls45f1-2/45g1-2/45h1-2have an edge wall width55. The evaporation wall width47is greater than the edge wall width55. This configuration may improve the efficiency of the overall distillation process in the apparatus. This design may increase the distillation capacity of the system, while keeping the height of the respective individual film sections within an efficient range (for example, the efficiency of the filmwise evaporation/condensation may be adversely affected by the film thickness).

For example, as shown inFIG. 3, the chamber12fincludes a first inlet46fadjacent to a first baffle48f, as well as a second baffle88fpositioned on an inner surface36fof a first evaporation wall34fof the first chamber12f. The second baffle88fis positioned below the first baffle. A third baffle92fis positioned on the first evaporation wall34fadjacent to a second inlet90f. An input conduit14fconnects to the first inlet46fand to the second inlet90ffor delivering a production fluid into the first chamber12fvia the first baffle48fand the third baffle92f, respectively. The first chamber12ffurther includes a collection outlet (not shown) adjacent to the second baffle88fA collection conduit (not shown) is connected to the collection outlet to transfer fluid collected by the second baffle88ffrom the first chamber12fand transferred to the waste collection52fThe first chamber12ffurther includes a first transfer (such as an outlet100fshown inFIG. 4A) adjacent the fourth baffle94f. A transfer conduit (such as a transfer conduit102fshown inFIG. 4A) is connected to the transfer outlet of the first chamber12ffor conveying aqueous distillate from the inner surface42fof the condensation wall40fto a condensate collection compartment54f.

The second chamber12gincludes an inlet46gadjacent to a first baffle48g. The first baffle48greceives a production fluid from a transfer conduit18fextending from the first chamber12f. The second chamber12galso includes a second baffle88gpositioned on an inner surface36gof an evaporation wall34gof the second chamber12gbelow the first baffle48g. The second baffle88gis adjacent to a collection outlet (not shown). A collection conduit (not shown) is connected to the collection outlet to transfer fluid collected by the second baffle88gfrom the second chamber12gand transferred to the waste collection compartment52gg. The second chamber12gincludes a third baffle92gpositioned below the second baffle88gand on the inner surface36gof the evaporation wall34g. The third baffle92gis adjacent to an inlet (not shown). A small pipe connects from the transfer18fto the inlet of the third baffle92g. The second chamber12gfurther includes a fourth baffle94gpositioned on an inner surface42gof a condensation wall40gof the second chamber12g. The fourth baffle94gis adjacent to a transfer outlet (such as a transfer outlet100gshown inFIG. 4A). A transfer conduit (such as a transfer conduit102gshown inFIG. 4A) is connected to the transfer outlet100gof the second chamber12gfor conveying aqueous distillate from the inner surface42gof the condensation wall40gto a condensate collection compartment54g(shown inFIG. 3).

The third chamber12hincludes an inlet46hadjacent to a first baffle48h. The first baffle48hreceives the production fluid from a transfer conduit18gextending from the second chamber12fand connected to the inlet46hof the third chamber12h. The third chamber also includes a second baffle88hpositioned on an inner surface36hof an evaporation wall34hof the second chamber12h. The second baffle88his adjacent to a collection outlet (not shown). A collection conduit (not shown) is connected to the collection outlet to transfer fluid collected by the second baffle88hfrom the third chamber12hto the third waste collection compartment52h. The third chamber12halso includes a third baffle92hpositioned below the second baffle88hand on the inner surface36hof the evaporation wall34h. The third baffle92his adjacent to an inlet (not shown). A small pipe connects from the transfer18gto the inlet of the third baffle92g. The third chamber12hfurther includes a fourth baffle94hpositioned on an inner surface42hof a condensation wall40hof the third chamber12h. The fourth baffle94his adjacent to a transfer (such as a transfer outlet100hshown inFIG. 4A). A transfer conduit (such as a transfer conduit102hshown inFIG. 4A) connects to the transfer outlet100hof the third chamber12hfor conveying aqueous distillate from the inner surface42hof the condensation wall40hto a condensate collection compartment54h(shown inFIG. 4).

The fourth chamber12iincludes an inlet46iadjacent to a first baffle48i. The first baffle48hreceives the production fluid from a transfer conduit18hextending from the third chamber12hand connected to the inlet46iof the fourth chamber12i. The fourth chamber also includes second baffle88ipositioned on an inner surface36iof an evaporation wall34iand located below the first baffle48i. The second baffle88iis adjacent to a collection outlet (not shown). A collection conduit (not shown) is connected to the collection outlet to transfer fluid collected by the second baffle88ifrom the fourth chamber12ito the fourth waste collection compartment52i. The fourth chamber12ifurther includes a third baffle92ion the inner surface36iof the evaporation wall34iand below the second baffle88i. A small pipe connects from the transfer18hto the inlet of the third baffle92i. The fourth chamber12ialso includes a fourth baffle94ion an inner surface42iof a condensation wall40i. The fourth baffle94iis adjacent to an outlet96i. The outlet96iis connected to a transfer conduit98i, which connects to a condensate collection compartment54i.

The distillation system10balso includes valves, heat exchangers, and pumps, which are located in substantially similar positions, function substantially similar to, and are constructed of substantially the same materials and sizes as the valves, heat exchangers, and pumps of distillation system10a.

The disclosed distillation systems10/10a/10bmay significantly reduce piping requirements and provide a compact design that may significantly reduce costs and allow for fabrication of high performance simple, portable desalination and distillation systems than can work with a variety of low grade heat sources including waste heat, natural gas, geothermal heat, and solar energy. Moreover, since the majority of vaporization occurs at the interface of the liquid coating and the saturated vapor of each chamber12, salt deposition problems on the evaporation walls and maintenance needs may be minimized. In at least certain embodiments, the pumping requirements may be minimal per barrel of distilled fluid or water. For example, in one non-limiting embodiment, pumping power is about 0.004 kWhe (kilowatt hours electric) per barrel of distilled water, which at an electricity price of $0.12/kWhe, provides a pumping cost of less than $0.001 per barrel.

Now referring toFIG. 5, shown therein is another embodiment of a distillation system210. The distillation system210may be referred to as a “parallel feed” system. The distillation system210includes a first chamber212, a second chamber214adjacent the first chamber212, and a third chamber216adjacent the second chamber214. The distillation system210also includes a first input conduit218connected to the first chamber212, a second input conduit220connected to the second chamber214, and a third input conduit222connected to the third chamber216. The distillation system210may further include a first pressure reducing valve224positioned on the first input conduit218to control the pressure of a production fluid250being conveyed into the first chamber212; a second pressure reducing valve225positioned on the second input conduit220to control pressure of the production fluid250being conveyed into the second chamber214; and third pressure reducing valve228positioned on the third input conduit222to control pressure of the production fluid250being conveyed into the third chamber216. Before entering each of the chambers212,214, and216, the production fluid goes through one of the pressure reducing valves224,226, or228to reach pressure equilibrium with the respective chamber.

The distillation system also includes a first waste output conduit230connected to the first chamber212, a first condensate output conduit232connected to the first chamber212, a second waste put outlet234connected to the second chamber214, a second condensate output conduit236connected to the second chamber214, a third waste put outlet238connected to the third chamber216, a third condensate output conduit240connected to the third chamber212. A first pump242may be positioned on the first condensate output conduit232for discharging an aqueous distillate from the first chamber212. A second pump244may be positioned on the second condensate output conduit236for discharging an aqueous distillate from the second chamber214. A third pump246may be positioned on the third condensate output conduit240for discharging an aqueous distillate from the third chamber216.

The first chamber212includes a first internal pressure, a first top end260a, a first bottom end262a, an first evaporation wall264ahaving an inner surface266aand an outer surface268a, and a first condensation wall270apositioned opposite the evaporation wall264aand having an inner surface272aand an outer surface274a. The first chamber212further includes a first inlet276apositioned at the first top end260aand a first baffle278ato direct the production fluid250afrom the first inlet276ato the inner surface266aof the first evaporation wall264ato form a first liquid coating280aon the inner surface266aof the evaporation wall264a. The first chamber212also includes a first waste collection compartment284apositioned at the first bottom end262aadjacent to the first evaporation wall264ato receive the production fluid250afrom the first evaporation wall264aand a first condensate collection compartment286apositioned at the first bottom end262aadjacent to the first condensation wall270ato receive an aqueous distillate283afrom the first condensation wall270a. The first waste collection compartment284ahas a first waste outlet288a, and the first condensate collection compartment286ahas a first condensate outlet290a.

The inner surface266aof the first evaporation wall264ais constructed to maintain an evaporation surface temperature that is greater than a condensation surface temperature of the inner surface272aof the first condensation wall270asuch that when the production fluid250ais delivered from the second input conduit220into the first chamber212and the production fluid250aforms the fluid coating280a, which moves down the inner surface266bof the first evaporation wall264atowards the second waste collection compartment284a, a saturation pressure differential is created as water from the production fluid250aevaporates from the inner surface266aof the first evaporation wall264aand condenses on the inner surface272aof the first condensation wall270ato form an aqueous condensate282a, which moves down the inner surface272aof the first condensation wall270aand is collected as the aqueous distillate283ain the first condensation collecting compartment286a.

The second chamber214includes a second internal pressure, a second top end260b, a second bottom end262b, an second evaporation wall264bhaving an inner surface266band an outer surface268b, and a second condensation wall270bpositioned opposite the evaporation wall264band having an inner surface272band an outer surface274b. The second chamber212further includes a second inlet276bpositioned at the second top end260band a second baffle278bto direct the production fluid250from the second inlet276bto the inner surface266bof the second evaporation wall264bto form a second liquid coating280bon the inner surface266aof the evaporation wall264b. The second chamber214also includes a second waste collection compartment284bpositioned at the first bottom end262badjacent to the second evaporation wall264bto receive the production fluid250bfrom the second evaporation wall264band a second condensate collection compartment286bpositioned at the second bottom end262badjacent to the second condensation wall270bto receive an aqueous distillate283bfrom the second condensation wall270b. The second waste collection compartment284bhas a second waste outlet288a, and the second condensate collection compartment286bhas a second condensate outlet290b.

The inner surface266bof the second evaporation wall264bis constructed to maintain an evaporation surface temperature that is greater than a condensation surface temperature of the inner surface272bof the second condensation wall270bsuch that when the production fluid250bis delivered from the second input conduit220into the second chamber214and the production fluid250bforms the fluid coating280b, which moves down the inner surface266bof the second evaporation wall264btowards the second waste collection compartment284b, a saturation pressure differential is created as the water from the production fluid250bevaporates from the inner surface266bof the second evaporation wall264band condenses on the inner surface272bof the second condensation wall270bto form a aqueous condensate282b, which moves down the inner surface272bof the second condensation wall270band is collected as the aqueous distillate283bin the second condensation collecting compartment286b.

The second internal pressure of the second chamber214is less than the first internal pressure of the first chamber212such that the temperature required for the water to evaporate from the inner surface266bof the second evaporation wall264bof the second chamber214is less than the temperature required for the water to evaporate from the inner surface266aof the first evaporation wall264aof the first chamber212.

The third chamber214includes a third internal pressure, a third top end260c, a third bottom end262c, a third evaporation wall264chaving an inner surface266cand an outer surface268c, and a third condensation wall270cpositioned opposite the evaporation wall264cand having an inner surface272cand an outer surface274c. The third chamber214further includes a third inlet276cpositioned at the third top end260cand a third baffle278cto direct the production fluid250from the third inlet276cto the inner surface266cof the third evaporation wall264cto form a third liquid coating280con the inner surface266cof the evaporation wall264c. The third chamber214also includes a third waste collection compartment284cpositioned at the third bottom end262cadjacent to the third evaporation wall264cto receive the production fluid250from the third evaporation wall264cand a third condensate collection compartment286cpositioned at the third bottom end262cadjacent to the third condensation wall270cto receive an aqueous distillate283bfrom the third condensation wall270c. The third waste collection compartment284chas a third waste outlet288c, and the third condensate collection compartment286chas a third condensate outlet290c.

The inner surface266cof the third evaporation wall264cis constructed to maintain an evaporation surface temperature that is greater than a condensation surface temperature of the inner surface272cof the third condensation wall270c. When the production fluid250cis delivered from the third input conduit222into the third chamber216and the production fluid250cforms the liquid coating280c, which moves down the inner surface266cof the third evaporation wall264ctowards the third waste collection compartment284c, a saturation pressure differential is created as water from the production fluid250cevaporates from the inner surface266cof the evaporation wall264cand condenses on the inner surface272cof the third condensation wall270cto form a aqueous condensate282c, which moves down the inner surface272cof the third condensation wall270cand is collected as the aqueous distillate283cin the condensation collecting compartment286c.

The third internal pressure of the third chamber216is less than the second internal pressure of the second chamber214such that the temperature required for the water to evaporate from the inner surface266cof the third evaporation wall264cof the third chamber216is less than the temperature required for the water to evaporate from the inner surface266bof the second evaporation wall264bof the second chamber214.

The first, second, and third chambers212/214/216may be formed substantially the same as the chamber12described above with reference toFIG. 1. Likewise, the conduits218,220,222,230,232,234,238, and240may be made of substantially the same materials as the conduits14,18, and20described above in reference toFIG. 1. The pressure reducing valves224,226, and228may also be constructed substantially the same as the pressure reducing valve16described with reference toFIG. 1. Further, distillation system210may be equipped with heat exchangers constructed substantially similar the heat exchangers26and27described with reference toFIG. 1. Finally, the pumps241,242,243,244,245and246may be constructed substantially similar to the pumps28and29described above with reference toFIG. 1.

The distillation system210functions substantially similar to the distillation system10aexcept that with the distillation system210—each chamber212,214, and216connects to a separate input conduit, namely input conduits218,220, and222, respectively. This may increase heat efficiency by reducing thermal resistance. In the disclosure described with reference to distillation system10a, the production fluid increases in thickness each time it enters a subsequent chamber-having been distilled in the previous chamber. By providing a separate input conduit conveying production fluid to each chamber212,214, and216, the production fluid does not increase in thickness.

As shown inFIG. 5, the distillation system210is comprised of a series of the chambers212,214, and216, in which the condenser section (i.e., the condensation walls210a/270b/) of the upstream vapor chamber serves as the heat source for the evaporator section (i.e., the evaporation walls264b/264b) of the downstream chamber. In one embodiment, the vapor chambers212,214, and216may be vertically-oriented shallow steel boxes where the two large vertical faces serve as the evaporator and condenser walls and other faces are adiabatic. A production fluid, such as saline water, enters the vapor chambers212,214, and216in parallel feed arrangement; that is each chamber212,214, and216is directly connected to the production fluid (e.g., saline water) source.

In the high temperature end (i.e., chamber212) of the distillation system210or cascade, the production fluid250aor feed water is evaporated by a heat source, such as heat source296“q”, which is supplied heat through the first evaporator wall264a. Similar to distillation systems10/10a/10b, a variety of heat sources may be used including, but not limited to, natural gas, low pressure steam from a cogeneration power plant, or solar energy. An amount of saturated vapor300athen travels to the inner surface272aof the first condensation wall270aof the first chamber212. The first condensation wall270ahas a temperature that is lower than the temperature of the first evaporation wall264a. The saturated vapor300acondenses on the relatively colder first condensation wall270a. The aqueous distillate (or distilled water)283ais collected at the bottom of the chamber212and is discharged through the first condensate output232after its pressure is brought to equilibrium with the ambient via the pump242. Similarly, the non-evaporated portion of the production fluid250a-c(or aqueous fluid or feed water) is discharged through the first waste output conduit230after its pressure is increased to the atmospheric value. This process also occurs in the second and third chambers214and216. The thermal energy content of the discharging waste (or brine) and the aqueous distillate may be recovered to preheat the production fluid. For example, the pathway of the first input conduit218may be altered to pass through a first heat exchanger located at an intersection between the first waste output conduit230and second heat exchanger located at an intersection between the first input conduit218and the first condensate output pipe232. The paths of the second input conduit220and the third input222conduit may also be altered to pass through corresponding heat exchangers with the second and third waster output conduits and condensate output conduits, respectively.

The vapor temperature within each chamber212,214, and216is less than the temperature of the evaporator walls264a/264/b263cand greater than the temperature of the condensation walls270a/270b/270c, respectively. The pressure inside each of the chambers212/214/216is equal to the saturation pressure of the water vapor at the corresponding vapor temperature. Thus, as long as no non-condensable gases are present within a chamber, the pressure (and temperature) of the vapor in that chamber may be controlled by the temperatures of the evaporation and condensation walls.

The thermal energy released upon condensation of the vapor in chamber212is transferred through the wall (separating chambers212and214) to the falling liquid coating on the evaporator wall of chamber214. As a result, condensation and evaporation occur simultaneously on the opposite sides of the wall separating chambers212and214at slightly different temperatures and pressures. The saturated vapor created in chamber214moves to the condenser side (right hand side wall of chamber212inFIG. 5), where the vapor condenses due to the relatively lower temperature of the condenser wall. Additional vapor chambers can be added downstream of chamber214in a similar manner up to a point where the temperature of the generated vapor gets relatively close to the cooling medium, i.e. ambient air or the saline water.

The distillation system of the current disclosure comprises a chamber having an internal pressure, a top end, a bottom end, an evaporation wall having an inner surface, a condensation wall having an inner surface, the inner surface of the condensation wall facing the inner surface of the evaporation wall, an inlet positioned at the top end, a baffle to direct an aqueous fluid from the inlet to the inner surface of the evaporation wall to form a fluid coating on the inner surface of the evaporation wall, a waste collection compartment positioned at the bottom end adjacent to the evaporation wall to receive an aqueous waste fluid from the evaporation wall, and a condensate collection compartment positioned at the bottom end adjacent to the condensation wall to receive an aqueous distillate from the condensation wall, the waste collection compartment having a waste outlet, and the condensate collecting compartment having a condensate outlet; an input conduit fluidly connected to the baffle to deliver the aqueous fluid to the chamber; a pressure reducing valve connected to the input conduit and configured to cause the internal pressure of the chamber to be less than atmospheric pressure; a waste output conduit connected to the waste outlet of the waste collection compartment of the chamber; and a condensate output conduit connected to the condensate outlet of the condensate collection compartment of the chamber. The inner surface of the evaporation wall is constructed to maintain an evaporation surface temperature that is greater than a condensation surface temperature of the inner surface of the condensation wall when the aqueous fluid is delivered from the input conduit into the first chamber and the aqueous fluid forms the fluid coating which moves down the inner surface of the evaporation wall towards the waste collection compartment. A saturation pressure differential is created as water from the aqueous fluid evaporates from the inner surface of the evaporation wall and condenses on the inner surface of the condensation wall forming an aqueous condensate, which moves down the inner surface of the condensation wall and is collected as the aqueous distillate in the condensation collecting compartment.

The multiple-effect distillation system of the present disclosure comprises a first chamber comprising a first evaporation surface, a first condensation surface which faces the first evaporation surface, a first inlet positioned at a top end of the first chamber, a baffle to direct a first aqueous fluid from the inlet to the first evaporation surface to form a first fluid coating on the first evaporation surface, a first waste collection compartment positioned to receive a first aqueous waste fluid from the first evaporation surface and having a first waste outlet, and a first condensate collection compartment positioned to receive a first aqueous distillate from the first condensation surface and having a first condensate outlet; a first pressure reducing valve connected to the first chamber to reduce the internal pressure in the first chamber to be less than atmospheric pressure; a first waste output conduit connected to the first waste outlet of the first waste collection compartment of the first chamber; and a first condensate output conduit connected to the first condensate outlet of the first condensate collection compartment of the first chamber. The first evaporation surface is constructed to maintain a first evaporation surface temperature that is greater than a first condensation surface temperature of the first condensation surface when the first aqueous fluid forms the first fluid coating on the first evaporation surface. The multiple-effect distillation system also comprises at least a second chamber having a second evaporation surface, a second condensation surface which faces the second evaporation surface, a second inlet positioned at a top end of the second chamber, a baffle to direct the first aqueous waste fluid from the second inlet to the second evaporation surface to form a second fluid coating on the second evaporation surface, a second waste collection compartment positioned to receive a second aqueous waste fluid from the second evaporation surface and having a second waste outlet, and a second condensate collection compartment positioned to receive a second aqueous distillate from the second condensation surface and having a second condensate outlet, wherein the first condensation surface and the second evaporation surface comprise (1) facial surfaces of a first common wall shared by the first chamber and the second chamber, or (2) facial surfaces of separate but abutting walls of the first chamber and the second chamber, respectively; a second pressure reducing valve connected to the second chamber to reduce the internal pressure in the second chamber to be less than atmospheric pressure; a second waste output conduit connected to the second waste outlet of the second waste collection compartment; and a second condensate output conduit connected to the second condensate outlet of the second condensate collection compartment. The second evaporation surface is constructed to maintain a second evaporation surface temperature that is greater than a second condensation surface temperature of the second condensation surface when the first aqueous waste fluid forms the second fluid coating on the second evaporation surface.

The method of distilling an aqueous fluid of the present disclosure comprises (1) obtaining a multiple-effect distillation system, comprising: a first chamber comprising a first evaporation surface, a first condensation surface which faces the first evaporation surface, a first inlet positioned at a top end of the first chamber, a baffle to direct a first aqueous fluid from the inlet to the first evaporation surface to form a first fluid coating on the first evaporation surface, a first waste collection compartment positioned to receive a first aqueous waste fluid from the first evaporation surface and having a first waste outlet, and a first condensate collection compartment positioned to receive a first aqueous distillate from the first condensation surface and having a first condensate outlet, a first pressure reducing valve connected to the first chamber to reduce the internal pressure in the first chamber to be less than atmospheric pressure; a first waste output conduit connected to the first waste outlet of the first waste collection compartment of the first chamber, a first condensate output conduit connected to the first condensate outlet of the first condensate collection compartment of the first chamber; and at least a second chamber having a second evaporation surface, a second condensation surface which faces the second evaporation surface, a second inlet positioned at a top end of the second chamber, a baffle to direct the first aqueous waste fluid from the second inlet to the second evaporation surface to form a second fluid coating on the second evaporation surface, a second waste collection compartment positioned to receive a second aqueous waste fluid from the second evaporation surface and having a second waste outlet, and a second condensate collection compartment positioned to receive a second aqueous distillate from the second condensation surface and having a second condensate outlet, wherein the first condensation surface and the second evaporation surface comprise (a) facial surfaces of a first common wall shared by the first chamber and the second chamber, or (b) facial surfaces of separate but abutting walls of the first chamber and the second chamber, respectively, a second pressure reducing valve connected to the second chamber to reduce the internal pressure in the second chamber to be less than atmospheric pressure, a second waste output conduit connected to the second waste outlet of the second waste collection compartment, and a second condensate output conduit connected to the second condensate outlet of the second condensate collection compartment; (2) maintaining the first evaporation surface at a first evaporation surface temperature that is greater than a first condensation surface temperature of the first condensation surface when the first aqueous fluid is directed to the first evaporation surface forming the first aqueous distillate; (3) removing the first aqueous distillate from the first chamber; (4) transferring the first aqueous waste fluid to the second evaporation surface of the second chamber forming the second fluid coating on the second evaporation surface; (5) maintaining the second evaporation surface at a second evaporation surface temperature that is greater than a second condensation surface temperature of the second condensation surface forming the second aqueous distillate; and (6) removing the second aqueous distillate from the second chamber.

While the present disclosure has been described herein in connection with certain embodiments so that aspects thereof may be more fully understood and appreciated, it is not intended that the present disclosure be limited to these particular embodiments. On the contrary, it is intended that all alternatives, modifications and equivalents are included within the scope of the present disclosure as defined herein. Thus the examples described above, which include particular embodiments, will serve to illustrate the practice of the inventive concepts of the present disclosure, it being understood that the particulars shown are by way of example and for purposes of illustrative discussion of particular embodiments only and are presented in the cause of providing what is believed to be the most useful and readily understood description of procedures as well as of the principles and conceptual aspects of the present disclosure. Changes may be made in the devices, components and methods described herein, and in the steps or the sequence of steps of the methods described herein without departing from the spirit and scope of the present disclosure. Further, while various embodiments of the present disclosure have been described in claims herein below, it is not intended that the present disclosure be limited to these particular claims. Applicants reserve the right to amend, add to, or replace the claims indicated herein below in subsequent patent applications.