Abstract:
A method and apparatus for water degasification and distillation in an apparatus having a container for a reservoir of water to be degassed and distilled, a relatively small boiler adjoining the container and having a feed water conduit connecting the container and boiler so that a selected water level in the container will fill the boiler to the same level, a coiled tube condenser within the container immersed in the water therein, the condenser coil having a vertically disposed longitudinal axis, a second conduit in the boiler connecting the space above the water level therein to the inlet of the condenser so that steam flows from the boiler to the condenser, an outlet on the condenser extending through a container wall for discharging the condensed steam as degassed distilled water, a heater in the boiler for heating the water therein, a motor driven stirrer axially of the coiled tube condenser for generating a swirling movement of the reservoir water with formation of steam bubbles therein and an ozone generating device in the boiler for purifying the steam. Optionally, an oversized filter is mounted at the outlet of the condenser.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a distilling apparatus and more specifically to a novel and improved water degasification and distillation apparatus embodying improved means for eliminating and/or neutralizing contaminants in the steam phase prior to condensation. 
     2. Description of the Related Art 
     Known water distilling apparatus generally comprise: a closed boiler; means for continuously feeding water to the boiler; means for removing and means for condensing the steam and other vapors evolved in the boiler. As the water in the boiler is being heated to produce steam, any air in the boiler is forced out. In addition, volatilizable chemical components present in the water will boil off and combine with the steam being evolved. Because there is no air in the boiler, the volatile impurities cannot be oxidized. The steam together with the volatilized chemical components will become condensed in the condenser so that the resultant distillate will contain therein the (volatile) chemicals. In instances wherein the raw water exhibits a disagreeable odor such as is produced by sulfur compounds and the like, most of the known to the art distillation apparatus will tend to concentrate the odor compound in the distillate and make the distilled water even more distasteful than the raw water. The inventor hereof has long been concerned with this problem and is the inventor of several patents directed to improved water distillation and degasification systems. 
     The water distilling apparatus of this invention relates to the apparatus described in Applicant&#39;s prior patents U.S. Pat. Nos. 4,420,374, 4,612,090 and 5,203,970, which patents in turn constitute an improvement over the apparatus disclosed in Applicant&#39;s earlier patent U.S. Pat. No. 4,339,307. Briefly, the water distilling apparatus described in the above-referenced patents U.S. Pat. Nos. 4,420,374, 4,612,090 and 5,203,970 comprises a very small boiler containing therein an instantaneous heating means and a reservoir for the boiler much larger than the boiler. A condensing coil is immersed within the reservoir so the water in the reservoir functions to cool the condenser. An open connection between reservoir and boiler provides an automatic water supply for the boiler. 
     The water in the reservoir circulates to and from the boiler, and the boiler heat thus imparted directly to the water in the reservoir together with the heat imparted to the reservoir water from the condenser heats the reservoir water to a temperature that will effectively deaerate the water in the reservoir and boil off any volatilizable constituents present in the water in the reservoir. 
     The water degasification and distillation apparatus in accordance with these above-referenced patents and in accordance with the invention hereof, comprises in more detail, a relatively large reservoir container adapted to receive the water to be distilled and a small boiler mounted on and to one side of the reservoir. A fluid conduit connects the boiler and the reservoir so that the liquid level in the boiler will be controlled to the liquid level in the reservoir. A vapor outlet in the boiler above the water level thereof is coupled to the condenser coil disposed within the reservoir container and the condensate outlet of the condenser coil extends through the wall of the reservoir container. The condenser coil is positioned so that the liquid in the reservoir will cover a major part or all of the condenser coil. With this arrangement and with the heater(s) in the boiler energized, the water in the boiler will heat to boiling almost instantaneously and the steam generated in the boiler will be fed out to the condenser. Whenever the steam generated within the boiler exceeds the capacity of the boiler outlet to the condenser to remove the steam from the boiler the steam pressure will force water in the boiler through the fluid conduit back into the reservoir. Then, when the steam pressure is relieved (by outflow of water to the reservoir and of steam to the condenser), water will again flow from the reservoir into the boiler. Pulsation and recirculation of water as just described continues throughout during the operation of the distillation apparatus. 
     Since hot boiler water is returned to the reservoir through the fluid conduit periodically through the pulsation and since heat from the condenser is continuously added to the water within the reservoir, all water fed to the reservoir increases in temperature. In a word, the reservoir water becomes hot. Desirably, all undesirable volatile material contained in the water fed to the boiler is vaporized prior to entry of the water into the boiler and distillation thereof. 
     The cold water initially fed to the reservoir (at the top thereof) will normally sink to the bottom of the reservoir while hot water periodically recirculated from the boiler back into the reservoir container (near the bottom) will tend to rise. Thus, the water within the reservoir container tank is in constant movement and is mixing so that desirably all the water of the reservoir is maintained at about the same substantially elevated temperature so as to evolve the undesirable volatilizable components from the reservoir water before the water enters the boiler. 
     SUMMARY OF THE INVENTION 
     According to the present invention an ozone generator is placed in the boiler of a distillation or degasification apparatus. When water is forced back into the reservoir, a vacuum is created in the boiler which sucks in air through the condenser. The oxygen in the air is then turned into ozone, a strong oxidizing agent, with the ozone generator. Steam formed in the boiler must pass through the ozone before entering the condenser and therefore any contaminants in the steam are destroyed. 
     Discussion of the Invention 
     Ozone is a thermally unstable allotrope of oxygen. It is a powerful oxidizing agent which has seen increased industrial use in bleaching and chemical manufacturing processes requiring strong oxidizing agents. In the laboratory, ozone is usually generated by passing an electric spark through a stream of oxygen. However, ozone may also be prepared by exposing oxygen to ultraviolet light. Because ozone is such a strong oxidizing agent, it is receiving much attention for use in water purification. 
     The unique design of the degasification and distillation apparatus of this invention results in hot boiler water periodically returning to the reservoir. The flow of water into the reservoir generates a vacuum in the boiler. Air is sucked through the condenser into the boiler to fill the vacuum. By placing an ozone generator in the boiler, the oxygen in the air is oxidized into ozone. When the stream pressure is relieved, water again flows from the reservoir to the boiler. Steam generated in the boiler must now flow through ozone before entering the condenser. The ozone destroys and/or neutralizes any impurities in the water and this results in the production of very pure water. In addition, the oxygen level in the water is increased, improving the taste of the water. 
     Apparatus of the Invention 
     In the apparatus of this invention an ozone generator is placed in the boiler. The ozone generator is preferably placed above the water line where it can interact with the air brought in through the condenser during the periodic pulsation of the water in the boiler. Typically, the ozone generator makes ozone by generating an electric spark. However, the use of an electric spark for generating ozone is not necessary. Any process for generating ozone from air is sufficient for the operation of the invention. 
     Optionally included in the distillation apparatus of the invention may be a stirrer as taught in U.S. Pat. No. 5,203,970. The stirrer preferably is made part of a fan assembly such as the fan assembly that forms part of the distillation apparatus described in the related patents U.S. Pat. Nos. 4,420,374 and 4,612,890. Conveniently, the stirrer rod can be made an extension of the fan rotor. Advantageously, the fan removes the steam and gases that bubble up from the reservoir water. 
     Optionally included in the distillation apparatus of this invention may be a deflector insert in the conduit connecting reservoir and boiler and/or in the condenser coil tubing. The deflector(s) generates spin and turbulence in the water passing between reservoir and boiler, and/or causes turbulent fluid flow adjacent the tubular wall of the condenser coil. 
     Optionally included in the distillation apparatus may be an oversized filter, desirably a charcoal filter, at the delivery end of the condenser. 
     The above and other advantages of the invention will become more apparent from the following description and accompanying drawings forming part of this Application. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a fragmentary plan view of one embodiment of the distilling apparatus in accordance with the invention; 
     FIG. 2 is a cross sectional view of FIG. 1 taken along the line  2 — 2  thereof; 
     FIG. 3 is a cross sectional view of FIG. 1 taken along the line  3 — 3  thereof and illustrates air circulating means carried by the container; and 
     FIG. 4 is a cross sectional view showing the boiler and a fragmentary portion of the tank taken along the line  4 — 4  of FIG.  2 . 
     FIG. 5 is a diagrammatic view showing the condenser tube containing a deflector. 
     FIG. 6 is a diagrammatic view showing the fluid conduit containing a deflector. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the drawings and more specifically to FIGS. 1 and 2 it may be seen that the distilling apparatus in accordance with this invention comprises a cylindrical tank reservoir container  10  having a pair of handles  11  secured to the side thereof. A boiler  12  having instantaneous heating elements  13  and  14  therein is affixed to the side of the tank  10  by the fluid connectors  15  and  16 . The fluid connector  15  includes an elbow  17  having a shoulder  18  and a threaded shank extending through cooperating openings in the wall  19  of the boiler  12  and the wall of the container  10 . A nut  20  engages the shank of the fitting  15  and together with a resilient washer  21  provides a water-tight seal for both the tank  10  and the boiler  12 . A water inlet conduit  22  is fixedly coupled to the fitting  15  by means of a nut  23  so that water within reservoir container  10  will automatically feed into the boiler  12  until the water level within boiler  12  corresponds to the reservoir water level inside reservoir container  10 . It will also be observed that the water level is maintained at a level adequate to effect total or at least substantial immersion of the heating elements  13  and  14  in the water of boiler  12 . 
     The steam outlet fitting  16  is of conventional construction and includes an outlet pipe  24 , a threaded shank  24 ′ extending through the walls of reservoir container  10  and boiler  12  and secured thereto by a nut  25 . A sealing washer  26  is disposed between container and boiler to provide a watertight connection. In the preferred embodiment of the invention herein illustrated the condenser  27  is in the form of a coiled tube of metal such as stainless steel, copper or the like and has the inlet end portion  28  sealably connected to the fitting  16  within container  10 . The outlet  29  of the condenser  27  has a fitting  30  extending through the wall of container  10  and provides the condensate outlet  31 . Optionally, but desirably an oversized filter  115  is interposed at condensate outlet  31 . As best may be seen in FIG. 1, the coiled condenser tubing generates a cylindrical region  100  at the center of the reservoir container  10 . Reservoir container  10  further includes an overflow pipe  32  which is connected to a fitting  33  sealed to the wall of the container  10  and a drain cock  34  for draining water from the container (being useful for cleaning and maintenance). A water inlet valve  35  is at the upper portion of the reservoir container  10  and has an inlet  36 , an outlet  37  and a hand-wheel  38  for regulating the water supply in order to maintain an appropriate supply of water to the reservoir container  10 . 
     The boiler  12  is shown more clearly in FIG.  4  and in the preferred embodiment illustrated herein consists of two housing elements  39  and  40 . A wall  41  disposed between the housing elements  39  and  40  includes a peripheral seal  42  which is releasably clamped between the outer rims of the housing elements  39  and  40  by clips  43  at the periphery of the boiler  12 . This arrangement completely seals the boiler formed by the housing element  39  and the wall  41 . The whole boiler can be readily disassembled for cleaning. The heating elements  13  and  14  in the illustrated embodiment are carried by the wall  41  and are connected in series by a lead  44  connecting one terminal of one heater to one terminal of the other heater. The power line  45  has one lead  46  connected to the other terminal of the heater  14  while the second lead  47  is connected through a thermostat  48  to the other terminal of the heater  13 . The thermostat is mounted on a bracket  49  in close proximity to the heaters  13 . In the event the heater  13  reaches a temperature above the normal operating temperature, the thermostat will operate to open the circuit and de-energize both heaters  13  and  14 . It is evident, however, that the heaters  13  and  14  could be arranged for parallel operating or in the alternative a single electric heater may be employed in the boiler provided however it delivers the quantity of heat necessary for operation of the distillation apparatus. 
     Included in the boiler is the ozone generator  120 . Preferably, the ozone generator is inserted into the boiler through a port in housing element  39 . As illustrated in FIG. 1, the ozone generator  120  is powered by transformer  121 . It is not necessary, however, to have a separate power supply for the ozone generating means. The ozone generator may be powered by the same power supply used to operate heaters  13  and  14 . 
     In the preferred embodiment of the invention herein illustrated a forced air circulation means assists removal of steam and undesirable vapors liberated from the reservoir water within reservoir container  10 . The air circulating means which is shown in FIG. 3 comprises an inverted dished cover generally denoted by the numeral  50  over reservoir container  10  which includes a flat upper wall  51  that is perforated or apertured, an upwardly extending peripheral wall  52  and a downwardly curved peripheral wall  53 . The lower peripheral edge of the wall  53  carries three or more diagonally disposed rollers  54  each having spaced discs  55  rotatably carried by a shaft  56 . The discs  55  engage the rolled edge  10 ′ of the reservoir container  10  and accordingly provide an annular vent between the cover  50  and the top edge of the reservoir container  10 . 
     The flat apertured wall  51  of the air circulating means supports an electric motor generally denoted by the numeral  57  which powers a shaft  58  extending through the perforated wall  51 . The fan  59  is mounted on shaft  58 . Power is fed to the motor  57  by a cable  60  connected in a conventional manner to the motor. If desired, switch means may be provided for operation of the fan. The fan motor  57  is covered by a vented dome-shaped housing  61  that is securely fitted to the cover  50  and is attached thereto by any suitable means. In the illustrated embodiment of the invention, the dome-shaped housing  61  frictionally engages the peripheral wall  52  of the cover  50 . 
     In one mode of fan operation, air is drawn into the air circulating means assembly through an opening  62  in the dome-shaped housing  61  and then down through the perforated wall  51  whereupon it is directed downwardly over the reservoir water in reservoir container  10  and thereafter is discharged through the annular opening between the reservoir container  10  and its cover  50 . In the reverse mode of fan operation the fan  59  draws air in through the annular opening between reservoir container  10  and its cover  50  up through perforated wall  51  and opening out through vent  62  in motor housing  61 . 
     As may be seen in FIG. 3, a stirrer rod  101  extends from an integral connection with motor shaft  58  at the hub of fan  59  preferably but not necessarily axially of the cylindrical reservoir region  100  inside of condenser coil  27  and terminates at the stirrer blades  102  immersed in the reservoir water. The depth of immersion for stirrer blades  102  is not critical, but preferably, they are not deeper than the bottom of coil condenser  27 . In the mode illustrated herein, the stirrer rod was positioned modestly off-center to avoid interference with the outlet bend  29  of condenser coil  27 , see FIGS. 1 and 2. 
     In the operation of the distillation apparatus of this invention, the reservoir container  10  and boiler  12  are first filled with water to a level at least substantially covering the heating elements  13  and  14  as may be observed most clearly in FIG.  2 . It will be observed that when filling reservoir container  10 , water will automatically flow through conduit  22  into the boiler so that ultimately the level of the water in the reservoir container  10  will be the same as the water level in the boiler  12 . When energy is then supplied to the heating elements  13  and  14  they will function to boil the water within the boiler  12 . Oxygen in the air above the water is turned to ozone by ozone generator  120 . Steam generated from heating elements  13  and  14  rises through the ozone and enters inlet  24 . The steam then flows through the condenser coil  27  to be condensed therein. The condensed steam will then discharge through filter  115  as the distillate (liquid) product from the condenser outlet  31 . When first operating the distillation apparatus, it is generally desirable to discard the distillate product until the water inside reservoir container  10  has attained a normal operating temperature which preferably is 180.degree.-190.degree. F. (which is rapidly attained). Heaters  13  and  14  are designed to heat the water within the boiler at a rate faster than the condenser coil  27  can accommodate the steam produced. Accordingly, a head of steam is developed within the boiler  12  and the steam pressure will force liquid from the boiler back through the conduit  22  into the reservoir container  10  thereby relieving the steam pressure. The flow of the water from the boiler into conduit  22  generates a vacuum in the boiler. The vacuum causes air to be drawn through filter  115  into the condenser outlet  31 , traveling through the condenser and exiting in the boiler via outlet  24  and thereby providing fresh oxygen for the ozone generator  120 . As soon as the steam pressure within the boiler is relieved, water will again flow through the conduit  22  back into the boiler with the result that there will be a periodic reversal of water flow through the conduit  22  and air flow through the condenser  27 . This pulsating action results in a more rapid increase in temperature of the reservoir water within the container  10  by contributing heat over and above the heat imparted to the reservoir water by the action of the condenser coil  27 . It also results in a constant renewing of ozone in the boiler. The temperature of the reservoir water, however, is always below the boiling temperature (of the water in boiler  12 ) so that distillate will be condensed in condenser  27 . Preferably the reservoir water should be kept in the range of 180.degree. F. to 190.degree. F. This temperature level will boil off undesirable components from the reservoir water (prior to actual distillation thereof), and also serves to operate condenser  27  adequately. To maintain proper operation of the apparatus, a substantial proportion of the feed water which enters at the inlet  37  ultimately is discharged as overflow through tube  32  and outlet  35 . 
     As has already been pointed out, a mechanical expedient to facilitate maintenance of a distinct temperature across the condenser coil tubing is illustrated in FIG.  5 . Shown there is an enlarged partial cross-section of condenser coil tubing. Inside the tubing is a deflector  77  whose purpose is to generate spiral flow movement of steam and condensate to the tube wall. Also, flow becomes more turbulent thereby helping heat exchange across the tube wall. A like deflector  79  may be provided in the conduit connecting reservoir container  10  and boiler  12  (see FIG.  6 ). The purpose of deflector  77  is, of course, to create turbulent mixing of the water so as to avoid any temperature stratification either in reservoir container  10  or in boiler  12 . 
     An additional optional expedient which has been found advantageous in practice of this invention is the provision of a filter, preferably an oversized filter, at the condenser outlet  31 . In the embodiment illustrated herein the oversized filter  115  is a carbon filter. 
     Filter  115  absorbs any organic materials that are carried over with the condensate. It polishes the condensate, so to speak but also it achieves a superior aeration for the condensate. 
     As has already been pointed out the distillation apparatus of this invention operates in a pulsating fashion causing water to flow through the connecting conduit  22  back and forth between boiler  12  and reservoir  12 . The same pulsations affect condenser  27 . A pulse of (steam) pressure from boiler  12  passes through the condenser tubing in a forward direction during a steam generation pulse, sending condensate out through filter  115 . Then during the reverse suction pulse, air is drawn into the filter  115 , through the condenser, into the boiler. Thus, the filter  115  acts as much to filter air drawn into the condenser tubing, as it does to filter distillate leaving the condenser tubing. 
     Manifestly, the pulses are not equal in their effect. Steam is being generated in boiler  12 , then is condensed in condenser coil  27 . The distillate is discharged at the outlet  31  through filter  115 . A net movement outflow movement of distilled water through filter  115  results. At the same time, a small net inflow of air into filter  115  and condenser  27  results. The distillate, e.g., at 190.degree.-195.degree. F., is hot enough to heat filter  115  and prevents microbial contamination of the filter. This means that air which enters oversized filter  115  during the suction pulses is retained therein and becomes sterilized by the hot filter before entering condenser  27  and/or becoming absorbed in the distillate. The reason for providing a filter  115  that is oversized is precisely to increase the residence time therein of the inflowing air. Overall, the result is that air heated and sterilized in filter  115  partially aerates the distilled water improving the palatability thereof. 
     While only certain embodiments of the invention have been illustrated and described herein, it is understood that alterations, changes, and modifications may be made therein without departing from the true scope and spirit thereof.