US3302373A - Distillation apparatus - Google Patents

Description

W. R. WILLIAMSON DISTILLATION APPARATUS Feb.7, l967 Filed July 5, 1963 3 Sheets-Sheet} TUBULAR EXTENSION SEPARATOR CONDENSER To ED uc T0 2 E wy w FIG. 2

INVENTOR WILLIAM RODGER WILLIAMSON Feb. 7, 1967 w. R. WILLIAMSON DISTILLATION APPARATUS 3 Sheets-Sheet 2 Filed July 5, 1963 gONDEA/SEP HELL. 40

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T0 EDUCTOR SE PA RA'TUR FIG.4

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DISTILLATION APPARATUS Filed July 5, 1963 3 Sheets-Sheet 5 29 Fl G 6 INVENTOR WILLIAM RODGER WILLIAMSON United States Patent 3,302,373 DISTILLATIUN AFPARATUS William Rodger Williamson, Waterford, Conn, assignor to American Machine & Foundry Company, a corporation of New Jersey Filed July 3, 1963, Ser. No. 292,667 1 Claim. (Cl. 55-169) This invention relates in general to distillation apparatus and, more particularly, to a distilling plant for sea water and the like.

An object of this invention is to provide a horizontal and laterally chambered evaporator which will provide distillate in an associated condenser which will be of equal purity to that produced in vertically disposed, multichambered conventional apparatus.

Another object of this invention is to provide a distillation apparatus which may occupy as little as one half the cubic space required by equivalent conventional distillation apparatus having a completely vertical relationship between the chambering and bathing elements.

A further object of this invention is to provide a means for removing distillate from a high vacuum distillation apparatus using a relatively inexpensive pump which is operated by fluid at atmospheric pressure.

Many other objects, advantages and features of invention reside in the particular construction, combination and arrangement of parts involved in the embodiments of the invention and its practice as will be understood from the following description and accompanying drawing wherein:

FIGURE 1 is a longitudinal, vertical section through a distillation apparatus according to the first embodiment of this invention with the heating and condensing tube bundles broken away and with the areas occupied by the heating and condensing tube bundles outlined by broken lines;

FIGURE 2 is a vertical section taken on line 2-2 of FIGURE 1;

FIGURE 3 is a longitudinal vertical section through a second embodiment of this invention with the heating and condensing tube bundles broken away and with the areas occupied by the heating and condensing tube bundles outlined by broken lines;

FIGURE 4 is a vertical section taken on line 44 of FIGURE 3;

FIGURE 5 is a side view of the distillation apparatus of this invention connected by pumps and piping to a plentiful raw water supply for cooling the condenser and performing other functions; and

FIGURE dis a side view of the distillation apparatus of this invention connected to an air water separator which uses a vacuum pump operable by fluid at atmospheric pressure to remove condensate and non-condensibles from the condenser.

Referring to the drawing in detail, FIGURES 1 and 2 show the generally cylindrical shell which rests upon the supports 11. Extending into one end of shell 10 is the U-shaped shroud 12 which has a rounded bottom portion 13 and two upstanding side walls 14. A longitudinal slot 19 extends along the bottom of shroud 12. If it is desired, more than one slot 19 may be formed in the bottom of shroud 12, however, the total area of the single slot 19 or a plurality of slots 19 should be no greater than 25 percent of the open area of shroud 12 disposed above the slot or slots 19.

Shroud 12 assumes a cylindrical shape at one end 15 where it projects through the shell 10. End 15 carries the flange 16 to which a cover plate 17 may be fixed in any conventional and suitable manner. coils 18 extend through and are supported by the cover The heating 3,3h2,373 Patented Feb. 7, 1967 plate 17. Although the heating coils 18 are shown broken away in FIGURE 1, the space that they would occupy is indicated by a broken line.

The inwardly disposed end of shroud 12 butts against the baflle Ztl which extends transversely across the entire shell 10. The upper portion of baffle 20 contains a large number of perforations 21. If it is desired, the perforated and the solid portions of battle 20 may be fabricated from separate sheets of metal which are welded together. The unperforated portion of bafile 26 must be of a sufficient height to assure the complete wetting of the heating coils within shroud 12, and this height is about percent of the tube bundle height.

An outlet pipe 22 extends downward into shell 10 beyond bafile Zll and below the lower most perforations 21. A plate 90, which may contain a glass window for inspection or viewing purposes, may be secured to a tubular extension from a suitable location in shell 19. Sets of bars 23 and 24 are welded or otherwise fixed within the outlet pipe 22 to position a wire mesh separator 25 within it.

The tubular condenser shell 26 extends horizontally from an upward tubular extension 27 fixed to the top of outlet pipe 22. Extension 27 includes a swash plate 28 which extends above the bottom of condenser shell 26. The cooling coils 29 pass through and are supported by the dome-shaped end plate 3t) which is bolted to a flange 31 at the end of condenser shell 26. A condenser support brace 32 is welded or otherwise fixed between the shell 10 and the condenser shell 26 to support it.

The first embodiment of this invention operates in the following manner. Water to be treated is fed into the outer end of shroud 12 through the pipe 33. Heating water is supplied through the heating coils 18 while a suitable vacuum is drawn within the entire apparatus through the tube 34 by conventional means (not shown). Water is fed into the evaporator at a rate of from two to three times the rate of evaporation at a vacuum of about 26 inches Hg. Boiling water mixed with steam in a turbulent state rises between the side walls 14 of shroud 12 to fall downward between the walls 14 and the shell 10. This rapid circulation upward in the shroud 12 and downward between the shell 10 and the shroud 12 promotes a high heat transfer rate.

FIGURE 2 shows the low static head of water 35 to be treated within the shell 10. Since the area of slot 19 restricts the entrance of Water into the shroud, a static pressure head cannot build up over the heating tubes 18 to raise the boiling point at high vacuum. Thus the configuration shown greatly reduces any elevation in boiling point at deep vacuum.

Excess liquid in the form of steam and small droplets passes to the second chamber 36 through the apertures 21 in bafile 29. Within chamber 36 steam or vapors must make a degree reversal after moving downward about the outside of outlet pipe 22 to flow upward through it. Larger liquid droplets cannot make this reversal and fall by gravity to the base of chamber 36. Any fine mist entrained with the steam or vapor coheres on the mesh separator 25 to form larger droplets that fall back into chamber 36. As liquid concentrates collect in chamber 36, they are pumped out through pipe 37.

The dry steam now passes laterally from the extension portion 27 over the swash plate 23 into the condenser 26 where it contacts the cooling coils 29 to condense. The pure condensate is then pumped out through the pipe 38. Non-condensibles may also be pumped out through pipe 38 or they may be drawn out through pipe '34 using a separate pump as will be hereinafter explained.

Referring now to FIGURES 3 and 4, the second embodiment of this invention includes a shell 10 resting upon the supports 41. A U-shaped shroud 42 for the heating coils 43 extends within shell 40 as in the previous embodiment. Formed in the bottom of shroud 42 are one or more longitudinal slots 43 which are less than 25 percent of the area of the open space of shroud 42 above them. Shroud 42 butts against the transverse plate 44 which contains the perforations 45, the height of the lowest of which is at least 125 percent that of the bundle of tubes 43.

Behind plate 44 is the outlet pipe 46 which extends below the lowermost perforations 45 and contains the mesh separator 47 held in place by the sets of bars 48 and 49. The upper end of outlet pipe 46 has the con denser shell 50 extending horizontally from it and protruding through the end of shell 40. Cooling coils 51 extend into condenser shell 50 in front of the swash plate 51 formed by an upper portion of outlet pipe 46.

The second embodiment of this invention operates in the same manner described for the first embodiment. Fluid to be treated is introduced into the neck of the evaporator shroud 42 through the pipe 52. Condensate is drawn off through pipe 53 and non-condensibles may be drawn oil? through pipe 54. The second embodiment of this invention provides a single compact unit containing both an evaporator and a condenser. It is desirable to use the same materials of construction for the evaporator and the condenser when a single shell 40 is used for both. The heating and condensing tube bundles, whose positions are shown by broken lines, may be made of any standard sheet and tube construction and can be made so that the heating and condensing tubes are interchangeable.

Referring now to FIGURE 5, where there is a plentiful supply of raw water which may be used as a cooling medium, this invention may be coupled to auxiliary equipment in the following manner. A pump 55 supplies raw water at about 40 pounds per square inch to the cooling or condensing coils 29. As this water flows from the coils 29, it enters a T fitting 56 from which it flows into pipes 57 and 58. Pipe 57 leads to an air eductor 59 which draws non-condensibles through pipe 34 from the condenser shell 26. This water and the non-condensibles then flow from eductor 59 through pipe 60 to a drain pipe 61. Raw water flowing through pipe passes to the eductor 62 which draws brine or other concentrates through pipe 37 and passes them into waste line 61. A separate pump 63 may draw distillate through pipe 38 from condenser shell 26.

Referring now to FIGURE 6, if the raw water supply is limited, a closed refrigeration system, or a hot and cold gas system may be used for evaporating and condensing the water to be treated. For example, a refrigerant may be compressed and passed through the heating coils 18 and expanded and passed through the cooling coils 29. Alternatively, hot exhaust gases may be passed through the heating coils 18 and cooling air delivered by blower 64 through the cooling coils 29. In either case, the apparatus of this invention may be connected in the following manner. Tube 38 leads to an eductor 65 which draws both distillate and non-condensibles from the condensing shell 26 and delivers same through a pipe 74- to an air water separator tank 66. The tank is vented to the atmosphere through tube 67 which passes through tank cover 68. An overflow tube 69 leads from the upper portion of the air water separator 66. A ump 70 draws Water or distillate from the air water separator 66 through pipe '71 and discharges same through a T fitting 82 into a vertical line 83. A valve 72 in the lower end of line 83 is normally closed so that fluid from pump 70 passes through pipe 73 to eductor 65 and pipe 74 to enter the air 'water separator 66 below the level of the fluid '75 within it. Thus pump 70, which may be a relatively inexpensive pump having an intake below the level of fluid 75 in the air water separator 66, is not as costly as a high vacuum pump and need not draw any vacuum. Pump 70 provides enough fluid under pressure to operate eductor 65 to draw distillate and non-condensibles from the condenser shell 26. To operate properly, the eductor 65 must discharge below the surface of the fluid or distillate 75 within the air water separator 66. Within the air water separator 66, bubbles of non-condensibles rise to the surface and escape to the atmosphere through tube 67. As distillate accumulates within the air water separator 66, it overflows through tube 69 and may be collected.

Referring further to FIGURE 6, a cooling jacket 76 having a cooling fluid circulated through it through the tubes 77 may cool the fluid passing through pipe 73 and thus cool the liquid within the air water separator 66. The cooling of fluid 75 enables the air water separator 66 to function more effectively.

It if is desired to have pump deliver distillate under pressure, a valve 78 in tube 69 may be closed and a level switch 79 installed in the air water separator 66. Level switch 79 activates a control 80 which closes valve 72 as the level of fluid within air water separator 66 falls below a given level. Conversely, as distillate accumulates Within the air water separator 66, the level switch 79 actuates the control to open valve 72 so that some of the condensate under pressure from pump 70 will be delivered through pipe 81 and thus removed from the system.

While this invention has been disclosed in the best forms known, it will nevertheless be understood that these are purely exemplary and that modifications in the construction, arrangement and combination of parts and the substitution of equivalents may be made without departing from the spirit of the invention except as it may be more limited in the appended claim.

What is claimed is:

In a distillation plant, apparatus for removing distillate and. non-condensibles from a condenser comprising, in combination, an eductor, a tube leading to said eductor from the condenser through which distillate and noncondensibles may be drawn by said eductor, a pump, an air water separator vented to the atmosphere, a tube leading from near the bottom of said air water separator to the inlet of said pump, a discharge tube leading from said pump to said eductor, a tube leading from said eductor to said air water separator below the level of water therein, said pump drawing water from said air water separator and passing it through said eductor to return to said air water separator, and means bypassing said pump inlet when 'water within said air water separator rises above a given level, comprising a water level switch in said air water separator, a control unit connected to said water level switch, and a bypass line including a valve activated by said control unit, said bypass line being connected to the line leading from the pump to the eductor.

References Cited by the Examiner UNITED STATES PATENTS 1,790,911 2/1931 Gibson 55-165 1,910,088 5/1933 Cherry 55-165 2,180,050 11/1939 Hickman 202-205 2,339,369 1/1944- Baker 55165 2,605,856 8/1952 Kirkpatrick et al. 55165 2,853,149 9/1958 Gosselin 55-169 2,878,889 3/1959 Gilbert 55-170 2,880,146 3/1959 West 20'2-18O 3,070,935 1/1963 De Leon 55170 FOREIGN PATENTS 121,046 1/1931 Austria. 519,713 10/ 1930 Germany.

REUBEN FRIEDMAN, Primary Examiner.

NORMAN YUDKOFF, Examiner.

F. E. DRUMMOND, J. ADEE, Assistant Examiners.

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