Abstract:
The present invention is a modular tower structure comprising a common up-flow column topped with a covered header to which multiple independent down-flow and scavenger columns are attached. It employs a renewable energy process for extracting energy from the atmosphere. The process works by creating a vacuum into which atmospheric air is drawn through a vacuum operated motor driver. The motor in turn can operate other mechanisms as electric power generators. A scavenger column and a header operate independently to collect and remove air before it can accumulate in the tower header and interfere with the siphon process. The tower header is equipped to remove solids or floatables before they can collect at the top of the header and interfere with the process. The header cover is removable for inspection and ease of maintenance.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation-in-part of U.S. patent application Ser. No. 12/509,443 (hereinafter, the “Parent Application”) filed on Jul. 25, 2009. Said Parent Application is incorporated by reference herein in its entirety. This Present Application claims the benefit of and priority to said Parent Application. 
    
    
     BACKGROUND OF THE PRESENT INVENTION 
     The relevant prior art discloses a cumbersome and likely unworkable apparatus for extracting energy from atmospheric air, viz., U.S. Pat. No. 4,396,842 issued to Jhun on Aug. 2, 1963 (hereinafter “Juhn”), entitled “Tidal Power Generation Utilizing the Atmospheric Pressure.” Referring to FIG. 1 of Juhn, this invention relies on a dam 14 to create two different water levels, A and B. An inverted U-tube structure 20 having perpendicular corners straddles the dam. Juhn employs adjustable floats 50 and a sluice between pools A and B to accommodate continuously varying tidal levels while simultaneously maintaining water tube 20 on the level to avoid air pocket formation along the top 22 of air tube 20. Juhn also places the interface between small bubbles emerging from small holes inn air plate and the flowing medium at the top 22 corner of air tube 20. Flow regulating valves control air and water flow. Juhn furthermore make no provision for initial priming of the system or for purging any air/gas that may accumulate along the top 22 of air tube 20. In addition, because Juhn&#39;s inverted U-tube structure 20 straddles dam 14, it is captive to the location and design of the dam. 
     APPROACH TO SOLVING THE PROBLEM 
     The Present Invention provides a workable solution to the shortcomings of Juhn. It allows for a remote and/or convenient installation site away from pool A since it need not straddle a dam. A dam may not even be necessary if water is drawn from any elevated source. The Present Invention precludes the need to maintain a balance between pools A and B surface levels exploiting tidal or wave activity since the Present Invention is positioned on the pool B side only. Attached floats or floats combined with a counterweight system allows the Present Invention to automatically adjust to a constantly changing pool A surface level from tidal or wave activity. 
     The Present Invention overcomes the adverse effect from air/gas accumulation by incorporating a domed header configuration wherein air/gas can gather for removal through the header top via a scavenger system. A priming system necessary for startup is connected via the scavenger line. Micro-bubble diffusers mounted in the down-flow columns expose emerging small air bubbles directly into the downward flowing medium. 
     SUMMARY OF THE INVENTION 
     The Present Invention is a modular tower structure comprising a common up-flow column topped with a covered header to which multiple independent down-flow and scavenger columns are attached. The Present Invention incorporates the renewable energy process for extracting energy from the atmosphere that was disclosed in the Parent Application. The process works by creating a vacuum into which atmospheric air is drawn through a vacuum operated motor driver. The motor in turn can operate other mechanisms as electric power generators. 
     The scavenger column and header operate independently to collect and remove air and/or gas before they can accumulate in the tower header and interfere with the siphon process. The tower header is equipped for removing solids or floatables before they can collect at the top of the header and interfere with the process. The header cover is removable for inspection and ease of maintenance. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a flow diagram of a typical power tower. 
         FIG. 2  is a sectional view and process flow for a tower header and components. 
         FIG. 3  is a cross-section of a side inlet tower header. 
         FIG. 4  is a cross-section of a hydrophobic porous membrane micro-bubble diffuser 
         FIG. 5  is a cross-section of a micro-tube type micro-bubble diffuser. 
         FIG. 6  Illustrates a tower with side entry header positioned adjacent to and feeding from a channel. 
         FIG. 7A-7C  shows a tower with side entry header positioned in an ocean wave overtopping platform. 
         FIG. 7A  illustrates a left-half section elevation. 
         FIG. 7B  illustrates a full section elevation 
         FIG. 7C  illustrates an enclosed full section elevation. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The Vacuum Activated Modular Power Tower structure is unique as it can operate on relatively low head hydro resources normally incompatible with other energy producing systems. The modular design allows for a single or multiple unit installation as may be appropriate to any specific and available low head flow volume hydro source. Modules may also be “laddered” to fully exploit higher head but limited volume flow hydro sources. Fabrication using low weight commercially available materials lead to reduced transportation, assembly, foundation and maintenance costs. Minimal foundation requirements lead to minimal environmental impact. The modular design is flexible in that basic components can be arranged for specific applications. 
     Major Power Tower components and relative positions with respect to the process flow are shown in  FIG. 1 . A center-in-tank up-flow column module as illustrated in the drawing could receive piped in flow from a hydro source while setting in a natural catch basin or in a channel. 
     Basic components of an exemplary embodiment are shown in  FIG. 1 . A vertical tower  10  capped with a covered header  26  is seated in an open tank  11 . A water inlet manifold  12  and a water overflow fitting  13  are attached to tank  11 . Tower  10  has bottom openings. Scavenger column(s)  14  and down-flow column(s)  15  are spaced around the tower header  10 . Open tank  11  is supported over a separate drained catch basin. Scavenger and down-flow column(s)  14  and  15  extending downward penetrate the tank  11  bottom and protrude into the catch basin below the basin drain level. Sealing glands  16  close the clearances at the tank  11  base penetrations. 
     Removable tower header cover  27  seated on the top rim of header  26  and sealed using leak-tight O-ring or equal sealing medium is held securely in place once vacuum is applied. Simple latches  31  (see  FIG. 2 ), which hold the cover  27  in position during shipment, erection and start-up also allow easy access to the header for maintenance. 
     Internal scoop  32  mounted inside of header  26  connects to scavenger column header  22  are shown in  FIG. 2 . This provides a means for removing floatable materials and debris from the tower header  26 . The vacuum producing interaction between cascading water and the air/gas drawn from the header and entrained in the scavenger column down-flowing water is shown in the drawing. Micro-bubbles introduced into the down-flow water column by the micro-bubble diffuser are also shown in the drawing. 
     A micro-bubble diffuser  17  is mounted in the upper section of each down-flow column  15  as shown in  FIGS. 1 and 2 . Alternatively each diffuser  17  is positioned at the top inlet of the associated down-flow column within the side entry tower header as shown in  FIG. 6 . A lateral line  33  (see  FIG. 3 ) connects each diffuser  17  to a vacuum flow line  19  (see  FIG. 1 ). Flow line  19  connects the micro-bubble diffuser inlet nozzle  18  to a vacuum powered motor  20  exhaust port. A motor start-up valve  21  mounted in flow line  19  isolates the vacuum powered motor  20  from the micro-bubble diffuser  17 . 
     Vacuum flow line  23  connects the top of scavenger column header  22  to the purge manifold  28  mounted at the top of header cover  27  and to the inlet port of the vacuum priming start-up pump  24 . Vacuum backflow check valve  25  is mounted in vacuum line  23  between the vacuum priming pump  24  and the top of scavenger column header  22 . 
     System start-up begins with filling open tank  11  from a continuously available water source entering through inlet manifold  12 . Once tank  11  is filled, excess water passing through overflow fitting  23  will fill the separate catch basin which in turn will overflow when the drain level is reached. Once the separate catch basin is filled to overflow with the protruding lower ends of scavenger and down-flow columns  14  and  15  are submerged ( FIG. 3 ), the system may be primed by evacuating all air and/or gas from the system using the vacuum priming start-up pump  24 . Vacuum motor start-up valve  25  is closed during the priming phase. Siphoning of water from filled tank  11  into the catch basin will immediately begin once all air/gas have been removed from all columns and displaced with water. The natural force motivating upward flow in tower  10  and downward flow in the scavenger and down-flow columns  14  and  15  is the differential head between the filled tank surface and the separate catch basin drain level shown in  FIG. 1 . 
     Once siphoning begins, vacuum priming pump  24  is shut down. Check valve  25  in vacuum flow line  23  prevents air back streaming, which could disrupt the siphoning action. 
     The source of supplementary vacuum necessary to sustain continuous siphon flow with the vacuum priming pump  24  out of service is the gas entrainment process occurring within the scavenger column header  22  illustrated in  FIG. 2 . Air and/or gas, as they may appear in the tower header  26 , are drawn via vacuum flow line  23  into scavenger column header  22  before they can accumulate and interrupt the siphon effect. While minimal, the vacuum pumping speed generated by a working model scavenger column is sufficient to support a tower and several down-flow columns. Additional scavenger columns could provide additional pumping speed, as might be needed for a tower header with multiple down-flow columns or if outgassing is excessive. 
     Once siphon flow attains a steady state, motor start-up valve  21  is opened to allow atmospheric air to flow through vacuum operated motor  20  to micro-bubble diffuser  17  via flow line  19 . Motor  20  will begin operating immediately when a vacuum is applied and atmospheric air passes through. 
       FIG. 3  is a cross-section of a side-inlet tower header. The side-entry tower header can accommodate a more compact multiple element down-flow tube nest. Micro-bubble diffusers are inside the tower header as shown. Major components of micro-bubble diffuser  17  (see  FIGS. 4 and 5 ) are the outer casing  33 , the upper extension  34 , the lower extension  35 , the porous hydrophobic membrane  36  and the diffuser inlet nozzle  18  as illustrated in  FIG. 3 . A circumferential cavity  37  in casing  33  encircles porous hydrophobic membrane  36 . Extensions  34  and  35  connect respectively to upper and lower down-flow column  15  sections. 
     Major components of a micro-tube type micro-bubble diffuser  17  include the outer casing  33 , upper and lower extensions  34  and  35 , inlet nozzle  18 , cavity  37  with a micro-tube retainer supporting micro-tubes  38  are illustrated in  FIG. 4 .  FIG. 4  is a cross section of the hydrophobic porous membrane micro-bubble diffuser. The path for air entering into the micro-bubble diffuser via the intake fitting and into the circumferential cavity to flow freely around and pass through the porous membrane to be dispersed into the down flowing liquid is illustrated in the drawing. 
     Air drawn into diffuser  17  by the vacuum inherent to a siphon column enters through nozzle  18  into cavity  37  and passes through membrane  36  (or through micro-tubes  38 ) into down-flow column  15 . The air is dispersed as extremely small bubbles as it passes through the hydrophobic micro-bubble diffuser membrane  36  (or through micro-tubes  38 , shown in  FIG. 5 ). In  FIG. 5 , the micro-tubes  38  extend into the liquid and are flexible so as to bend toward the direction of the liquid flowing in the downward direction. Typically, the micro-tubes  38  have diameters less than or equal to ten microns. The micro-bubbles emerging from the diffuser  17  become entrained in the downward flowing liquid by the sweeping effect across the air-liquid interface to be discharged at the bottom of down-flow column  15 . The micro-bubbles formed are purposely so small that they are easily swept down and away before they can rise and interfere with the process. 
     Purge manifold  28  mounted on the header cover  27  (see  FIG. 2 ) includes a normally closed purge valve  28 A and normally open shut-off valve  28 B as shown in  FIG. 2 . These valves are activated as needed to remove any debris from the cover  27  air/gas outlet which could interfere with scavenger column  14  operation. Purge vessel  29  mounted on the purge manifold  28  may be filled with liquid. Momentary opening of valve  28 A and closing of valve  28 B will cause a vacuum induced downward surge, flushing out obstructions. 
     Purge manifold  28  may be used to facilitate a planned shutdown for maintenance. Opening valve  28 A with valve  28 B in normal open mode and vessel  29  void of liquid will cause a rapid and safe shutdown as entering atmospheric air displaces liquid. 
     The modular tower may be maintained in a fully charged static state to accommodate short periods of inactivity without re-priming prior to resuming normal operation by closing valve  21  to shut off air flow to diffuser  17 . 
     A surface level monitoring device (not shown) in tank  11  would signal valve  21  to close prior to sensing a head level insufficient to maintain siphon flow. A tidal operated system typically would encounter changing head levels with the ebb and flow of each tidal reversal. Siphon flow would continue until equilibrium is reached between up-flow and down-flow columns. All columns would then remain fully charged and ready for siphon flow to resume in the absence of any outside air intrusion sufficient to prevent siphon flow. Siphon flow would resume once tank  11  has refilled and valve  21  re-opened on a signal from level monitoring device. 
       FIG. 5  is a cross-section of a micro-tube type micro-bubble diffuser. The air path is the same as described in  FIG. 4  except that the air passing from the circumferential cavity is dispersed as micro-bubbles into the down flowing liquid via micro-tubes. 
     A side-mounted up-flow column module, as illustrated in  FIG. 6 , is compatible with differing tank/channel and/or side-to-side arrangements. Using floats, it could be adapted for harvesting tidal activity. A side-mounted up-flow module mounted in a low profile circular floating surface platform designed to exploit ocean wave activity is shown in  FIG. 7 . 
     A multiple element tower with a side entry header as shown in  FIG. 6  feeds from a channel. While having the necessary additional components as the center mounted tower header, a specially designed base tank is not required for support. 
     A tower with side-entry header installed in a floating low profile circular ocean wave overtopping platform is shown in  FIG. 7 .  FIG. 7A  illustrates a left-half section elevation.  FIG. 7B  illustrates a full section elevation.  FIG. 7C  illustrates an enclosed full section elevation. The apparatus has the appearance of a sea-saucer. Sea water elevated by being driven up the inclined ramp by wave action collects in bay  1 , progresses into bay  2  and then into bay  3  as shown. The circular shape precludes the need to position the platform facing wind/wave direction. Wave deflectors positioned along the platform ramp help direct sea water toward the center and into bay  1 . Sea water having entered the bay  1  wave facing side automatically flows by gravity to the rear and levels out uniformly. 
     The flow path from bay  1  to bay  3  is designed to minimize carryover of air entrained in the sea water by violent wave action into the tower up-flow column inlet. The bypass between bay  1  and bay  2  is near the bottom of each bay so entrained air will have opportunity to agglomerate into larger bubbles and rise to the surface. The inlet to the tower up-flow column in bay  3  also is purposely positioned as low as possible to allow as much entrained air as possible to be removed from the flow path between bays  2  and  3 .