Abstract:
A condensate removal system for removing condensate or infiltrate from a fluid reservoir containing a lubricating or scaling fluid. The condensate removal system includes a fluid conduit having a discharge leg with an outlet port. The condensate removal system prevents or inhibits evaporation of fluid within the discharge leg through the outlet port of the discharge leg while allowing fluid within the discharge leg to flow through the outlet port. The location of the outlet port of the discharge leg is adjustable to compensate for different specific gravities of the lubricating or sealing fluid.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     In many applications an enclosure or housing contains a primary liquid lubricant or sealing fluid. An example of a housing containing a primary liquid lubricant is an internal spur gear drive. An example of a housing containing a primary sealing fluid is the liquid seal for a clarifier or digester cover having a movable section, a fixed section, and a liquid seal assembly to prevent the free passage of gases from one side of the cover to the other. These housings are generally enclosed to exclude rain and contaminants, but they cannot be completely sealed against the ingress of humid air or the infiltration of liquid water, due to the nature of the movable components.  
         [0002]     The introduction of liquid water arising from condensation of water vapor, or the ingress of liquid water, into liquid seal assemblies and liquid lubricant sumps has long been a problem. If the primary fluid, such as a sealing fluid or lubricant, has a specific gravity lower than that of water, the water displaces the primary fluid.  
         [0003]     In a lubrication application, as would be found in internal spur gear drives, condensation and infiltrated water accumulating within reservoirs or sumps, displaces the primary fluid, which is usually a petroleum based lubricating oil, exposing bearing, gearing, and other surfaces to water, disrupting lubrication films and causing increased potential for corrosion. The accumulation of water in the drive housing can displace the primary fluid to the point of expulsion from the housing creating spillage.  
         [0004]     In water and wastewater treatment plants, including municipal and industrial plants, the local relative humidity is increased by water vapor that is present above process basins, tanks, or vats. The housings of gear drives and liquid seal housings may be exposed to direct sunlight during part or all of the day or the housing may be exposed to other varying heat sources or cycles. As the housing is heated, the internal air within the housing is also heated and expands. The increased internal pressure expels a portion of the air from within the housing to outside of the housing. When the heating cycle ends, such as due to a change in a process or a shifting of sunlight away from the housing, the housing cools and the internal air contracts. The volumetric contraction of the cooler air lowers the internal pressure within the housing, drawing in ambient exterior air, which is sometimes laden with moisture. As this air cools within the housing, the dew point of the water vapor is reached and the vapor condenses forming beads of liquid condensate within the housing. The condensate is drawn by gravity to the low points within the housing, which in many cases is through the lubricant, where it accumulates below the lubricant, due to the specific gravity difference of the fluids. Water that has infiltrated the housing from the outside will also tend to accumulate below the lubricant or sealing fluid.  
         [0005]     Within the housing, the condensate located below the lubricant does not evaporate as the heat input is generally less than the required latent heat of evaporation, and a lubricant such as oil, which has a lower specific gravity than water, forms a layer over the water condensate, thereby creating a vapor seal above the liquid water. Similar but more severe conditions exist when the housing is located within a cover that extends over a basin of liquid, such as water, wastewater or other process fluid, as the cover confines vapor in the vicinity of the drive housing.  
         [0006]     A sewage treatment clarifier may be covered as an odor control measure. A liquid seal is employed in those cases where a portion of the cover must be free to move or rotate about the center of the basin. The seal is normally made up of an annular chamber having sides and a bottom. This chamber contains the primary fluid, usually petroleum oil or silicone oil. A cylindrical wall extends into the annular chamber and is partially submerged into the primary fluid. The cylindrical wall is connected to the movable cover section while the annular chamber is connected to another cover section, or the positions can be reversed. If the primary fluid is petroleum oil, the accumulation of water in the annular chamber can displace the petroleum oil to the point of oil spillage over the top of the chamber walls.  
         [0007]     If the primary fluid has a specific gravity greater than water, as does silicone oil, the water remains above the primary fluid. Again, the water can accumulate to overflow the chamber walls. Before this, however, the water retained above the primary fluid can become a breeding place for flies, mosquitoes, and the like. A layer of petroleum oil can be poured over the silicone primary fluid to seal the water surface from the breeding insects, but again water can accumulate to overflow the chamber walls carrying the petroleum oil before it, leaving the water surface exposed.  
         [0008]     Manual and continuous operating or automatic condensate systems have been developed to drain condensate and infiltrate from the housing. The manual system drains the condensate periodically by means of a manual valve or a motorized valve and switch arrangement. The continuous system drains the condensate as it appears or “automatically”.  
         [0009]     Condensate removal systems previously used and as currently in use are generally V or U-shaped devices consisting of a collection leg and a discharge leg, and in some cases a transverse leg. A primary or first fluid, such as oil, and a secondary fluid, such as water, of different densities or specific gravities are contained within the V or U-shaped devices. The secondary fluid constitutes the liquid condensate, liquid infiltrate, or liquid condensate and liquid infiltrate combined, all hereinafter referred to collectively as “condensate”. Liquid water condensate has a specific gravity of approximately 1.00. Liquid water condensate collects in a sump within the housing and is drained into the collection leg of the removal system. The primary fluid, such as oil, is intentionally placed within the housing to act as a lubricant, as a sealing fluid, and/or as a corrosion inhibitor among other functions. The primary fluid, such as oil, usually has a specific gravity less than that of the secondary fluid or condensate, such as water. The elevation of the interface surface between the primary fluid and the secondary fluid is thereby established by setting the elevation at which the secondary fluid in the discharge leg of the removal system is allowed to discharge, and by the volume of the primary fluid in the housing which determines the elevation of the oil and water interface in the collection leg.  
         [0010]     Condensate removal system designs attempt to adjust the discharge elevation of the discharge leg during initial installation to accommodate primary fluids with a narrow range of specific gravities. These designs, however, result in the fixing of the discharge elevation at the time of installation without provision for additional adjustment during the service life of the equipment.  
         [0011]     If, in the case of a gear housing, a primary fluid, such as a lubricant, is used that is outside of this range of initial installation parameters, the system may not operate properly. This has been one of the causes of operational problems in preceding condensate removal systems. The condensate removal system may be rendered inoperable due to a replacement of the first fluid by a third fluid of a lower or higher density or specific gravity than that of the first fluid, which causes the elevation of the interface of the third fluid and the second fluid in the collection leg to move outside of the design range.  
         [0012]     If the specific gravity of the third fluid is higher than that of the first fluid, the elevation of the interface between the third fluid and the second fluid in the collection system is lowered relative to the elevation of the interface of the first fluid and the second fluid. When the fluid interface between the second fluid and the third fluid reaches the level of the connection between the collection and discharge legs, the third fluid is no longer sequestered in the collection leg portion of the V or U-shaped device and will flow to the discharge leg, resulting in a loss of the third fluid, such as lubricating oil, from the housing reservoir. The addition of make-up third fluid to raise the third fluid free surface to design levels only forces more third fluid from the reservoir and collection leg, while potentially ejecting it from the discharge point.  
         [0013]     During normal seasonal lubricant replacement, the primary fluid may be replaced with a third fluid of lesser density or specific gravity than that of the primary fluid. The elevation of the interface between the third fluid and the second fluid within the collection leg rises relative to the elevation of the interface of the first fluid and the second fluid. When the fluid interface reaches the level of critical surfaces, such as bearing races and rolling elements or gear teeth, lubrication breaks down and lubricant starvation results. Corrosion also accelerates under these conditions. Additionally, the free surface of the third fluid may be raised resulting in the lubricant being expelled from the housing through seals not normally exposed to the original primary fluid. These situations have not been addressed in the industry.  
         [0014]     Another common cause of failure in continuous condensate removal systems that has not previously been addressed is the loss of liquid condensate from the collection leg due to evaporation of condensate from the discharge leg through the discharge port without adequate replacement of liquid condensate to the system by the accumulation of condensate within the housing reservoir. This may seem in conflict with the desired result, which is the removal of condensate from the system. However, the height of the column of condensate within the collection leg must be maintained at a relatively constant elevation. When condensate within the housing arrives at the collection leg an equivalent volume of condensate is discharged through the discharge port of the discharge leg maintaining the system in balance.  
         [0015]     When condensate evaporates from the discharge leg, and an equivalent volume of condensate is not collected within the housing, the lost volume is not replaced. The elevation of the fluid interface in the collection leg will be lowered. Addition of lubricant based on fill port levels, dipstick measurements, or sight glass levels will only further lower the lubricant-water interface in the collection leg. Continued unbalanced evaporation of condensate from the discharge leg can cause a transfer of the lubricant from the collection leg to the discharge leg. The lubricant or primary fluid will migrate to the top of any condensate remaining in the discharge leg. This results in lubricant discharge from an otherwise functional system, thus upsetting the balance of the system further.  
         [0016]     The lubricant that is drained into the discharge leg is no longer available to the drive mechanism through the collection leg. If condensate forms within the drive housing it will migrate to the collection leg. The lubricant that has migrated to the discharge leg is then raised to the discharge port and discharged. When the primary and secondary fluid interface in the collection leg rises above its design elevation, gear teeth, bearings or other components are potentially exposed to the condensate, and the volume of the lubricant present to lubricate components or to act as a seal is reduced resulting in decreased drive system reliability.  
       SUMMARY OF THE INVENTION  
       [0017]     A condensate removal system for removing condensate such as liquid water from a fluid reservoir of a housing including a primary fluid such as a lubricant or sealing fluid. The condensate system includes a fluid conduit having a discharge leg with a first end and a second end. The first end is adapted to be connected in fluid communication with the fluid reservoir. The second end of the discharge leg includes an outlet port adapted to be placed in fluid communication with the atmosphere. The discharge leg may include a segment having a reduced cross-sectional area to inhibit evaporation of fluid within the discharge leg through the outlet port. The discharge leg may include a seal mechanism including a seat and a seal member wherein the seal member is adapted to engage the seat and create a seal therewith to inhibit evaporation of fluid within the discharge leg through the outlet port. The seal member is adapted to disengage from the seat to allow fluid within the discharge leg to flow through the outlet port. The discharge leg may include a first segment including the first end of the discharge leg and a second segment including the outlet port. The second segment is slidably attached to the first segment such that the position of the outlet port can be selectively adjusted with respect to the first segment of the discharge leg. 
     
    
     BRIEF DESCRIPTION OF THE DRAWING FIGURES  
       [0018]      FIG. 1  shows a prior art condensate removal system in connection with a liquid seal.  
         [0019]      FIG. 2  is a side cross-sectional view of the condensate removal system of  FIG. 1 .  
         [0020]      FIG. 3  shows a prior art condensate removal system in connection with a drive mechanism.  
         [0021]      FIG. 4  is a side cross-sectional view of the condensate removal system of  FIG. 3 .  
         [0022]      FIG. 5  is a side cross-sectional view of the condensate removal system of  FIG. 4 , but shown after evaporation of a portion of the condensate from the discharge leg through the discharge port.  
         [0023]      FIG. 6  is a side cross-sectional view of the condensate removal system of  FIG. 5  shown after evaporation of a sufficient amount of condensate to sufficiently lower the first fluid-second fluid interface to allow the first fluid to be discharged from the discharge port.  
         [0024]      FIG. 7  shows a side cross-sectional view of the condensate removal system of  FIG. 4  shown after the first fluid is replaced by a third fluid.  
         [0025]      FIG. 8  shows a side cross-sectional view of the condensate removal system of  FIG. 4  shown after the first fluid is replaced by a fourth fluid.  
         [0026]      FIG. 9  shows a condensate removal system of the present invention having a discharge leg with reduced cross-sectional area at the discharge port.  
         [0027]      FIG. 10  is a side cross-sectional view of a modified embodiment of the condensate removal system of the present invention including a seal mechanism at the discharge end of the discharge leg.  
         [0028]      FIG. 11  is a side cross-sectional view of a further modified embodiment of the condensate removal system of the present invention including a reduced cross-sectional area and a seal mechanism at the discharge end of the discharge leg.  
         [0029]      FIG. 12  is a side cross-sectional view of a further modified embodiment of the condensate removal system wherein the discharge leg includes a fixed segment and a vertically movable segment.  
         [0030]      FIG. 13  is a side cross-sectional view of view of another modified embodiment of the condensate removal system wherein the discharge leg includes a fixed segment and a vertically movable segment having a sealing mechanism at the discharge end of the movable segment.  
         [0031]      FIG. 14  is a partial side cross-sectional view of a discharge leg including a pivotal seal member.  
         [0032]      FIG. 15  is a top plan view taken along line  15 - 15  of  FIG. 14 .  
         [0033]      FIG. 16  is a partial cross-sectional view showing a condensate removal system of the present invention having a discharge leg formed integrally with the housing.  
         [0034]      FIG. 17  is a top plan view taken along line  17 - 17  of  FIG. 16 .  
         [0035]      FIG. 18  is a side view taken along line  18 - 18  of  FIG. 17 . 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0036]      FIGS. 1 and 2  show a seal mechanism  10  including a top  11  and a side skirt  12 . The bottom end of the skirt  12  is immersed in a primary fluid  28  retained in a fluid reservoir  13  of a housing  26 . The skirt  12  is adapted to seal the interior of a hollow closed interior chamber  16  while allowing rotation, translation, or oscillation about a vertical axis  14  and translation about any horizontal axis  15  that is perpendicular to the axis  14 . At least a portion of the skirt  12  is located within the housing  26  and is immersed in the first fluid  28  of the seal mechanism  10 . The housing  26  communicates with the hollow closed chamber  16  and with an open external chamber  17 . The housing  26  is adapted to contain the primary or first fluid  28 . The housing  26  includes a sump  30  which is adapted to collect fluid within the fluid reservoir  13  and direct it to a port  32  in the housing  26 . The first fluid  28  may be a liquid such as petroleum or mineral oil. A condensate removal system  36  is in communication with port  32  of the housing  26  and the atmosphere.  
         [0037]      FIGS. 3 and 4  show a drive mechanism  20  including a gear  22 , such as a spur gear, worm gear or the like, in connection with a housing  26 . The gear  22  is adapted to rotate about a vertical axis  24 . At least a portion of the gear is located within the fluid reservoir  13  of a housing  26 . The housing  26  and gear  22  form an open internal chamber  18  and an open external chamber  19 , both of which communicate with the atmosphere. A condensate removal system  36  is in communication with the fluid reservoir  13  of the housing  26  and with the atmosphere.  
         [0038]     As shown in  FIGS. 1-4  the prior art condensate removal system  36  includes a generally U-shaped tubular conduit  38  having a collection leg  40 , a discharge leg  46 , and a connecting leg  52 . The collection leg  40  includes a first end  42  and a second end  44 . The first end  42  of the collection leg  40  is adapted to be attached to the housing  26  in fluid communication with the port  32 . The discharge leg  46  includes a first end  48  and a second end  50 . The connecting leg  52  is attached at one end to the second end  44  of the collection leg  40  and at a second end to the first end  48  of the discharge leg  46 . The second end  50  of the discharge leg  46  includes an outlet port  54 . Each of the legs  40 ,  46 , and  52  include a respective hollow bore in fluid communication with one another such that the inlet port  32  is in fluid communication with the outlet port  54 . The collection leg  40  and discharge leg  46  are generally vertical and parallel to one other. The U-shaped conduit  38  is adapted to contain a second fluid  60  in each of the legs  40 ,  46  and  52 . The second fluid  60  has a higher density or specific gravity than the density or specific gravity of the first fluid  28 . For example, the second fluid  60  may typically comprise liquid water having a specific gravity of approximately 1.00, while a lubricant that comprises the first fluid  28  may typically have a specific gravity between approximately 0.850 and 1.000. The first fluid  28  will in this example therefore float on top of the second fluid  60 .  
         [0039]     The first fluid  28  has a top surface  62  located in the housing  26 , and the second fluid  60  has a top surface  64  located at the outlet port  54  of the discharge leg  46 . The first fluid  28  contacts the second fluid  60  within the collection leg  40  at a fluid interface  66 . The top surface  64  of the second fluid  60  is located at the outlet port  54  at an elevation between the respective elevations of the fluid interface  66  and the top surface  62  of the first fluid  28 . As water vapor contained in the air located in the housing chambers above the first fluid  28  condenses, the liquid condensate will flow downwardly through the first fluid  28  and will be collected in the sump  30 . The condensate will then flow from the sump  30  through the port  32  and into the second fluid  60  contained in the collection leg  40 . As a volume of condensate flows into leg  40 , an equal volume of second fluid  60  in the discharge leg  46  will be discharged through the outlet port  54 , such that the fluid interface  66  remains at a relatively constant elevation. The top surface  62  of the first fluid  28  thereby also remains at a relatively constant elevation.  
         [0040]      FIG. 5  shows the condensate removal system  36  after a portion of the second fluid  60  in the discharge leg  46  evaporates through the outlet port  54  and is not replaced with a corresponding volume of condensate that is collected by the sump  30 . As can be seen when compared to  FIG. 4 , the elevation of the top surface  62  of the first fluid  28 , the elevation of the top surface  64  of the second fluid  60 , and the elevation of the fluid interface  66  are all lower in  FIG. 5  than in  FIG. 4 . The gear  22  as shown in  FIG. 5  is, therefore, in contact with a lower elevation of first fluid  28  such that the gear  22  is not as well lubricated, as is the gear  22  shown in  FIG. 4 . The improper lubrication of the gear  22  as a result of the lower level of the first fluid  28  as shown in  FIG. 5  can result in damage to the drive mechanism  20 .  
         [0041]     As shown in  FIG. 6 , when a sufficient volume of second fluid  60  has evaporated from the discharge leg  46  through the outlet port  54 , without a corresponding volume of condensate being collected by the sump  30  for introduction into the collection leg  40 , the fluid interface  66  is further lowered to a position within the connecting leg  52 . The first fluid  28  may thereby flow from the fluid reservoir  13  in housing  26  through the collection leg  40  and connecting leg  52  into the discharge leg  46 . First fluid  28  then collects above the second fluid  60  in the discharge leg  46 . The first fluid  28  may then be discharged through outlet port  54 . As shown in  FIG. 6 , the top surface  62  of first fluid  28  is no longer in contact with the gear  22  resulting in potential damage to the drive mechanism  20 . If additional first fluid  28  is added to the reservoir  13  in order to raise the level of the first fluid  28  to the original elevation, this additional first fluid  28  will also migrate to the discharge leg  46 . If a large enough quantity of first fluid  28  is added to the reservoir  13  in an attempt to return the first fluid surface  62  to the operating level shown in  FIG. 4 , the top surface  65  of the first fluid  28  within discharge leg  46  will reach the level of discharge outlet port  54  and may potentially be discharged onto machinery, walkways or other surfaces, where it can create a hazard. Similarly, if condensate forms in chambers  18 - 19 , or if water infiltrates into chambers  18 - 19 , the first fluid  28  located above the second fluid  60  in the discharge leg  46  will rise and will be discharged through outlet port  54 .  
         [0042]      FIG. 7  shows the drive mechanism  20  wherein the first fluid  28  is replaced by a third fluid  27 . The third fluid  27  may be a lubricating fluid. The third fluid  27  has a lower specific gravity than the first fluid  28 . Replacement of the first fluid  28  with a third fluid  27  is common during seasonal lubricant replacement. The second fluid  60  and third fluid  27  have a fluid interface  67 . The elevation of the fluid interface  67  between the second fluid  60  and third fluid  27  will be higher than the elevation of the fluid interface  66  between the first fluid  28  and second fluid  60  as shown in  FIG. 4 , while the elevation of the top surface  64  of the second fluid  60  in the discharge leg  46  will be unchanged, and the top surface  61  of the third fluid  27  will be at the same elevation as the top surface  62  of the first fluid  28  as shown in  FIG. 4 . The distance between the top surface  61  of the third fluid  27  and the fluid interface  67  of the third fluid  27  and second fluid  60  is less than the distance between the top surface  62  of the first fluid  28  and the interface  66  of the first fluid  28  and second fluid  60 . This reduction in lubricant depth may expose portions of the gear  22 , or other components, to the second fluid  60  rather than the third fluid  27 , thus degrading lubrication and increasing the risk of corrosion.  
         [0043]      FIG. 8  shows the drive mechanism  20  in which first fluid  28  is replaced by a fourth fluid  29 . The fourth fluid  29  may be a lubricating fluid. The fourth fluid  29  has a greater specific gravity than the first fluid  28 . Replacement of the first fluid  28  with a fourth fluid  29  is common during seasonal lubricant replacement. Second fluid  60  and fourth fluid  29  will have a fluid interface  68 . The elevation of the fluid interface  68  between the second fluid  60  and fourth fluid  29  is lower than the elevation of the fluid interface  66  between the first fluid  28  and second fluid  60  as shown in  FIG. 4 . The elevation of the top surface  64  of the second fluid  60  in the discharge leg  46  will be unchanged, and the top surface  63  of the fourth fluid  29  will be at the same elevation as the top surface  62  of the first fluid  28  shown in  FIG. 4 . The distance between the fourth fluid top surface  63  and the fluid interface  68  of the second fluid  60  and fourth fluid  29  is greater than the distance between the top surface  62  of the first fluid  28  and the fluid interface  66  of the first fluid  28  and second fluid  60  as shown in  FIG. 4 . As compared to the embodiment of  FIG. 4 , when a smaller volume of second fluid  60  evaporates from the discharge leg  46  through the outlet port  54 , without a corresponding volume of condensate being collected by the sump  30  for introduction into the collection leg  40 , the fluid interface  68  is further lowered to an elevation approaching the second end  44  of the leg  40  which is in communication with the connecting leg  52 . The fourth fluid  29  may thereby flow from the fluid reservoir  13  through the collection leg  40  and connecting leg  52  into the discharge leg  46 . The fourth fluid  29  may then be discharged through outlet port  54 . Similar to what is shown in  FIG. 6 , the elevation of the top surface  63  of the fourth fluid  29  will be lowered and may no longer be in contact with the gear  22  resulting in potential damage to the drive mechanism  20 . If additional fourth fluid  29  is added to the reservoir  13  in order to raise the level of the fourth fluid  29  to the original elevation, additional fourth fluid  29  will also migrate to the discharge leg  46 . If a large enough quantity of fourth fluid  29  is added to the reservoir  13  the fourth fluid  29  will enter the discharge leg  46  and upon reaching the level of outlet port  54 , may be discharged onto machinery, walkways or other surfaces where it can create a hazard in a manner similar to that as shown in  FIG. 6 . If evaporation of the second fluid  60  were to continue and no additional fourth fluid  29  were added to return the fourth fluid top surface  63  to the elevation of the top surface  62  of first fluid  28  as shown in  FIG. 4 , the level of the fourth fluid  29  could fall below the gear  22  resulting in unlubricated operation.  
         [0044]      FIG. 9  shows the condensate removal system  70  of the present invention in connection with the drive mechanism  20 . The condensate removal system  70  includes a generally U-shaped tubular fluid conduit  72 . The U-shaped conduit  72  includes a collection leg  74 , a discharge leg  76 , and a connecting leg  78 . The collection leg  74  includes a first end  80  and a second end  82 . The first end  80  of the collection leg  74  includes an inlet port adapted to be attached in fluid communication with the port  32  and reservoir  13  in the housing  26 . The discharge leg  76  includes a first end  86  and a second end  88 . The connecting leg  78  is attached at one end to the second end  82  of the collection leg  74  and at a second end to the first end  86  of the discharge leg  76 . The second end  88  of the discharge leg  76  includes a spout  90  having an outlet port  92 . Each of the legs  74 ,  76 , and  78  include a respective hollow bore in fluid communication with one another such that the inlet port  32  is in fluid communication with the outlet port  92 . The collection leg  74  and discharge leg  76  are generally vertical and parallel to one other.  
         [0045]     The discharge leg  76  includes a lower segment  94  that is connected to the connecting leg  78  and an upper segment  96  that is attached to and extends between the lower segment  94  and the spout  90 . The lower segment  94  includes a bore having a first diameter and a first cross-sectional area and the upper segment  96  includes a bore having a second diameter and a second cross-sectional area. The second diameter of the bore of the upper segment  96  is smaller than the first diameter of the bore of the lower segment  94 . The second cross-sectional area of the upper segment  96  is smaller than the first cross-sectional area of the lower segment  94 . The collection leg  74  includes a bore having a cross-sectional area that is approximately equal to the cross-sectional area of the bore of the lower segment  94  of the discharge leg  76 . As shown in  FIG. 9 , the top surface  64  of the second fluid  60  is located within the upper segment  96  of discharge leg  76  such that the surface  64  has a reduced cross-sectional area in fluid communication with the atmosphere through the outlet port  92 , as compared to the cross-sectional areas of the lower segment  94  and collection leg  74 , to reduce the rate of evaporation of the second fluid  60  through the outlet port  92 . A cross-sectional area reduction in the upper segment  96  from that of the lower segment  94  in the range of thirty-five percent to ninety-five percent is preferred, although a cross-sectional area reduction of as little as fifteen percent can have a beneficial result on the rate of evaporation. The relatively large diameter and cross-sectional area of the lower segment  94  allows the lower segment  94  to contain a relatively large volume of second fluid  60 , than if it had the same cross-sectional area of the upper segment  96 .  
         [0046]      FIG. 10  shows a modified embodiment of the condensate removal system designated with the reference number  100 . The condensate removal system  100  includes a generally U-shaped fluid conduit  102  having a collection leg  104 , a connecting leg  108  and a discharge leg  106 . The connecting leg  108  connects the discharge leg  106  to the collection leg  104 . The collection leg  104  is attached in fluid communication with the port  32  of the housing  26 . The discharge leg  106  includes a first end  110  connected to the connecting leg  108  and a second end  112  including a spout  114  having an outlet port  116 . The second end  112  of the discharge leg  106  also includes a seal mechanism including an annular peripheral seat  118  adapted to removably receive a seal member  120 .  
         [0047]     The seal member  120  is adapted to engage the seat  118  of the discharge leg  106  to create a fluid-tight seal between the bore within the discharge leg  106 , that is located between the seat  118  and the first end  110 , and the outlet port  116 . As the second fluid  60  contained within the discharge leg  106  below the seat  118  is not in fluid communication with the atmosphere through the sealed seat  118 , the second fluid  60  is prevented from evaporating and passing beyond the seat  118  and seal member  120  out the outlet port  116 . The seal member  120  and the seat  118  thereby prevent evaporation of the second fluid  60  through the outlet port  116 . However, the seal member  120  is adapted to break its seal with seat  118  when the second fluid  60  in the discharge leg  106  forces the seal member  120  upwardly out of engagement with the seat  118  such that a volume of second fluid  60  can be discharged from the discharge leg  106  through the outlet port  116 , as second fluid  60  condenses within or infiltrates into the reservoir  13  and passes downwardly through the first fluid  28  and into the collection leg  104 . A volume of second fluid  60  equal to the volume of the fluid that is collected in the collection leg  104  is thereby discharged through the seat  118  and the outlet port  116 . The seal member  120  has a sufficiently large diameter such that it will not pass through the spout  114  or outlet port  116 . The seal member  120  is preferably constructed as a spherical member or conical member to sealingly engage the seat  118 .  
         [0048]      FIG. 11  shows a further modified embodiment of the condensate removal system of the present invention designated with reference number  126 . The condensate removal system  126  is constructed substantially similar to the condensate removal system  70  as shown in  FIG. 9  and similar elements are numbered with the same reference numbers. The discharge leg  76  of the condensate removal system  126  includes a seal mechanism having a seat  128  and a seal member  130 . The seat  128  and seal member  130  are constructed and function in the same manner as the seat  118  and seal member  120 . The condensate removal system  126  includes a reduced diameter upper segment  96  in the discharge leg  76 , which provides a reduced cross-sectional area of the top surface  64  of the second fluid  60  to thereby reduce evaporation through the outlet port  92 . The releasable seal member  130  is adapted to form a seal with the seat  128  to also prevent evaporation of the second fluid  60  through the outlet port  92 .  
         [0049]      FIG. 12  shows a further modified embodiment of the condensate removal system of the present invention designated with reference number  136 . The condensate removal system  136  includes a generally U-shaped fluid conduit  138  having a collection leg  140 , a discharge leg  142  and a connecting leg  144  extending between the collection leg  140  and discharge leg  142 . The discharge leg  142  includes a lower segment  146  having a first end  148  and a second end  150 , and an upper segment  152  having a first end  154  and a second end  156 . The second end  156  of the upper segment  152  includes a spout  158  having an outlet port  160 . The lower segment  146  and the upper segment  152  are generally linear and tubular such that the upper segment  152  can slide coaxially with respect to the lower segment  146  within the bore of the lower segment  146  either downwardly, such that the first end  154  moves toward the first end  148  of the lower segment  146 , or upwardly, such that the first end  154  of the upper segment  152  moves toward the second end  150  of the lower segment  146 . The elevation of the outlet port  160  can thereby be selectively adjusted and set to a desired elevation to accommodate a replacement of the first fluid  28  by a third fluid  27  of lower specific gravity than the first fluid  28 , or the replacement of the first fluid  28  by a fourth fluid  29  of greater specific gravity than the first fluid  28 .  
         [0050]     A sleeve seal member  162  seals the upper segment  152  to the lower segment  146 . The sleeve seal member  162  has a first end  164  and a second end  166 . The first end  164  of the sleeve seal member  162  extends around the second end  150  of the lower segment  146  and is stationarily attached thereto. The second end  166  of the sleeve seal member  162  extends around the outer circumference of the upper segment  152  and creates a fluid-tight sliding seal therewith. The sleeve member  162  seals the second end  150  of the lower segment  146  to the upper segment  152  to prevent leakage of fluid from between the lower segment  146  and the upper segment  152 . The lower segment  146  has a bore with a first cross-sectional area and the upper segment  152  has a bore with a second cross-sectional area which is smaller than the first cross-sectional area of the lower segment  146 . The area of the top surface  64  of the second fluid  60  at the second end  156  of the upper segment  152  adjacent the outlet port  160  is thereby smaller than the cross-sectional area of the lower segment  146  and of the collection leg  140  to reduce evaporation.  
         [0051]     Another modified embodiment of the condensate removal system of the present invention is shown in  FIG. 13  and is identified with reference number  170 . The condensate removal system  170  is constructed substantially similar to the condensate removal system  136  as shown in  FIG. 12  and like elements are numbered with the same reference numbers. The condensate removal system  170  includes a seal mechanism having a seat  172  and a seal member  174  at the second end  156  of the upper segment  152  of the discharge leg  142 . The seat  172  and member seal  174  are constructed and function in the same manner as the seat  118  and seal member  120 . The condensate removal system  170  thereby includes a reduced cross-sectional area upper segment  152  in which the top surface  64  of the second fluid  60  is located, to reduce evaporation of the second fluid  60  through the outlet port  160 , and a seat member  172  and a seal member  174  adapted to selectively seal the second fluid  60  in the upper segment  152  from the outlet port  160  to also prevent evaporation of the second fluid  60  through outlet port  160 .  
         [0052]      FIGS. 14 and 15  show a modified embodiment of a discharge leg  180  of a condensate removal system. The discharge leg  180  includes a first end  182  and a second end  184 . The second end  184  includes a spout  186  having an outlet port  188 . The second end  184  of the discharge leg  180  also includes a seal mechanism having a seat  190  and seal member  192 . The seal member  192  includes a substantially planar lower surface and is pivotally attached at an end  194  to the spout  186 . The seal member  192  comprises a flap adapted to pivot upwardly away from the seat  190  to allow the second fluid  60  to pass through the seat  190  and to be discharged through the outlet port  188  in response to the collection of condensate within the collection leg of the condensate removal system. The seal member  192  is adapted to pivot downwardly to create a seal with the seat  190  to prevent the second fluid  60  within the discharge leg  180  from evaporating through the outlet port  188 . If desired, the seal member  192  and seat  190  of  FIG. 14  may be repositioned to the outer edge of the outlet port  188 . The end  194  of the seal member  192  that is pivotally attached to the spout  86  would be repositioned to the top of the spout  186 .  
         [0053]      FIGS. 16, 17  and  18  show another embodiment of the condensate removal system of the present invention designated with reference number  200 . The condensate removal system  200  is formed integrally with the housing  220  of the drive mechanism. The condensate removal system  200  includes a generally U-shaped conduit  202  having a collection leg  204  formed between a first wall  206  and a second wall  208  of the housing  220 . The condensate removal system  200  includes a discharge leg  210  formed in part by the exterior surface of the second wall  208 . The discharge leg  210  is in fluid communication with the collection leg  204 . The discharge leg  210  includes a first end  212  in fluid communication with collection leg  204  and a second end  214  having a spout  216  and an outlet port  218 . The discharge leg  210  may include a reduced cross-sectional area segment at the second end  214 , a seal member and seat, or an upper segment that is slideable with respect to a lower segment of discharge leg  210 , or any combination thereof, if desired.  
         [0054]     It should be noted that if the first fluid  28  has a specific gravity greater than that of water, condensate and infiltrate water will float on the surface of the first fluid  28 . In this case, the condensate removal system inlet port in the collection leg is located at or slightly above the top surface  62  of the first fluid  28  to remove only the floating water, thereby preventing the accumulation of water above the first fluid top surface  62 .  
         [0055]     Various features of the invention have been particularly shown and described in connection with the illustrated embodiments of the invention, however, it must be understood that these particular arrangements merely illustrate, and that the invention is to be given its fullest interpretation within the terms of the attached claims.