Abstract:
Conservation of oily liquid sealant in coaxial odor trap cartridges for waterless urinals is accomplished in the present invention by the addition of a liquid-flow-diverting structure having at least one helical fin encircling the outer surface of the cylindrical partition that extends downwardly from the cartridge top cap. In a preferred embodiment two similar diametrically-opposed helical fins conserve sealant by modifying the otherwise vertical downward flow path to a downward incline that minimizes down-the-drain sealant loss by intensifying recovery of stray traces of sealant that become detached from the main layer of sealant and get swept along with the downward flow of wastewater in the outer chamber during a usage event. The sealant recovery action of the helical fins that takes place in the outer chamber is further enhanced by specially proportioning the cross-sectional flow area of the three chambers in the cartridge to maximize the cross-sectional flow area of the outer chamber. The upper portion of at least one helical fin may be utilized to implement sealant-level-gauging capability that can be readily observed from above the cartridge. The bottom region of the cartridge is reshaped to provide a drip ring at the base of the stand-tube to facilitate replacement manipulation by preventing migration of wastewater and residue outwardly onto the bottom surface of the cartridge.

Description:
PRIORITY 
     Benefit is claimed under 35 U.S.C. 119(e) of U.S. provisional application No. 61/709,043, filed Oct. 2, 2012. 
     FIELD OF THE INVENTION 
     The present invention relates to the field of waterless urinals that save water otherwise lost in flushing, thus providing substantial savings in the costs of water and wastewater treatment as well as conserving fresh water resources. More particularly the invention relates to improvements in coaxial odor trap cartridges for plug-in installation in waterless urinals as the active operational component utilizing an oily or oil-like liquid sealant, the improvements including internal structural additions and modifications that reduce maintenance requirements and costs by conserving sealant, and that further facilitate the low maintenance by enablement of sealant level gauging. 
     BACKGROUND OF THE INVENTION 
     With increasing emphasis on water conservation, there is renewed interest in toilets and urinals designed to minimize the amount of water consumed in flushing and thus counteract increasing demands on water supplies as well as on wastewater disposal systems, both of which have tended to become overloaded with increasing populations. 
     Sanitation codes require all drain-connected items such as bathtubs, sinks, toilets and urinals, to provide an odor seal to contain gasses and odors which develop in the drain system, often developing positive sewer-pressure that can slightly exceed atmospheric pressure. Odor-sealing is conventionally performed by the well known P-trap or S-trap in which the seal is formed by a residual portion of the flushing water. As a marginal inherent disadvantage, P-traps and S-traps can become temporarily disfunctional due to “dry” failure in regions or periods of low humidity where infrequent usage trap could result in depletion of the residual liquid portion by evaporation to the extent that, in an eventual sealing failure, odors would escape. 
     In the category of urinals for males, “waterless” urinal facilities have been proposed and utilized to some extent in the past for their advantage of substantial savings of water usage and associated cost savings relative to water-flushed facilities. However, as a trade-off for these savings, the most viable approach, a “waterless” odor-trap cartridge for replaceable installation in a urinal bowl and utilizing an oily liquid sealant, still requires maintenance in the form of periodic inspection and replenishment of the oily liquid sealant, compared to relatively lower maintenance requirements of water-flushed urinals. Although not subject to evaporation and associated potential “dry” failure of P and S traps as described above, liquid sealant type waterless urinals generally require maintenance in the form of periodic inspection and replenishment of sealant loss, presumably in small droplets becoming detached from the sealant layer and swept down the drain with the wastewater flow at each usage and/or under surges of intensive usage or pressure hosing. Sealant replenishment is typically required in known waterless urinals after approximately 1,500 usages average, depending on frequency of usage. 
     In past time periods of plentiful water supply and non-overloaded wastewater disposal facilities, the conventional water-flushed type of urinal became generally accepted and widely used as the standard. More recently, marketplace demand driven by need for water conservation and the benefit of cost savings has resulted in ongoing replacement of pre-existing water-flushed urinals by waterless urinals as well as an increasing role in new construction. Waterless urinals that utilize oily liquid odor sealant have been approved under U.S. plumbing standards, e.g. the American National Standard for Plastic Urinal Fixtures, ANSI Z124.9-1993, particularly section 7.8: “Testing of waterless urinals”, and ASUE A112.14.14, and have gained increasing substantial acceptance throughout the world. 
     It is estimated that each of about 150,000 waterless urinal now in use saves an average of about 30,000 gallons of water per year per urinal compared to a flushed urinal, amounting to a saving of about 45 billion gallons of water annually. The financial savings include not only the initial treated water costs, but even more importantly the costs of sewage water treatment that run typically nearly three times the initial water cost, per gallon. 
     In many foreign countries, water-saving urinals in a different category, i.e. with moving parts, are allowed and are marketed and used in competition with waterless urinals that utilize liquid odor sealant. This category of urinals with moving parts claim as advantage the potential of being maintenance-free, however, due to awareness of potential risks of inherent unreliability and failure of moving parts due to debris, contamination and/or corrosion, U.S. plumbing and sanitation codes do not recognize or allow the category of odor traps that utilize flap technology, valves or other moving parts, whether of metal or flexible material. 
     DISCUSSION OF KNOWN ART 
     A wastewater pipe S-trap into which a disinfectant or deodorizer is introduced was disclosed in U.S. Pat. No. 303,822 to D&#39;Heureuse. 
     The use of an oil as a recirculated flushing medium in a toilet system was disclosed in U.S. Pat. No. 3,829,909 to Rod et al. 
     The use of oil in toilets to form an odor trap has been disclosed in German patent 121356 to Beck et al and in U.S. Pat. Nos. 1,050,290 to Posson and 4,028,747 to Newton. 
     German patent 72361 to Beetz in 1891 disclosed an oil-sealed odor lock for stall urinals: a partitioned cylindrical liquid compartment forms a bell trap having an oily liquid barrier that forms a seal through which urine permeates downwardly. Due to its configuration and cast iron metal structure, the Beetz odor lock was made of three parts and designed for easy disassembly since this was required for daily maintenance: cleaning and coating the internal parts and surfaces with oil to prevent clinging of the urine, according to the Beetz specification; however, even such daily maintenance failed .to corrosion of the metal parts rendering the trap useless. 
     A more recent version of the Beetz coaxial oil-sealed waterless urinal, related to German patent 28 16 597.1, and Swiss patent 606 646, trademarked SYSTEM-ERNST, has been used publicly in Europe: typically the liquid compartment odor trap is mounted beneath floor level and embedded in a concrete swale that functions as a trough type or stall urinal of a type which is no longer recognized in U.S. building and sanitation codes. 
     A flushless urinal disclosed in U.S. Pat. No. 4,244,061 to Webster et al uses no oil and instead of complete sealing it relies on a small “plug flow” entrance opening associated with a P trap, and is based on the premise that “the urine in the trap during normal use will be fresh and therefore without unpleasant odour”. 
     .U.S. Pat. Nos. 6,053,197 and 6,425,411 B1 to Gorges disclose liquid sealant type odor trap cartridges that, while made cylindrical in external shape for urinal bowl installation, are configured internally with structure that is clearly non-concentric in shapes representing distinctive approaches to preservation of oil sealant. 
     U.S. Pat. No. 5,711,037 to Reichardt et al disclosing a WATERLESS URINAL utilizing an oily liquid sealant type odor trap cartridge of totally concentric structure, both externally and internally, that has earned worldwide success and that has saved many millions of gallons of water, is incorporated herein by reference for purposes of detailed description, since it provides the basis upon which the improvements disclosed herein have been accomplished. Field experience with the waterless urinal odor trap cartridge disclosed in the &#39;037 patent has established levels of performance standards and maintenance requirements that serve as reference benchmarks with which to relate the improvements provided by the present invention. 
     The continued and further increasing emphasis on the economy of conserving water consumption and reducing the risks of overloading existing wastewater and sewage systems have motivated pursuit of the present invention to further develop and refine co-axial oil-sealed waterless urinal cartridges with particular emphasis on the competitive importance of further reducing maintenance requirements by preservation of the liquid sealant through more complete rescue and recovery of detached escaping traces or droplets of sealant. 
     OBJECTS OF THE INVENTION 
     It is a primary object of the present invention to provide improvements for incorporation into a known totally coaxial oil-sealed odor trap cartridge for installation in a no-flush waterless urinal, the improvements representing an advancement of the state of the art in this technology to a reduced level of maintenance requirements directed to increasing sales and utilization of this technology, yielding associated benefits of increased conservation of fresh water and substantial savings in water costs and in wastewater treatment costs. 
     It is a further object to provide the desired improvements through modifications in the internal structure of an existing coaxial odor trap cartridge that will continue to be economical and readily producible in manufacture, and interchangeable with current plug-in odor trap cartridges in existing urinal bowls. 
     It is a still further object to provide sealant level gauging for purposes of facilitating maintenance monitoring, being readily viewable by a user from above the cartridge. 
     It is a still further object, in the discharge from the low end of the stand-tube to the drain, to prevent the discharged wastewater and accompanying debris from migrating outwardly onto the bottom surface of the cartridge where it interferes with cartridge replacement handling. 
     SUMMARY OF THE INVENTION 
     The above-mentioned objects and advantages have been realized in the present invention by improvements in coaxial oil-sealed odor trap cartridges for waterless urinals accomplished by the addition of at least one helically-shaped fin added to extend outward from the outer surface of the cylindrical partition that extends downwardly from the cartridge top cap. In a preferred embodiment two similar fins are added, each shaped as a helix that extends from top to bottom of the tubular partition. To further the benefit of the fin(s) in redirecting escaping droplets of sealant back to the sealant layer, the cross-sectional flow areas of the outer down-flow intake chamber, the intermediate up-flow chamber and the stand-tube down-flow exit chamber are specially proportioned to maximize the cross-sectional flow area of the intake chamber and thus maximize the area of the fin(s) that is active in redirecting and thus preserving traces of sealant that would otherwise escape down the drain. As further improvements and benefits, (a) the structure at the upper portion of the fin(s) enables implementation of sealant level gauging capability that can be observed from above the cartridge, and (b) the bottom region of the cartridge is reshaped to provide a drip ring at the base of the stand-tube to ensure that all wastewater and residue are released directly into the drain and prevented from migrating outwardly and fouling the bottom surface of the cartridge. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and further objects, features and advantages of the present invention will be more fully understood from the following description taken with the accompanying drawings in which: 
         FIG. 1  is an elevational view showing the external appearance of a known coaxial odor trap cartridge for installation and usage in a waterless urinal. 
         FIG. 2  is a cross-section of a known odor trap cartridge having an external appearance as in  FIG. 1 . 
         FIG. 3  is an elevational view of the cap/partition portion shown removed from the main body portion of the known odor trap of  FIG. 2 . 
         FIG. 4  is an elevational view of a cap/partition portion of a sealant-preserving odor trap cartridge in accordance with a preferred embodiment of the present invention, shown removed from the main body portion as the functional replacement counterpart of the known cap/partition portion in  FIG. 3 . 
         FIG. 5  shows the subject matter of  FIG. 4  as viewed from a perpendicular direction. 
         FIG. 6  is a cross-section of an odor trap cartridge in accordance with a preferred embodiment of the present invention, utilizing finned cap/partition structure as in  FIGS. 4 and 5 . 
         FIG. 7  is a perspective view of the subject matter of  FIG. 5 . 
         FIG. 8  is a perspective view of an embodiment of the present invention showing a novel drip ring configured in the bottom region. 
         FIG. 9  is a top view of an embodiment of the present invention including a novel sealant level gauge system. 
         FIGS. 9A and 9B  show details, in vertical cross-section and as viewed from above, of the sealant level gauge system of  FIG. 9  indicating a full sealant condition. 
         FIGS. 9C and 9D  show details, in vertical cross-section and as viewed from above, of the sealant level gauge system of  FIG. 9  indicating a depleted sealant condition. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  is an elevational view showing the external appearance of a replaceable odor trap cartridge  10  for use in a mating waterless urinal fixture. Included in the category having this general appearance are a product line of well-known odor trap cartridges utilizing oily liquid sealant, typified by the main product of the Waterless Company, a coaxial odor trap cartridge which was disclosed in the above-mentioned &#39;037 U.S. patent, and which has been marketed widely in the U.S. since 1991 and worldwide since 1998. This view shows the exterior of two main portions of cartridge  10 : (1) the main enclosure  12  with its cylindrically-shaped outer sidewall  12 A and (2) the cap/partition portion  14 , of which the upper surface of cap  14 A is shown in profile. This exterior view also generally represents the outward appearance of an embodiment of the presently disclosed invention that is intended to be mutually interchangeable physically with the present Waterless urinal cartridge product as disclosed in the above-mentioned &#39;037 U.S. Patent. 
       FIG. 2  is a cross-section taken through the central axis of a known replaceable co-axial odor trap cartridge  10  having exterior appearance as shown in  FIG. 1 , applicable to the aforementioned Waterless liquid-sealant-based coaxial product disclosed in the &#39;037 patent. 
     The main body portion  12  includes the cylindrical outer sidewall  12 A extending downwardly past a chamferred lower region to a generally flat bottom panel  12 B, configured centrally with a integral tubular stand-tube  12 C extending upwardly to an open top end as shown, located at a designated distance below the upper edge of the outer sidewall  12 A. 
     The cartridge  10  is molded from suitable plastic such as polypropylene in two parts, i.e. the main cartridge body portion  12  and the cap/partition portion  14 . When assembled together these form three concentric annular liquid chambers: (1) the outer down-flow intake chamber between outer sidewall  12 A and partition  14 C, (2) the intermediate up-flow chamber between partition  14 C and stand-tube  12 C, and (3) the tubular central down-flow exit drain chamber formed by stand-tube  12 C. Chambers (1) and (2) communicate in a common lower chamber region immediately above the bottom panel  12 B, while chambers (2) and (3) communicate in the region beneath cap  14 A. 
     Partition  14 C is secured firmly to the main body portion  12  at the upper region thereof by an array of  20  spacers  14 B molded around the edge of cap  14 A, each including a small protrusion for engaging an annular groove configured around the inner surface of sidewall  12 A of main body  12 , such that cap/partition portion  14  and main body portion  12  can be easily assembled and held firmly together in a detent action. To provide strength for such detent action and for mounting purposes, a thickened and tapered rim is formed at the upper peripheral edge of outer sidewall  12 A. 
     In the known odor seal cartridge  10 , the lower edge of tubular partition  14 C engages a set of four support pedestals formed integrally with the floor  10 D and arranged in a circular array. The upper end of each pedestal is formed with a channel for engaging the lower edge of partition  14 C to ensure concentricity. 
     In the outer region of the liquid chamber, sealing is provided by a body of oily liquid sealant  20  that has a lower specific gravity, preferably less than 0.9, compared to 1.0 for water or urine/wastewater, since the operation of the urinal is based on the differential between the specific gravity of the oily liquid  20  and that of urine/wastewater  18 , typically near 1.0. A preferred composition of the oily liquid  14  comprises an aliphatic alcohol containing 9-11 carbons in the chemical chain: the specific gravity is 0.84 at 68 degrees, the specific gravity of the oily liquid should be made as low as possible, preferably under 0.9. At the top surface of the sealant  20 , newly received urine immediately permeates downwardly in a turbulent flow through and past the outer edge of the body of sealant  20  floating on the upper surface of the wastewater  16  in the outer down-flow entry chamber. The flow path proceeds past the bottom of partition  14 C and then the wastewater  18  flows upwardly in the intermediate liquid chamber to the top of stand-tube  12 C where it overflows and runs down though stand-tube  12 C to an external drain system. The sealant  20  remains in place floating on top as shown where it serves as an odor and gas seal. 
     In addition to permeation through sealant  20  as described above, since urine  16  is introduced from cap portion  12 A, close to the outer edge as shown, some of the urine  16  tends to divide into droplets and gravitate downwardly, initially concentrated at the inner wall surface of the outer liquid chamber, thus furthering both the disposal and the sealing performance. 
     As part of normal operation small traces of sealant  20  become separated from the main body and swept along with the downward wastewater flow in the outer entry chamber, where the detached sealant traces are acted upon by two opposing forces: (1) a downward drag force from the downward flow of wastewater during each urinal usage and for a settling time afterwards as the downward drag force decays to zero unless the settling time is cut short by a subsequent usage, and (2) a constant upward buoyant force due to the low specific gravity of the sealant  20 . The net result of these forces acts on the sealant traces to assert their inherent water-repellence and move upwardly. A portion (a) of the sealant traces remaining in the outer down-flow intake chamber will rise and return to the main sealant body while the other portion (b) of sealant traces that get carried under the partition  14 C will then rise into the intermediate up-flow chamber and become lost down the drain. 
     In the known odor trap cartridge of the &#39;037 patent the dimensioning of the three chambers result in approximately the following cross-sectional flow areas and volumes: 
     
       
         
               
               
               
               
             
           
               
                 TABLE 1 
               
               
                   
               
               
                   
                 Chamber diameter 
                 Cross- 
                 Chamber  
               
               
                   
                 at outer wall  
                 sectional 
                 volume 
               
               
                   
                 of chamber 
                 flow area 
                 (depth = 5.3 cm) 
               
               
                   
               
             
             
               
                 down-flow exit  
                 2.68 cm 
                 11.74 cm{circumflex over ( )}2 
                  62.2 cc 
               
               
                 stand-tube 
                   
                   
                   
               
               
                 intermediate up-flow  
                  8.3 cm 
                 37.94 cm{circumflex over ( )}2 
                 201.8 cc 
               
               
                 chamber 
                   
                   
                   
               
               
                 outer down-flow intake  
                 10.1 cm 
                 39.61 cm{circumflex over ( )}2 
                 209.9 cc 
               
               
                 chamber 
               
               
                   
               
             
          
         
       
     
     In the known odor trap cartridge of the &#39;037 patent, a 3 fluid ounce charge of sealant  20 , having a volume of 88.72 cc, will have a depth of 88.72/39.61=2.24 cm, i.e. 42.2% of the 5.3 cm chamber height, and typically requires replenishing after about 1500 average usages, thus there is a loss of about 0.06 cc per usage. The 3 fluid ounce charge is considered to be an optimal tradeoff between a smaller charge that would require more frequent replenishment and a larger charge that would extend further down, requiring the urine to penetrate a thicker layer of sealant, and reducing the flow path length in the region beneath the sealant body, thus reducing the odds of recovering detached traces of sealant, i.e. actually increasing the sealant loss. The sealant  20  is dyed a blue color and is made biodegradable to prevent escaping traces from harming the environment. 
     The present invention is directed primarily to improvements from modifications and additions in the internal structure of the coaxial odor trap cartridge of the &#39;037 patent that act to substantially increase the recovery ratio: portion (a)/portion (b) of the detached sealant traces, thus conserving more of the sealant  20  and reducing maintenance costs and requirements of waterless urinals. 
       FIG. 3  is an elevational view of the cap/partition portion  14  shown removed from the main body portion  12  of the known odor trap  10  of  FIG. 2 . 
       FIG. 4  is an elevational view, in direction 9-9 of  FIG. 9 , of a cap/partition portion  24  of a sealant-preserving odor trap cartridge in accordance with a preferred embodiment of the present invention, shown removed from the main body portion  12  as the functional replacement counterpart of the known cap/partition portion  14  in  FIG. 3 . In comparison, the novel partition  24 C ( FIG. 4 ) is made much smaller in diameter and is configured with a diametrically-opposed pair of fins  24 C′ and  24 C″ that each encircle the main tubular portion  24 C with a single full 360 degree revolution, each forming a helix with a slope of about 10 degrees. 
     Fins  24 C′ and  24 C″ extend outward radially, typically configured with a horizontally-oriented elongate rectangular cross-sectional shape typically made with the same material and thickness as the cylindrical partition  24 C, e.g. polypropylene, approximately 1.5 mm thick. 
     As a matter of design choice, taking into account potential impact on performance, the invention could be practiced with an alternative number of fins, e.g.  1 ,  3  or more, and the helix formed by each fin could be made to extend to more or less than the single 360 degree encirclement of tubular partition  24 C as shown, and to slope more or less than the 10 degrees angle shown as an illustrative embodiment, or even configured with compound, segmented or smoothly varying slopes. The downward flow path, as viewed from above, could be made counterclockwise, as an alternative to the clockwise direction shown. 
       FIG. 5  shows the subject matter of  FIG. 4 , viewed in direction  5 - 5  of  FIG. 9 , i.e. perpendicular to the direction  4 - 4 -in  FIG. 4 , showing the relationship between the upper edge of the fin  24 C′ and the two nearest ones of the spacers  24 B formed around the perimeter of cap  24 A with an opening between them that will be utilized to enable implementation of sealant level gauging capability. A view from the opposite side would show fin  24 C″in the same relationship with the corresponding two spacers  24 B. The sealant level gauging system enabled by this relationship is described below in connection with  FIGS. 9-9D . 
       FIG. 6  is a cross-section of an odor trap cartridge  20  in accordance with a preferred embodiment of the present invention, utilizing finned cap/partition structure  24  as in  FIGS. 4 and 5 . The fins  24 C′ and  24 C″, extending outwardly as shown, are dimensioned to provide a working sliding fit at the inner surface of cylindrical sidewall  22 A that enables easy assembly insertion and maintains the concentric location of partition  24 C with no need for support spacers under the partition such as have been utilized in known odor trap cartridges. 
     The helical flow paths provided by fins  24 C′ and  24 C″ conduct the wastewater downward indirectly in a long slope at a shallow angle of about 10 degrees as apposed to the short, direct vertical flow path in the known odor trap cartridge, e.g. as disclosed in the &#39;037 patent and described above in connection with  FIG. 2 . 
     This redirection of the flow path onto and down the helical fins  24 C′ and  24 C″ serves to preserve sealant by prolonging the time period for traces of sealant  32 , that have become detached from the main sealant body and temporarily caught up in the wastewater flow, to disassociate from the wastewater and migrate upwardly while still within the outer chamber where they will automatically float upwardly and rejoin the overhead main sealant body. This separating tendency is continuous due to the constant upward force from the inherent buoyancy of the sealant traces, but the actual separation is an ongoing process that takes place over time. 
     During usage events, the active flow of wastewater  30  down the fins  24 C′ and  24 C″ will tend to separate into a quasi-laminar flow with the densest portion (e.g. metallic compounds) at the lowermost laminations of the flow in the sloping passageway and the least dense in the upper laminations, e.g. traces of sealant whose inherent upward buoyancy force will act to at least slow down the flow rate of the upper flow laminations, possibly stopping or even reversing it; in any case, increasing the percentage of sealant traces that have had time to detach and migrate upwardly to rejoin the main body. This recovery action intensifies and the recovered percentage further increases during the ensuing settling time period following a usage event, as the main lower lamination flow rate decays and the upper laminations carrying sealant traces typically reverse direction and move upwardly at an increasing flow rate. Finally, at the conclusion of the settling time period, with the main flow settled to zero, in the absence of a subsequent usage event, 100% of sealant traces remaining anywhere on the relatively large (compared to known art) area of the top side of the fins will sooner or later yield to their buoyancy force, disassociate from surrounding wastewater and float back up through the helical passageways to rejoin the main body of sealant. 
     The bottom panel  22 B is made in the modified arcuate cross-sectional shape as shown forming a drip ring  22 B′ which serves to prevent outward radial migration of wastewater and debris onto the bottom surface of bottom panel  22 B; instead drip ring  22 B′ is shaped to discharge all wastewater and debris directly into the drain, thus preventing annoying bottom-side pollution in maintenance replacement handling. 
     In comparison to the dimensional information regarding the three chambers of the known odor trap cartridge of the &#39;037 patent as shown in Table 1 above, the following Table 2 shows the modified dimensioning of the cap/partition  24  of the odor trap cartridge  20  of the present invention: 
     
       
         
               
               
               
               
             
           
               
                 TABLE 2 
               
               
                   
               
               
                   
                 Outer  
                 Cross- 
                 Chamber  
               
               
                   
                 diameter 
                 sectional 
                 volume 
               
               
                   
                 of chamber 
                 flow area 
                 (depth = 5.3 cm) 
               
               
                   
               
             
             
               
                 down-flow exit  
                 2.69 cm 
                 5.67 cm{circumflex over ( )}2 
                 30.05 cc 
               
               
                 stand-tube 
                   
                   
                   
               
               
                 intermediate up-flow  
                 4.06 cm 
                 5.67 cm{circumflex over ( )}2 
                 30.05 cc 
               
               
                 chamber 
                   
                   
                   
               
               
                 outer down-flow intake  
                 10.1 cm 
                 80.1 cm{circumflex over ( )}2 
                 424.5 cc 
               
               
                 chamber 
               
               
                   
               
             
          
         
       
     
     Comparing Table 1 (previous) and Table 2 (present), while the exterior size and shape of the odor trap cartridge and thus the exterior diameter of the outer down-flow intake chamber all remain practically unchanged in order to retain cartridge interchangeability, the stand-tube cross-sectional area has been reduced to 50% of previous and the intermediate chamber cross-sectional area is now reduced to 15% of its previous value to make it equal to that of the stand-tube. 
     Since the re-proportioning increased the volume of the outer down-flow entry chamber to more than twice its former value, retaining the established 2.31 cm sealant depth now allows the former 3 fluid ounce charge and the expected sealant life expectancy to be more than doubled, even without the addition of the fins  24 C′ and  24 C″. 
     The addition of the fins  24 C′ and  24 C″ is estimated to have the potential of at least further doubling the sealant life expectancy for a total estimated increase to over 4 times the former life expectancy by altering the travel path of the wastewater from the essentially vertical downward path in coaxial odor trap cartridges of known art, e.g. as in the &#39;037 patent. The proportioning of the chambers described above represents a preferred embodiment considered to be generally optimal overall, however the helical fin concept of the present invention can be practiced with practically any selected proportioning of the chambers with varying impact on performance results regarding sealant preservation. 
     As a design option, in a preferred embodiment the fins  24 C′ and  24 C″are molded integrally as part of the tubular partition  24 C. Alternatively; the fin(s) could be molded integrally as part of the outer sidewall  22 A, or else fabricated separately, made and arranged to be deployed as a stand-alone component or to be attached adhesively or otherwise to tubular partition  24 C or to outer sidewall  22 A. 
       FIG. 7  is a perspective view of the subject matter of  FIG. 5  taken from a viewpoint that is at a lower level than the bottom end of partition  24 C, showing a portion of the underside of cap  24 A. 
       FIG. 8  is a perspective view of an embodiment of the present invention, taken from the same viewpoint as in  FIG. 8 , showing the cylindrical sidewall  22 A and the arcuate bottom panel  22 B, configured with the novel drip ring  22 B′. 
       FIG. 9  is a top view of an embodiment of an odor trap  20  in accordance with the present invention indicating the cross-sectional axes of  FIGS. 4 ,  5  and  9 A, and including a novel sealant level gauge system including the two encircled directional symbols  34  marked on the cap  24 A. The visibility of sealant  32  from above is indicated in the peripheral entry openings bounded by cap  24 A, cylindrical sidewall  22 A and adjacent spacers  24 B. 
       FIG. 9A  is an enlarged cross-section, taken at axis  9 A- 9 A′ of  FIG. 9 , showing details of the sealant level gauge system of the present invention indicating a full sealant condition. A narrow portion of fin  24 C′ appears above the surface level of the sealant  32 , near the right hand end of the opening between two spacers  24 B corresponding to the wide end of triangular marking  34  on cap  24 A. 
       FIG. 9B  is an enlarged top view of the lower circled portion of  FIG. 9 , showing the sealant level gauge system of the present invention indicating a full sealant condition. A narrow portion of fin  24 C′ appears above the surface level of the sealant  32 , near the right hand end of the opening between two spacers  24 B corresponding to the wide end of triangular marking  34  on cap  24 A. 
       FIG. 9C  is an enlarged cross-section, taken at axis  9 A- 9 A′ of  FIG. 9 , showing details of the sealant level gauge system of the present invention indicating a depleted sealant condition. A relatively wide portion of fin  24 C′ appears above the surface level of the sealant  32 , approximating full width of the opening between two spacers  24 B and corresponding to the full length of triangular marking  34  on cap  24 A. 
       FIG. 9D  is an enlarged top view of the lower circled portion of  FIG. 9 , showing details of the sealant level gauge system of the present invention indicating a depleted sealant condition. A relatively wide portion of fin  24 C′ appears above the surface level of the sealant  32 , approximating full width of the opening between two spacers  24 B and corresponding to the full length of triangular marking  34  on cap  24 A. 
     The sealant level gauge system shown in  FIGS. 9-9D  represents an illustrative embodiment that teaches the basic concept of utilizing an upper end portion of one or more fins  24 C′ of the invention to serve as the basis of a sealant level gauge system. This basic concept could be practiced with alternative details such as applying a special coloring or coating on the upper portion of the fins to enhance visibility, modifying the slope of the fin(s) in this upper region, modifying the spacing between spacers  24 B, e,g, omitting one or more of these spacers  24 B from the array, and arranging for some form of illumination to increase the visibility of the gauge in a dark environment. 
     A further option regarding sealant level indication would be an indicator lamp, typically LED, connected to a pair of electrodes extending into the sealant layer, where they would conduct or generate electric current and illuminate the lamp only in the event that sealant depletion allows the electrodes to come in contact with the conductive wastewater instead of the normal contact with only the non-conductive sealant. 
     The invention may be embodied and practiced in other specific forms without departing from the spirit and essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description; and all variations, substitutions and changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.