Abstract:
An apparatus for continuously controlling fluid flow in a sewer conduit, comprising: a) moisture sensors detecting levels of fluid in this conduit; b) an inflatable bladder, mounted in the sewer conduit for releasably sealing in fluid tight fashion a section of this conduit; an air compressor, for inflating the bladder; and a control box including a CPU, sensitive to the moisture sensor and actuating the air compressor responsively to conduit fluid level conditions reaching beyond a preset threshold value. The performance of the apparatus is independent of the speed of fluid flow in the sewer conduit.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to the field of fluid flow control systems concerned with a fluid backup preventing system for sewer ducts and the like. 
       BACKGROUND OF THE INVENTION 
       [0002]    There exists a plurality of situations wherein it is desirable to control accidental fluid backup flow in specific circumstances. 
         [0003]    In a building or other structures serviced via an underground sewer line, it sometimes occurs that the main sewer line or the branch line leading from the building to the main sewer line becomes clogged. Indeed, the problem of basement flooding from sewer line water backup flow has become prevalent in recent years. The backup may be caused by a variety of problems including when the flow capacity of the sewer system is exceeded by the rain water inflow rate into the system. 
         [0004]    The risk of water backup is present in most storm sewer systems where the storm sewers are rarely of a sufficient size to accommodate unusually heavy rain storms. This risk is sometimes present in sanitary sewer system where there is a water leakage into the sewer system through manholes, cracks in sewer line joints or where improper roof down spout connections are made to the system which normally should carry only the water and sewage draining from sinks, toilets, washing machines drain lines and basement floor drains. 
         [0005]    Clogging of the sewer line may be caused by many factors including broken or misaligned pipes. Such broken or misaligned pipes present projections, ridges or sharp bends on which bulk material hangs up and causes a nucleus fore clogging. Other times, roots from surface plants invade the pipe in search of moisture which may be leaking from poorly formed joints in the pipe and these roots also can form the nucleus of the clog in the pipe. Whatever the cause of the clog, the effect is that the sewage becomes backed up in the line and eventually the backflow will overflow from the fixtures and drains in the building. 
         [0006]    Modern sewer systems are equipped with clean out pipes or outlets. The clean out is accomplished by inserting a Tee or Y joint in the sewer line just outside the building or in the basement. Leading from the Tee or Y joint is a vertical or near vertical clean out pipe which is kept or plugged near the ground surface. While this type of clean out allows for access to the sewer line for removal of clog, it does not prevent the backflow or sewage through the sewer line which will eventually overflow from the fixtures or drain inside of the building. 
         [0007]    Backup problem in sanitary sewer lines leading to an individual home can be substantially eliminated by the application of a backflow preventing valve in the pipe line extending between the home and the underground sanitary sewer line running along the street involved. When backup water pressure builds up, the backflow preventing valve is closed or closes to prevent the water in sanitary sewer lines from backing up into the user&#39;s home. 
         [0008]    However, many home owners simply do not wish to incur such systems. Indeed, conventional flow protection usually consists of a simple check valve, more particularly a flap valve mounted inside the sewer duct, which functions as a pivotable gate providing for unidirectional flow of the fluid in the sewer line away from the source. However, these pivotal gates are only efficient when the fluid flow inside the sewer is at fast speed, since the gate will then be forcibly pivotally biased against its annular seat inside the sewer duct by the hydrodynamic forces. Such pivotal gate valve systems are however ineffective in conditions of sewer duct clogging, since the fluid level inside the sewer duct raises quite progressively, and the fluid flow speed is usually small, which would not provide a hydrodynamic force suitable for pivotally biasing the pivotal gate against its annular seat in a fluid tight fashion. 
         [0009]    Inflatable bladders may be used in place of pivotal gate valves, although these bladders create a phenomenon of fluid flow turbulence. When these bladders are in their inoperative deflated condition, they remain in a radially inwardly projecting condition inside the sewer duct passage that constitutes a partially obstructive element. 
         [0010]    Furthermore, most conventional fluid backflow mitigating prior art systems are not efficient in early detection of fluid and thus are relatively unreliable and inefficient. 
       SUMMARY OF THE INVENTION 
       [0011]    Accordingly, there exists a need for an improved fluid backup preventing system that can be used in a variety of situations such as in sewer lines to prevent sewer backup into basements. 
         [0012]    In accordance with the teachings of the invention, there is disclosed an apparatus for continuously controlling fluid flow in a conduit, comprising: a) sensor means, for detecting the level of fluid in this conduit; b) conduit sealing means, for releasably sealing in fluid tight fashion a section of this conduit; c) main power means, for actuating said sealing means; and d) control means, sensitive to said sensors means and actuating said main power means responsively to a conduit fluid level reaching beyond a threshold value; wherein the performance of said control means is independent of the speed of the fluid flow in the conduit. 
         [0013]    Preferably, said control means are further sensitive to the deactivation of said main power means, and further including power backup means, whereupon said control means automatically activating said conduit sealing means independently of fluid level in the conduit when said main power means becomes deactivated. Said control means preferably further includes a self test function for the power backup means that checks at predefined regular time intervals if said conduit sealing means is operative, and further including alarm means (sound, light or otherwise) issuing an alarm detectable by the apparatus user upon said control means detecting that said power backup means has become inoperative. 
         [0014]    Preferably also, said conduit sealing means includes an inflatable bladder for mounting into the conduit section, and further including inflating means for inflating the bladder between a deflated inoperative condition and an operative inflated condition for sealingly closing the conduit section. Said inflatable bladder could then have in its operative inflated condition a portion of toroidal shape for sealingly engaging the conduit section. Said bladder could be elongated with two opposite end portions each forming a convex half sphere. Said sensors means could include at least one pair (preferably two pairs) of positive and negative electrical cables, said cables extending between said control means and said bladder, and moisture sensors mounted at the end of said cables located about said bladder. Said moisture sensors are preferably covered by non corrodible fluid proof conducting alloys, and uses electrical conductivity measures for determining the fluid level in the conduit. 
         [0015]    The invention also relates to a method for operating an apparatus for continuously controlling fluid flow in a conduit, the apparatus of the type comprising sensor means for detecting levels of fluid in this conduit, conduit sealing means for releasably sealing in fluid tight fashion a section of this conduit, main power means for actuating said sealing means, and control means, sensitive to said sensors means and actuating said main power means responsively to a conduit fluid level reaching beyond a threshold value so that the performance of said control means is independent of the speed of the fluid flow in the conduit; wherein the method comprises the following steps: 
         [0016]    a) said sensor means sensing a fluid level beyond said threshold value; 
         [0017]    b) said control means analysing data coming from the sensors means; and 
         [0018]    c) said control means actuating said conduit sealing means responsively to said data. 
         [0019]    Preferably, there is further included the following steps: 
         [0020]    d) having said sensor means detecting fluid level returning to condition short of said threshold level; 
         [0021]    e) said control means analysing this latter data from said sensors means; and 
         [0022]    f) said control means deactuating said main power means responsively to the latter data. 
         [0023]    The invention also relates to the combination of sewer conduit for fitting to a dwelling, said conduit having a clean-out duct mounted transversely thereto and opening into said fluid flow channel, and the above-noted apparatus. 
         [0024]    The invention also relates to a method for installing and releasably locking a valve apparatus inside a clean-out duct of a sewer conduit, the valve apparatus for continuously controlling fluid flow in the conduit, the apparatus including: a) sensor means, for detecting the level of fluid in this conduit; b) conduit sealing means, for releasably sealing in fluid tight fashion a section of this conduit; c) main power means, for actuating said sealing means; and d) control means, sensitive to said sensors means and actuating said main power means responsively to a conduit fluid level reaching beyond a threshold value; wherein the performance of said control means is independent of the speed of the fluid flow in the conduit, the apparatus further including a discoid support member releasably mounted inside the clean-out duct, a hang screw rod assisting in the positioning of said discoid support system in said clean-out duct, said sealing means being an inflatable bladder, said inflatable bladder in deflated configuration movable to a set position inside the clean-out duct, and further including retaining clips to prevent accidental release of said apparatus from its said set position, wherein said method comprises the following steps: a) said hang screw rod moving the said apparatus inside said clean-out duct; and b) said inflatable bladder in deflated configuration emitting a sound cue emitted through said rod, indicating said deflated bladder has reached its said set position inside the clean-out duct. 
         [0025]    Preferably, said sensor means could then include power cables and, upon release of said valve apparatus being required, further including the following step: c) pulling out said apparatus from said fixed position in said clean-out duct, by upwardly pulling said power cables. 
         [0026]    Preferably, said clean-out duct defines an annular recess fully clearing said channel, said conduit sealing means including an inflatable bladder mounted into said annular recess, and inflating means for inflating the bladder, said bladder when in an inoperative condition remaining fully inside said annular recess and fully clearing said channel to prevent fluid flow turbulence in the conduit when deflated, and when in an operative inflated condition further extending radially into said channel and fully sealingly closing said channel. 
         [0027]    The present invention therefore provides a system for blocking fluid flow within a conduit and utilizing an inflatable component which is located permanently in the conduit or a section that allows access to the conduit wanted to protect from fluid flow backup. An electrical moisture sensor capable of rapidly and accurately detecting the fluctuation of fluid in a conduct and transmitting the information to the circuitry forms part of the invention. 
         [0028]    A circuitry receives the information from the moisture sensors and then decides whether or not it will activate the inflatable component to prevent fluid backup. 
         [0029]    A backup battery of the circuitry is also provided, in case of electrical mains supply blackout, so as to enable relying on backup battery that will automatically activate the inflatable component by default, independently of fluid level inside the sewer conduit. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0030]      FIG. 1 : is a longitudinal sectional view of an intermediate section of sewer conduit, showing a fluid backup preventing system in accordance with an embodiment of the present invention mounted on a transverse clean-out duct into the sewer conduit, the inflatable bladder being shown in a retracted deflated inoperative position inside the clean-out duct; 
           [0031]      FIG. 2 : is a view similar to  FIG. 1 , but with the inflatable bladder being inflated in a fully inflated operative configuration, extending radially into the sewer conduit and fully closing a section of the latter; 
           [0032]      FIG. 3 : is a partly schematic enlarged plan view of the control box of a fluid backup preventing system in accordance with an embodiment of the present invention; 
           [0033]      FIG. 4 : is a partial plan view of a control panel part of a fluid backup preventing system in accordance with an embodiment of the present invention; 
           [0034]      FIG. 5 : is a partial enlarged perspective view of a pneumatic tube and electrical wire assembly from the fluid backup preventing system in accordance with an embodiment of the present invention; 
           [0035]      FIG. 6 : is an enlarged view of the area circumscribed by ellipse  6  in  FIG. 5 ; 
           [0036]      FIG. 7 and 8 : are partial elevated views of the inflatable bladder, suggesting the adjustable nature of cable sleeve connection between electrical circuits and the inflatable bladder of the fluid backup preventing system in accordance with the present invention; 
           [0037]      FIG. 9 : is a partial perspective view of the inflatable bladder, showing in phantom lines the fluid sensor part inside the bladder of a fluid backup preventing system in accordance with an embodiment of the present invention; 
           [0038]      FIG. 10 : is a enlarged cross-sectional view taken along lines  10 - 10  of  FIG. 1 , showing how the inflatable bladder clears the sewer conduit in the retracted inoperative condition thereof in accordance with the present invention; 
           [0039]      FIG. 11 : is a partly broken perspective view of the sewer duct, showing the inflatable bladder in its operative fully inflated condition, similarly as in  FIG. 2 ; 
           [0040]      FIG. 12 : is an enlarged cross-sectional view of the discoid support system installed in the clean-out duct taken along line  25 - 25  of  FIG. 1 , in accordance with an embodiment of the present invention; and 
           [0041]      FIG. 13 : is an enlarged longitudinal sectional view of an intermediate section of the clean-out duct, showing the discoid support system from  FIG. 12  installed therein, the inflatable bladder being shown in a retracted deflated inoperative position inside the clean-out duct. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0042]    Referring to  FIGS. 1 and 2 , there is shown a fluid backup preventing system  11  in accordance with an embodiment of the present invention mounted into a clean-out duct  12  transversely opening into the channel  13  of sewer conduit  14 . A fluid F, for example a liquid, may flow inside channel  3  at a low fluid level L 1 , along a normal flow direction D 1 . 
         [0043]    The clean-out duct  12  is preferably provided with a distal threaded segment  12   a  so as to threadingly receive a mounting cap  16  provided with a cap aperture  18  extending centrally there through. The cap aperture  18  is configured and sized so as to fittingly receive at an intermediate section of a cable sleeve  20  for protectively enclosing various operative cables (pneumatic line  36  and electrical wires  43 ,  43 ′,  43 ″,  43 ′″) hereinafter disclosed and also for supporting the valve components in a suitable overlying relationship relative to the sewer conduit  14 . 
         [0044]    As mentioned previously, it should be understood that although the fluid backup preventing system is shown in  FIGS. 1 through 11  and hereinafter disclosed is being used in the context of sewer conduits, it could also be used in various other contexts without departing from the scope of the present invention. 
         [0045]    The sleeve  20  is connected at a proximal end portion thereof to a casing  22  by a suitable connecting ring  24  and at a distal end thereof to a valve means  26 . The valve means  26  preferably takes the form of an inflatable component, typically an inflatable bladder  30  at least partially mounted within a bladder sleeve  28 . Bladder  30  is mounted inside clean-out duct  12 . The bladder  30  is adapted to be inflated to an inflated configuration illustrated in  FIGS. 2 and 11  wherein its inflated flow obstricting section  32  projects radially inwardly of channel  13  and abuttingly fully contacts the interior wall  14 A of the duct  14  in fluid tight fashion so as to prevent accidental backflow into the latter when fluid overflow conditions are met. That is to say, fluid flow direction D 2  ( FIG. 2 ) is prevented, being a reversal of the direction of original normal fluid flow direction D 1  ( FIG. 1 ), which is associated with a fluid overflow condition of fluid F inside sewer duct  14  ( FIG. 2 ). 
         [0046]    The bladder  30  further includes a distal contacting portion  34  located opposite its flow obstructing portion  32 , which is adapted to inflate to a contacting configuration also shown in  FIG. 2  when the pre-set fluid overflow condition is met. 
         [0047]    As shown in  FIGS. 3 and 5 , bladder  30  is pneumatically coupled to a pneumatically circuitry located within the casing  22  by an outer pneumatic line  36  protectively enclosed within the sleeve  20 . The outer pneumatic line  36  extends integrally into an inner pneumatic line  38  protectively enclosed within the casing  22 . An inner pneumatic line  38  is pneumatically coupled to a pneumatic compressor  40  through a conventional pressure regulator  42  having a built in automatic shut off function and a conventional pneumatic distributor  44  typically having three way two position functions so as to allow for selective inflation and deflation of the bladder  30 . 
         [0048]    Referring to  FIGS. 5 to 9 , the sleeve  20  also protectively encloses a contact sleeve  46  enclosing at least one pair of wires  43  and  43 ′, where one is negative and the other positive, and preferably two pairs of wires  43 ,  43 ′, and  43 ″,  43 ′″ for redundancy purposes, to be used with a corresponding number of moisture sensors  48 . When the moisture level is high enough, the two pairs of electric wires  43 ,  43 ′, . . . will start conducting electric current. By moisture level, it is meant a gazeous moisture level, or a liquid moisture level, depending on the type of fluid circulating in channel  13 . The wires  43 ″,  43 ′″,  43 ″″ and  43 ′″″ could use a different type of sensor depending on the type of fluid that needs to be detected, for example a two wire methane sensor could be combined with the existing moisture sensor  43  and  43 ′. 
         [0049]    These electrical sensors will be of the type working at a low level of voltage, for example at the 0.3 volt and 0.1 Ampere range. The moisture sensors  48  are mounted about an intermediate section  34  of inflatable bladder  30 , forming the electrical ends of wires  43 ,  43 ′,  43 ″,  43 ′″. Sensors  48  should preferably be covered by a non corrodible fluid proof conducting alloy. The moisture sensors  48  are preferably welded to the bladder  30  by a conventional sonic welding method or any other suitable method, so that these wire portions  43 A,  43 B become integral to and concealed by the wall of inflatable bladder  30  about bladder portion  34 A. Only the end moisture sensor tips  48 ,  48 ′,  48 ″,  48 ′″, project freely through the intermediate wall of bladder  30 , at a peripheral intermediate location of bladder  30  opposite outer end  34  of bladder  30 . 
         [0050]    Returning to  FIG. 3 , wires  43 ,  43 ′, . . . extend internally into an internal contacting sleeve section  50  protectively enclosed within the casing  22 . The wires  43 , . . . are electrically coupled to both a water sensor unit  52  and a programmable central processing unit  54 . CPU  54  preferably takes the form of an electronic card. The electronic card  54  is electrically coupled through an internal connecting wire  56  to a relay component  58 . An alarm means preferably of the audible piezo type  60  is further operationally mounted within the casing  22  to CPU  54 . 
         [0051]    The power to the components within the casing  22  is provided by a battery type component  62  being chargeable through a battery charger and converter component  64  preferably of the 120 volt/12 volt DC type. A transformer is adapted to be plugged into a conventional external mains electrical wall outlet through the use of a conventional male plug  66 . 
         [0052]    An outlet cable  68  is electrically coupled to the relay  58  at a proximal end thereof and at a distal end thereof to a display panel  70  ( FIG. 4 ) mounted on the cover of the casing  22 . The display panel  70  preferably includes a first display area  72  for providing visual cue as to the inflation status of the bladder  30 , a second display area  74  providing visual cue information on the moisture detection status, a third visual display area  76  for providing visual cue as to the working status of the system as whole, and a fourth display area  78  adapted to provide visual cue indication preferably with a three color code as to the condition of both the battery component  62  and charger component thereof. 
         [0053]    A first control button  80  is provided for allowing reset of the internal clock conventionally integral to the CPU  54 , a second button control  82  is provided for setting of the internal clock, a third control button  84  is provided for manual testing of the system; while a fourth control button  86  is provided for stopping the audible alarm. 
         [0054]    It should be understood that various modifications can be made to the control panel  70  without departing from the scope of the present invention and that the herein above description only refers to an example of such display panel  70 . 
         [0055]    In use, the moisture sensors  48  are adapted to sense moisture and/or detect by physical engagement with a liquid inside sewer conduit  14  a preset level and, once a moisture upper threshold level or liquid detection has been reached, to activate the air compressor  40  so as to inflate the bladder  30 . 
         [0056]    The central processing unit  54  preferably has a built in self test feature that periodically measures the conductivity of the moisture sensor  48 , and/or could activate the compressor  40 , so as to ensure that the latter maintains a predetermined pressure inside the bladder  30 . The self test also preferably includes monitoring of the battery  62  and of the battery charger  64 . The self test makes sure that the battery  62  is sufficiently charged to allow the full deployment of the inflatable bladder  30  in case there is a mains electrical input power blackout. 
         [0057]    Preferably and as illustrated in  FIGS. 10 and 11 , a toroidal shape of the section  32  of the inflatable bladder  30  releasably sealing the sewer duct  14 , assists in hydrodynamic fluid management. Preferably, the opposite long axis ends of toroidal bladder  30  each forms convex half spheres  32 A,  32 B, for optimal hydrodynamic fluid flow management. 
         [0058]    Preferably and as illustrated in  FIG. 12 and 13 , to facilitate handling of bladder  32 , there is provided a discoid support system  92  which is installed transversely inside clean-out duct  12  at the inner end thereof opposite outer closure cap  16 . As suggested by arrows  25 - 25  in  FIG. 1 , the discoid support system  92  illustrated in  FIG. 12  from this perspective of  FIG. 1  is spacedly proximate to the main conduct  14 . Access to the free top face of discoid support system  92  is easily achieved simply by removing screw cap  16 , and by an operator reaching out with his aim through the clean-out duct  12  for maintenance thereof. Inflatable bladder  30  peripherally abuts against and is fixedly mounted to the under face of discoid support system  92 . Discoid support system  92  with two facing half moon holes  96 ,  98  comprising there between a hang screw rod  100  for positioning the discoid support system inside the clean-out duct  12 . An air valve  36  is provided on disk  92  to inflate the inflatable bladder  30  in inflated configuration. An air valve system anchor  93  proximate valve  36  assists in the positioning of the present discoid support system. The sensor cable connectors  46  (see  FIG. 6 ) are inside a sheathed anti-corrosive cable that reaches the sensors  43 ,  43 ′ . . . that are inside the inflatable bladder  30  at its extremity. The present discoid support system  92  is solid, light weight, and doesn&#39;t require any measurements for its installation, since a sound cue, for example a “click” sound, is felt thru the installation rod that reveals it has reached its operational set position in the clean-out duct  12 , see  FIG. 12 . This sound cue comes from the shape of the inflatable bladder  30  in inflated configuration. It is easy to remove the discoid support system from its set position inside the clean-out duct  12  by first pulling the clips of power cable protection  95  to unfix and upwardly pullback the discoid support system. 
         [0059]    The present invention provides an improved fluid backup preventing system. Advantages of the present invention include the fact that the system in accordance with the present invention may be readily adapted to existing sewer conduits without the need for special tooling, manual dexterity or other expensive commodities. 
         [0060]    Also, the present invention provides a built in sensing means for actuating the valve in predetermined conditions. Furthermore, the present invention provides a system having a self checking feature so as to improve overall reliability. 
         [0061]    Also, the present invention uses a duct sealing means that is deformable so as to provide an efficient seal even in situations wherein the sewer conduit is warped or otherwise damaged. 
         [0062]    Furthermore, the present invention provides a built in audible warning means for alerting the dwelling occupants of the flood threatening situation.