Abstract:
A portable solar-powered fluid level alarm system which uses a fluid level sensor electrically connected to electronic controls in a control box. The control box is mounted on an elongated member extending from a base which holds the system upright. The electronic controls within the control box operate up to four different alarms, including an audio alarm, a visual alarm, a remote notification signal via a global positioning system (“GPS”), and a remote notification signal via Voice over Internet Protocol (VoIP). The alarm system is also a keyed system so that once an alarm sounds only authorized personnel may deactivate it.

Description:
CROSS REFERENCES TO RELATED APPLICATIONS 
     This original non-provisional application claims priority to and the benefit of U.S. provisional application Ser. No. 61/799,767, filed Mar. 15, 2013, and entitled “Solar Powered Fluid Level Alarm System,” which is incorporated by reference herein. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable. 
     BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The present invention concerns a solar powered portable fluid level monitoring system with an audio and visual alarm, as well as a remote notification system for those who cannot see or hear the audio and visual alarms. 
     The following description of the related art and the preferred embodiment relates the present invention to an oilfield application in the oil and gas industry. It will be appreciated, however, by those with ordinary skill in the art that the present invention may have application in other fields such as, for example, the waste management industry, the flood control industry, or any other industry concerned with monitoring fluid levels. 
     2. Description of the Related Art 
     In the oil and gas industry, hydraulic fracturing (known as “fracking” or “fracing”) has become a commonplace procedure to unlock and recover hydrocarbons and gas trapped within shale formations deep below the surface of the Earth. During fracing operations, large amounts of water, sand, and proprietary chemicals, known as frac fluid, are injected at the surface of a wellbore and flow into perforations created within the formation. Injecting the frac fluid creates fractures within the formation, which unlock the hydrocarbons and gas trapped therein. As part of the process, large amounts of used frac fluid are generated and subsequently recovered from the wellbore. The used frac fluid must be treated before it can be re-used or before it can be released back in to the environment. 
     Used frac fluid is often stored in one or more large, open holding tanks on the surface. These tanks may be located in the vicinity of the drilling rig or may be located a good distance away from the rig. Regardless of where the tanks are located, it is critical to monitor the amount of frac fluid to ensure that the tanks do not get overfilled and leak. 
     However, monitoring the level of frac fluid in a holding tank on a drill site is challenging. The surface operations are often noisy and require extreme attention to detail. With attention focused on the surface operations, monitoring frac fluid holding tanks often becomes an afterthought and operators are reminded of this important task only after a spill has already occurred. 
     Though systems for monitoring frac fluid levels exist, these systems tend to be cumbersome, difficult to install, and permanent in nature. For example, electrical lines may have to be run to the monitoring system at the tank and would have to be removed when the drill site closes. Installing these systems and removing them takes time and costs money. Additionally, current systems do not allow for remote notification when the monitoring system is located a distance from the holding tank and, if an alarm does sound, anyone can disable the alarm without accountability. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention is directed to a portable fluid level monitoring system. It is solar powered and easy to install. It uses a fluid level sensor electrically connected to electronic controls in a control box. The control box is mounted on an elongated member that extends from a base which holds the system upright. The electronic controls within the control box operate up to four different alarms: (1) an audio alarm; (2) a visual alarm; (3) a remote notification signal via a global positioning system (“GPS”); and (4) a remote notification signal via Voice over Internet Protocol (VoIP). It is also a keyed system so that once an alarm sounds only authorized personnel may deactivate it. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a preferred embodiment of the present invention being used in combination with a frac fluid holding tank. 
         FIG. 2  show a perspective view of the base of the embodiment of  FIG. 1 . 
         FIG. 3  shows a side elevation view of the base shown in  FIG. 2 . 
         FIG. 4  shows a front elevation view of the base shown in  FIG. 2 . 
         FIG. 5  shows a partially exploded perspective view of an embodiment showing a first elongated member separated from a second elongated member and a control box separated from a mounting plate on the second elongated member. 
         FIG. 6  is a partial side elevation view of an embodiment showing an audio alarm and a visual alarm, as well as a mounting hook on the rear side of the second elongated member. 
         FIG. 7  is a side elevation view of an embodiment with a portion of the first elongated member removed at its upward end for illustration purposes. 
         FIG. 8  is an exploded perspective view showing the front cover of the control box removed for illustration purposes. 
         FIG. 9  is a circuit diagram of the electronic controls. 
         FIG. 10  is a side elevation view of the control box with a front cover removed to illustrate electronic controls within the interior of the control box. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIG. 1 , a fluid level alarm system  10  has a fluid level sensor  12  floating within fluid  14  in a holding tank  16 . The fluid level sensor  12  is a float sensor; however, consideration should be given to the type of fluid  14  in the holding tank  16  and the environmental conditions the fluid level sensor  12  will encounter (e.g., heat, cold, rain, snow, etc.). For example, the density of the particular fluid  14  within the holding tank  16  and its effect on the buoyancy should be taken into account if a float sensor is used. 
     One float sensor which has been found acceptable in the frac fluid environment is a SJE Signalmaster® Control Switch Model No. 30SGMPCNO sold by the SJE Rhombus® Company. This float sensor closes the circuit (see  FIG. 9 ) to activate the alarm system  10  when it is tipped slightly above horizontal. In this embodiment, the preferred fluid level sensor  12  is mounted to a pole  18  which is anchored to a weight  20  in the holding tank  16 . The length of the pole  18  and position of the fluid level sensor  12  on the pole  18  is determined by the height of the holding tank  16  so that the preferred fluid level sensor  12  tips slightly above horizontal when the level of fluid  14  approaches the maximum capacity of the holding tank  16 . 
     The fluid level sensor  12  is electrically connected to the alarm system  10  via a fluid sensor cable  22  extending from the fluid level sensor  12  to electronic controls  24  (see  FIG. 10 ) in a control box  26 . The control box  26  is mounted on an elongated portion  28  of the system  10  which extends from a base  30 . The base  30  holds the elongated portion  28  upright. Preferably, the base  30  and the elongated portion  28  are constructed of a lightweight, rigid material durable enough to withstand the environmental challenges encountered by the alarm system  10 . For example, in an oilfield application where the alarm system  10  encounters constant exposure in an outdoor environment it has been found that hollow steel tubing with a square profile is a suitable material given its relatively light weight and durability. 
     A solar panel  32  is mounted to the alarm system  10 , preferably in a position between the elongated portion  28  and the base  30 . However, the solar panel  32  could be mounted elsewhere on the alarm system  10 . The solar panel  32  is electrically connected via a solar connection cable  34  to a solar charge controller  36  that is part of the electronic controls  24  in the control box  26  (see  FIG. 10 ) as discussed in more detail infra. Preferably, the solar connection cable  34  has a plug-in connector  38  between the control box  26  and the solar panel  32 , which allows the solar panel  32  to be disconnected from the electronic controls  24  for transport. 
     A battery  40  is electrically connected to the electronic controls  24  in the control box  26  via a battery connection cable  42 . The specific connection of the battery  40  to the electronic controls  24  is further discussed below; however, it should be presently noted that battery connection cable  42  also preferably has a plug-in connector  44  between the control box  26  and the battery  40  to aid in transport. In this regard, the battery  40  may be disconnected from the electronic controls  24  at the plug-in connector  44  and the battery  40  removed from the base  30  to decrease the overall weight of the alarm system  10  during transport. 
     An audio alarm  46  and a visual alarm  48  are shown mounted on the elongated portion  28  of the alarm system  10 . Preferably, these items are mounted near an upper end  50  of the elongated portion  28  so that light from the visual alarm  48  and sound from the audio alarm  46  can be seen and heard at greater distances due to an elevated position. It should also be noted that the audio and visual alarms  46 ,  48  should be selected according to the particular application and environment in which they are used. In the oilfield, for example, the audio alarm  46  should be loud enough to alert others despite competing noise from other oilfield equipment. One such audio alarm  46  found suitable in this environment is a thirty watt (30 W), outdoor-rated siren manufactured by DSC® with Model Number SD30W and having a 120 db sound level. As for the visual alarm  48 , a blue LED beacon manufactured by ECCO® and having Model Number 7970B was found suitable for oilfield applications because it can be seen through fog, but any number of lights may be used depending on the particular application of the alarm system  10 . 
     As shown in  FIG. 2 , the base  30  is rectangular; however, it can be any shape or configuration which will maintain the elongated portion  28  in an upright position. An alternative configuration for the base  30 , for example, may be a tripod configuration (not shown). In its preferred configuration, however, one or more base supports  52  extend from the perimeter of the rectangular base  30  to a position  54  along the elongated portion  28 . Additionally, the preferred base  30  has a cross member  56  which extends from opposite sides of the base  30  along the midline of the rectangle. The elongated portion  28  is preferably welded to the cross member  56  and extends upwardly therefrom. 
     A holding platform  58  and a locking bracket  60  are also attached to the cross member  56 . The holding platform  58  provides a surface  62  for the battery  40  to rest on when the battery  40  is installed on the alarm system  10 . 
     As shown in  FIG. 3 , the locking bracket  60  extends from a hinge  64  mounted on the cross member  56 , over the battery  40 , and to a lock assembly  66  extending from and mounted to the elongated portion  28 . To install the battery  40 , the locking bracket  60  is rotated away from the elongated portion  28  and the battery  40  is placed on the surface  62  of the holding platform  58 . The locking bracket  60  is then rotated about the hinge  64  to the lock assembly  66  and the lock assembly  66  is locked, thereby preventing the battery  40  from being lifted from the holding platform  58 . Additionally, the surface  62  of the holding platform  58  has sides  68  extending upwardly therefrom which prevent the battery  40  from being laterally removed from its position under the locking bracket  60  (see  FIG. 4 ). 
       FIG. 4  shows a solar panel mounting bracket  70  mounted on two of the base supports  52 . The solar panel mounting bracket  70  is sized to correspond with the selected solar panel  32 . In this regard, the solar panel  32  fits within sides  72  of the solar panel mounting bracket  70  and rests against resting surfaces  74  on mounting bracket  70 . The resting surfaces  74  prevent the solar panel  32  from falling through the solar panel mounting bracket  70 . The solar panel  32  is secured to the solar panel mounting bracket  70  by tightening one or more bolts  100  threaded through sides  72  of the mounting bracket  70  against the perimeter of the solar panel  32 . The elongated portion  28  is formed by a first elongated member  76  and a second elongated member  78 . 
     As shown in  FIG. 5 , the first elongated member  76  extends from the base  30  and the second elongated member  78  is mounted on the first elongated member  76  when the alarm system  10  is assembled. The first elongated member  76  and the second elongated member  78  may be made from the same or differing materials, depending on the application. In the oilfield application, for example, both are made from hollow steel tubing with a square profile, but the square profile area of the first elongated member  76  is larger than the square profile of the second elongated member  78 . 
     The control box  26 , the audio alarm  46 , and the visual alarm  48  are preferably mounted to the second elongated member  78 . The control box  26  may be attached with bolts  80  (see  FIG. 8 ) extending through a mounting plate  82  which is preferably welded to one side  84  of the second elongated member  78 . The audio and visual alarms  46 ,  48  are preferably mounted to the second elongated member  78  above the control box  26  and may be mounted in any manner which securely fixes these components thereto. For example,  FIGS. 5 and 6  show different configurations of securing the audio and visual alarms  46 ,  48  to the second elongated member  78 . 
     Mounting the second elongated member  78  to the first elongated member  76  is achieved with a mounting hook  86  attached to the second elongated member  78 . The mounting hook  86  is preferably welded to the second elongated member  78  on a side  88  of the second elongated member  78  opposite the side  84  on which the mounting plate  82  is welded. Mounting hook  86  may be attached slightly above the control box  26  as shown in  FIG. 6  or could be positioned elsewhere on the second elongated member  78 . Mounting hook  86  is shaped to fit at least partially within an open cavity  90  on an upward end  92  of the first elongated member  76 . The open cavity  90  on the upward end  92  of the first elongated member  76  is the hollow interior of the preferred steel tubing and a portion of the mounting hook  86  is inserted therein. The inserted mounting hook  86  holds the second elongated member  76  in position on the first elongated member  78 , as shown in  FIG. 7 . 
       FIG. 8  shows a front cover  94  removed from the control box  26  and a keyed deactivation switch  96  from the back side of the front cover  94 . The front cover  94  is secured to the control box  26  using one or more screws  98 . Preferably, screws  98  are tamper-resistant so that unauthorized people cannot remove the front cover  94  from the control box  26 . For example, a version of the Torx screw known as “Security Torx,” “Tamper-Resistant Torx,” or “pin-in-Torx” which has a post in the center of the head and prevents a standard Torx driver from engaging the head may be used. 
     The keyed deactivation switch  96  allows an authorized person (i.e., someone with the key) to deactivate the alarm system  10  after the fluid level causes the alarm system  10  to be activated. The front side of the keyed deactivation switch  96  on the front cover  94  is shown in  FIGS. 1 and 5 . As discussed in more detail below, the keyed deactivation switch  96  causes and ceases the flow of electrical current to certain components of the electronic controls  24 . 
       FIG. 9  shows a schematic circuit diagram of the electronic controls  24  of the alarm system  10 . In some regards, the electronic controls  24  may be considered as two subsystems. The first is a subsystem  200  with components directly powered with direct current (DC) from the twelve-volt battery  40 . The second is a subsystem  202  with components powered with current from a twelve-volt to twenty-four volt DC converter  204 . It should be noted, however, that at least a portion of both the first and second subsystems  200 ,  202  may be powered and may be operational when the fluid level causes the alarm system  10  to sound. 
     Before discussing the first and second subsystems  200 ,  202  separately, it should initially be noted that the keyed deactivation switch  96  is open. As noted above, the keyed deactivation switch  96  allows an authorized user to deactivate the alarm system  10  by creating the open circuit. However, when discussing operation of the subsystems  200 ,  202  it should be presumed that the keyed deactivation switch  96  is closed. 
     As mentioned supra, the battery  40  sends current directly to components of the first subsystem  200 . The battery  40  may be any twelve volt battery; however, an absorbed glass mat (AGM) deep cycle battery has proven to be successful in the oilfield environment. The battery  40  powers the audio and visual alarms  46 ,  48  as well as a GPS module  206  when the fluid  14  reaches a certain level within the holding tank  16  (see  FIG. 1 ) and the fluid level sensor  12  is activated. When the certain level is reached and the fluid level sensor  12  closes, current flows from the battery  40  to the audio and visual alarms  46 ,  48  and the GPS module  206  to power those items. 
     Current to the audio and visual alarms  46 ,  48  powers those items to create the audible and visual signals discussed above. Power to the GPS module  206  requires further explanation. The GPS module  206  has a GPS module unique identifier assigned to it. Prior to deployment of the alarm system  10  in the field, the GPS module unique identifier is correlated with an alarm system unique identifier assigned to the particular alarm system  10  on which the particular GPS module  206  is being used upon. 
     When the GPS module  206  is activated after the fluid sensor  12  closes the circuit and current flows to it, the GPS module  206  sends a signal to a satellite (not shown) indicating that the fluid level has reached a critical point. A GPS satellite administrator (not shown) who monitors the satellite receives notification from the satellite that a particular GPS module  206 , having a specified GPS module unique identifier, has been activated. The administrator matches the GPS module unique identifier with the alarm system unique identifier to determine which particular alarm system  30  has been activated. 
     Using this information, the proper authority may be notified of an alarm condition at the identified alarm system  10 . For example, in the oilfield application the “company man” may be called on a mobile device (e.g., cellphone, smart phone or the like) or satellite phone or may be emailed on a mobile device (e.g., cellphone, smart phone, tablet or the like) depending on the particular network infrastructure(s) involved. 
     Concerning the second subsystem  202 , this remains inactive unless a toggle switch  208  between the battery  40  and the converter  204  is closed. As shown in  FIG. 9 , toggle switch  208  is open; however, for purposes of the following discussion, it should be presumed that it is closed (not shown). When the toggle switch  208  is closed, current flows from the battery  40  to the converter  204 . The converter  204  converts the twelve volt DC voltage at its input end to twenty-four volt DC voltage at its output end, which will ultimately be supplied to a controller  210  such as the 8028 Session Initiation Protocol (SIP) compatible doorphone controller manufactured by Algo Communications Products Ltd. as further described below. As for the converter  204 , the “SCADALink PSC-24” Model offered by Bentek Systems has proven to be successful. 
     As with the first subsystem  200 , current flow in the second subsystem  202  is dependent upon activation of the fluid level sensor  12 . When the fluid level sensor  12  is activated, current flows from the battery  40  through a relay switch  212 . Activating relay switch  212  closes a connection  214  between a first pin  216  and a second pin  218  through the relay switch  212 , which completes the circuit and allows current to flow and power the second subsystem  202 . Understanding the circuit of the second subsystem  202 , however, requires a discussion of the components connected to the controller  210 . 
     The controller  210  is connected to a telephone wiring jack  220  via a standard phone line  222  plugged into and extending between the controller  210  and the wiring jack  220 . A first terminal  224  from the wiring jack  220  is electrically connected to the first pin  216  of the relay switch  212  and a second terminal  226  of the wiring jack  220  is connected to the second pin  218  of the relay switch  212 . When relay switch  212  is activated and the connection  214  is closed, a closed circuit is created to activate the controller  210 . In this regard, current that flows to the controller  210  from the converter  204  also flows into the wiring jack  220  through a first wire (not shown) within phone line  222 , and, closing the connection  214  in the relay switch  212  allows current to flow back to the controller  210  through a second wire (not shown) in the phone line  222 . In other words, the first and second terminals  224 ,  226  are connected to the phone line  222  within the wiring jack  220  to achieve such a current flow back to the controller  210  when the relay switch  212  connection  214  is closed. 
     Additionally, closing the connection  214  across the relay switch  212  causes current to flow from within the wiring jack  220  to a microphone/speaker component  228  which is electrically connected to the wiring jack  220 . Current to the microphone/speaker component  228  activates it and also causes a return signal over the phone line  222  to the controller  210 . In this regard, sound from the audio alarm  46  is received by the microphone/speaker component  228  and electronically transmitted back to the controller  210 . 
     Current flow back to the controller  210  activates the controller  210 , causing it to dial a specified Internet Protocol (IP) address to where the controller  210  will send a Voice over Internet Protocol (VoIP) signal. The VoIP signal is transmitted from the controller  210  through a Category 5 (Cat5) cable  230  or other type of suitable cable extending between the controller  210  and a Power over Ethernet (PoE) injector  232 . After passing through the PoE injector  232 , the VoIP signal travels to a wireless bridge  234  and is transmitted from alarm system  10  through an antenna  236 . One wireless bridge  234  which has been found suitable for the present alarm system  10  in the oilfield application is a “Wireless Outdoor Access Point &amp; Client Bridge” Model Number EOC1650 offered by the EnGenius® Company, which include the PoE injector  232  as a part of the product. 
     The VoIP signal is transmitted via the antenna  236  to and received by a corresponding IP address at another wireless bridge (not shown). Included in the transmitted VoIP signal is the sound of the audio alarm  46  which the microphone/speaker component  228  receives when the connection  214  through the relay switch  212  is closed. That sound is carried back to the controller  210  with an electronic signal through the wiring jack  220  as previously discussed. On the receiving end of the transmitted VoIP signal, a person will then hear the audio alarm  46  transmitted via the VoIP signal. 
     Referring still to  FIG. 9 , the solar panel  32  is electrically connected to the charge controller  36 . The charger controller  36  controls the amount of charging current that flows to the battery  40  and will eliminate the charging current altogether if the battery  40  is fully charged. One charging controller that has been found to work in the oilfield environment, for example, is the “Solar Boost 2000E” offered by Blue Sky Energy, Inc. As for the solar panel, a sixty watt (60 W) panel has been found to provide sufficient power for the electronic controls  24  discussed herein, however, the wattage of the solar panel  32  may need to be increased or decreased depending on the particular application and the particular electronic controls  24 . 
     Referring now to  FIG. 10 , the control box  26  from a front elevation view with the front cover  94  is removed to reveal and illustrate the actual shape of some of the electronic controls  24  previously discussed. Though many of the electronic controls  24  are housed within the control box  26  it should be pointed out that the GPS module  206  is not. The GPS module  206  is mounted on a top surface  238  of the control box  26  so that a connection can be established between the GPS module  206  and the satellite (not shown). Also shown outside the control box  26  is a portion of the antenna  236  which, like the GPS module  206 , is better suited to communicate if positioned outside the control box  26  (see  FIGS. 1 ,  5 - 8 ). 
     Although the present invention has been described with reference to a specific embodiment, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternative embodiments of the invention will become apparent to persons skilled in the art upon the reference to the above description of the invention. It is, therefore, contemplated that the appended claims will cover such modifications that fall within the scope of the invention.