Patent Publication Number: US-8111497-B2

Title: Device for electrically discharging samples of an electrically non conductive liquid

Description:
This application is based on Provisional Application No. 61/188,682, filed Aug. 12, 2008 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to devices for collecting samples from drums and vessels containing liquids and, more particularly, to collecting samples from drums and vessels containing electrically nonconductive liquid with an electrical static charge buildup thereupon. 
     2. Background of the Prior Art 
     Oil refineries and chemical plants routinely analyze hydrocarbon liquids in their process flow streams to determine if the resulting products meet specifications. Generally, a person will dip a collection tube into a drum, vessel or similar container to collect a sample of a hydrocarbon liquid within. After collecting a sample, the person carries the collection tube and sample therein back to a lab for analysis. 
     A dangerous situation occurs when a statically charged hydrocarbon liquid sample is collected. The statically charged hydrocarbon liquid in the collection tube can transfer a substantial quantity of the static charge to the collection tube, irrespective of the collection tube being fabricated from electrically conductive or nonconductive material, resulting in an electrical arc when the collection tube engages a grounded structure. The electrical arc can start a fire or initiate an explosion if the surrounding area provides an explosive atmosphere. 
     A need exists for a grounded metal collection tube that includes inner members capable of discharging the static charge from a nonconductive hydrocarbon liquid while the hydrocarbon liquid is collected from inside a barrel, vessel or similar container. 
     SUMMARY OF THE INVENTION 
     A principle object of the present invention is to provide a device for electrically discharging samples of an electrically nonconductive liquid. A feature of the device is an electrically conductive outer member. Another feature of the device is an electrically conductive inner member. Yet another feature of the device is an electrically conductive member that electrically connects the conductive inner member to the conductive outer member. An advantage of the device is that an electrically nonconductive liquid that is statically charged is allowed to enter the outer member via an open bottom and rise within the outer member to engage the inner and outer members, and the connecting member, thereby safely removing the static charge from a selected quantity of the nonconductive liquid that will ultimately be analyzed. 
     Another object of the present invention is to electrically ground the outer and inner members, and the connecting member before allowing the device to engage a statically charged nonconductive liquid. A feature of the device is a grounding cable with electrically conductive clamps attached to opposite ends of the grounding cable. Another feature of the device is a collar for detachably receiving one of the electrically conductive clamps, the collar being electrically connected to the inner member. An advantage of the device is that the collar and clamp cooperate to electrically ground the statically charged nonconductive fluid immediately upon contacting the outer and inner members, thereby preventing electrical arcs that could cause an explosion. 
     Yet another object of the present invention is to seal the outer member such that the collected sample therein will not escape after removing the device from a drum or vessel containing the electrically nonconductive liquid. A feature of the device is upper and lower plugs for the outer member that are forcibly urged into the outer member by a spring cooperating with a channel spacer. An advantage of the device is that the outer member and the sample therein can be manually transported to an analyzing location without endangering the person or the environment. 
     Briefly, the invention provides a device for electrically discharging samples of an electrically non-conductive liquid comprising an electrically conductive outer member; an electrically conductive inner member disposed within said electrically conductive outer member; means for allowing an electrically non-conductive liquid to enter said electrically conductive outer member when said device is disposed in the non-conductive liquid; means for electrically discharging the non-conductive liquid entering said outer conductive member; means for maintaining a selected volume of the non-conductive liquid in said outer conductive member after said device is removed from the non-conductive liquid; and means for electrically grounding said inner and outer electrically conductive members, and said electrical discharging means for the non-conductive liquid entering said outer conductive member. 
     The invention further provides a system for electrically discharging non-conductive liquid samples before being removed from a vessel comprising means for receiving a predetermined quantity of non-conductive liquid; means for electrically discharging the non-conductive liquid as the non-conductive liquid enters and fills said receiving means, said electrical discharging means comprising an electrically conductive inner member that engages the non-conductive liquid entering said receiving means; and means for grounding said electrically conductive inner member, said grounding means being detachably secured to said electrically conductive inner member and an electrically grounded structure; means for manually sealing a predetermined quantity of the non-conductive liquid in said receiving means; and means for manually releasing the non-conductive liquid from said receiving means, thereby providing a sample of the non-conductive liquid for evaluation. 
     The invention also provides a method for removing static charge from a selected quantity of non-conductive liquid, said method comprising the steps of providing an electrically conductive container with bottom and top apertures; inserting an electrically conductive inner member into said container, said inner member ultimately engaging an inner wall of said container; installing plugs on bottom and top portions of said inner member, said plugs being configured and dimensioned to seal said bottom and top apertures in said container after a selected quantity of non-conductive liquid has entered said container; providing means for manually urging said inner member in said container to ultimately seal said bottom and top apertures in said container via said plugs, said plugs being slidably disposed upon said inner member; and connecting grounding means to said inner member, whereby the non-conductive liquid entering said container is electrically discharged until said grounding means is detached from said inner member, whereupon, the container and the electrically discharged non-conductive liquid therein are transported to a testing lab. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other objects, advantages an novel features of the present invention, as well as details of an illustrative embodiment thereof, will be more fully understood from the following detailed description and attached drawings, wherein: 
         FIG. 1  is a front elevation view of a device for electrically discharging the static charge in samples of an electrically non-conductive liquid in accordance with the present invention. 
         FIG. 2  is an exploded view of the device of  FIG. 1 . 
         FIG. 3  is a phantom view of the device of  FIG. 1  without the grounding cable. 
         FIG. 4  is a phantom view of the device of  FIG. 3 , but with metal spheres included therein in accordance with the present invention. 
         FIG. 5  is a phantom view of the device of  FIG. 4 , but with metal screens included therein in accordance with the present invention. 
         FIG. 5   a  is a top elevation view of the screens of  FIG. 5 . 
         FIG. 6  is a phantom view of the device of  FIG. 5 , but with metal bars forming a grid pattern replacing the screens and spheres therein in accordance with the present invention. 
         FIG. 6   a  is a top elevation view of the grid pattern of  FIG. 6 . 
         FIG. 7  is a front elevation view of the device of  FIG. 1 , but with an alternative handle design in accordance with the present invention. 
         FIG. 8  is an exploded view of the device of  FIG. 7 . 
         FIG. 9  is a front elevation view of the device of  FIG. 1 , but with a modified upper portion in accordance with the present invention. The device of  FIG. 9  is depicted with a lower plug disposed in a closed position to prevent a sample from escaping an outer member of the device. 
         FIG. 10  is an exploded perspective view of the device of  FIG. 9 . 
         FIG. 11  is a front elevation view of the device of  FIG. 9 , but with a channel spacer removed and a lower plug disposed in an open position to allow a sample to flow into an outer member of the device in accordance with the present invention. 
         FIG. 12  is a front elevation view of the modified upper portion of  FIG. 9 . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to  FIGS. 1 and 2 , a device for electrically discharging the static charge on samples of an electrically non-conductive liquid in accordance with the present invention is denoted as numeral  10 . The device  10  includes an electrically conductive outer member  12 ; an electrically conductive inner member  14  spirally disposed within the outer member  12 ; an electrically conductive rod  16  with upper and lower plugs  18  and  19  secured thereto to maintain a non-conductive fluid in the device  10 , the rod  16  being electrically connected to the outer and inner members  12  and  14 ; an electrically non-conductive rod handle  20  secured to a top portion  21  of the rod  16  for manually disposing the rod  16  inside the outer member  12 ; an electrically non-conductive handle  22  secured to a top portion  24  of the outer member  12  for manually holding the outer member  12  while the rod  16  is manually disposed inside the outer member  12 ; and an electrically conductive ground cable  26  detachably secured to the rod  16 , whereby the static charge in an electrically non-conductive liquid in a container or vessel is ultimately discharged to ground via the non-conductive liquid engaging the outer member  12 , inner member  14  and rod  16 , which are electrically grounded via the cable  26 . 
     The outer member  12  is a thin-walled, cylindrically configured tube dimensioned to provide a volume that promotes insertion into a vessel or container to withdraw a predetermined volume of non-conductive liquid for testing and evaluation. The outer member  12  is manufactured from a relatively light weight electrically conductive metal such as aluminum or copper, and includes upper and lower apertures  28  and  30  to receive and remove the non-conductive liquid. The non-conductive handle  22  is fabricated from plastic or similar material and secured to the top portion  24  of the outer member  12 . The handle  22  promotes the manual grasping of the outer member  12  while protecting the operator from static electricity in the non-conductive liquid when engaged by the outer member  12  as the operator inserts the device  10  into the liquid. 
     The inner member  14  is an electrically conductive piece of copper or aluminum spiraling about the rod  16  such that outer portions  32  of the inner member  14  engage an inner cylindrical wall  34  of the outer member  12 , thereby promoting electrical continuity between the outer and inner members  12  and  14 , and the rod  16  to ultimately discharge the static charge in the non-conductive liquid collected in the outer member  12  to ground via the ground cable  26 . The inner member  14  is secured to the rod via soldering or similar methods. Two enlarged couplings  35  are integrally secured to the rod  16  to provide a relative large surface area to better secure the inner member  14  to the rod  16 . The spiraling inner member  14  is suitable for relatively viscous or “thick” liquids. In the event a relatively non-viscous or “thin” liquid requires discharging, a plurality of small spherical copper or aluminum balls  36  may be disposed in the outer member  12  (see  FIG. 4 ) such that the balls  36  engage the inner and outer members  12  and  14 , and the rod  16  to provide increased static discharge capability; or the balls  36  alone may fill the outer member  12  without the inner member  14 , but including the rod  16  such that the balls  36  engage the outer member  12  and the rod  16 . Alternatively, a series of conductive screens  38  may replace the inner member  14  (see  FIGS. 5 and 5a ), or a combination of screens  38  and balls  36  can be utilized. Further, a plurality of relative long, “thin” copper or aluminum “flat bars”  40  may be integrally joined to form a grid  42  configuration (see  FIGS. 6 and 6   a ). 
     Irrespective of the configuration of electrically conductive elements included in the outer member  12 , the goal is to remove the electrostatic charge from the non-conductive liquid before the device  10  is manually removed from the vessel or container holding the non-conductive liquid. The electrostatic charge is removed via the non-conductive liquid entering the lower aperture  30  of the outer member  12 , then rising within the outer member  12  and around or through the inner member  14  and/or balls  36 , screens  38  or flat bars  40  until rising to a level that provides a sufficient volume of electrostatically discharged, non-conductive liquid for laboratory testing and evaluation. The more engagement between the volume of non-conductive liquid and the outer member  12 , inner member  14  or substitute elements, and the rod  16 , the lower the electrostatic charge remaining on the non-conductive liquid when the device is removed from the vessel or container, thereby reducing the chance of an electrostatic arc which could cause a fire or explosion in the event of combustive or explosive vapors being present. 
     The non-conductive liquid is manually collected in the device  10  by the operator holding the device  10  via non-conductive handles  20  and  22  to prevent the operator from being exposed to a static charge, the operator then pushes on the handle  20  secured to the top portion  21  of the rod  16  by threads or similar methods, until a frustoconically configured lower plug  19 , manufactured from a deformable material such as rubber or a conductive or semi-conductive material, is separated from the lower aperture  30 . The lower plug  19  is dimensioned to cooperate with the diameter of the lower aperture  30  such that the lower plug  19  is capable of sealing the bottom end of the outer member  12  after the non-conductive liquid enters the outer member  12 . The operator then grounds the rod  16 , the inner and outer members  14  and  12  electrically connected thereto, and any balls  36  or screens  38  inside the outer member  12  by manually attaching a first clamp  58  to a collar  56  and a second clamp  60  to a ground bar  62  or similar well grounded metal structure, the ground cable  26  provides electrical continuity between the clamps  58  and  60 . The operator then inserts the lower end  44  of the outer member  12  into the non-conductive liquid such that a tip portion  46  of the rod  16  first engages the liquid, thereby reducing the chance of an arc between the surface of the non-conductive liquid and the device  10 . The operator inserts the lower end  44  of the outer member  12  deeper into the liquid until the liquid rises inside the outer member  12  to a level that provides a predetermined volume of liquid inside the device  10  for removal from the container, whereupon, the operator pulls the rod handle  20  upward until the lower plug  19  is re-inserted into the lower aperture  30  to prevent the non-conductive liquid from escaping from the outer member  12 . To prevent the liquid from spilling from the upper aperture  28  in the outer member  12 , the upper plug  18 , manufactured from the same deformable frustoconically configured material as the lower plug  19 , is manually pushed into the upper aperture  28 , thereby sealing the non-conductive liquid inside the device  10 , and allowing the device  10  to be removed from the container; whereupon, the second clamp  60  is ultimately detached from the ground bar  62  and the device  10  with the non-conductive liquid therein is transported by the operator to a distal location where the liquid is tested and/or evaluated. 
     The lower plug  19  is removably secured to the threaded tip portion  46  of the rod  16  by a washer  48  and nut  50 . The upper plug  18  is slidably maintained on the treaded top portion  21  of the rod  16  by a nut  52 . The nut  52  cooperates with two washers  54  and the rod handle  20  to maintain the longitudinal position of the metal collar  56  upon the top portion  21  of the rod  16  such that the rod  16  is electrically connected to the collar  56 , resulting in electrical continuity between the rod  16 , the metal clamps  58  and  60 , the cable  26  and the grounded bar  62  to effectively ground the static charge in the collected non-conductive liquid. The collar  56  detachably receives the first clamp  58  which is secured to a first end of the grounding cable  26 . A second end of the grounding cable  26  is secured to the second clamp  60  which detachably secured to the selected grounded metal bar  62  or similar grounded structure. 
     Referring now to  FIGS. 7 and 8 , an alternative design for the handle of the device  10  is depicted and designated as numeral  70 . The handle is manufactured from a non-conductive material and includes a “T” configuration to promote better grasping by the operator to allow the operator impart more force upon device  10  when inserting or removing the upper and lower plugs  18  and  19  from cooperating upper and lower apertures  28  and  30 . The handle  70  is secured to the top portion  21  of the rod  16  by threads such that the top portion  21  is completely threaded and inserted into a base portion  72  of the handle  70  to ultimately dispose a tip portion  74  of the base portion  72  into the upper aperture  28  in the outer member  12 , thereby stabilizing the handle  70  after the upper plug  18  is slid down the base portion into the upper aperture  28 . A cross member  76  is snugly and removably inserted through an aperture  78  in the base portion. The cross member  76  is configured and dimensioned such that the operator&#39;s entire hand grasps the cross member  76 , thereby promoting increased manual force longitudinally upon the rod  16 , resulting in tighter seals between the upper and lower plugs  18  and  19 , and cooperating ends of the outer member  12 . 
     Referring now to  FIGS. 9-12 , a modified upper portion for the device  10  in accordance with the present invention is denoted as numeral  80 . The modified upper portion  80  includes an elongated collar  82  with a threaded aperture  84  that rotationally receives the threaded top portion  21  of the conductive rod  16 , a cylindrical spring  86  that slides upon a cylindrical lower portion  88  of the elongated collar  82 , a channel spacer  90  that is forcibly disposed upon the lower portion  88  of the elongated collar  82 , a washer  92  that slides upon the lower portion  88 , and an upper plug  94  that is forcibly disposed upon the lower portion  88 . 
     The elongated collar  82  is manufactured from a single piece of aluminum and further includes a threaded cylindrical top portion  96  that rotationally inserts into the handle  20 , and first and second cylindrical clamp retainers  98  and  100  with a cylindrical clamp portion  102  therebetween for receiving the first clamp  58 . The first and second clamp retainers  98  and  100  are separated a distance corresponding to the axial dimension of the clamp portion  102  required to allow the first clamp  58  to snugly insert between the first and second clamp retainers  98  and  100 , then be removably secured to the clamp portion  102 . The first and second clamp retainers  98  and  100  have planar inner walls  104  with radial dimensions sufficient to engage and retain the first clamp  58 , thereby preventing the clamp  58  from sliding off the clamp portion  102 . The first clamp retainer  98  includes an arcuate outer wall  106  configured to snugly engage a bottom portion  107  of the handle  20 . The second clamp retainer  100  includes a conically configured outer wall  108  dimensioned to cooperatively engage a first end  110  of the spring  86 , such that the spring remains concentrically disposed about the lower portion  88  when compressed, thereby preventing the spring  86  from engaging and damaging the lower portion  88 . 
     The lower portion  88  includes an axial dimension that is relatively longer than the combined axial dimensions of the spring  86  (not compressed), channel spacer  90 , washer  92  and upper plug  94 , thereby preventing the upper plug  94  from sliding off the elongated collar  82  during operation of the device  10 . The spring, washer  92  and upper plug  94  must be slid upon the elongated collar  82  before the threaded top portion  21  of the conductive rod is rotationally inserted into the elongated collar  82 . The channel spacer  90  has one side open and therefore can be disposed upon the lower portion  88  after the top portion  21  is rotationally secured to the lower portion  88 . 
     The spring  86  is manufactured from stainless steel and includes an axial dimension approximately one-half the longitudinal dimension of the channel spacer  90  when the spring  86  is in a non-compressed state. The axial dimension of the spring  86  and longitudinal dimension of the channel spacer  90  cooperate to maintain sufficient pressure on the upper plug  94  to prevent the upper plug  94  and/or the lower plug  19  from allowing a sample collected in the outer member  12  from escaping until the collected sample is intended to be removed from the outer member  12 . The spring  86  includes an inner diameter slightly longer than the outer diameter of the lower portion  88 , and an outer diameter relatively smaller than the outer diameter of the second clamp retainer  100 , thereby allowing the spring  86  to snugly slide onto the lower portion  88  until engaging the conical outer wall  108  of the second clamp retainer  100 . The spring  86  compression parameters are such that a person using the device  10  can compress the spring  86  to a position that ultimately provides sufficient bias to the channel spacer  90  to maintain the positions of the upper and lower plugs  94  and  19  in the outer member  12  such that no sample will escape the outer member  12 . 
     The channel spacer  90  includes a base side  112  and two retaining sides  114  perpendicularly joined to the base side  112  such that the retaining sides  114  are laterally separated a distance slightly less than the outer diameter of the lower portion  88 . The lateral separation of the retaining sides  114  allows an operator of the device  10  to forcibly urge the base side  112  and the retaining sides  114  of the channel spacer  90  into longitudinal engagement with the lower portion  88 , thereby providing a bias that retains the channel spacer  90  upon the lower portion  88  after the operator releases the channel spacer  90 . After the operator takes a sample and forces the upper and lower plugs  94  and  19  into the outer member  12 , the spring  86  is compressed and the channel spacer  90  inserted between the spring  86  and washer  92  such that a first end  116  of the channel spacer  90  forcibly engaging a second end  118  of the spring  86 , a second end  120  of the channel spacer  90  forcibly engaging a first side  122  of the washer  92 , and a second side  124  of the washer  92  forcibly engages the upper plug  94 , thereby maintaining the upper and lower plugs  94  and  19  in the outer member  12 . 
     The washer  92  is manufactured from stainless steel and dimensioned to engage the second end  120  of the channel spacer  90  and the upper plug  94 . The upper plug  94  is configured and dimensioned substantially the same as the lower member  19 , except that the axial aperture through the upper plug  94  has a diameter relatively larger than the diameter of the axial aperture through the lower member  19 . Also, the axial aperture through the upper plug  94  is relatively smaller than the outer diameter of the lower portion  88  of the elongated collar  82  to forcibly maintain the upper plug  94  upon the lower portion  88  during slidable operation of the upper plug  94  upon the lower portion  88  when collecting samples with the device  10 . 
     In operation, a device  10  having a modified upper portion  80  is grounded via the first clamp  58  detachably secured to the clamp portion  102  of the elongated collar  82 , and the second clamp  60  detachably secured to a grounded metal bar  62  or similar grounded structure. The channel spacer  90  is removed and the lower portion  88  of the elongated collar  82  is forced into the outer member  12  via the handle  20  to force the lower plug  19  out of the lower aperture  30  of the outer member  12 . The device  10  is then inserted into a tank, drum or vessel to collect a sample. Upon collecting a sample, the lower plug  19  is urged back into the lower aperture  30  of the outer member  12  to capture the sample, whereupon, the upper plug  94  is forcibly urged into the upper aperture  28  in the outer member  12  via the washer  92 , the first end  110  of the spring  86  is compressed against the conical outer wall  108  of the second clamp retainer  100  via the first end  116  of the channel spacer  90  forcibly urging the second end  118  of the spring  86  axially toward the conical outer wall  108 , and the channel spacer  90  is disposed upon the lower portion  88  of the elongated collar  82  such that the second end  120  of the channel spacer  90  forcibly engages the first side  122  of the washer  92 , thereby forcibly and constantly urging the upper and lower plugs  94  and  19  into the outer member  12  to maintain the sample within the outer member after the outer member  12  is withdrawn from the tank, drum or vessel. 
     The foregoing description is for purposes of illustration only and is not intended to limit the scope of protection accorded this invention. The scope of protection is to be measured by the following claims, which should be interpreted as broadly as the inventive contribution permits.