Abstract:
A suspended solids filter system including a container for receiving contaminated liquid, and a filter assembly disposed within the container for filtering the contaminated liquid so that contaminants separated from the liquid remain in the container.

Description:
TECHNICAL FIELD 
       [0001]    The present invention is directed to the filtering of contaminated water generated during industrial processes such as oil drilling. 
       BACKGROUND 
       [0002]    During an oil drilling process, debris (comprised of water, oil, stone, soil, metal fragments, mud and other components) is generated and stored in a pond adjacent to the drilling rig as sludge. This sludge must be treated according to industry standards set for maximum contaminant levels. These concerns stem from the potential adverse health effects of the contaminated water reentering the aquifer. The contaminated water, which is removed, must be trucked to disposal areas and pumped below the aquifer into detention areas, which are then sealed. Contaminated water removal has conventionally been a slow process, as the contaminants must be removed before transport. The only method currently available for removing contaminants from the water uses a sock type filter. This method is slow and cumbersome and requires many changes of the filter, causing serious time delays when filling the transport trucks. 
         [0003]    While other types of water filters are available in different industries, the sock method is the only technique which has been acceptable to date for the filtering of contaminants from drilling sites. However, as mentioned previously, frequent filter changes are required, substantially slowing the transport process. Further, following scheduled filter replacements is crucial to eliminate the possibility of contamination, but not knowing the volume of sludge in the water does not allow for regular filter replacements. Thus, the operator must wait until the filter clogs, before replacing the filter. This slows the filtering process, substantially increasing the waiting time and operating costs. 
         [0004]    One of the key difficulties faced in using the sock method is the complexity of the contaminated water. The water may contain particles of varying sizes, oil and tar. Filter life is dependent on how much of these components are present in the contaminated water and there is no easy way to segregate out the most damaging components to improve filter life. 
       SUMMARY OF THE INVENTION 
       [0005]    The present invention is directed to an improved water filter that operates continuously with minimal energy requirements and is more effective in the removal of sludge and other pollutants from contaminated water sources. 
         [0006]    A water filter according to an exemplary embodiment of the present invention comprises: a housing; at least one cylindrical filter component disposed within the housing; an inflow pipe extending through, and parallel to a longitudinal axis of, the at least one cylindrical filter component, the inflow pipe comprising a series of openings arranged along the length of the inflow pipe so as to cause a cyclonic motion of the contaminated water out of the inflow pipe and into contact with the at least one cylindrical filter component; a first outflow pipe that delivers filtered water from the at least one cylindrical filter component; and a second outflow pipe that delivers contaminants from the at least one cylindrical filter component. 
         [0007]    According to at least one exemplary embodiment, the at least one cylindrical filter component comprises a first cylindrical filter component disposed within a second cylindrical filter component. 
         [0008]    According to at least one exemplary embodiment, the water filter further comprises a collection chamber that collects solid debris filtered from the contaminated water. 
         [0009]    According to at least one exemplary embodiment, the water filter further comprising a pre-filter, and the pre-filter comprises: a hose comprising a distal end portion and a proximal end portion, the proximal end portion being connected to the inflow pipe; a vacuum inlet connect to the distal end portion of the hose; and a vacuum filter connected to the vacuum inlet that filters the contaminated water. 
         [0010]    According to at least one exemplary embodiment, the water pressure at the first outflow pipe is between 0-5 psi when the water filter is in operation. 
         [0011]    According to at least one exemplary embodiment, water pressure at the first outflow pipe is between 0-3 psi when the water filter is in operation. 
         [0012]    According to at least one exemplary embodiment, the at least one cylindrical filter component is removable for replacement with another cylindrical filter component. 
         [0013]    According to at least one exemplary embodiment, the inflow pipe comprises a viewing element. 
         [0014]    According to at least one exemplary embodiment, the contaminated water comprises oil. 
         [0015]    According to at least one exemplary embodiment, the contaminants in the second outflow pipe for passing contaminants comprise oil. 
         [0016]    According to at least one exemplary embodiment, the water filter further comprises a third outflow pipe for delivering small debris particles from the at least one cylindrical filter component. 
         [0017]    According to at least one exemplary embodiment, the series of openings arranged along the length of the inflow pipe further comprise louvers. 
         [0018]    According to at least one exemplary embodiment, wherein the housing comprises a top portion, and the louvers are spaced from the top portion of the housing. 
         [0019]    A method of filtering contaminated water according to an exemplary embodiment of the invention comprises the steps of: providing a water filter comprising: a housing; at least one cylindrical filter component disposed within the housing; and an inflow pipe extending through, and parallel to a longitudinal axis of, the at least one cylindrical filter component, the inflow pipe comprising a series of openings arranged along the length of the inflow pipe; and delivering the contaminated water through the inflow pipe so as to cause a cyclonic motion of the contaminated water out of the inflow pipe and into contact with the at least one cylindrical filter component. 
         [0020]    According to at least one exemplary embodiment, the method further comprises the steps of: delivering filtered water from the at least one cylindrical filter component; and delivering contaminants from the at least one cylindrical filter component. 
         [0021]    According to at least one exemplary embodiment, the step of delivering contaminants comprises delivering relatively light in weight contaminants to an upper portion of the housing and delivering relatively heavy in weight contaminants to a lower portion of the housing. 
         [0022]    According to at least one exemplary embodiment, the relatively light in weight contaminants comprises oil. 
         [0023]    According to at least one exemplary embodiment, the step of delivering contaminants comprises limiting speed of the cyclonic motion of the contaminated water 
         [0024]    According to at least one exemplary embodiment, the step of delivering contaminants comprises limiting speed of the cyclonic motion of the contaminated water out of an upper portion of the inflow pipe. 
         [0025]    According to at least one exemplary embodiment, the method further comprises the steps of providing a pre-filter, the pre-filter comprising: a hose comprising a distal end portion and a proximal end portion, the proximal end portion being connected to the inflow pipe; a vacuum inlet connect to the distal end portion of the hose; and a vacuum filter connected to the vacuum inlet that filters the contaminated water. 
         [0026]    A suspended solids filter system according to an exemplary embodiment of the present invention comprises: a container for receiving contaminated liquid; and a filter assembly disposed within the container for filtering the contaminated liquid so that contaminants separated from the liquid remain in the container. 
         [0027]    According to at least one exemplary embodiment, the container is made of steel. 
         [0028]    According to at least one exemplary embodiment, the suspended solids filter system further comprises an external inflow pipe that delivers contaminated liquid into the container. 
         [0029]    According to at least one exemplary embodiment, the suspended solids filter system further comprises an internal inflow pipe in communication with the external inflow pipe, the internal inflow pipe comprising one or more nozzles for delivery of the contaminated water into the container. 
         [0030]    According to at least one exemplary embodiment, the suspended solids filter system further comprises shield elements that protect the container from contact with the liquid delivered from then nozzles. 
         [0031]    According to at least one exemplary embodiment, the filter assembly comprises at least one perforated plate and at least one woven screen. 
         [0032]    According to at least one exemplary embodiment, the filter assembly further comprises at least one layer of aggregate. 
         [0033]    According to at least one exemplary embodiment, the aggregate is made up of at least one of coal slag, iron ore slag, crushed granite or coarse sand. 
         [0034]    According to at least one exemplary embodiment, the filter assembly comprises an upper filter assembly and a lower filter assembly. 
         [0035]    According to at least one exemplary embodiment, the suspended solids filter system further comprises an outflow pipe through which filtered liquid is drawn out of the container. 
         [0036]    According to at least one exemplary embodiment, the container comprises an opening and a door that is moveable between a closed position in which the door covers the opening and an open position in which the door allows contaminants to be removed from the container through the opening. 
         [0037]    According to at least one exemplary embodiment, the liquid is water, sewage, diesel fuel, crude oil, saltwater or invert drilling fluid. 
         [0038]    According to at least one exemplary embodiment, the container has a capacity within the range of 30 cubic yards to 40 cubic yards. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0039]    Various exemplary embodiments of this invention will be described in detail, with reference to the following figures, wherein: 
           [0040]      FIG. 1  is a perspective view of a water filter according to an exemplary embodiment of the present invention; 
           [0041]      FIG. 2  is an exploded perspective view of the water filter of  FIG. 1 ; 
           [0042]      FIG. 3  is a perspective view of an inflow pipe useable with the water filter of  FIG. 1  according to an exemplary embodiment of the present invention; and 
           [0043]      FIG. 4  is a diagram illustrating a process by which sludge is removed from a body of water according to an exemplary embodiment of the present invention. 
           [0044]      FIG. 5  is a perspective view of a filter system according to an exemplary embodiment of the present invention; 
           [0045]      FIG. 6  is a cross-sectional view of the filter system of  FIG. 5 ; and 
           [0046]      FIG. 7  is a cross-sectional view of a filter assembly according to an exemplary embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0047]      FIGS. 1 and 2  illustrate a water filter, generally designated by reference numeral  1 , according to an exemplary embodiment of the present invention. Water filter  1  includes a housing  10 , large piece debris basket  11 , fitting  12 , small, heavy particle outflow pipes  18  extending from the bottom of the housing  10 , and a lid  13  with a retaining collar and seal that encloses the top of the housing  10 . The size of the housing  10  may be selected according to the required capacity of the filter  1 . An oil outflow pipe  14 , a small, light particle outflow pipe  15 , a main contaminated water inflow pipe  16  and discharge pipe  17  may pass through the lid  13 . All of the pipes may have valves that control their rate of flow and which can be adjusted in order to control the operation of the filter  1 . Discharge pipe  17  extends downwards into the perimeter of the housing  10  to draw filtered water out from below the floating oil and debris. 
         [0048]    As described in more detail below, filter components are disposed within the housing  10 . If there is too much inflow pressure due to an imbalance between the inflow and outflow of water relative to the filter components, small particles and oil may pass through the filter  1  and float to the top of the clean water area. The balance of pressures achieved through use of the various inflow and outflow pipes of the filter  1  substantially reduces passage of the particles and oil through the filter components. 
         [0049]    According to an exemplary embodiment of the invention, the filter components disposed within the housing  10  may include a first filter component  23 , a second filter component  24  and a third filter component  26 . The filter components  23 ,  24 ,  26  may be cylindrical in shape and structured so as to progressively filter the contaminated water. The first filter component  23  may be, for example, 5/32″ perforated 0.22″ galvanized metal. A 6″ high separator ring may be attached and sealed around the top of the first filter component  23  for containing oil within the contaminated water so that the oil does not pass through the filter  1 . The separator ring may be, for example, 6″ thick, although this thickness value is not intended to be limiting. The second filter  24  may be, for example, a 200-mesh, grade T316 stainless steel gauge 0.002″ screen. In an exemplary embodiment of the invention, the housing  10  is designed such that the second filter  24  can be easily removed and replaced with other filters having different mesh sizes, such as, for example, 60 mesh to 800 mesh, so as to accommodate different sized debris. The third filter component  26  may be made of, for example, 16 gauge steel with ¼″ holes. The filter components  23 ,  24 ,  26  may be bound by bands  25  so that the filter components  23 ,  24 ,  26  do not bellow out or separate. The bands  25  may have a diameter of, for example, 24″, and dimensions of, for example, ⅛″×1″. Heavy, but small particles that are not collected in the debris basket  11  settle out to the edge of the bottom of the housing  10  on the clean water side and are discharged via pipes  18 . The filter components  23 ,  24 ,  26  may be sealed in place with gaskets  40 , each of which may be held between two metal rings  19 ,  20 . 
         [0050]    It should be clearly understood that the minimum size of the particles to be screened can be adjusted according to the mesh of the screen used in the second filter component  24 . It should also be clearly understood that while water is the preferred aqueous solution, the filter system embodied herein can be used to filter other solutions and solids. 
         [0051]    As shown in  FIG. 4 , contaminated water may be suctioned from a pit through a hose using a pump  30 . The pump may be rated at, for example, 0-25 psi. The flow rate may be adjusted to keep the filter pressure between 0-5 psi. As the pond drains, the level in the filter intake  33  lowers with the water level inside the filter  1  and requires more suction. To achieve this, the pump speed may be increased, preferably while the pressure at the discharge pipe  17  remains at 0-3 psi. The debris volume may be monitored through a viewing section  27 , which may form a part of the contaminated water inflow pipe  16 , located on the top of the lid  13 . The viewing section  27  may be made of transparent material, such as, for example, glass or plastic. A flowmeter may be used to keep a volume count on the water inflow coming through the inflow pipe  16  for control purposes. As shown in  FIG. 2 , another debris viewing section may be attached and located at bottom cleanout  28 . Adjustments may be made to the flow rates so that the bottom cleanout  28  does not get clogged with sand, mud or other debris. 
         [0052]    In an exemplary embodiment of the invention, contaminated water inflow fills the inflow pipe  16  and is propelled from the inflow pipe  16  into a cyclonic motion with varying speeds at different levels of the inflow pipe  16 . Specifically, the water exiting the central portion of the inflow pipe  16  may have the greatest rotational speed whereas the water exiting upper and lower portions may have lower speeds. The inflow pipe  16  may include, for example, a first section including a 4 inch wide steel, threaded, solid pipe section of 12 inch length and a second section  21  that is welded to the first section and which includes 15½ inch long, 14 gauge steel, rolled and welded into a tube with a closed bottom that has two alternating columns of holes  21 A, the first column being of five units, the second column being of six units, all having angled louvers  21 B and alternating around the circumference of the inflow pipe  16 . The holes  21  may have a diameter of, for example, one inch has four rows of six holes 5 inches on center, to which the exit louvers  21 B, are attached. These louvers  21 B are about two and half inch cylinders, angular cut and welded around the hole. The louvers  21 B are angled so as to direct the flow of water in a circular motion. The bottom of the pipe  16  is welded close to complete the assembly. The louvers  21 B are positioned in a central location along the inflow pipe  16  and are not present near the ends of the pipe, thus effecting a greater rotational speed in the central portion of the inflow pipe  16 . 
         [0053]    The design embodied in this invention uses these separate layers to generate a circular flow within the filter  1  and to segregate the components of the contaminated water in conjunction with gravity. The holes  21 A and the louvers  21 B control the speeds and flow at the different levels. The separation of the different layers and the speed of the rotating water are important to the function of the gentle outflow through the filter screens. The oil layer and light debris will tend towards the upper portion of the filter where the rotational speed is reduced so as to exert minimal flow pressure, while heavier sand and large debris will tend downwards due to gravity. If the flow pressure is too great it can force the oil through the filter screens compromising the efficiency of the filter. The sandwiched filtration media restrains the larger particles of debris which are then collected at the large particle collector  12 . Smaller particles are filtered and float to the top and exit through a small particle outflow pipe  15 . The oil is removed through an oil outflow pipe  14 . 
         [0054]    As shown in  FIG. 4 , an exemplary embodiment of the present invention may include a pre-filter. The pre-filter prohibits large stones, debris, etc. from entering the filter  1 . Additionally, the pre-filter provides the first separation of oil from entering the filter system. A hose from the inflow pipe  16  to the contaminated pond connects the pre-filter to the main filtering system. An air chamber  31  keeps the pre-filter floating on the surface of the oil and the water mixture. As the oil sometimes mixes with the water and sits below the main exposed oil level, an intake pipe  38  may extend through the air chamber  31  and spread out to a vacuum intake chamber  33 . On the lower side of the vacuum intake chamber  33  is a large size opening with a mesh screening  34 . The mesh screening  34  sits at the bottom of the vacuum. The vacuum intake chamber  33  and mesh screening  34  are located away from the bottom of the air chamber  31  so as to prevent oil floating on top of the water from entering into the vacuum intake chamber  33 . Side baffles  32  may be used to contain the turbulence in the water that is created when the water is suctioned into the intake chamber  33 , thereby inhibiting oil from mixing into the water. The entire assembly may be attached to support legs  35 , which sit on a sled  36 . The height of the sled  36  may be adjustable depending upon the type of material being suctioned from the ponds. The sled  36  may have holes drilled in the bottom to allow water to circulate up into the intake chamber  33 . As the water level goes down, the sled  36  keeps the vacuum off of the sludge area at the base of the pond. The type and density of the sludge may be monitored through the sight glass  27  located just before the water enters the main filter  1 . A valve  29  and pump  30 , such as, for example, a 0-25 psi pump with a capacity of 0-400 gallons per minute, may be used to control the volume and flow of water. 
         [0055]    An additional aspect of the present invention is the ability of the pump  30  to be reversed. This is particularly useful in situations when the contaminated water is relatively clean and has primarily small particles. Another advantage of being able to run the filter in reverse is to flush out the filter  1  and clear out any potential clogs. 
         [0056]    The ability to run the filter  1  in reverse provides significant gain in efficiency in field use. An exemplary embodiment of the present invention using a combination of a pre-filter and main filter may generally achieve a pumping rate of about 100 to 350 gallons/minute of water during operation, depending on the degree of contamination. This is a rate comparable to a sock filter. However, whereas the present invention can fill up a truck of water in about 25-40 minutes at this pumping rate, the sock filter may be changed 1-3 times during the course of loading the truck, with each change taking about 10 minutes. Further, a tear in the sock or mishandled change can contaminate an entire truck. The filter of the present invention may be run constantly as it is self-cleaning, by adjusting the flow valves, thus keeping the filtration system in continuous operation. 
         [0057]    In an exemplary embodiment of the invention, the entire filter assembly may sit on a trailer, which also contains the pumps and hoses connecting the filters. The floor of the trailer may have angular siding that prevents any potential spills from reaching the ground level. 
         [0058]      FIG. 5  is a perspective view of a filter system, generally designated by reference number  100 , according to an exemplary embodiment of the present invention and  FIG. 6  is a cross-sectional view of the filter system  100 . The filter system  100  may be used to filter out solids from liquid, such as, for example, water, diesel fuel, crude oil, saltwater, invert drilling fluids, and fluids originating from sewage lagoons. Accordingly, the filter system  100  may be used useful in operations involving, for example, oil drilling, hydrovacing and fracking. 
         [0059]    The filter system  100  includes a generally rectangular-shaped container  102  made of, for example, steel. The container  102  may have a capacity within the range of 30 cubic yards to 40 cubic yards, and in at least one exemplary embodiment the container  102  has a capacity of 33 cubic yards. The container may be able to withstand approximately  27  pounds of vacuum. An external inflow pipe  104  is mounted on the container  102  and in communication with internal inflow pipes  110  that are housed within the container  102 . The internal inflow pipes  110  may include one or more branches (not shown) as they traverse across the container  102  so as to reduce pressure of the liquid entering the external inflow pipe  104  at high speeds. The internal inflow pipes  110  include nozzles  112  through which the incoming liquid is directed onto shield elements  114 . The shield elements  114  may include steel plates that are angled so as to shield the sidewalls of the container  102  from the liquid leaving the nozzles  112 . The shield elements  114  prevent damage of the side walls from the high pressure liquid, while allowing the liquid to still travel downwards onto the filter assembly  120  located at the bottom portion of the container  102 . As explained in more detail below, the filter assembly  120  filters out solids from liquid that is piped into the container  102 , and the filtered liquid is removed from the container  102  through outflow pipe  108 . The container  104  may operate under vacuum so that the liquid is drawn through the filter assembly  120  and through the outflow pipe  108 , leaving behind the filtered particulate material within the container  102 . The container  102  may include an opening at one end covered by a door  106  that can opened for removal of the particulate material. According to an exemplary embodiment, the container  102  may be configured for attachment to a waste collection vehicle that transports the container  102  to a waste treatment facility and dumps the filtered particulate material out of the container  102  through the door  106 . In this regard, any suitable latching or locking mechanism may be used to operate the door  106 . Prior to disposal of the collected waste, the external inflow pipe  104  may be closed via an inlet valve and vacuum may be applied to dry the filtered waste materials, thus allowing for easier disposal. 
         [0060]      FIG. 7  is a cross-sectional view of a filter assembly  120  that is supported within the container  104 . The filter assembly  120  includes an upper filter assembly  122  and a lower filter assembly  132 . The upper filter assembly  122  may be supported within the container  104  on a sub-floor  130  that is welded or otherwise made integral with the container  104 . In this regard, the sub-floor  130  may be made of, for example, spaced structural tubing. The upper filter assembly  122  includes an upper filter assembly top layer  124 , an upper filter assembly intermediate layer  126  and an upper filter assembly bottom layer  128 . The upper filter assembly top layer  124  may be made of a stainless steel (type A36) perforated plate having ½″ diameter holes with an 11/16″ stagger. The upper filter assembly intermediate layer  126  may be made of a 40 mesh stainless steel (type 304) woven wire. The upper filter assembly bottom layer  128  may be made of a stainless steel (type 304) perforated plate having 1/16″ diameter holes with an ⅛″ stagger. 
         [0061]    The lower filter assembly may be spaced vertically downwards from the upper filter assembly by a distance D of, for example, 3 inches, and may include a lower filter assembly top layer  134 , a lower filter assembly first intermediate layer  136 , a lower filter assembly second intermediate layer  138  and a lower filter assembly bottom layer  140 . The lower filter assembly top layer  134  may be made of a stainless steel (type A36) perforated plate having ½″ diameter holes with an 11/16″ stagger. The lower filter assembly first intermediate layer  136  may be made of aggregate, such as, for example, coal slag, iron ore slag, finely crushed granite, and coarse sand. In general, the size of the aggregate may be in the range of 1/64″ to 1/32″ in diameter. The lower filter assembly second intermediate layer  138  may be made of a 20 mesh stainless steel (type 304) woven wire. The lower filter assembly bottom layer  140  may be made of a stainless steel (type A36) perforated plate having ½″ diameter holes with an 11/16″ stagger. 
         [0062]    It should be appreciated that the various materials and sizes mentioned above are not intended to be limiting, and any other suitable materials and sizes may be used to achieve the desired filtering. 
         [0063]    The filtered water that collects at the bottom of the container  104  below the upper and lower filter assemblies  122 ,  132  may be sucked out of the container  104  through the outflow pipe  108  via a vacuum source (not shown). 
         [0064]    While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in form and details may be made therein without departing from the spirit and scope of the invention.