Patent Publication Number: US-2018045152-A1

Title: Dewatering system for use with industrial excavation equipment

Description:
RELATED APPLICATION 
     The present invention is a continuation-in-part of U.S. patent application Ser. No. 14/034,705 filed Sep. 24, 2013, the entire contents of which is incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present invention relates to the field of industrial vacuum equipment, and, more particularly, to a dewatering system for use with industrial excavation equipment and related methods. 
     BACKGROUND 
     Industrial vacuum equipment has dozens of wet and dry uses such as locating underground utilities (potholing), hydro excavation, air excavation and vacuum excavation. In addition, the equipment can be used for directional drilling slurry removal, industrial clean-up, waste clean-up, lateral and storm drain clean-out, oil spill clean-up and other natural disaster clean-up applications, signs and headstone setting, for example. The vacuum systems may be mounted to a truck or trailer and are typically powered by gas or diesel engines. Both the wet and dry material is vacuumed up and stored in a debris tank. From there, the material may be hauled away and disposed of offsite or the tank may be emptied at the site. 
     The industrial vacuum equipment utilizes a high volume induced flow through a filter chamber to carry water and debris into the chamber, where they are separated. The dewatering process includes filtering out the debris from the water or other fluids and removing for disposal. Truck mounted vacuum equipment may utilize different stages of filtration for the debris and water. For example, the incoming flow may be directed into a settling chamber allowing the debris to settle out of the water. Filters may also be used to help quickly separate the water from the debris. A problem often encountered with the filters is that they can become clogged as the debris collects on the filters and the flow path is restricted causing the reduction in suction power of the vacuum equipment. In addition, removing the debris from the filters is time consuming and reduces the efficiency of the dewatering process. 
     Therefore, a need exists in the art for a dewatering system that resists clogging while remaining efficient in separating the water from the debris and is easy to maintain. However, in view of the prior art at the time the present invention was made, it was not obvious to those of ordinary skill in the pertinent art how the identified needs could be fulfilled. 
     SUMMARY 
     In a particular embodiment, a dewatering system for use with industrial excavation equipment is disclosed. The dewatering system includes a debris tank configured to receive a slurry through an inlet, a dewatering filter installed in the debris tank, and a bar screen forming a curvilinear surface of the dewatering filter, where the curvilinear bar screen is configured to prevent debris from passing through and into an interior space of the dewatering filter. A first end of the dewatering filter is in communication with a discharge port to remove filtered liquid from the interior space of the dewatering filter. In addition, a vibratory device is secured to the dewatering filter and configured to shake the dewatering filter to remove debris and clean an exterior surface of the dewatering filter. 
     Other aspects, advantages, and features of the present disclosure will become apparent after review of the entire application, including the following sections: Brief Description of the Drawings, Detailed Description, and the Claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an elevational view of a particular embodiment a dewatering filter of a dewatering system; 
         FIG. 2  is a top view of the dewatering filter taken in the direction of line  2 - 2  of  FIG. 1 ; 
         FIG. 3  is a cross-sectional elevational view of the dewatering filter taken in the direction of line  2 - 2  of  FIG. 3 ; and 
         FIG. 4  is a partial sectional view of the dewatering system with the dewatering filter installed within a debris tank. 
     
    
    
     DETAILED DESCRIPTION 
     The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout. 
     Referring now to  FIGS. 1-2 , a dewatering filter  102  is disclosed that is generally cylindrical in shape. One end of the dewatering filter  102 , for example the bottom end  104 , may be sealed so that liquids flow through to the interior of the dewatering filter  102  and out through the opposing top end  108  of the dewatering filter  102  that is open. Alternatively, the top end  108  may be sealed and the bottom end  104  of the dewatering filter may be open. The dewatering filter  102  includes a curvilinear bar screen  106  that filters debris from the liquids. 
     The dewatering filter  102  includes a plurality of structural hoops  110  that are parallel to one another in addition to the top and bottom ends  108 ,  104  of the dewatering filter  102 . The curvilinear bar screen  106  overlays and covers the hoops  110 . The curvilinear bar screen  106  includes a plurality of tightly spaced elements to act as a screen that is sized to allow liquid to pass and to prevent debris from flowing through to the interior of the dewatering filter  102 . For example, the spacing between the tightly spaced elements of the curvilinear bar screen  106  may be approximately 4/1000ths of an inch. In addition, the dewatering filter  102  is secured to a vibration device that imparts a shaking type motion that causes particulates to shake loose from the curvilinear bar screen  106 . This shaking type motion assists in keeping the dewatering filter  102  relatively clean and operating at high efficiency without having to stop and backwash the dewatering filter  102 . 
     Referring now to  FIG. 4 , the dewatering filter  102  is installed in a debris tank  112  that may be generally cylindrical in shape. Alternatively, the debris tank  112  may be rectangular or any other shape. The debris tank  112  is also adapted to be mounted on and attached to a truck or trailer. The interior of the debris tank  112  is configured to collect and store a slurry of debris  120  and liquid  122 . The debris tank  112  includes an inlet port  126  that is mounted to a front end of the debris tank  112 . The inlet port  126  may include quick clamp type adapters for securing a length of flexible hose (not shown) to enable a worker to apply suction to remove the slurry of debris and water from a job site using the hose. An outlet port  128  is also disposed on the front end of the debris tank  112 . The outlet port  128  may be used to empty the debris tank  112 , where the outlet port  128  is generally located proximate a lower surface of the debris tank  112  so that the contents of the debris tank  112  may be removed by gravity flow. 
     The debris tank  112  is in communication with an external blower  115  or pump and a discharge port  114  as shown in  FIG. 4  that is used to provide the vacuum or suction to the debris tank  112 . The external blower  115  may be coupled to an exterior air filter chamber  117  and a muffler  119 . A substantially enclosed float ball housing (not shown for clarity) may be disposed within the debris tank  112  and proximate an upper surface that allows liquid  122  (e.g., water) to enter the housing. The float ball housing is adapted to prevent water  122  from exiting the debris tank  112  and entering the blower  115  and otherwise indicates when the debris tank  112  is full. A generally spherically shaped float within the float ball housing may be adapted to float on top of the liquid  122  in the debris tank  112  and rises with the level of liquid  122  within the debris tank  112 . The float may be sized and configured to cover a circular aperture between the discharge port  114  and interior of the debris tank  112  when the float reaches the top of the housing, which stops the suction. Once the float has stopped the suction, removal of the liquid  122  from the debris tank  112  through a decanting process is desirable so that additional slurry may be vacuumed into the debris tank  112 . 
     In operation, the debris tank  112  is filled with the slurry of liquid  122  and debris  120  using suction. As the debris tank  112  is filled, the liquid  122  may be removed from the debris tank  112  and returned to the site or otherwise disposed. This allows for filling the debris tank  112  with additional slurry as the volume of the liquid  122  is removed. Accordingly, the dewatering filter  102  is installed inside the debris tank  112  that is used during the decanting process to remove liquids  122  from the debris tank  112  while sediment and debris  120  remain in the debris tank  112 . In a particular embodiment, a submersible pump  118  is within the dewatering filter  102  and is used to pump the liquid  122  out through a discharge port  114  and discharge hose  116  to expel the liquid  122  from the debris tank  102 . 
     As explained above, the dewatering filter  102  includes a closed bottom end  104  and an exposed filter surface and sidewall that is the curvilinear bar screen  106 . The dewatering filter  102  is orientated such that the liquid flow is radially inwardly with the filtered particulate material (i.e., debris  120 ) being trapped on the outer surface of the dewatering filter  102 , which is the curvilinear bar screen  106 . 
     When the blower is operating during the vacuum process, an induced draft is created through the debris tank  112  which draws air carrying liquid  122  and debris  120  through the inlet port  126  and into the debris tank  112 . As the liquid  122  and debris  120  enters the debris tank  112  there is an immediate drop in air velocity, which causes the heavier and larger particles and objects to fall to the bottom of the debris tank  112 . The particulate-laden air continues to flow in a forward direction through the debris tank  112 . Most of the heavier and larger materials entrained in the air flow are removed in the debris tank  112 . Thus, the air exiting the debris tank  112  and entering an exterior air filter chamber  117  generally contains smaller particulate materials. Additional gravity settling occurs in the debris tank  112  as the debris  120  collects on the floor of the debris tank  112  for eventual discharge through the outlet port  128  or by opening the front end of the debris tank  112  and dumping. 
     As the decanting process proceeds, the dewatering filter  102  may become increasingly saturated with retained particulate material and the dewatering filter  102  must be periodically cleaned. Backwashing the dewatering filter  102  results in the shutdown of the system and temporarily removes the system&#39;s filtering capacity. This is disruptive and requires a large air supply to provide a pulse or jet of compressed air adequate to clean the dewatering filter  102  at one time. Accordingly, a vibratory device  124  of the present system is secured to the dewatering filter  102  that continually, or periodically, shakes the dewatering filter  102  to dislodge particulates and debris from the curvilinear bar screen  106  so that the system does not have to be shut down for routine backwashing. Thus, the system can operate longer between backwashing the dewatering filter  102 , which results in less disruptions and higher efficiency in the operation of the system. 
     Many modifications and other embodiments of the invention will come to the mind of one skilled in the art having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is understood that the invention is not to be limited to the specific embodiments disclosed, and that modifications and embodiments are intended to be included within the scope of the appended claims.