Abstract:
A method for suppressing dissemination of dust from a pile of dust-producing bulk material, such as a pile of petroleum coke. The pile has a surface. The method comprises placing a sprayer apparatus on the pile, and discharging a liquid from the sprayer in a manner to distribute the liquid to at least an area of the surface of the pile.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    This invention relates to methods for suppressing dust emissions from piles of dust producing bulk solid materials.  
           [0002]    In many industries, dust-producing bulk solid particulate materials (e.g., petroleum coke, coal, mine mill tailings, fertilizers, etc.) are heaped to form large piles for storage. The piles are generally out in the open and subject to wind and other environmental conditions. Wind blowing over the piles erodes the piles by blowing some of the particulate material off the piles. Wind erosion causes economic waste by depleting material from the piles. Also, the airborne particulate material (i.e., dust emissions) pose environmental, health and safety issues in many industrial environments.  
           [0003]    A conventional approach to suppressing dust emissions from a typical pile is to employ fixed spray nozzles to periodically spray water on the pile. Generally, the fixed spray nozzles must be positioned remote from the pile to avoid interfering with necessary equipment. For example, in a typical coke storage yard, stacking and reclaiming equipment is often positioned adjacent the pile on rails on opposite sides of the pile. To make room for the equipment, the fixed spray nozzles are generally no closer than fifty feet from the pile edge. Because the nozzles are positioned a substantial distance from the pile, a relatively high water pressure and flow rate is needed to spray the pile. However, wind often negatively affects the spray trajectory. The wind may cause much of the spray to miss the pile and/or cause portions of the pile to not be sprayed at all, thereby decreasing the effectiveness of the spraying operation. Moreover, because of uncertainty caused by unpredictable wind conditions, pile surface conditioning agents cannot be applied to the pile via the spray nozzles.  
         SUMMARY OF THE INVENTION  
         [0004]    Among the several advantages of the present invention may be noted the provision of an improved method for suppressing dissemination of dust from a pile of dust-producing bulk material; the provision of such a method which is effective in distributing a liquid to the surface of the pile; the provision of such a method which can compensate for changes in wind speed and wind direction; the provision of such a method which may be employed to distribute water and/or a chemical agent to the pile; and the provision of such a method which may be employed even in harsh operating environments.  
           [0005]    In general, a method of the present invention is for suppressing dissemination of dust from a pile of dust-producing bulk material, such as a pile of petroleum coke. The pile has a surface. The method comprises placing a sprayer apparatus on the pile, and discharging a liquid from the sprayer in a manner to distribute the liquid to at least an area of the surface of the pile.  
           [0006]    Other advantages and features of the present invention will be in part apparent and in part pointed out hereinafter. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]    [0007]FIG. 1 is a top plan view of a sprayer mechanism of the present invention;  
         [0008]    [0008]FIG. 2 is a side elevational view of the sprayer mechanism of FIG. 1;  
         [0009]    [0009]FIG. 3 is a side elevational view of the sprayer mechanism of FIGS. 1 and 2 being pushed upward along a surface of a petroleum coke pile via PVC tubing; and  
         [0010]    [0010]FIG. 4 is a front elevational view of two sprayer mechanisms of the present invention positioned on the petroleum coke pile of FIG. 3.  
         [0011]    Corresponding reference characters indicate corresponding parts throughout the several views of the drawings. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0012]    Referring now to the drawings and first more particularly to FIGS. 1 and 2, a sprayer mechanism of the present invention is indicated in its entirety by the reference numeral  20 . The sprayer mechanism  20  comprises a sled-like lower portion  22 , a central pipe section  24 , and a sprinkler head  26 . The sled-like lower portion  22  comprises first and second runners  30 ,  32 . Each runner  30 ,  32  has an upwardly sloping forward end and an upwardly sloping rearward end. Preferably, the runners  30 ,  32  are rigidly connected to the central pipe section  24  via cross bars  34 . The runners  30 ,  32  enable the sprayer mechanism to slide or glide along a surface of a dust-producing bulk material particulate pile (discussed below) when a pushing or pulling force is applied to the central pipe section. The sprinkler head  26  is preferably connected to a discharge end of the central pipe section  24  via an elbow  36  or some other suitable connector. The sprinkler head  26  is preferably a rotarytype sprinkler of the type conventionally used for lawn irrigation. The sprinkler head  26  has a discharge nozzle  38  through which water or other liquid is discharged. A suitable connector  40  is secured to an intake end of the central pipe section  24  to facilitate attachment of a conduit (discussed below) to the pipe section.  
         [0013]    Referring now to FIG. 3, a first feed pipe  42  is releasably connected to the central pipe section  24  of the sprayer mechanism  20  via the connector  40  (FIG. 1 and  2 ). Although the connector  40  is shown as being a threaded male connector, it is to be understood that the connector could alternatively be a quick-connect connector without departing from the scope of this invention. The first feed pipe  42  is shown in FIG. 3 as connected end-to-end to a second feed pipe  44 . The feed pipes  42 ,  44  have two primary purposes: (1) to act as a conduit to convey liquid from a liquid source to the sprayer mechanism  20  to enable the liquid to be discharged from the mechanism&#39;s discharge nozzle  38 ; and (2) to serve as a push rod to enable a user to push the sprayer mechanism up the side of a pile of dust-producing bulk material, such as a pile of petroleum coke, generally indicated by the reference number  46 . Preferably, the feed pipes  42 ,  44  are sufficiently rigid to enable a user to push the sprayer mechanism  20  upward along the surface of the coke pile  46 . More particularly, the feed pipes are preferably sufficiently stiff such that application by the user of a pushing force F at the upstream end of the second feed pipe  44  (i.e., the right most end as viewed in FIG. 3) causes the sprayer mechanism  20  to move upwardly along the inclined surface of the coke pile  46 , even when the inclined surface is inclined at a forty-five degree angle from horizontal. Preferably, the feed pipes  42 ,  44  are of a schedule  80  polyvinyl chloride (PVC), and are more preferably of a schedule  80  CPVC. However, it is to be understood that other suitable tubing, including other types of polymeric tubing may be employed without departing from the scope of this invention. Also, the terms tubing and piping are used herein in a broad sense and are intended to be interchangeable. In other words, the term “pipe” is intended to cover tubes and pipes, and the term “tube” is intended to cover both tubes and pipes. Moreover, although two feed pipes  42 ,  44  are shown, it is to be understood that one, two, or more feed pipes may be employed without departing from the scope of this invention. What is important is that the feed pipe or feed pipes employed are sufficiently long to enable the user to move the sprayer apparatus  20  to a desired location on the coke pile  46 .  
         [0014]    In operation, the intake end of the second feed pipe  44  (i.e., the rightmost end as viewed in FIG. 3) is preferably connected to source of pressurized liquid via a flexible hose  50 . The user places the sprayer mechanism  20  near the base (i.e., lowermost part) of the coke pile  46 . The user then grasps the second feed pipe  44  and applies the pushing force F thereto to push the sprayer mechanism  20  up the surface of the coke pile  46 . As shown in FIG. 4, the sprayer mechanism  20  is pushed up the pile  46  to a first operating location L 1 . The liquid from the liquid source (not shown) is then pumped or otherwise transported through the flexible hose  50  and through the feed pipes  42 ,  44  and to the sprayer mechanism  20  where it is discharged through the discharge nozzle  38  (FIGS. 1 and 2) while the sprayer mechanism is maintained at the first operating location L 1  . As the liquid is being discharged from the discharge nozzle  38 , the sprinkler head  26  rotates relative to the central pipe section  24  about an axis X (FIGS. 1 and 2) such that the discharged liquid is distributed to and covers a first area A 1  of the surface of the pile  46  (FIG. 4). Preferably, the liquid is an aqueous mixture comprising a residual dust-control agent, such as that commercially available from Benetech, Inc. (the assignee of the present invention) under the trade designation GDS-12. More preferably, the liquid comprises six parts water and one part the chemical agent. Alternatively or additionally, the liquid may comprise one or more of the following: a pile sealer, an encrusting agent, an anti-oxidizing agent, a spontaneous combustion suppressant, and a liquid fire suppressant. As shown in FIG. 4, the apex of the pile  46  is at an elevation E above the base of the pile. Preferably, the elevation of the first operating location L 1  is sufficiently high (e.g., at an elevation E/ 2  above the surface of the base) such that the area covered with the liquid extends to the apex. As shown in FIG. 4, the liquid pressure is sufficiently great to cover an area that extends from the apex to the base. However, it is to be understood that smaller areas could be covered without departing from the scope of this invention.  
         [0015]    After the first area A 1  is coated with the liquid via the sprayer mechanism  20 , liquid flow is stopped and the user moves the sprayer apparatus to a second operating location (not shown) which is spaced from the first operating location L 1 . The liquid flow is then turned on to discharge the liquid from the discharge nozzle  38  to coat a second area (not shown) of the surface of the pile  46 . Preferably, this process is repeated until the entire pile  46  is coated with the liquid. Additional sprayer mechanisms (a second one of which is indicated generally at  60  in FIG. 4) may be employed and operated simultaneously with the sprayer mechanism  20  to coat the pile more quickly.  
         [0016]    Although the sprayer mechanism  20  is preferably maintained in an operating location when liquid is being discharged therefrom, it is to be understood that the sprayer mechanism  20  could be moving while liquid is being discharged. Also, although the sprinkler head  26  is preferably a rotarytype sprinkler head, it is to be understood that other types of sprinkler heads could be employed without departing from the scope of this invention.  
         [0017]    In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.  
         [0018]    As various changes could be made in the above constructions and methods without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.