Patent Publication Number: US-2007099135-A1

Title: Waste oil heater system

Description:
TECHNICAL FIELD  
      This invention pertains to a waste oil heater system, and more particularly to such systems which include a supply pump located at or near the waste oil burner, and a feed pump located at or near to the source of waste oil.  
     BACKGROUND OF THE INVENTION  
      Waste oil heating systems have been in use for many years, and three examples of such systems are: U.S. Pat. No. 5,240,405, issued to Schubach on Aug. 31, 1993; U.S. Pat. No. 4,797,089, issued to Schubach on Jan. 10, 1989, and U.S. Pat. No. 4,877,395, issued to Schubach on Oct. 31, 1989; and all three of which are hereby incorporated by this reference into this application as though fully set forth herein.  
      In the typical waste oil burner system, the waste oil is contained in and pumped from a reservoir, and thereafter delivered to a nozzle. The aperture in the nozzle atomizes the waste oil in a spray configuration. The atomized waste oil is then ignited to produce the flame and consequent heat.  
      There are two known means to force the waste oil through the atomization nozzle. The predominant means is an air induced system in which pressurized air is introduced to the flow of waste oil at or near the atomization nozzle, thereby providing the force to push the oil through the aperture of the nozzle. The pressurized air further mixes with the waste oil, thereby breaking up the oil to create] and [ultimately a low flow volume rate], as compared to a system with no air introduced.  
      A second way to force the waste oil through the nozzle is a hydraulic-driven waste oil combustion system, wherein the high pressure force which pushes the waste oil through the aperture of the atomization nozzle is created by the oil pump pushing the waste oil to the atomization nozzle (see: U.S. Pat. No. 4,877,395 issued to Schubach on Oct. 31, 1989).  
      The force created by the flow, the closed system, and the size of the aperture in the atomization nozzle, result in waste oil being forced through the aperture and atomized in a given pattern.  
      It has been an industry practice to locate a single positive displacement waste oil pump at the oil tank to provide a flow of waste oil into the conduit and to the burner. The systems using a positive displacement pump at a constant flow rate have heretofore been unable to sufficiently and consistently optimize efficiency because of their inability to sufficiently control the flow rate. These systems have further not had sufficiently easy or precise adjustability to be efficiently adaptable to oils of different types, weights and other combustion properties.  
      Existing systems are not indefinitely adjustable to achieve different desired flow rates for fuels of different properties. For instance, when light fuels are used, they typically have a lower energy content per volume, and therefore, the user receives a reduced heat output for a given volume or flow rate.  
      The flow rate created by the positive displacement pump, in conjunction with the size and shape of the aperture of the atomization nozzle and the air pressure utilized, determines the spray pattern of the waste oil exiting the atomization nozzle and fuel consumption rate in any given system.  
      It is desirable to provide a waste oil burner and heater combustion configuration wherein the distance from the feed pump to the atomization nozzle will be fixed during manufacture so that the settings can be made during manufacture, with a separate supply pump being utilized to supply waste oil to one or more feed pumps on the waste oil heaters.  
      It is therefore an object of some embodiments this invention, to provide an improved and more consistent waste oil pumping and combustion system which will require less or no adjustment after the initial setup at time of manufacture.  
      Other objects, features, and advantages of this invention will appear from the specification, claims, and accompanying drawings which form a part hereof. In carrying out the objects of this invention, it is to be understood that its essential features are susceptible to change in design and structural arrangement, with only one practical, and preferred embodiment being illustrated in the accompanying drawings, as required.  
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      Preferred embodiments of the invention are described below with reference to the following accompanying drawings.  
       FIG. 1  is an elevation schematic representation of one embodiment of the invention depicted in a structure to be heated; and  
       FIG. 2  is a schematic view of one embodiment of a waste oil heater system as contemplated by this invention.  
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      Fasteners, materials, drive mechanisms, control circuitry, manufacturing and other means and components utilized to make and implement this invention are known and used in the field of the invention described, and their exact nature or type is not necessary for an understanding and use of the invention by a person skilled in the art or science; therefore, they will not be discussed in significant detail. Furthermore, the various components shown or described herein for any specific application of this invention can be varied or altered as anticipated by this invention and the practice of a specific application or embodiment of any element may already be widely known or used in the art or by persons skilled in the art or science; therefore, each will not be discussed in significant detail.  
      The terms “a”, “an”, and “the” as used in the claims herein are used in conformance with long-standing claim drafting practice and not in a limiting way. Unless specifically set forth herein, the terms “a”, “an”, and “the” are not limited to one of such elements, but instead mean “at least one”.  
      In embodiments of this invention, providing an integrated oil supply pump at or on the waste oil burner presents Gallons Per Hour (GPH) consistency for all unit models a particular manufacturer may offer. This consistency is due at least in part to providing a system with a known common distance that the oil will travel horizontally and/or vertically, between the feed pump located at the waste oil heater or burner, and the burner nozzle for atomization. This may provide a more consistent flow rate and flame. This constant in the distance from the oil pump located at or on the waste oil burner eliminates the GPH or oil flow rate] differentials encountered due to variances in the oil feed lines orifice size lengths, widths, paths, diversions or other variations affecting the flow rate of the waste oil through the oil feed conduit. This reduces variances due to varying frictions with different viscosities and flow restrictions, when varying lengths and oil line sizes will be encountered from the oil supply tank which in prior systems may have required increasing or decreasing the pump revolutions per minute (RPM) to overcome the variances or restrictions.  
      The placement of a feed pump at or on the burner, or a fixed distance from the burner (or burner nozzle), allows the pump to be set to a fixed RPM with little or no effect on the GPH with varying oil viscosities. This in turn provides better quality control by the manufacturer and reduces or eliminates the need to make corrections to the pump RPM&#39;s in the field during or after the installation of the waste oil burner combustion system. Once the factory or manufacturer settings are made for the feed pump, (i.e. the pump mounted at or near the burner or burner nozzle), field adjustments for burn quality or other burner characteristics (which are well known in the art) are reduced or eliminated. One minor exception to later field adjustments that may be made would be those adjustments that may be expected due to overcome any GPH loss caused by normal wear on the pump from extended usage. Typical operating RPM&#39;s for the supply pump or the feed pump may be 1,725 RPM&#39;s or 3,450 RPM&#39;s. The predetermined RPM&#39;s for a given application will be as needed for propert flow rate or gallons per hour, as varying heater modules require.  
      Some of the embodiments discussed and illustrated herein further may reduce or eliminate the need to have a single pump located at or near the oil supply tank at a certain maximum distance from the waste oil heater or burner. As is well known by those of ordinary skill in the art, with typical existing systems, there are maximum distances (horizontal and/or vertical) which the oil supply tank and supply pump may be placed away from the waste oil heater or burner to still have an acceptable burn. This invention will greatly reduce or eliminate the need for such limitations on distances in most or all applications.  
       FIG. 1  illustrates an embodiment of a waste oil heater combustion system  100  contemplated by this invention, located in the interior space  103  of a building structure  101  with roof  102 .  
       FIG. 1  shows oil supply tank  112  with oil supply conduit  113  submerged or partially submerged within oil supply tank  112 . Oil supply conduit  111  may be integral or separate from oil supply conduit  113 , and is connected, attached or operatively connected to supply pump  110 , which also may be referred to as the supply pump  110 . While supply pump  110  is preferably a positive displacement pump  110 , it will be appreciated by those of ordinary skill in the art that the supply pump  110  may be other types of pumps as well, all within the scope or contemplation of the invention. In an embodiment of the invention, the supply pump  110  may be a Delta, model number varies, and manufactured by Combu of Italy.  
      Second oil supply conduit  109  is operatively attached to supply pump  110  to receive oil therefrom and provide it to feed pump  107 . Like the supply pump  110 , while the feed pump  107  is preferably a positive displacement pump, it will be appreciated by those of ordinary skill in the art, that the feed pump  107  may be of a pump type other than a positive displacement pump, all within the scope or contemplation of the invention. In an embodiment of the invention, the feed pump  107  may be a Delta, model number varies, and manufactured by Combu of Italy.  
       FIG. 1  also illustrates that feed pump  107  attached at or near the waste oil heater  104  (with waste oil heater housing  104   a,  which also may be referred to as the framework or assembly), and the waste oil heater burner  108 , is configured to receive oil from the oil conduit  109  from the supply pump  110 . Feed pump  107  is preferably attached to, at or integral with the waste oil burner or heater  108 . This consistent attachment of the feed pump  107  a given piping or conduit distance (vertical and/or horizontal) allows for a consistent distance between the pump and the waste oil burner  108 , which provides for a consistent supply of waste oil to the waste oil burner  108 , which in turn will provide a consistent oil flow rate and flame within the waste oil heater  104 .  
      Waste oil heater  104  further includes fan  114  and exhaust conduit  105 , both of which are well known in the art and need not be further described herein.  
      There is no required size or length for the oil supply conduit  109 , however one example may provide such an oil supply conduit  109  with a minimum three-eights of an inch diameter piping to the feed pump  107 .  
      In embodiments of this invention, providing a supply pump  110  as a high volume remote oil supply pump allows oil or waste oil of different viscosities to be drawn from locations varying in distances with a shorter priming time for the pump, as compared to a typical flow control oil pump whose RPM&#39;s may be only a fraction of that for a high volume remote oil supply pump (and which may require longer pump priming times). Using a higher RPM supply pump may also reduce cavitation of the oil in the pumps.  
      In embodiments of this invention, the high volume remote oil supply pump may be adjusted to provide a given pressure on the oil pressure conduit, which would assure there is an adequate supply of oil or waste oil to the feed pump  107  (which may be an integrated oil supply pump) located at or near the waste oil burner  108  or at the pump  110 . In some prior typical configurations, the use of a single low volume supply pump near the oil supply required manual GPH adjustments as the length of the oil supply conduits varied (vertically and horizontally) and orifice size of conduit] and were a factor in obtaining constant flow of waste oil to the burner or burner nozzle.  
       FIG. 2  is a schematic view of one embodiment of a waste oil heater system as contemplated by this invention, illustrating waste oil supply tank  150  (which contains waste oil), a source of oil, waste oil supply conduit  152  partially submerged in waste oil supply tank  150  and connected or operably attached to supply pump  153 , which is preferably (but not limited to) a positive displacement type of pump. The supply pump  153  is preferably located at, near or proximate the oil supply tank  150 , although the supply pump  153  may be located further from the oil supply tank  150 , depending on the specific application. The speed of the supply pump  153  may be powered or spun by a variable speed motor  154 , the speed of which in turn may [be] controlled by variable speed motor control  155 . While this is one embodiment for the control of the supply pump  153 , it will be appreciated by those of ordinary skill in the art that the invention is not limited to any one configuration, but instead may be any one of a number of different configurations.  
       FIG. 1  also shows feed pump  107 , the feed pump in this case, mounted either to the waste oil heater housing  104 a or mounted to the waste oil burner assembly  108 , as it may be mounted to either or both, within the scope of the invention.  
      In the configuration of the system illustrated in  FIG. 1 , as will be appreciated by those of ordinary skill in the art, the supply pump  110  is preferably a high speed or high volume remote oil supply pump which more easily primes, whereas the feed pump  107  is preferably a low revolution pump. For instance a pump operating at one hundred RPM&#39;s is harder to prime to pump than a pump operating at three thousand RPM&#39;s.  
       FIG. 2  also shows waste oil intermediate oil conduit  156  which receives oil or waste oil from supply pump  153  and provides a conduit through which the waste oil may flow to feed pump  157 . The feed pump  157  is preferably (but not necessarily) a positive displacement type of pump which is mounted at, on or near the waste oil burner assembly or waste oil furnace assembly, housing or framework (shown in  FIG. 1 ).  
       FIG. 2  shows atomization nozzle  158  with nozzle spray,  159  output from the nozzle  158 , providing the spray or atomized waste oil for combustion in a combustion chamber  163 . The distance  162  between the exit of the feed pump  157  and the output end  158 a of the atomization nozzle  158  is a pre-determined distance which is preferably fixed from the time the waste oil heater system leaves the manufacturer&#39;s facility and through the installation. In typical situations with prior devices, there is only one pump and it is installed at or near the oil supply tank, and it is not typically known ahead of time by the manufacturer the exact distance from the single pump to the atomization nozzle because it is dependent on the specific installation site.  
      By providing a feed pump which is mounted integral to, at or near the burner or waste oil heater, this invention fixes the distance from the feed pump or feed pump in this case, to the atomization nozzle, which makes the pre-setting of the system operational parameters by the manufacturer more accurate and which will result in a oil flow rate spray and burn.  
      The primary role of the supply pump  153  in some embodiments of the invention therefore may merely provide oil to feed pump or feed pump  157 . The feed pump, if it is the only pump in the system, would otherwise need to be located at or near the oil supply tank for operational and other reasons, such as the ability to prime the pump, the ability to draw oil from the oil supply tank to the pump, due to its inherent low RPM rate, and others. Some applications of systems may have the oil supply tank and sole pump within about five feet of the waste oil burner or furnace, while others may be fifteen feet, thirty feet or even one hundred feet away, giving merely three examples. In some of the more extreme distances, a booster pump may have been employed at some variable and lesser distance away from the waste oil burner. It is generally preferable not to have the primary supply pump physically located at a fixed distance from the oil burner, nor having a fixed oil line orifice size. Even when a distance of anything more than physically close or attached minimizing the length of oil feed to the nozzle variances in oil flow and flame can occur.  
      This variation introduces error or room for variations that this invention seeks to reduce or eliminate through the addition of a feed pump at or near the burner or furnace. This variation also provides an opportunity for installer error in the initial setup or adjustment of the system, as opposed to the preferred configuration and method wherein the factory fixes the distance and conduit size from the feed pump outlet to the atomization nozzle.  
       FIG. 2  also illustrates first optional oil return line  180  and second optional oil return line  181 , returns from the oil pump at the burner to the oil supply tank (only shown in  FIG. 2 ). As will be known and appreciated by those of ordinary skill in the art, the optional oil return lines may be utilized instead of a regulator if desired in a particular application.  
      In a typical system configuration, it generally takes about twenty pounds per square inch (20 psi) at the feed pump to provide approximately two gallons of waste oil per hour to the waste oil burner approximately one hundred feet away.  
      Environmental regulation generally limits the output of waste oil burners commonly sold to five hundred thousand (500,000) BTU&#39;s, which limits the flow or volume of oil that can be combusted on a typical system.  
      Those of ordinary skill in the art of waste oil heating systems will appreciate that there is a typical or rule of thumb loss for flow loss through a typical system based on the elevation at which the system is operating. Therefore, the operational parameters of a system tested at sea level will for instance be different if that system is installed at a higher elevation. The rule of thumb for a give system for instance may be a four percent (4%) loss for every one thousand feet of elevation at which the system operates.  
       FIG. 2  also illustrates another embodiment of the invention, which is another feature of the invention, and that is the ability to utilize one supply pump  153  to supply more than one waste oil burners in the same facility.  FIG. 2  shows second oil atomizer nozzle  173  within second combustion chamber  174 , providing a source of heat from waste oil to a second desired location. Second feed pump  171  is operatively attached to second intermediate oil conduit  170  to receive oil or waste oil, and also operatively connected to feed conduit  172  which is operatively connected to the atomization nozzle  173  within a second waste oil burner (of which the atomization nozzle  173  is a part and which may be the same as waste oil burner  108  shown in  FIG. 1 ) to provide atomized waste oil to the burner in the combustion chamber  174 .  
      As will be appreciated by those of reasonable skill in the art, there are numerous embodiments to this invention, and variations of elements and components which may be used, all within the scope of this invention.  
      In one embodiment for example, a waste oil burner feed and control apparatus is provided for improved control of the output flame of a waste oil burner, the apparatus comprising: a first waste oil supply conduit configured to receive waste oil; a supply pump operatively attached to the first oil supply conduit, and which is configured to receive waste oil from the first oil supply conduit and which pumps the waste oil into an intermediate oil conduit; a feed pump operatively attached to the intermediate oil conduit to receive oil therefrom and to pump it to an oil feed conduit; and a waste oil burner with an atomization nozzle operatively connected to the oil feed conduit to receive oil and atomize the waste oil.  
      In compliance with the statute, the invention has been described in language more or less specific as to structural and methodical features. It is to be understood, however, that the invention is not limited to the specific features shown and described, since the means herein disclosed comprise preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims appropriately interpreted in accordance with the doctrine of equivalents.