[0001] The invention relates in general to gas fueled devices. More particularly, the present invention relates to an orifice assembly adapted for use with a low gas pressure or low velocity gas flow, respectively, passed toward a propane gas fueled or powered device.
[0002] The use of a great many types of propane fueled devices, to include for example camp stoves, lanterns, heaters, outdoor barbeque grills, and weed burners, are known. The great majority of these devices are supplied with propane from either a 20 pound refillable gas cylinder or a disposable storage bottle where the gas is typically passed at a relatively high flow rate and operating pressure to the burner such that the gas supply is exhausted relatively quickly.
[0003] Additionally, most propane fueled devices use a carburetor or other gas metering or throttling apparatus which typically includes an orifice in close proximity to the burner. One such example of a conventional orifice and burner assembly is disclosed in U.S. Pat. No. 4,759,339, assigned to the Coleman Company, Inc. of Wichita, Kans., which discloses a single burner propane camp stove having an orifice formed as a part of the burner assembly.
[0004] However, the use of a new type of a propane-fueled device, for example an insect trap, has been developed in which the device uses a low gas flow rate, for example no more than approximately {fraction (1/3)} of a pound per square inch operating pressure, as only minimal amounts of heat are required to be generated for heating an insect attractant or bait. One example of such a device is the Mosquito Deleto™ series of flying insect traps manufactured and distributed by the Coleman Company, Inc.
[0005] Another example of such a device is seen in U.S. Pat. No. 6,145,243, which discloses a method and device for producing carbon dioxide gas used to trap insects. As disclosed in the '243 patent, the device uses a catalytic burner to generate carbon dioxide. The catalytic burner is provided with the propane as the fuel gas fed to the burner through a carburetor assembly, which assembly includes a restrictor, i.e., an orifice, as an integral part thereof. The carburetor assembly is enclosed within a housing provided as a part of the device.
[0006] Due, therefore, to the fact that an insect trap type of a propane fueled device operates at such relatively low gas pressures, a 20 pound propane cylinder could last in the range of anywhere from one to three months of operation. The possibility becomes very real then that any condensates present within the gas line may gather and collect on the inside of the supply line, and more particularly bridge across and thus effectively seal or block the orifice. Moreover, turning the gas supply off and back on in such an instance will not typically clear the obstruction out of the orifice, as the pressure of the gas flow does not have enough velocity or force to blow or clear this type of an obstruction from out of the orifice. This problem is further complicated by the fact that the orifice is typically disposed within or as a part of the burner assembly, and access thereto is further restricted by the enclosure or housing within which the burner is held, thus making it somewhat difficult to gain access to the orifice for cleaning, repair, or replacement.
[0007] For example, where a relatively high volume usage of propane gas occurs, the propane gas is exhausted from the supply relatively quickly and any condensates or liquids that may be present in the line, i.e., any vapors or aerosols, would be vented from the line, and thus the device, when the propane gas supply is replaced. However, in low flow applications, as the propane cylinder may be attached to the gas supply line for upwards of three months, there is no such opportunity for aerosols, vapors, or liquids to be vented or otherwise passed from the gas supply line, and thus the greater proclivity of these materials to bridge across and block the orifice that occurs in the more widely known high volume, high pressure propane gas applications.
[0008] What is needed, therefore, but seemingly unavailable in the art, is an improved orifice assembly for use with either a low pressure gas flow and/or a low velocity gas flow, respectively, which orifice assembly will be more resistant to blockage of the orifice in usage, and which may be readily removed and replaced or cleaned, as desired, and is adapted for use in either new or retrofit applications.
[0009] The present invention provides an improved orifice assembly that may be placed in-line and used in low pressure gas flow applications, and which overcomes some of the design deficiencies of the known art.
[0010] In a first embodiment, the invention discloses an orifice assembly adapted for use with a gas fueled device conventionally supplied with a pressurized gas flow, a gas end-use device, for example a burner, and a gas supply line extended in fluid communication between the gas supply and the end-use device. The orifice assembly comprises an elongate body formed about a longitudinal axis, the body having a first end and a spaced second end. The body of the orifice assembly is constructed so as to be removably placed in fluid communication with the gas supply line if so desired.
[0011] A bore extends in the lengthwise direction of the body, and is constructed to allow for the bore to be placed in fluid communication with the gas supply line so that the gas flow passes therethrough. An orifice is positioned or formed within the bore, which orifice may be coaxially disposed along the longitudinal axis of the body. The orifice is sized and shaped so as to meter the gas passed therethrough and to also at least partially induce the condensation of any condensates, e.g., aerosols, vapors, or any entrained particulates, that may be present in the gas, upstream of the orifice.
[0012] In another embodiment, the orifice assembly may have a filter cartridge positioned within the bore upstream of the orifice, which filter cartridge may be removably received within the bore.
[0013] A method of removing condensates, aerosols, vapors, and/or entrained particulates that may be present within a gas flow is also taught by the present invention. In a preferred embodiment, the method includes the steps of passing the gas flow through a gas supply line toward an end-use device, positioning an orifice assembly in the gas supply line upstream of the end-use device, and passing the gas flow through an orifice in order to meter the gas flow as it passes therethrough and to also cause at least a portion of any condensates and/or particulates that may be present in the gas flow or stream to condense within the gas supply line, or the orifice assembly, upstream of the orifice.
[0014] It is, therefore, an object of the invention to provide an improved orifice assembly, and methods of use.
[0015]
[0016]
[0017]
[0018]
[0019]
[0020]
[0021]
[0022]
[0023] Referring now in detail to the drawings, in which like reference characters indicate like parts throughout the several views, a first embodiment of an orifice assembly
[0024] An elongate bore
[0025] As illustrated in
[0026] As shown in
[0027] Referring now to
[0028] Referring now to
[0029] Referring now to
[0030] Another externally fabricated orifice unit
[0031] The orifice assembly
[0032] An exemplary gas fueled system
[0033] A gas supply line
[0034] A first ferrule assembly
[0035] A second ferrule assembly
[0036] As known, where the gas is supplied from a twenty pound refillable propane gas tank, for example, and the device/system is being used in relatively warm ambient temperature conditions, it is expected that as the propane vaporizes while being passed from the supply tank into the gas supply line that the vaporized gas will be cooled as a part of the gas vaporization process. Although this is not a problem in itself, where the ambient temperature(s) are somewhat warmer than the temperature of the cooled gas, and the device is operated for relatively long time periods of continuous operation in a low gas flow condition, it has been observed that condensation of some of the vaporized gas within the gas supply line or fueling system may occur due to these temperature differences coupled with the dwell time of the vaporous gas within the gas supply line.
[0037] Accordingly, when supplying a low pressure gas flow from a twenty pound propane or other gas storage cylinder, or other high volume gas supply devices or sources, to include a pressurized commercial gas supply, over a continuous period of time, the gas supply could last in the range of anywhere from one to three months of operation. The likelihood that condensates will gather and collect on the inside of the gas supply line, and will bridge across and thus effectively seal or block the orifice becomes quite real. In contrast, in high gas flow applications, the supply tank is exhausted in a relatively short period of time, and any condensates in the gas supply line will likely be drained or vented to atmosphere while changing out gas supply. By placing the orifice assembly
[0038] The orifice
[0039] Accordingly, the orifice preferably will at least partially cause any condensation that may occur within the gas supply lines/feed system to take place at a selected location, namely within the gas supply line or hose
[0040] Accordingly, in heretofore unknown fashion, should condensation occur within the system, and should it bridge across the orifice
[0041] In a preferred embodiment, the orifice
[0042] Although the orifice assembly of the invention has been described above for use with propane as a fuel gas, it is anticipated that the orifice assembly of this invention, and the features and benefits thereof, can be used with any type of a fuel gas, or with other fluids, particularly gases, which may be subject to having condensates, either vapors, aerosols, particulates, or liquids, therein. Moreover, although the specific orifice dimensions discussed above are for use with propane gas and the operating parameters described above, it is anticipated that in those instances where propane gas is not used, the size of the orifice will be determined by the caloric content of the gas used. If, for example, the orifice assembly is to be used with natural gas, a larger diameter orifice opening will be required than that described based on the caloric content of natural gas contrasted to that of propane, as well as the BTUs to be produced by the end-use device.
[0043] Although several embodiments of the invention have been disclosed in the foregoing specification, it is understood by those skilled in the art that many modifications and other embodiments in the invention will come to mind to which the invention pertains, having the benefit of the teaching presented in the foregoing description and the associated drawings. It is thus understood that the invention is not limited to the specific embodiments disclosed hereinabove, and that many modifications and other embodiments are intended to be included within the scope of the invention.
[0044] Moreover, although specific terms are employed herein, they are used in the generic and descriptive sense only, and are not intended to limit the scope of the invention; and the words “a,” “and,” or “the” as they appear herein may mean one or more, depending upon the context in which the words are used, and are not otherwise intended to limit the scope of the disclosed invention.