CONDENSER AND SPRAY CONDENSER

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority from U.S. Provisional Patent Application No. 61/800,419, filed on March 15, 2013, which is incorporated by reference herein in its entirety.

BACKGROUND

[0002] The extraction of bio-oil from biomass for use as a biofuel is an area of interest in the search for reliable alternative energy sources. Pyrolysis of biomass may form a hot pyrolysis vapor, which is condensed in a hot vapor condenser or a spray condenser to assist in the extraction of bio-oil from the vapor. However, condensing of the hot pyrolysis vapor in a pyrolysis system may result in accumulation of excessive amounts of "tar-like" deposits on the interior surfaces of the hot vapor condenser or spray condenser.

[0003] A device is needed for mechanically removing a tar-like deposit layer from within a hot vapor condenser or a spray condenser.

SUMMARY

[0004] In one embodiment, a hot vapor condenser is provided, the hot vapor condenser comprising: a condenser housing comprising: an interior, an intermediate portion, a hot vapor inlet, and a condensed vapor outlet; a rotating scraper oriented at least partially within the interior, wherein the rotating scraper comprises a scraper arm oriented substantially parallel to an interior wall of the condenser housing in at least the intermediate portion; and wherein the scraper arm is configured to physically displace a tar-like deposit layer built on the interior wall of the condenser housing in at least the intermediate portion. [0005] In another embodiment, a spray condenser is provided, the spray condenser comprising: a condenser housing comprising: an interior, and a hot vapor inlet; a rotating scraper oriented at least partially within the hot vapor inlet, wherein the rotating scraper comprises a scraper arm oriented substantially parallel to an interior wall of the hot vapor inlet; and wherein the scraper arm is configured to physically displace a tar-like deposit layer built on the interior wall of the hot vapor inlet.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The accompanying figures, which are incorporated in and constitute a part of the specification, illustrate example apparatuses and are used merely to illustrate example embodiments.

[0007] FIG. 1 illustrates an example arrangement of a hot vapor condenser comprising a mechanical scraper.

[0008] FIG. 2 illustrates a sectional view of an example arrangement of a hot vapor condenser comprising a mechanical scraper.

[0009] FIG. 3 illustrates an example arrangement of a spray condenser comprising a mechanical scraper.

DETAILED DESCRIPTION

[0010] FIG. 1 illustrates an example arrangement of a hot vapor condenser 100. Hot vapor condenser 100 may comprise a condenser housing 102 comprising a hot portion 104, an intermediate portion 106, and a cold portion 108. Condenser housing 102 may comprise a hot vapor inlet 110 and a condensed vapor outlet 112.

[0011] In one embodiment, hot vapor condenser 100 comprises a condensing liquid 114 comprising a liquid layer 116 oriented on at least a portion of the interior surface of condenser housing 102 in cold portion 108. Hot vapor condenser 100 may comprise a tarlike deposit layer 118.

[0012] In one embodiment, hot vapor condenser 100 comprises a rotating scraper 120 configured to contact and at least substantially displace tar-like deposit layer 118. Rotating scraper 120 may be operatively connected to and configured to rotate by means of a motor 122. Motor 122 may be oriented substantially outside of condenser housing 102, and may transfer mechanical energy through a gas seal 124 in a wall of condenser housing 102, such that motor 122 causes actuation of rotating scraper 120.

[0013] In operation, hot vapor condenser 100 may be configured to accept and condense a hot pyrolysis gas produced by a pyrolysis process. The hot pyrolysis gas may enter hot vapor condenser 100 and cool to a temperature near an ambient temperature. In one embodiment, the hot pyrolysis gas may enter hot vapor condenser 100 at a temperature between about 350 °C and about 650 °C. In another embodiment, the hot pyrolysis gas may enter hot vapor condenser 100 at a temperature between about 400 °C and about 600 °C. In another embodiment, the hot pyrolysis gas may enter hot vapor condenser 100 at a temperature between about 450 °C and about 550 °C.

[0014] In one embodiment, the hot pyrolysis gas is generated from fast pyrolysis of biomass, and may comprise condensable organics that can potentially be used as liquid fuels. Hot vapor condenser 100 may be configured for rapid thermal quenching of organic vapors from a high temperature gas state into an intermediate temperature stage (e.g., about 300 °C) before it exits the device at vapor outlet 112. The hot pyrolysis gas may form tar-like deposits (e.g., tar-like deposit layer 118) and other highly viscous condensate residues during condensation on surfaces that are colder than about 400 °C. In one embodiment, the hot pyrolysis gas may form a tar-like deposit and other highly viscous condensate residues during condensation on surfaces that are colder than about 400 °C, but which are still hot enough to cause bio-oil polymerization and decomposition. Such surfaces may be unavoidable in hot vapor condenser 100, as a transition from hot to cold surfaces (i.e., hot portion 104 to cold portion 108) requires some surface with intermediate temperatures (i.e., intermediate portion 106).

[0015] The hot pyrolysis gas may comprise any of hot bio-oil vapors, water vapor, and non-condensable gases.

[0016] The deposit of tar-like material, such as tar-like deposit layer 118, may be undesirable in hot vapor condenser 100, as tar-like deposit layer 118 may cause inefficiency, restricted flow, and/or contamination of hot vapor condenser 100 elements. In one embodiment, hot vapor condenser 100 is part of a continuous-mode pyrolysis system and hot vapor condenser 100 may operate for extended periods of time.

[0017] In one embodiment, hot vapor condenser 100 utilizes indirect cooling. In one embodiment, hot vapor condenser 100 comprises a heat exchanger (not shown). The heat exchanger may comprise sufficient heat capacity to process the hot pyrolysis gas with any of various volume flow rates, volumes, densities, and compositions. In another embodiment, the heat exchanger is configured to handle a highly viscous condensate created during condensation of the pyrolysis gas.

[0018] In one embodiment, hot vapor condenser 100 utilizes direct cooling (as illustrated in FIG. 1). Direct cooling may involve contacting hot pyrolysis gas having a higher temperature with condensing liquid 114 having a lower temperature. In one embodiment, condensing liquid 114 is a previously-condensed bio-oil. In this embodiment, separation of the condensation product and condensing liquid 114 is unnecessary as the two may be substantially the same. In another embodiment, condensing liquid 114 is any liquid other than previously-condensed bio-oil, including for example a water, a fuel, or a solvent. In this embodiment, separation of the condensation product and condensing liquid 114 may be necessary. In one embodiment, condensing liquid 114 is oriented in liquid layer 116, for example by flowing condensing liquid 114 along at least one interior wall of condenser housing 102. In one embodiment, liquid layer 116 is configured to resist the depositing of tar-like deposits as the surface of liquid layer 116 is renewable (e.g., via flow and/or circulation of condensing liquid 114).

[0019] In one embodiment, the hot pyrolysis gas enters condenser housing 102 via hot vapor inlet 110. The hot pyrolysis gas may be directed toward condensed vapor outlet 112 by a flow of hot pyrolysis gas through hot vapor condenser 100. The hot pyrolysis gas may be at a temperature between about 450 °C and about 600 °C as described above, and at a pressure about atmospheric pressure. In one embodiment, the hot pyrolysis gas enters condenser housing 102 in a gas/vapor state.

[0020] The hot pyrolysis gas may contact condensing liquid 114 in liquid layer 116. Contacting the hot pyrolysis gas with condensing liquid 114 may cause quenching and condensation of the hot pyrolysis gas. In another embodiment, the hot pyrolysis gas contacts a surface of a heat exchanger (not shown), which surface is at a lower temperature than the hot pyrolysis gas.

[0021] Condensing liquid 114 may be at a temperature between about ambient temperature and about the boiling temperature of condensing liquid 114. In another embodiment, condensing liquid 114 is at a temperature less than about ambient temperature.

[0022] In one embodiment, the hot pyrolysis gas comprises large amounts of water vapor, and the boiling temperature of the condensates of the hot pyrolysis gas is about 100 °C. In another embodiment, the bio-oil vapor component of the hot pyrolysis gas and the water vapor component of the hot pyrolysis gas condense into a liquid at about 100 °C. In one embodiment, the bio-oil vapor component of the hot pyrolysis gas and the water vapor component of the hot pyrolysis gas condense into a liquid at or near contact of the hot pyrolysis gas with liquid layer 116. In this embodiment, at least a portion of the tar-like deposit may form on flowing liquid layer 116 rather than an interior surface of condenser housing 102, such as cold portion 108. Deposit of the tar-like deposit on flowing liquid layer 116 causes at least a portion of the tar-like material to be carried away with liquid layer 116.

[0023] In one embodiment, intermediate portion 106 comprises a temperature between about 100 °C and about 400 °C. In another embodiment, tar-like deposit layer 118 or other condensates form on the interior of condenser housing 102 at or near intermediate portion 106.

[0024] In one embodiment, rotating scraper 120 extends along at least one interior surface of condenser housing 102. In another embodiment, rotating scraper 120 extends along at least intermediate portion 106 of the interior of condenser housing 102. Rotating scraper 120 may contact and physically displace tar-like deposit layer 118.

[0025] In one embodiment, at least intermediate portion 106 of condenser housing 102 comprises a substantially circular cross-section. Rotating scraper 120 may comprise a radial arm 126. Radial arm 126 may connect at its distal end to a scraper arm 128. In one embodiment, scraper arm 128 at least substantially parallels at least intermediate portion 106 of condenser housing 102 and at least partially contacts tar-like deposit layer 118. In another embodiment, scraper arm 128 at least substantially parallels hot portion 104 of condenser housing 102 and at least partially contacts tar- like deposit layer 118. Radial arm 126 may be connected at its proximal end to a shaft 130. Shaft 130 may operatively connect radial arm 126 to motor 122. [0026] In one embodiment, motor 122 transfers mechanical energy to cause shaft 130 to rotate, which in turn causes radial arm 126 to rotate about an axis substantially orthogonal to, and in contact with, radial arm 126's proximal end. Rotation of radial arm 126 causes scraper arm 128 to move in an annular pattern, wherein at least a portion of scraper arm 128 at least partially contacts and physically displaces tar-like deposit layer 118. In one embodiment, scraper arm 128 is configured to remove at least a portion of tar-like deposit layer 118 from the interior wall of condenser housing 102. In another embodiment, scraper arm 128 is configured to cause at least a portion of the tar-like deposit in tar-like deposit layer 118 to be displaced toward at least one of liquid layer 116 and condensed vapor outlet 112.

[0027] In one embodiment, scraper arm 128 comprises one or more solid rods that move in close proximity to the interior of condenser housing 102 in at least intermediate portion 106, and any other surfaces where tar-like deposit may form. In one embodiment, scraper arm 128 is heated through electrical resistance heating or conductive heating such that its surface temperature is at least about 400 °C. In one embodiment, scraper arm 128 is heated to a temperature between about 300 °C and about 500 °C.

[0028] In one embodiment, scraper arm 128 comprises as few rods as necessary in order to minimize the buildup of tar-like deposit on the rods. In another embodiment, scraper arm 128 comprises rods having the smallest cross-sectional dimension necessary in order to minimize the buildup of tar-like deposit on the rods. In one embodiment, scraper arm 128 comprises any of a variety of materials, including a metal, an alloy, and a ceramic. In another embodiment, scraper arm 128 comprises any dimensions and material having sufficient rigidity to remove at least a portion of tar-like deposit layer 118 from the interior wall of condenser housing 102. In another embodiment, scraper arm 128 comprises one or more metal rods having a diameter of about 6.35 mm. In one embodiment, scraper arm 128 comprises rods having a substantially circular cross-section. In another embodiment, scraper arm 128 comprises rods having a substantially non-circular cross-section.

[0029] In one embodiment, scraper arm 128 comprises a construction having a desired balance of thermal conductivity and external surface area, such that heat exchange between scraper arm 128 and the hot pyrolysis gas is minimized. The lower end of scraper arm 128 may at least partially contact cold portion 108 of condenser housing 102, and/or condensing liquid 114. Accordingly, at least that portion of scraper arm 128 may comprise a temperature below about 400 °C, such that the tar-like deposit and other condensates may form on scraper arm 128. In order to avoid deposit of tar-like material on scraper arm 128, scraper arm 128 geometry and material should be selected so as to minimize the length of the portion of scraper arm 128 contacting cold portion 108 and/or condensing liquid 114.

[0030] In one embodiment, scraper arm 128 comprises at least one small diameter rod configured to minimize heat conduction in scraper arm 128' s material. In another embodiment, scraper arm 128 comprises a thin wall tubing configured to further reduce heat conduction in scraper arm 128. In another example, scraper arm 128 comprises a stainless steel material comprising reduced thermal conductivity relative to other metals.

[0031] In one embodiment, scraper arm 128 comprises a profile configured to substantially follow the interior wall profile of condenser housing 102 in at least intermediate portion 106. In one embodiment, scraper arm 128 is minimally offset from the interior wall of condenser housing 102 in at least intermediate portion 106. In another embodiment, scraper arm 128 is offset from the interior wall of condenser housing 102 by between about 3.18 mm and about 6.35 mm.

[0032] In one embodiment, motor 122 is oriented on the exterior of condenser housing 102. Motor 122 may be in an environment with temperatures substantially lower than those inside condenser housing 102. In one embodiment, motor 122 comprises a low speed motor. In another embodiment, motor 122 comprises a reducer configured to reduce the speed of shaft 130 relative to the speed of motor 122. In one embodiment, shaft 130 may rotate at a rotational velocity between about 5 rpm and about 200 rpm. In another embodiment, shaft 130 may rotate at a rotational velocity between about 10 rpm and about 100 rpm. In another embodiment, shaft 130 may rotate at any rotational velocity capable of removing and/or preventing substantial deposits of tar-like material within condenser housing 102.

[0033] Shaft 130 may extend through at least one wall of condenser housing 102. In one embodiment, gas seal 124 at least substantially surrounds shaft 130. In one embodiment, gas seal 124 is configured to at least substantially prevent a gas from entering or exiting the interior of condenser housing 102, while allowing shaft 130 to extend from the exterior of condenser housing 102 to the interior of condenser housing 102. The mixing of ambient air outside of condenser housing 102 with hot pyrolysis gas inside of condenser housing 102 may cause combustion of the hot pyrolysis gas.

[0034] FIG. 2 illustrates a sectional view 2-2 of hot vapor condenser 100 of FIG. 1. Hot vapor condenser 100 may comprise a condenser housing 102 comprising a condensed vapor outlet 112.

[0035] Hot vapor condenser 100 may comprise at least one tar-like deposit layer 118 oriented upon an interior portion of condenser housing 102. Condenser housing 102 may be substantially circular. At least one scraper arm 128 may be oriented adjacent an interior portion of condenser housing 102 and configured to rotate about the interior portion of condenser housing 102. At least one scraper arm 128 may be configured to contact and/or remove at least a portion of tar-like deposit layer 118. [0036] FIG. 3 illustrates an example arrangement of a spray condenser 300. Spray condenser 300 may comprise a condenser housing 302 comprising a hot vapor inlet 310.

[0037] Spray condenser 300 may comprise a tar-like deposit layer 318 oriented about a portion of its interior. Tar-like deposit layer 318 may deposit near hot vapor inlet 310, where temperatures may be such that condensation may occur. Tar-like deposit layer 318 may deposit in at least a portion of hot vapor inlet 310. Tar-like deposit layer 318 may deposit in hot vapor inlet 310 at or near its junction with the interior of condenser housing 302.

[0038] Spray condenser 300 may include a rotating scraper 320 configured to contact and at least substantially displace tar-like deposit layer 318. Rotating scraper 320 may be operatively connected to and configured to rotate by means of a motor 322. Motor 322 may be oriented substantially outside of condenser housing 302 and may transfer mechanical energy through a wall of condenser housing 302 (which may include a seal (not shown) to prevent heat and other substances to pass to or from condenser housing 302) such that motor 322 causes actuation of rotating scraper 320.

[0039] In operation, spray condenser 300 may be configured to accept and condense a hot pyrolysis gas produced by a pyrolysis process through hot vapor inlet 310. The hot pyrolysis gas may enter spray condenser 300 and cool to a temperature near an ambient temperature. In one embodiment, the hot pyrolysis gas may enter spray condenser 300 at a temperature between about 350 °C and about 650 °C. In another embodiment, the hot pyrolysis gas may enter spray condenser 300 at a temperature between about 400 °C and about 600 °C. In another embodiment, the hot pyrolysis gas may enter spray condenser 300 at a temperature between about 450 °C and about 550 °C. In one embodiment, the hot pyrolysis gas is cooled to a temperature less than about 100 °C inside spray condenser 300. [0040] In one embodiment, the hot pyrolysis gas is generated from fast pyrolysis of biomass, and may comprise condensable organics that can potentially be used as liquid fuels. Spray condenser 300 may be configured for rapid thermal quenching of organic vapors from a high temperature gas state into a cold liquid state (e.g., about ambient temperature). The hot pyrolysis gas may form a tar-like material (e.g., tar-like deposit layer 318) and other highly viscous condensate residues during condensation on surfaces that are colder than about 400 °C. In one embodiment, the hot pyrolysis gas may form tar-like materials and other highly viscous condensate residues during condensation on surfaces that are colder than about 400 °C, but which are still hot enough to cause bio-oil polymerization and decomposition. Such surfaces may be unavoidable in spray condenser 300. A portion of hot vapor inlet 310 at or near a junction of hot vapor inlet 310 and condenser housing 302 may include a temperature colder than about 400 °C.

[0041] The hot pyrolysis gas may comprise any of hot bio-oil vapors, water vapor, and non-condensable gases.

[0042] The deposit of a tar-like material, such as tar-like deposit layer 318, may be undesirable in spray condenser 300, as tar-like deposit layer 318 may cause inefficiency, restricted flow, and/or contamination of spray condenser 300 elements. In one embodiment, spray condenser 300 is part of a continuous-mode pyrolysis system and spray condenser 300 may operate for extended periods of time.

[0043] In one embodiment, spray condenser 300 may comprise a spray bar 340 configured to spray a cooled substance, including for example a cooled bio oil (at the temperatures indicated above with respect to a condensing liquid), into contact with a hot pyrolysis gas. Contacting the hot pyrolysis gas with a cooled material may cause condensation of at least a portion of the hot pyrolysis gas yielding at least one of a condensation product (e.g., bio oil) and non-condensable gases (not shown). As a result, tarlike deposit layer 318 may form on a portion of condenser housing and/or hot vapor inlet 310.

[0044] Rotating scraper 320 may be oriented within a portion of, or in communication with, hot vapor inlet 310. In one embodiment (not shown), rotating scraper 320 may be oriented opposite hot vapor inlet 310 and extend across condenser housing 302 to contact and at least substantially displace tar-like deposit layer 318.

[0045] In one embodiment, at least the portion of hot vapor inlet 310 near the junction of hot vapor inlet 310 and condenser housing 302 comprises a substantially circular cross- section. Rotating scraper 320 may comprise a radial arm 326. Radial arm 326 may connect at its distal end to a scraper arm 328. In one embodiment, scraper arm 328 at least substantially parallels at least a portion of an interior wall of hot vapor inlet 310 and at least partially contacts tar-like deposit layer 318. Radial arm 326 may be connected at its proximal end to a shaft 330. Shaft 330 may operatively connect radial arm 326 to motor 322.

[0046] At least a portion of rotating scraper 320 may be oriented within at least a portion of hot vapor inlet 310. Hot vapor inlet 310 may include a pipe or tube configured to duct hot vapor to condenser housing 302. At least a portion of rotating scraper 320 may be oriented within the pipe or tube of hot vapor inlet 310. Motor 322 may be oriented outside hot vapor inlet 310, while the remainder of rotating scraper 320 may be partially or completely within hot vapor inlet 310.

[0047] In one embodiment, motor 322 is oriented outside hot vapor inlet 310 and causes rotation of shaft 330, which may extend through a wall of hot vapor inlet 310 and interact with radial arm 326 via a gear drive, including for example a right angle gear drive. Motor 322 may be oriented outside hot vapor inlet 310 near a bend or elbow in hot vapor inlet 310, and may cause rotation of shaft 330, which may extend through a wall of the bend or elbow to cause rotation of the remainder of rotating scraper 320 oriented within hot vapor inlet 310. Where at least a portion of rotating scraper 320 extends through a wall of hot vapor inlet 310, it may include a gas seal to prevent hot vapor or other gases from undesirably exiting or entering hot vapor inlet 310 at that point. In any of these embodiments or orientations, scraper arm 328 may be oriented substantially parallel to an interior of hot vapor inlet 310, and configured to at least partially contact and/or displace at least a portion of tar-like deposit layer 318.

[0048] In one embodiment, at least a portion of condenser housing 302 comprises a substantially circular cross-section. In one embodiment, scraper arm 328 at least substantially parallels at least a portion of condenser housing 302 and at least partially contacts tar-like deposit layer 318. Radial arm 326 may be connected at its proximal end to a shaft 330. Shaft 330 may operatively connect radial arm 326 to motor 322.

[0049] In one embodiment, motor 322 transfers mechanical energy to cause shaft 330 to rotate, which in turn causes radial arm 326 to rotate about an axis substantially orthogonal to, and in contact with, radial arm 326's proximal end. Rotation of radial arm 326 causes scraper arm 328 to move in an annular pattern, wherein at least a portion of scraper arm 328 at least partially contacts and physically displaces tar-like deposit layer 318. In one embodiment, scraper arm 328 is configured to remove at least a portion of tar-like deposit layer 318 from the interior wall of condenser housing 302, hot vapor inlet 310, or both. In another embodiment, scraper arm 328 is configured to cause at least a portion of the tar-like material in tar-like deposit layer 318 to be displaced and discharged from condenser housing 302.

[0050] In one embodiment, scraper arm 328 includes materials, properties, dimensions, manners of use, number, heating methods, temperatures and the like as described above with respect to FIG. 1 and 2. In one embodiment, scraper arm 328 is oriented within hot vapor inlet 310 and is heated via convection by the hot vapor therein. As a result, scraper arm 328 may be heated to a temperature above about 400 °C and thus, may not collect the tar-like material during operation. Alternatively, scraper arm 328 may be heated to a temperature above about 100 °C and thus, may not collect the tar-like material during operation. Alternatively, scraper arm 328 may be heated to a temperature between about 300 °C and about 600 °C and thus, may not collect the tar-like material during operation.

[0051] In one embodiment, motor 322 is oriented on the exterior of condenser housing 302 and/or hot vapor inlet 310. Motor 322 may be in an environment with temperatures substantially lower than those inside condenser housing 302 and/or hot vapor inlet 310. In one embodiment, motor 322 comprises a low speed motor. In another embodiment, motor 322 comprises a reducer configured to reduce the speed of shaft 330 relative to the speed of motor 322. In one embodiment, shaft 330 may rotate at a rotational velocity between about 5 rpm and about 200 rpm. In another embodiment, shaft 330 may rotate at a rotational velocity between about 10 rpm and about 100 rpm. In another embodiment, shaft 330 may rotate at any rotational velocity capable of removing and/or preventing substantial deposits of tar-like material within condenser housing 302 and/or hot vapor inlet 310.

[0052] Shaft 330 may extend through at least one wall of condenser housing 302 and/or hot vapor inlet 310. In one embodiment, a gas seal (not shown) at least substantially surrounds shaft 330. In one embodiment, the gas seal is configured to at least substantially prevent a gas from entering or exiting the interior of condenser housing 302 and/or hot vapor inlet 310 about the periphery of shaft 330, while allowing shaft 330 to extend from the exterior of condenser housing 302 to the interior of condenser housing 302 and/or from the exterior of hot vapor inlet 310 to the interior of hot vapor inlet 310. The mixing of ambient air outside of spray condenser 300 with hot pyrolysis gas inside of spray condenser 300 may cause combustion of the hot pyrolysis gas.

[0053] To the extent that the term "includes" or "including" is used in the specification or the claims, it is intended to be inclusive in a manner similar to the term "comprising" as that term is interpreted when employed as a transitional word in a claim. Furthermore, to the extent that the term "or" is employed (e.g., A or B) it is intended to mean "A or B or both." When the applicants intend to indicate "only A or B but not both" then the term "only A or B but not both" will be employed. Thus, use of the term "or" herein is the inclusive, and not the exclusive use. See Bryan A. Garner, A Dictionary of Modern Legal Usage 624 (2d. Ed. 1995). Also, to the extent that the terms "in" or "into" are used in the specification or the claims, it is intended to additionally mean "on" or "onto." To the extent that the term "selectively" is used in the specification or the claims, it is intended to refer to a condition of a component wherein a user of the apparatus may activate or deactivate the feature or function of the component as is necessary or desired in use of the apparatus. To the extent that the term "operatively connected" is used in the specification or the claims, it is intended to mean that the identified components are connected in a way to perform a designated function. To the extent that the term "substantially" is used in the specification or the claims, it is intended to mean that the identified components have the relation or qualities indicated with degree of error as would be acceptable in the subject industry. As used in the specification and the claims, the singular forms "a," "an," and "the" include the plural. Finally, where the term "about" is used in conjunction with a number, it is intended to include ± 10% of the number. In other words, "about 10" may mean from 9 to 1 1.

[0054] As stated above, while the present application has been illustrated by the description of embodiments thereof, and while the embodiments have been described in considerable detail, it is not the intention of the applicants to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art, having the benefit of the present application. Therefore, the application, in its broader aspects, is not limited to the specific details, illustrative examples shown, or any apparatus referred to. Departures may be made from such details, examples, and apparatuses without departing from the spirit or scope of the general inventive concept.