Abstract: A gas turbine engine assembly includes first and second annular members having different first and second thermal expansion coefficients connected together with dual arm V brackets. Brackets include first and second arms angularly spaced apart from a bracket centerline and extending axially away from bracket bases attached to a first one of the first and second annular members. Arms are attached to a second one of the first and second annular members. A turbine frame includes struts extending between outer and inner rings. An annular mixer and centerbody substantially made from a ceramic matrix composite materials is connected to and supported by the outer and inner rings with first and second sets respectively of the dual arm V brackets. Bracket bases of the first and second sets are attached to the outer and inner rings respectively. Arms of the first and second sets are attached to mixer and centerbody respectively.

Abstract: Directional feeders having a feed slide, a feed pocket and multiple flappers on a rotor are disclosed. The rotor may be configured to have a horizontal axis of rotation such that gravity conveys feed down the feed slide to a feed pocket which redirects the feed into a rotor housing.

Abstract: Combustion burner panels, submerged combustion melters including one or more of the panels, and methods of using the same are disclosed. In certain embodiments, the burner panel includes a panel body having a first major surface defined by a lower fluid-cooled portion of the panel body, and a second major surface defined by an upper non-fluid cooled portion of the panel body. The panel body has at least one through passage extending from the first to the second major surface, the through passages accommodating a set of substantially concentric inner and outer conduits. The inner conduit forms a primary passage for fuel or oxidant, and the outer conduit forms a secondary passage between the outer conduit and the inner conduit for fuel or oxidant. A protective member is associated with each set. The burner panels promote burner life and melter campaign length.

Abstract: A spray disc arrangement for a fluid injector includes a first disc having a dimple with an orifice defined through the dimple. A second disc includes a dimple and a plurality of orifices defined through the dimple. The first disc dimple is received in the second disc dimple. The second disc includes a plurality of channels defined along a concave surface of the dimple, with the plurality of orifices located in the channels. The first disc and the second disc are coupled together such that a convex surface of the dimple of the first disc contacts a concave surface of the dimple of the second disc. The first disc is disposed along a downstream side of a valve seat of the fluid injector.

Abstract: An exhaust assembly may include an exhaust body and a pivoting attachment feature. The exhaust body, such as a center body or a nozzle, may be configured to direct an annular exhaust stream exiting from a gas turbine engine. The pivoting attachment feature may be coupled the exhaust body and may be configured to pivotally couple the exhaust body to an engine flange. The pivoting attachment feature may be one of a plurality of attachment features circumferentially distributed around the exhaust body. The exhaust body may be a center body and the plurality of attachment features may be coupled to a radially inward surface the center body. The pivoting attachment feature may enable a degree of relative thermal expansion movement between the engine flange/turbine exhaust case and the exhaust body while mitigating detrimental thermal loads, according to various embodiments.

Abstract: Nozzle Assemblies and methods of use for producing a liquid jet are disclosed that may be permit adjustable time delays between mixing of fluids and observation of reactions. An example nozzle assembly includes: a housing having an inlet and an outlet and a first channel defined therebetween, where the housing includes a gas focusing aperture defining the housing outlet; an intermediate tube disposed within the first channel of the housing, where the intermediate tube has an inlet and an outlet and defines a second channel therebetween; and a central tube disposed within the second channel of the intermediate tube, where the central tube has an inlet and an outlet and defines a third channel therebetween, where the central tube outlet is longitudinally spaced apart from the intermediate tube outlet such that the intermediate tube outlet is disposed between the central tube outlet and the gas focusing aperture's inlet.

Abstract: Submerged combustion burners having a burner body and a burner tip connected thereto. The burner body has an external conduit and first and second internal conduits substantially concentric therewith, forming first and second annuli for passing a cooling fluid therethrough. A burner tip body is connected to the burner body at ends of the external and second internal conduits. The burner tip includes a generally central flow passage for a combustible mixture, the flow passage defined by an inner wall of the burner tip. The burner tip further has an outer wall and a crown connecting the inner and outer walls. The inner and outer walls, and the crown are comprised of same or different materials having greater corrosion and/or fatigue resistance than at least the external burner conduit.

Abstract: Combustion burner panels, submerged combustion melters including one or more of the panels, and methods of using the same are disclosed. In certain embodiments, the burner panel includes a panel body having a first major surface defined by a lower fluid-cooled portion of the panel body, and a second major surface defined by an upper non-fluid cooled portion of the panel body. The panel body has at least one through passage extending from the first to the second major surface, the through passages accommodating a set of substantially concentric inner and outer conduits. The inner conduit forms a primary passage for fuel or oxidant, and the outer conduit forms a secondary passage between the outer conduit and the inner conduit for fuel or oxidant. A protective member is associated with each set. The burner panels promote burner life and melter campaign length.

Abstract: A sprinkler includes a handle, a nozzle, a tube, a valve and a switch. The nozzle is connected to the handle. The tube is made in the handle and includes a window, a main channel in communication with a channel made in the nozzle, and an extensive channel in communication with the main channel via an intersection. The valve includes a gate, a positioning portion formed on the gate, and a connective portion formed on the positioning portion. The valve is rotationally inserted in the main channel so that the connective portion extends out of the tube. The switch includes an arched wall, a fin formed on an arched face of the wall, and a connector formed on an upper edge of the wall and connected to the connective portion of the valve so that the switch is movable with the valve. The fin is movable in the window.

Abstract: An interior of a nozzle in an ejector is formed with a swirling space in which a refrigerant swirls, and a refrigerant passage in which the refrigerant that has flowed from the swirling space is depressurized. The refrigerant passage includes a minimum passage area part most reduced in the refrigerant passage area, and a divergent part that gradually enlarges in the refrigerant passage area from the minimum passage area part toward a refrigerant ejection port. Plate members, which reduce a velocity component of the refrigerant flowing into the minimum passage area part in a swirling direction, are disposed within the refrigerant passage.

Abstract: A system includes a gasification feed injector. The gasification feed injector includes a tip portion disposed at a fluid exit region of the gasification feed injector, and a tip cap coupled to the tip portion of the gasification feed injector and configured to serve as a thermal barrier for the tip portion during gasification reactions.

Abstract: A fuel injector for a gas turbine engine includes a nozzle tip assembly having a substantially monolithically formed nozzle body. The nozzle body has an annular outlet chamber for issuing a spray from the nozzle tip. A feed channel is in fluid communication with the outlet chamber through a feed passage. A heat shield void substantially surrounds the feed channel(s).

Abstract: A combustor includes a combustor wall defining a combustion zone and a fuel nozzle. The fuel nozzle includes a forward face, an aft face downstream from the forward face and adjacent to the combustion zone, a plurality of mixing tubes extending between the forward face and the aft face, an outer sleeve positioned radially outward of the plurality of mixing tubes, a heat shield positioned radially inward of the outer sleeve, and a baffle plate between the forward face and the aft face. At least one of the plurality of mixing tubes includes a sidewall that includes an injection opening defined therethrough. The baffle plate is oriented to channel fuel between the plurality of mixing tubes and between the baffle plate and the aft face prior to the fuel being channeled through the injection opening.

Abstract: A system includes a gasification feed injector. The gasification feed injector includes a tip portion that has an outer wall and a feed outlet, and an injection axis of the gasification feed injector extends through the feed outlet of the tip portion. The gasification feed injector also has at least one fastener extending radially from the outer wall relative to an injection axis of the gasification feed injector through the feed outlet of the tip portion. An attachment location of the at least one fastener is located away from the feed outlet of the tip portion. The system also includes a heat shield, which includes a tile radially disposed on the at least one fastener and radially secured to the outer wall via fastening the tile to the at least one fastener. In addition, the tile wraps around a distal end portion of the tip portion.

Abstract: A system includes a gasification feed injector. The gasification feed injector includes a tip portion disposed at a fluid exit region of the gasification feed injector, and a tip cap coupled to the tip portion of the gasification feed injector and configured to serve as a thermal barrier for the tip portion during gasification reactions.

Abstract: A combustor nozzle includes a downstream surface having an axial centerline. A plurality of passages extend through the downstream surface and provide fluid communication through the downstream surface. A plurality of slits are included in the downstream surface, and each slit connects to at least two passages. A method for modifying a combustor nozzle includes machining a plurality of slits in a downstream side of a body. The method further includes connecting each slit to at least two passages that pass through the body.

Abstract: An insulated solution injector may include an outer tube and an inner tube arranged within the outer tube. The outer tube and the inner tube may define an annular space therebetween, and the inner tube may define a solution space within. The annular space may be configured so as to insulate the solution within the solution space. As a result, the solution may be kept to a temperature below its decomposition temperature prior to injection. Accordingly, the decomposition of the solution and the resulting deposition of its constituents within the solution space may be reduced or prevented, thereby decreasing or precluding the occurrence of a blockage.

Abstract: A fuel injector includes a flow path for fuel air mixture to a combustor extending longitudinally through the fuel injector. The fuel injector may also include a liquid fuel gallery at least partially encircling the flow path. The gallery may include a plurality of fuel spokes configured to deliver liquid fuel from the gallery to the flow path. The fuel injector may also include an annular outer housing circumferentially positioned about the gallery to form an insulating air cavity at least partially around the gallery. The outer housing may include at least one purge hole to provide communication between the insulating air cavity and outside the outer housing of the injector.

Abstract: A burner tip, and method of manufacture, has a support layer with an external surface exposed to combustion reactions and an unexposed internal surface defining at least one a passage therethrough to deliver fuel and combustion gasses, and a thermal protective layer disposed on at least part of the unexposed surface of the burner tip support layer. The thermal protective layer 22 has from about 5% to about 40% of an inorganic adhesive, from about 45% to about 92% of a filler, and from about 1% to about 20% of one or more emissivity agents.

Abstract: An injector assembly for a rocket engine includes a thermal insulating layer adjacent to an oxidizer cavity.

Abstract: A method for reducing NOx formation, including the steps of: providing a furnace with a plurality of secondary air injection ducts, asymmetrically positioned in an opposing manner; injecting fuel with primary air through a first stage prior to injection of a second air; injecting secondary air and aqueous urea solution through the plurality of reagent injection ducts; controlling the asymmetrical injection to produce a high velocity mass flow and a turbulence resulting in dispersion of the urea solution into the combustion space, thereby providing reduced NOx formation in the combustion process.

Abstract: A combustor includes a combustor wall defining a combustion zone and a fuel nozzle. The fuel nozzle includes a forward face, an aft face downstream from the forward face and adjacent to the combustion zone, a plurality of mixing tubes extending between the forward face and the aft face, an outer sleeve positioned radially outward of the plurality of mixing tubes, a heat shield positioned radially inward of the outer sleeve, and a baffle plate between the forward face and the aft face. At least one of the plurality of mixing tubes includes a sidewall that includes an injection opening defined therethrough. The baffle plate is oriented to channel fuel between the plurality of mixing tubes and between the baffle plate and the aft face prior to the fuel being channeled through the injection opening.

Abstract: A coaxial injection device for injecting and dispersing reagents into a reactor, including an exterior duct for high-velocity gas injection; an outer-middle injector with at least one nozzle for liquid injection; an inner-middle duct for low-velocity gas injection; and an interior injector with nozzle for liquid injection; wherein, the exterior duct is formed by the internal wall of an insert and the external wall of the outer-middle injector; and is located externally to and circumferentially surrounds all other injectors and ducts; the outer-middle injector is formed by two concentric cylinders with end plate and injector nozzles; the inner-middle duct is formed by interior wall of the outer-middle injector and the exterior wall of the interior injector; the interior injector is formed by a cylinder with an endplate, the endplate having a nozzle; thereby ensuring the mixing and dispersion of the liquids and gases into the reactor to increase reaction homogeneity, reaction efficiency, reactor efficiency and

Abstract: A fuel nozzle is provided. The fuel nozzle includes a heat shield, a fuel tube and a plurality of support members. The support members are radially interposed between the heat shield and the fuel tube. The support members are preferably cylindrical tubes, thus creating voids or pockets between the heat shield and the fuel tube. The cylindrical tubes are connected to one another at a first end are free at an opposed end. As such, the tubes can move or slide relative to one another. Further, the tubes preferably only contact one another with at most line contacts. The fuel nozzle may also include a tip portion that includes a tip heat shield that extends radially outward from the primary heat shield. The tip heat shield defines a cavity that connects with the central cavity of the heat shield. The fuel tube extends through the tip heat shield.

Abstract: In a fuel injection device and method for injecting hydrocarbon fuel into a fuel reformer, the temperature of the fuel injection device is regulated by simultaneously heating the fuel and cooling the fuel injection device.

Abstract: A nozzle includes an inlet at an upstream end of the nozzle, a discharge outlet at a downstream end of the nozzle, and a fluid delivery passage extending between the inlet and the discharge outlet. Exterior and interior walls of the nozzle have downstream tip ends that are relatively longitudinally movable at one or more interfaces. An internal insulating gap is interposed between the interior and exterior walls to insulate fuel from ambient temperature conditions exterior to the nozzle. One or more flexible seal structures internal to the nozzle isolate a portion of the insulating gap from any ambient fluid entering into the gap through the one or more interfaces while providing relative movement between interior and exterior walls of the nozzle.

Abstract: A shower arrangement (10) includes a mixer valve assembly (110) and conduit means (120) for the supply of water to the assembly (110). The conduit means (120) includes a conduit casing (2) defining an interior (122), a hot water pipe (3) defining a passage (103) for hot water and a cold water pipe (4) defining a passage (104) for cold water, the hot and cold water pipes (3, 4) being located in the interior (122).

Abstract: A fuel nozzle is provided. The fuel nozzle includes a heat shield, a fuel tube and a plurality of support members. The support members are radially interposed between the heat shield and the fuel tube. The support members are preferably cylindrical tubes, thus creating voids or pockets between the heat shield and the fuel tube. The cylindrical tubes are connected to one another at a first end are free at an opposed end. As such, the tubes can move or slide relative to one another. Further, the tubes preferably only contact one another with at most line contacts. The fuel nozzle may also include a tip portion that includes a tip heat shield that extends radially outward from the primary heat shield. The tip heat shield defines a cavity that connects with the central cavity of the heat shield. The fuel tube extends through the tip heat shield.

Abstract: Presented is a pre-filming fuel nozzle that is readily manufacturable and consists of a fuel injector, a nozzle insert that fits over the fuel injector outlet, and a housing that generally encloses the fuel injector and nozzle insert. The housing has an atomizing lip, a fuel inlet passage, and an air passage. The nozzle insert has openings near the fuel injector that allows air to flow into the insert. During operation, the fuel injector impinges fuel on an inner surface of the insert and is pulled towards the atomizing lip from air flow through the insert. The air flow through the insert and air flow through the housing join at the atomizing lip, resulting in air flows shearing fuel droplets off of the atomizing lip. The nozzle may have swirler means such as a swirler fin and/or swirler passages on the insert to aid in swirling the air flow.

Abstract: The present invention provides a fuel injector, comprising a housing having a sealable injector seat; a fuel injector pin disposed within the housing proximate) the injector seat such that the injector seat may be sealed and unsealed by displacing the fuel injector pin; a resilient element biasing the fuel injector pin in an unsealed direction; a piezoelectric actuator disposed within the housing proximal to the fuel injector pin configured to actuate to force the injector pin towards the injector seat to seal the injector seat; and a thermal compensating unit disposed within the housing proximal to the actuator and configured to compensate for thermal expansion or contraction of a component of the fuel injector.

Abstract: An injection module comprises a housing (1), inside of which an actuator element (2) and an injection valve are arranged. The actuator element (2) is designed for controlling the injection valve by a setting stroke. A compensating element (6) is provided that is connected to the actuator element (2) in order to compensate for the change in length of the housing (1) caused by thermal expansion.

Abstract: A procedure to control pests in fruits without damaging the quality of the fruit by exposing the fruit to a high phosphine concentration at low temperature during an extended period of time.

Abstract: A fuel nozzle configured to channel fluid toward a combustion chamber within a gas turbine engine and a method for assembling the same are provided. The fuel nozzle includes a first hollow tube fabricated from a first material that has a first coefficient of thermal expansion and a second tube fabricated from a second material that has a second coefficient of thermal expansion that is different from the first coefficient of thermal expansion. The second tube is coupled within the first tube such that the first tube substantially circumscribes the second tube, and the second tube thermally expands approximately at a same rate as the first tube during fuel nozzle operation.

Abstract: A dosing mechanism for fuels, particularly for the input into a chemical reformer to obtain hydrogen, has a metering-in device for metering fuel into a supply line, which opens out at at least one dosing aperture into a transporting line transporting a tempered material flow. A holding device for accommodating the metering-in device has an insulating body which thermally insulates the metering-in device from the transporting line that transports the tempered material flow.

Abstract: A droplet generation apparatus is applied to a nebulizer. The droplet generation apparatus comprises a vibratable member, a nozzle disc, a housing and a connection member or a fastening plate or both the connection member and the fastening plate. The vibratable member has a first through hole. The nozzle disc has a plurality of apertures facing the first through hole, and is combined with the vibratable member. The connection member is disposed between the vibratable member and the nozzle disc, and has a second through hole corresponding to the first through hole. Alternatively, the fastening plate is combined with the nozzle disc. The housing covers up the combination of the vibratable member, the nozzle disc and the connection member or the fastening plate. Vibration efficiency generated by the vibratable member is improved through the connection member. An accommodation space is formed by the fastening plate and the nozzle disc.

Abstract: An injector includes a valve body, a needle valve, and a thermal expansion member. The valve body includes an internal space and a bottom portion having a nozzle hole. One end side of the space is covered with the bottom portion. The needle valve is accommodated in the space such that a fuel passage leading to the hole is formed between an inner surface of the valve body and an outer surface of the needle valve. The passage is opened or closed with respect to the hole by movement of the needle valve, so fuel injection is started or stopped. The inner surface of the bottom portion is opposed to a one end surface of the needle valve. The member is attached on the one end surface. The member is made of a material having a larger coefficient of thermal expansion than a material of the needle valve.

Abstract: An atomization system for fuels, particularly for charging a chemical reformer for obtaining hydrogen, features at least one metering device, accommodated in a supporting device, for metering fuel into a temperature-adjusted substance stream, which introduces the fuel directly into the temperature-adjusted substance stream without the interpolation of a supply line.

Abstract: A fuel nozzle sheath has a lateral opening for admitting air about a nozzle stem. The stress distribution along the perimeter of the window is smoothed out by increasing the corner radius of the window corner presenting higher stress concentration.

Abstract: A fuel injector for use with an internal combustion engine. The fuel injector comprises a valve group subassembly and a coil group subassembly. The valve group subassembly includes a tube assembly having a longitudinal axis that extends between a first end and a second end; a seat that is secured at the second end of the tube assembly and that defines an opening; an armature assembly that is disposed within the tube assembly; a member that biases the armature assembly toward the seat; an adjusting tube that is disposed in the tube assembly and that engages the member for adjusting a biasing force of the member; a filter that is at least within the tube assembly; and a first attachment portion. The coil group subassembly includes a solenoid coil that is operable to displace the armature assembly with respect to the seat; and a second attachment portion that is fixedly connected to the first attachment portion.

Abstract: The invention relates to a sprayer (1), comprising a pneumatic turbine (5), capable of rotating a bowl (6), the turbine being connected to a pressurized gas supply line (11), for driving said turbine and to a drive gas exhaust line (12). The exhaust line (12) is equipped with an inner sleeve (13) which defines the exhaust gas flow volume (V13), an annular gap (E) with a non-zero thickness being provided between the outer surface of the sleeve (13) and the inner surface of the line (12). The structure is compatible with a temperature gradient between the optionally low-temperature exhaust gas flow volume (V13) and the material (2) which forms the exhaust line (12), the risk of condensation being thus limited.

Abstract: Disclosed is an injector nozzle through which fluid is delivered and which has a port (17) having an internal surface and a valve member (13) having a complementary external surface. The valve member (13) is movable relative to the port (17) to respectively provide a passage between the internal and external surfaces for delivery of fluid in the form of a spray. Alternatively, sealed contact of the surfaces will prevent the delivery of fluid. The nozzle includes a flow control body (30) located beyond an extremity of the port (17). The flow control body (30) has a control surface (33) arranged downstream of the port (17) in the direction of movement of the valve member (13). The control surface (33) is configured and positioned to promote the fluid spray established by the fluid issuing from the port (17) to in part follow a path determined by the shape of the control surface (33).

Abstract: A fuel injector is provided which has an injector body with a metallic tip having an outer surface. A non-metallic insulator, such as a ceramic, is attached to the tip and covers a portion of the outer surface. Injector tip overheating can be a problem, especially during sustained two-cycle boosted engine compression release braking. In addition, injector tip overheating can be a problem when an engine is experiencing simultaneous engine compression release braking and exhaust braking.

Abstract: Disclosed is a silencer system configured to allow for thermal growth thereof while attenuating noise created by expansion of high-pressure fluid flowing therethrough. The silencer system comprises a tubular inner sleeve, a tubular flexible bellows, a tubular vent stack and a muffler disc. The inner sleeve has a sleeve inlet and a sleeve outlet. The inner sleeve is concentrically disposed in spaced relation within the bellows which is concentrically disposed in spaced relation within the vent stack. The bellows is configured to allow for axial and lateral movement of the inner sleeve relative to the vent stack when fluid passes through the silencer system to minimize excessive deflective forces and bending moments on the silencer system. The muffler disc is oriented relative to the sleeve outlet such that the high-pressure fluid impinges the muffler disc prior to creating shockwaves which may otherwise result in the production of high noise levels.

Abstract: A fuel injector has an actuator which is situated in an actuator housing connected by force-locking to a valve member at an end on the valve-needle side. The actuator is braced on the end of the actuator housing which is opposite thereto. A compensation section of the actuator housing is made of a material having virtually no, or having negative, temperature expansion, so that the temperature expansion of the actuator housing and the valve member, in the sequence up to a valve-sealing seat, essentially corresponds to the temperature expansion of the actuator and transmission elements situated up to the valve-sealing seat. The actuator housing is surrounded radially on the outside by a fuel chamber through which fuel flows.

Abstract: A coal gasification feed injector is disclosed having an oxidation-resistant insert which prevents oxidative corrosion of the shield, and the subsequent damage to the underlying face of the feed injector. The life of the feed injector, and thus the length of a single gasification campaign, is thereby extended.

Abstract: Thermal stress relief in a nozzle head of a gas turbine fuel nozzle is provided by forming a slit through each selected air passages of the nozzle head. The strategic location of stress-relief slits contributes to extend the fatigue life of the nozzle with minimal cost and impact on the nozzle aerodynamics.

Abstract: A fuel injector is described, in particular an injector for fuel injection systems in internal combustion engines, that includes a valve needle having a valve-closure member which cooperates with a valve-seat surface arranged in valve-seat member to form a sealing seat and which has several injection orifices which are arranged downstream from the sealing seat, and are sealed by sealing seat against a fuel supply. A disk element is arranged downstream from the sealing seat, the disk element having at least one valve section, which changes its shape when the temperature changes. Valve section is connected to a heating element and optionally covers an injection orifice.

Abstract: A new and improved bead-type hot melt adhesive dispensing nozzle, and a new and improved bead-type hot melt adhesive applicator nozzle assembly having the new and improved bead-type hot melt adhesive dispensing nozzle operatively incorporated thereon, is disclosed wherein the external peripheral surface portion of the bead-type hot melt adhesive dispensing nozzle has a thermal protective ring member, fabricated from a suitable plastic material, such as, for example, polyetheretherketone (PEEK), fixedly mounted thereon. In this manner, maintenance or operator personnel can manually manipulate the bead-type hot melt adhesive dispensing nozzle without being exposed to potential burn and safety hazards.

Abstract: A burner apparatus comprises a conduit adapted to convey preheated oxidant and having outlet and inlet ends, and a conduit adapted to convey preheated fuel and having outlet and inlet ends. The conduit adapted to convey preheated fuel is substantially parallel to the conduit adapted to convey preheated oxidant. The conduit adapted to convey preheated oxidant is positioned substantially vertically above the conduit adapted to convey preheated fuel. The conduit adapted to convey preheated oxidant and the conduit adapted to convey preheated fuel each are positioned within its own respective elongate cavity in a refractory burner block. Each of the conduits are positioned in their respective cavity such that a substantially annular region is present between an outer surface of each conduit and its respective cavity. Each conduit inlet end extends through a respective plenum for receiving an ambient temperature fluid, the plenums adapted to pass the ambient temperature fluid into the respective annular regions.

Abstract: The present invention discloses a thermal spray apparatus with improved thermal efficiency and wear resistance in both the nozzle and barrel combustion chamber. Specifically, disclosed herein is a thermal spray apparatus for spraying substrate coatings, comprising a high velocity oxygen fuel (HVOF) gun wherein said gun includes a combustion chamber generating heated flow therefrom and a nozzle downstream from said chamber. The nozzle and/or chamber contain a first layer of material heated by the flow, and a second layer of material which contacts the first layer when said first layer is heated. The first layer has a thermal conductivity that is lower than said second layer and preferably a lower thermal expansion coefficient. In use, the contact of the first heated layer of material with the second layer operates to remove heat from the first layer therein providing automatic/self-regulating temperature control of the HVOF apparatus.