Rail Heater and Method of Use

This disclosure is directed to railroad rail heaters.

Rails for a railroad/railway should be installed (e.g., laid down on the railroad ties) at a neutral temperature. The neutral temperature is established by railroads based on the regional ambient temperature extremes that the rail will encounter annually. It is important that the rail be installed at the neutral temperature so that expansion and contraction of the welded rail can be controlled by rail anchors or resilient fasteners to prevent “pull-aparts” (rail breaking at welds because of extreme tension due to cold temperatures) or sun kinks where the track structure is unable to be contained by the ballast and the track kinks (e.g., alters into an S shape) to relieve the excessive compressive forces built up by heat.

Due to the requirement to install rails at the neutral temperature, in cold environments (i.e., when the ambient temperature is less than the neutral temperature), rail heaters are used when rails for a railroad/railway are to be installed. The rail heater raises the temperature of the rail to the neutral temperature so the rail can be installed in a manner that will reduce the likelihood of pull-aparts and/or sun kinks.

Most of the rail heaters currently in use are propane fueled, which has several disadvantages. Because these rail heater machines are used in large mechanized production gangs and propane is only required for these particular machines and none of the other machines in the rail gang, it is often difficult to coordinate the delivery and dispensing of the propane to the rail heater onboard tanks. Additionally, because mobile propane tanks must be periodically hydro-tested, they must be programmed into a maintenance shop to accomplish said hydro-testing. Propane tanks are also required to be placarded when transported over the highway.

One exemplary rail heater is produced by Teleweld, Inc as a Series 1 propane fired rail heater. This particular rail heater uses propane as it heating fuel source and diesel fuel as its fuel to drive the locomotion along the rail via a diesel engine and operatively coupled drive system.

Using diesel fuel as the fuel (i.e., heat/combustion source) for a rail heater is attractive because many or all of the other machines in the production gang use diesel fuel for powering their engines, and most gangs have their own fuel truck. Diesel fuel is also easily stored and handled by the gang's own personnel without requiring a vendor's truck to come onto railroad property.

Drapeau Corporation provides its FD-Heater 48T3/T4, which uses diesel as the fuel source that is combusted to heat the rail. This rail heater has flame outlet nozzles above both sides of the web of the rail that heats the rail from the top down. This rail heater may have a powered blower to provide combustion air to create a blown flame.

While previous diesel rail heating machines have been more advantageous than propane rail heaters, there is still room for improvement. For example, while diesel rail heaters use diesel fuel and an ignition system, it is difficult to detect the presence of the flame, the strength of the flame, the burning temperature of the flame, or the combustion efficiency of the flame.

To address some of these needs, amongst other advantages, various embodiments of the present disclosure provide a rail heating machine, or simply a rail heater, which has multiple diesel fuel combustion chambers that allow the flame to develop properly within the chambers, then discharge the flame in a torch-like or jet-like out the bottom side of each combustion chamber directed to the web of the rail. In one embodiment, a burner assembly on or adjacent each rail includes multiple combustion chambers on both sides of the rail that is being heated. The number of combustion chambers is determined by the heat output required. In one particular example, each burner outputs 175,000 btu/hr., however other values are clearly possible depending on the application specific needs and requirements of the heating operation.

One example of the present disclosure provides a rail heater that has two burner assemblies, wherein a first burner assembly is on or adjacent a first rail and a second burner assembly is on or adjacent a second rail. The diesel fuel is controlled by electronic controls that utilize flame sensors to assure proper starts/ignition and operation. In one particular embodiment, there is a single ignitor on or in the first combustion chamber in a series of combustion chambers on each side of the rail. This configuration may have connector tubes which fluidly link the interior volumes of each combustion chamber and allow the flame to spread from the single ignitor. It is believed that the use of combustion chambers that are in fluid communication with each other, as opposed a plurality of separate, distinct, or segregate combustion chambers, provides more adequate assurance of diesel fuel ignition, especially in windy conditions. This configuration may also result in less smoke. Proper air flow to the burners is provided by a plenum which provides even flow or substantially even flow to all burners in a series of burners.

In one aspect, an exemplary embodiment of the present disclosure may provide a rail heater comprising: a frame having rail-engaging wheels; a fuel source; and a burner assembly coupled, directly or indirectly, to the frame, wherein burner assembly is positioned closely adjacent a first rail of a railroad, wherein the burner assembly includes at least one combustion chamber that ignites fuel supplied from the fuel source and directs a flame from the at least one combustion chamber at a neutral axis of the first rail. This exemplary embodiment or another exemplary embodiment may further include an air intake in fluid communication with the at least one combustion chamber, wherein the air intake supplies air to the combustion chamber for combustion with the fuel. This exemplary embodiment or another exemplary embodiment may further include a plenum having an inlet and an outlet, wherein the inlet is in fluid communication with the air intake and the outlet is in fluid communication with the at least one combustion chamber. This exemplary embodiment or another exemplary embodiment may further include a burner unit coupled to the at least one combustion chamber; and tubing that connects the outlet of the plenum to the burner unit.

This exemplary embodiment or another exemplary embodiment may further include a first plurality of combustion chambers aligned in a first row on a field side of the first rail; and tubing that fluidly connects each combustion chamber from the first plurality of combustion chambers. This exemplary embodiment or another exemplary embodiment may further include at least one flame outlet on each combustion chamber from the first plurality of combustion chambers; wherein the flame output from each of the at least one flame outlet is a torch-like flame pointed at the neutral axis on the field side of the first rail. This exemplary embodiment or another exemplary embodiment may further include a single ignitor connected to a burner unit that is connected to one combustion chamber in the first plurality of combustion chambers, wherein the single ignitor ignites fuel in the one combustion chamber and ignition thereof causes the remaining combustion chambers to ignite via the tubing that connects each combustion chamber from the first plurality of combustion chambers.

This exemplary embodiment or another exemplary embodiment may further include a second plurality of combustion chambers aligned in a second row on a gauge side of the first rail; and tubing that fluidly connects each combustion chamber from the second plurality of combustion chambers. This exemplary embodiment or another exemplary embodiment may further include at least one flame outlet on each combustion chamber from the second plurality of combustion chambers; wherein the flame output from each of the at least one flame outlet is a torch-like flame pointed at the neutral axis on the gauge side of the first rail. This exemplary embodiment or another exemplary embodiment may further include a single ignitor connected to a burner unit that is connected to one combustion chamber in the second plurality of combustion chambers, wherein the single ignitor ignites fuel in the one combustion chamber and ignition thereof causes the remaining combustion chambers to ignite via the tubing that connects each combustion chamber from the second plurality of combustion chambers.

This exemplary embodiment or another exemplary embodiment may further include an exhaust pipe located between the first plurality of combustion chambers and the second plurality of combustion chambers.

This exemplary embodiment or another exemplary embodiment may further include a cabin for an operator of the rail heater, wherein the cabin is located forward of the burner assembly relative to a drive direction of the rail heater.

In another aspect, an exemplary embodiment of the present disclosure may provide a rail heater comprising: a frame having rail-engaging wheels, the frame having a forward end and a rear end, wherein the rail heater is configured to move in a forward direction of travel along a railroad; a fuel source, which may be diesel; a burner assembly coupled, directly or indirectly, to the frame, wherein burner assembly is positioned closely adjacent a first rail of the railroad, wherein the burner assembly directs a flame toward the first rail; and a cabin on the frame, wherein the cabin is position forwardly from the burner assembly.

In yet another aspect, an exemplary embodiment of the present disclosure may provide a rail heater comprising: a frame having rail-engaging wheels; a fuel source, which may be diesel or possible another fuel; and a burner assembly coupled, directly or indirectly, to the frame, wherein burner assembly, wherein the burner assembly includes a plurality of combustion chambers that are in fluid communication with each other via tubing, wherein the plurality of combustion chambers ignite fuel supplied from the fuel source and direct a flames toward the first rail.

Similar numbers refer to similar parts throughout the drawings.

With respect to continuous welded rail (CWR) among other rails, railroads face the challenge of dealing with thermal expansion. Rails contract in low temperatures and experience tensile stress. In high temperatures, rails expand and compress under stress. If not managed properly, this can lead to issues like heat kinks, which can force the rail out of gauge and even cause derailments. In the 19th century, railroads used jointed rail held together by fishplates or joint bars. These joints required meticulous maintenance to prevent wear on rail ends. However, the jointed rail had an advantage: it could handle thermal expansion by allowing a tiny, lubricated gap between the rails at the joint. CWR replaced jointed rail, offering smoother rides and reduced maintenance. But without joint bars, CWR had little-to-no leeway for expansion. When the rail expanded due to heat, it would buckle under pressure. Prior to installing a section of CWR, railroads ensure the rail meets its stress-free temperature (known as the rail neutral temperature or RNT). If the rail is below the desired temperature, it is gradually heated to expand. The rail is heated with a rail heater. However, as previously mentioned, a need exists to improve conventional rail heater technology.

Unlike conventional rail heaters, some embodiments of the present disclosure does not use a simple flame like the previous rail heaters. Some embodiments of the present disclosure provides an improvement in the form of a jet-like or torch-like flame that is a result of blowing air, which contains oxygen, into a combustion chamber to create the jet-like or torch-like flame that is directed toward a neutral axis of the rail. A torch flame results in more intense heat and more controllable heat. Further, the combustion chamber provides a more complete combustion of the fuel compared to the previous simple flames, resulting in less smoke and soot.

While it is primarily envisioned and shown that the fuel source used in conjunction with the embodiments of the rail heater is diesel supplied from a diesel fuel source, or simply diesel fuel, it is entirely possible to utilize other fuel types in the combustion chambers detailed herein. For example, instead of diesel fuel propane or gasoline could be utilized.

The Figures depict various embodiments and features of an exemplary rail heater. The rail heatermay include a framehaving wheelsthat engage a railhaving a neutral axis. The neutral axisof the rail, or any beam, is an imaginary line passing through the cross-section of the rail that does not experience any longitudinal stress (compressive or tensile). This means that in the vicinity of this axis, the railneither contracts nor expands at the rail neutral temperature, remaining essentially “neutral” to the effects of bending.

There is at least one fuel sourcecarried by the frame. The at least one fuel source is in fluid communication with at least one burner assembly. In the exemplary embodiment of rail heaterthere are two burner assemblies, with each burner assembly being on opposite sides of the rail heatersuch that the burner assemblyon the right side of the rail heaterwould heat the right railand the burner assembly on the left side of the rail heaterwould heat the left rail. In one particular embodiment, each burner assembly is configured and mirrored opposite to the other relative to longitudinal axis.

The burner assemblyis coupled, directly or indirectly, to the frame. The burner assemblyis positioned closely adjacent to the first railof a railroad. The burner assemblyincludes at least one combustion chamberthat ignites fuel supplied from the fuel sourceand directs a torch-like flame or jet-like flame from the at least one combustion chamberto the railthe neutral axis.

Rail heatermay have an air intake assemblyin fluid communication with the at least one combustion chamber. The air intake assemblysupplies air to the combustion chamberfor combustion with the fuel from fuel source. There is at least one plenumhaving an inlet and an outlet. The inlet of the plenumis in fluid communication with and receives air from the air intake assembly. The plenumis in fluid communication with and causes air to move to the at least one combustion chamber. There is a burner unitcoupled to the at least one combustion chamber. A pipe, tubing or tubeconnects the outlet of the plenumto the burner unit.

The shown embodiment of burner assemblylocated on the first side of the rail heaterhas a first plurality of combustion chambersaligned in a first row on a field side of the first rail. There is a tubetubing that fluidly connects each combustion chamberfrom the first plurality of combustion chambers together. There is also a second plurality of combustion chambers aligned in a second row on a gauge side of the first rail. There are more tubesor tubing that fluidly connects each combustion chamber from the second plurality of combustion chambers. There is at least one flame outleton each combustion chamber. The flame that is output from each outletis a torch-like flame pointed at the neutral axisof the first rail. The outletsfrom the first plurality of combustion chambersare pointed at the field side of the railat the neutral axis and the outlets from the second plurality of combustion chambersare pointed at the gauge side of the railat the neutral axis.

In one particular embodiment, there is a single ignitorconnected to a burner unitthat is connected to one combustion chamber in the first plurality of combustion chambers. The single ignitorignites fuel in the one combustion chamberand ignition thereof causes the remaining combustion chambersto ignite via the tubingthat connects each combustion chamberfrom the first plurality of combustion chambers. On the gauge side of the rail, there is a single ignitorconnected to a burner unitthat is connected to one combustion chamberin the second plurality of combustion chambers, wherein this single ignitorignites fuel in the one combustion chamber and ignition thereof causes the remaining combustion chambers to ignite via the tubingthat connects each combustion chamberfrom the second plurality of combustion chambers.

The torch-like flame that is output from each outleton each combustion chamberis significantly different than a simple fuel flame. A torch-like flame (similar to as a blow torch flame) is exceptionally hot and concentrated, and produces a strong, directed flame. Visually, the torch-like flame is a sharp, pointed flame that results in the flame being focused and powerful. In contrast, a simple fuel flame (like a candle or matchstick), provides a flame that is relatively cooler compared to a torch-like flame. A simple fuel flame spreads out and lacks the intense concentration of a torch flame. Visually, a simple fuel flames has gentle appearance representing a dancing flame that wavers due to air currents.

depicts that the rail heaterincludes a forward endand a rear enddefining a longitudinal direction therebetween. The forward endfaces the direction of travel of the rail heater. Rail heateralso includes a first sideand a second side(see) defining a transverse direction therebetween. The transverse direction is orthogonal to the longitudinal direction. The longitudinal axisextends longitudinally and is centered transversely between the first sideand the second side. A vertical direction is orthogonal to the transverse direction and the longitudinal direction.

Rail heaterincludes a cabinthat is supported from below by the frame. Within the cabinmay be one or more electronic control units (ECUs) that have a non-transitory computer readable storage medium with instructions encoded thereon, that when executed by one or more processors, implement a process to perform a rail heating operation as substantially described herein. One or more switchesmay be within the cabinto control the operation of the burner assembly. One relevant feature of the cabinis that it is positioned forwardly (i.e., closer to the forward end) from the burner assembly. The purposeful positioning of the cabinforward of the burner assemblyis that it allows the rail heater to move in a forward direction of travel (to the left in) in a manner which will prevent heat and smoke or other exhaust in the combustion chamber from affecting the operator within the cabin. Stated otherwise, the forwardly positioned cabin is advantageous and enables the operator to drive the rail heaterforward without driving or traversing through heat, smoke or exhaust from the heating operation, which is be described in greater detail herein. This purposeful placement of the cabinis a novel improvement over previous devices which had their operator cabins located rearward of their burner assemblies.

With continued reference to, a vibratormay be connected to the frameat its forward end. The vibratoris configured to vibrate the railto loosen debris and other materials in preparation for the heating operation, which will be described in greater detail herein.

Rail heateradditionally includes a diesel enginethat powers the rail heaterfor locomotion. The diesel enginemay be located rearward (closer to the rear end) from the burner assembly. The diesel engine may also be located rearward from the at least one fuel source. In the shown embodiment the fuel sourceis a diesel fuel tank. Remarkably, the at least one fuel sourceis a diesel fuel tank that is used to supply fuel to the burner assembly. However, the fuel sourcedoes not supply diesel fuel to the diesel engine. Rather, there is a secondary fuel sourcethat supplies the diesel fuel to the diesel engine. Purposefully separating the two diesel fuel sources, namely, fuel sourceand secondary fuel source, is advantageous because both the burner assemblyand the diesel engineutilize diesel fuel. If both of these devices were supplied from a single diesel fuel source, then there would be a chance that the burner assemblycould use all the diesel fuel in the single supply tank during the heating operation and not leave the enginewith the necessary fuel needed to return from its working location. As such, rail heaterpurposefully separates the diesel fuel utilized for the burner assemblyfrom the diesel fuel in the secondary fuel sourcethat is utilized for the engine. This enables the rail heaterto ensure there is enough diesel fuel in the secondary fuel sourceto enable the rail heaterto return from its working location regardless of whether the burner assemblydepletes the diesel from its fuel source.

Rail heatermay further include a hydraulic assemblythat is in operative communication with the diesel engine. Hydraulic assemblymay power or move various components on the rail heateras one having ordinary skill in the art would understand. For example, there may be a hydraulically powered motor with a gear sprocket and chain operatively coupled to a corresponding gear on a drive axle extending between the wheels.

The rail heatermay also carry a water tankthat is configured to store water therein that can be used to either pre-wet the rail ties prior to heating with the burner assemblyor be used to extinguish a fire inadvertently created by the burner assembly. The water tankcan be filled with either a primary fill port located at the top of the tankor it may be filled with a secondary fill tube that extends upward from the tank.

depicts that the rail heatermay also include a debris blower assembly. Debris blower assemblyis located partially rearward from the cabinand forward of the water tank. The debris blower assemblyis transversely located between the burner assemblyon the first side of the rail heater(see—first burner assembly-) and the second burner assembly on the second side of the rail heater(see—second burner assembly-). Debris blower assemblyincludes a primary blower unit that intakes air and directs the air through tubing. The end of the tubing may pivot up and down as indicated by arrowsuch that the outlets of tubingcan be directed to blow air onto the railto remove debris prior to heating with the burner assembly.

Adjacent to the debris blower assemblyis a fluid nozzlethat is part of a wetting assembly in fluid communication and supplied with water from the water tank. In addition to the debris blower assemblyblowing debris from the rail ties near the rail, the wetting assembly may expel water from the fluid nozzleto pre-wet the rail ties. Wetting the rail ties is advantageous to prevent them from significantly burning when the railis heated with the burner assembly. As such, the fluid nozzleand the outlet to the tubingof the debris blower assemblyare located forward of the rear end of the burner assembly.

depicts enlarged side elevation view of the burner assemblythat is on the first side of the rail heater. A duplicate burner assembly (i.e., second burner assembly-) is on the second side of the rail heater and the details of which are not repeated for brevity as it is understood that it is mirrored opposite the longitudinal axis. Each burner assemblyhas a first plurality of combustion chamberspositioned on the field side of the rail. A second plurality of combustion chambers are aligned in a row and positioned on the gauge side of the rail. The first gas combustion chamber-is the forwardmost combustion chamber in the row of combustion chambers defining the first plurality of combustion chambers. In the shown embodiment there are ten combustion chambers aligned in a row extending longitudinally from the forwardmost first combustion chamber-to the rearmost combustion chamber-. The other combustion chambers-through-correspond to the other combustion chambers that make up the plurality of first combustion chambers. Each combustion chamberis connected with its own burner unitat the top thereof. Each combustion chambermay be a box defining an internal volumethat combusts the fuel supplied by the fuel source. The combustion chamber defining the interior volume may have any external configuration to meet the application specific needs of the rail heater. In the shown embodiment, each of the combustion chambershave a plurality of sidewalls defining an octagonal box that is vertically elongated extending between an upper end and a lower end. The upper end of the octagonal box of each combustion chamberis connected with one burner unit. The outleton each box or combustion chamberis adjacent to the lower end and opened in a direction that will propagate a torch-like flame toward the neutral axisof the rail. Flame outletis depicted as a hole or opening that directs the torch-like flame outward from the combustion chamber, however other embodiments can include an adjustable nozzle that allows a user control of the flame to move the flame more precisely onto a desired location of the rail.

Air intake assemblyincludes an intake blower coupled with a Y-fittingthat receives air from the blower of the air intake assemblyand can divert it outwardly between two outlets on the Y-fitting. A baffle or plate can be electronically controlled to divert air towards one of the two plenums. Namely, a switch inside the cabinmay control the operation of the baffle or diverter plate inside the Y-fittingto move air towards the plenumoperatively connected to the first burner assembly-on the first side of the rail heateror the plenumoperatively connected to the second burner assembly-on the second side of the rail heater. The Y-fittingis in operative communication with a pipe or tubethat extends from the Y-fittingto an inlet of the plenum. Inthe tubeis shown cut away for display purposes, however it is to be understood that this tube established a continuous fluid communication between the air intake assemblyand the inlet of plenum. Tubemay be a flexible tube that bends or flexes in response to vertical movement of the burner assembly. The air intake assemblyis located approximately halfway between the forward end of the burner assemblyand the rear end of the burner assembly. However, other locations of the air intake assemblyare entirely possible. In the shown embodiment, the air intake assemblyis located forward of the water tank.

As shown in, the burner assemblyis connected to a frame subassembly. Frame subassemblyis configured to move or permit the vertical movement of the burner assemblyto raise and lower the burner outletsrelative to the rail. The frame subassemblymay include vertically elongated frame members that are connected with actuatorsthat receive electrical control signals from the ECU in the cabinto raise or lower the burner assembly. Frame subassemblymay additionally be connected to a lock mechanismthat can operatively lock the burner assemblyin either the raised position or the lowered position.

With continued reference to, a burner unitis operatively connected to the top of each combustion chamber. Each burner unitis supplied with fuel via fuel linethat is in fluid communication with the primary diesel fuel source. The burner unitis also in open communication with the tubethat receives air from the plenum. The air is pumped into the plenumthrough the air intake assemblyvia tube.

depicts that there are two burner assemblieslocated on each respective side of the rail heater. These burner assembliesare configured to be moved up and down in the vertical direction or raised and lowered in the vertical direction via the frame subassembly. The first burner assembly-is associated with or positioned on the first sideof the rail heaterand the second burner assembly-is located on the second sideof the rail heater. Each burner assemblyincludes a first plurality of combustion chambersaligned on the field side of the rail and a second plurality of combustion chambers aligned in the longitudinal direction on the gauge side of the rail.

is a cross section view depicting the plenumas having an upper chamberand lower chamberthat are in communion with each other via an aperture. The plenumis connected with a platethat is rigidly secured with a lower end of a vertical beamon the frame subassembly. The beamhas an upper end that is in communication with the lock assembly. Lock assemblymay be actuated as indicated by arrowto disengage the beam from the lock assembly. The actuatormay be extended as indicated by arrowto raise and lower the burner assembly.

With continued reference to, in addition to being able to raise and lower the burner assemblyas indicated by arrows, a user may also utilize adjustment rodsto couple with spacers to set the bottom limit of travel of the burner assembly. Spacers may be connected to the adjustment rodsthat correspond to placing the outletsat a location that directs the flame(see) at the neutral axisof rail.

The plenumis supported from below by a beamthrough which the flame outletsextend from each respective combustion chamber. The space between the two respective beamsthat straddle each side of the railhas an upper portion that is in open communication with an exhaust pipethat permits heat and other residual smoke to be exhausted out after the flame is output from the flame outlet. The movement of exhaust is represented by arrows.

depicts air movement into the plenum. The air intake assemblyintakes air and moves air through the tubethat is in fluid communication with the inlet to the plenum. Movement of the air into the plenumthrough tubeis represented by arrows. The air moving in the direction of arrowsis input into the lower chamberof the plenum. Then air may move upwardly to the upper chamberthrough the aperturesas indicated by arrows. After the air moves into the upper chamber, the air flows through upwardly as indicated by arrowsthrough each respective tubeinto each respective burner unitwhere it can be mixed with fuel from fuel lineand combusted within the combustion chamber.

is a transverse cross section depicting one combustion chamberfrom the first plurality of combustion chambers and a second combustion chamberfrom a second plurality of combustion chambers all on the first burner assembly-. It is to be understood that this same configuration is mirrored on the second burner assembly-on the other side of the rail heater. The beamdefines a spacebetween the respective sides of beamwhere the railwill be located. Both flame outletsface inwardly towards the space. Each combustion chamberincludes an interior volumewhere combustion of fuel and air will occur to cause a complete or near-complete combustion. The side wall of each combustion chambermay be in open communication or define an aperture that receives tubeto fluidly connect the interior volumeof one combustion chamber with an adjacent combustion chamber in that same row. As such, the first plurality of combustion chambers aligned in a row are in fluid communication with each other and the combustion chambers in the second plurality of combustion chambers are fluidly connected to each other via tubing. This allows flames to move through the tubessuch that only a single ignitoris needed at the forward most combustion chamber-that will ignite the entire plurality of combustion chambers aligned in that row.

In one exemplary embodiment, the aperture that receives tubeis located approximately halfway between the bottom end and the top end of the combustion chamber-. However, other embodiments may provide the location of the aperture that receives tubeat a different location. In this example, the aperture that receives tubeis located at a height that is greater than the flame outlet, yet it may be possible to place the tubeat a location that is lower than the flame outlet. In the shown example, the aperture that receives tubeis a circular aperture, however other shapes are entirely possible. Thus, while a circular tubeis shown, a different internal diameter profile and/or external diameter profile is possible. The length of the tubelocated between adjacent combustion chambers is aligned in the longitudinal direction and may have a length dimension that is in a range from about three inches to about twenty-four inches. Further, although only a single tubeis shown as linking the adjacent combustion chambers, it is possible to have more than one tubethat links adjacent combustion chambers.

With continued reference to, and as shown in, the burner unitthat is connected to the upper end of each combustion chambermay also include a cad cell flame sensor. The cad cell flame sensoris in electric communication with the ECU inside the cabinthat is utilized to confirm that combustion is occurring within the interior volumeof the combustion chambers. Thus, the cad cell flame sensoris a visual sensor to detect the presence of a flame. The burner unitadditionally includes other standard components that feed fuel from the fuel linehaving a nozzle at an end thereof.

depicts the operation of rail heaterin which the rail heateris moving in the forward direction along railas indicated by arrow. The vibratorlocated at the forward end of the rail heaterhas been lowered to engage the rail as indicated by arrow. The vibrator vibrates the rail and thereby imparts vibrations to the rail ties and rail plates. This assists to loosen debris. The debris blower assemblymay lower its tubingas indicated by arrow. The blower portion of the debris blower assemblymoves air through the tubingto discharge the air from the outlet of the tubingto blow air, as indicated by arrow, to move the debris. The fluid nozzlemay expel waterthat was stored within tank. The waterexpelled or discharged from the fluid nozzlepre-wets the rail ties and the surrounding ground surface near the railsuch that it reduces the likelihood of the rail ties or other errant debris from catching fire during the rail heating operation which is described herein.

depicts the lowering of one of the burner assembliesfrom its raised and stored position to its lowered and operating position. As the rail heater moves forwardly along the track, as indicated by arrow, the lock assemblymay be unlocked. The disengagement of the lock assemblyfrom the beamoccurs by moving a hook out of its engagement from a corresponding aperture in beam. When the lock assemblyis unlocked, the actuatorsmay be extended as indicated by arrow, which imparts a lowering movement to the burner assembly, as indicated by arrow. When the burner assemblyis lowered toward the rail, the beamstraddles each side of the rail. Stated otherwise, the lowering of the burner assemblywill position the first plurality of combustion chambers aligned in a row on the field side of the railand the second plurality of combustion chambers aligned in a row on the gauge side of the rail. The rail occupies the space between the respective sides of the beam.