JP6074314B2 - Hot air generator for melting snow - Google Patents

Description

  The present invention relates to a hot-melt generator for melting snow, and more particularly to a hot-air generator for melting snow that burns fuel gas or the like with a burner and mixes the generated high-temperature combustion gas with air to generate hot air for melting snow.

  Conventionally, many snow melting devices have been proposed in order to prevent damage caused by snow accumulation in winter (for example, Patent Documents 1 to 3). Snow melting devices are roughly classified into those that use water and those that do not use water, and those that do not use water burn oil fuel or gas fuel with a burner and take in the heat generated from the outside. The air is warmed to hot air and used for melting snow. In particular, in railways, snow melting at the point part is important to ensure stable operation of the point part that switches the track, and a large amount of air is sent to the burner stored in the storage box to generate hot air. It has been practiced to guide this to a plurality of point portions located at discrete positions in the duct and use them for melting snow (for example, Patent Documents 4 to 6).

  However, according to the knowledge obtained by the present inventor, the above-mentioned type of snow melting device mainly used in railways often does not ignite the burner when used during snowfall, especially during snowstorms, and the snow melting device. There was a problem that it does not function as.

  When the inventor searched for the cause of such trouble, when the trouble occurred, moisture was attached to the spark plug of the burner and the flame detector. For this reason, the spark plug did not work or the spark plug It turns out that even if the burner is ignited once, the flame detector does not work and the safety device works and the burner is immediately extinguished.

  Moisture adheres to spark plugs and flame detectors that are stored in the storage box and should be isolated from the outside. This is because snow particles and water droplets are mixed into the air taken in from the outside when the snow melting device is operating. It is thought that this may come in contact with the spark plug or flame detector and adhere as moisture. However, in a snow melting apparatus of the type that heats air with a burner to generate hot air, it is necessary to take in a large amount of air from the outside during operation. Although the outside air intake is usually designed to face downward so that snow does not directly flow in, snow particles and water droplets rise and scatter in the event of a snowstorm. It is inevitable that the snow is taken into the snow melting device from the intake. Although it is not conceivable to attach a filter to the outside air intake to prevent snow particles and water droplets from being taken in, it is possible to send the air taken into the burner when a filter is attached to the outside air intake. There is a drawback that it is necessary to increase the blowing capacity of the blower, and the snow melting device is increased in size.

JP 2001-279636 A JP 2003-239235 A JP-A-2005-36426 JP 2000-144604 A JP 2000-303402 A JP 2001-132904 A

  The present invention was made in order to eliminate the above-mentioned disadvantages of the prior art, and in a hot air generator for melting snow that needs to take in a large amount of outside air as a hot air source and combustion air during snowfall, It is an object of the present invention to provide a hot air generator for melting snow that can be expected to be stable without moisture adhering to the vessel.

  As a result of intensive research to solve the above problems, the present inventor has focused on the fact that snow particles and water droplets mixed in the air taken in from the outside have a mass larger than that of air of the same volume, and the burner Covering the combustion air inlet of the combustion cylinder containing the gas with a bottomed guide cylinder to prevent the air containing snow particles and water droplets taken in directly from entering the combustion cylinder. Combustion cylinder which is opened in the guide cylinder by reversing the flow direction of only light air with a lower pressure than in the air passage through which the air taken in from outside passes. The present invention has been completed by finding that it can be made to flow into the combustion air inlet.

That is, this invention solves said subject by providing the hot air generator for snow melting provided with following (1)-(6).
(1) An outer cylinder having an air inlet at the rear and an air outlet at the front,
(2) A guide tube whose bottom end is bottomed and whose front end is open, wherein the bottomed rear end is positioned on the rear side of the outer tube, and the open front end is the outer tube A guide cylinder which is disposed in the outer cylinder so as to be positioned on the front side of the outer cylinder and forms a first air passage between the inner cylinder and the inner peripheral surface of the outer cylinder,
(3) A combustion cylinder having a combustion air inlet at the rear and a combustion gas outlet at the front, wherein the combustion air inlet is located in the guide cylinder so as to be positioned in the guide cylinder. Combustion that is arranged with the outer cylinder aligned in the front-rear direction, forms a second air passage between the outer cylinder and the inner peripheral surface of the outer cylinder, and forms a combustion air passage between the outer cylinder and the inner peripheral surface of the guide cylinder Tube,
(4) A burner disposed in the combustion cylinder so that the flame is directed forward of the combustion cylinder;
(5) a spark plug and / or a flame detector disposed in the combustion cylinder, and
(6) Means for setting the pressure in the guide cylinder to a pressure lower than the pressure in the second air passage.

  In the hot air generating apparatus for snow melting according to the present invention, as described above, the combustion air inlet of the combustion cylinder containing the burner is covered with the guide cylinder, so that the air containing snow particles and water droplets taken in is not contained. Without passing directly into the combustion air inlet, it passes through the first air passage and the second air passage formed between the outer peripheral surface of the guide tube and the combustion tube and the inner peripheral surface of the outer tube. However, in the hot air generator for melting snow according to the present invention, means for reducing the pressure in the guide cylinder to be lower than the pressure in the second air passage is provided, so that there is a gap between the guide cylinder and the second air passage. Differential pressure is generated. And, due to such differential pressure, a part of the air having a relatively small mass and a small inertia is sucked and flows into the guide cylinder by reversing the flow direction, while snow particles and water droplets having a relatively large mass Since the inertia is large, the flow direction is directly reversed without passing through the second air passage together with other air and flows out from the air outlet of the outer cylinder. Therefore, only air that does not contain snow particles or water droplets is introduced into the guide cylinder and flows into the combustion cylinder as combustion air, and moisture adheres to the detection end of the spark plug or flame detector. Is prevented.

  As a means for making the pressure in the guide cylinder lower than the pressure in the second air passage, any means may be used as long as the pressure in the guide cylinder is lower than that in the second air passage. Is preferably a flow resistance provided in the second air passage, a blower that sends air in the guide cylinder toward the combustion air inlet of the combustion cylinder, or both. As the flow path resistance provided in the second air passage, for example, a throttle plate that protrudes inward from the outer cylinder toward the combustion cylinder, or conversely, a throttle plate that protrudes outward from the combustion cylinder toward the outer cylinder Can be mentioned. When such a flow path resistance is provided in the second air passage, the pressure in the second air passage increases, and as a result, a differential pressure is generated between the guide cylinder and the second in the guide cylinder. The pressure is relatively lower than that of the air passage. Similarly, when there is a blower that sends air in the guide cylinder toward the combustion air inlet of the combustion cylinder, the air in the guide cylinder is sucked by the blower, so the second air passage in the guide cylinder The pressure can be lower than that. Such a blower may be a fan or a blower.

  If necessary, a filter may be attached to the combustion air passage formed between the outer peripheral surface of the combustion cylinder and the inner peripheral surface of the guide cylinder. When such a filter is attached to the combustion air passage, even if some snow particles and water droplets are still mixed in the air that is reversed in the flow direction and guided into the guide cylinder, this Since it is removed by the filter, it is possible to more completely prevent snow particles and water droplets from flowing into the guide tube. The filter may be any filter that can remove snow particles and water droplets. For example, a line filter (air filter), a mist filter, or both may be used in combination.

  Further, if necessary, a baffle plate may be attached to the combustion air passage formed between the outer peripheral surface of the combustion cylinder and the inner peripheral surface of the guide cylinder. When such a baffle plate is attached to the combustion air passage, even if some snow particles and water droplets are still mixed in the air that is reversed in the flow direction and guided into the guide cylinder, Since it collides with this baffle plate and is trapped by the baffle plate, it is possible to more completely prevent snow particles and water droplets from flowing into the guide tube.

  The guide cylinder in the hot air generator for snow melting according to the present invention has, in a preferred embodiment thereof, an expansion portion at its front end that gradually expands toward the front. When the front end of the guide cylinder has such an expanded portion, the first air passage formed between the outer peripheral surface of the guide cylinder and the inner peripheral surface of the outer cylinder is narrowed by the expanded portion. Since the speed of the air passing through this narrow portion is increased, the straightness of snow particles and water droplets mixed in the air is further increased, and separation from the air whose direction of flow is reversed by the differential pressure is further ensured. .

  In a preferred embodiment, the snow-melting hot air generator of the present invention includes a blower that feeds air toward the air inlet of the outer cylinder. As a general matter, this blower can take any structure and blower mechanism as long as it can take in a large amount of air from the outside and send it toward the air inlet of the outer cylinder. Preferably, an axial blower is used. An axial blower is a blower that sucks in from the axial direction and blows in the axial direction, can be formed relatively compact, can be placed in a small space, and when an axial blower is used as a blower It is preferable because it becomes easier to separate snow particles and water droplets from air. That is, when an axial flow blower is used, air containing snow particles or the like sucked from the outside is blown into the outer cylinder while swirling. It will flow outside the two air passages. Therefore, the inside of the first air passage and the second air passage becomes air with relatively few snow particles and water droplets, and by introducing the air inside the guide tube by the differential pressure, the contamination of snow particles and water droplets is further reduced. Can be made.

  Further, even when a blower that is not an axial blower as described above is used as the blower, for example, by attaching an air swirl blade that swirls flowing air to the first air passage, the first air passage And the flow of air in the second air passage is a swirl flow, the mass is large, the snow particles and water droplets flowing outside the first air passage and the second air passage by centrifugal force, the mass is small, the first air passage and It is possible to separate the air flowing inside the second air passage. The air containing snow particles and water droplets flowing through the first air passage receives a force rotating in the circumferential direction by contacting with the air swirl blade, and passes through the first air passage and the second air passage while swirling. It will be. In addition, even when an axial blower is used as a blower, it is needless to say that an air swirl vane may be used, and when an axial blower and an air swirl vane are used in combination, the swirl flow is further increased. Snow particles and water droplets that are strong and have a large mass and flow outside the first air passage and the second air passage by centrifugal force, and air that has a small mass and flows inside the first air passage and the second air passage Can be better separated.

  In the hot air generating apparatus for snow melting according to the present invention, the blower may be fixedly attached to the outer cylinder. However, from the viewpoint of ease of maintenance and ease of carrying, the blower is external. It is desirable that it is detachably attached to the cylinder. Similarly, from the viewpoint of ease of maintenance and portability, the guide cylinder, combustion cylinder, and burner constituting the snow melting hot air generator of the present invention are detachably attached to the outer cylinder. It is desirable.

  The hot air generator for melting snow according to the present invention has an air outlet of its outer cylinder connected to a duct, and is mainly used for melting snow on a railway track, but is not limited to melting snow on a railway track, and melts snow using hot air. Of course, any object may be used for melting snow on any object as long as it is.

  According to the hot air generator for melting snow of the present invention, even if snow particles or water droplets are inevitably mixed in the air taken in from the outside, moisture does not adhere to the spark plug of the burner or the flame detector. Even in the event of a snowstorm, the burner can be ignited reliably, and there can be obtained an advantage that snow can be melted at a necessary location without any trouble and without trouble.

It is a fragmentary sectional view which shows an example of the hot air generator for snow melting of this invention, and an air blower. It is a fragmentary sectional view which shows an example of the hot-air generator for snow melting of the state to which the air blower was connected. It is a fragmentary sectional view which shows another example of the hot air generator for snow melting of this invention. It is a fragmentary sectional view which shows another example of the hot air generator for snow melting of this invention. It is a fragmentary sectional view which shows another example of the hot air generator for snow melting of this invention.

  Hereinafter, although the hot-air generator for snow melting of this invention is demonstrated using drawing, this invention is not limited to the thing of illustration.

  FIG. 1 is a partial cross-sectional view showing an example of a hot air generator for melting snow according to the present invention. In FIG. 1, 1 is a hot air generator for snow melting of the present invention, 2 is an outer cylinder constituting the hot air generator 1 for snow melting, 3 is a guide cylinder, 4 is a combustion cylinder, 5 is a burner, and 6 is a burner 5. A fuel gas supply pipe for supplying fuel gas, 7 is a spark plug, 8 is a flame detector, 9 is a control device, 10 is a fuel gas source, 11 is a throttle plate, and 12 is a blower.

  In this example, the outer cylinder 2 has a cylindrical shape with the front and rear opened, and has an air inlet 2a at the rear and an air outlet 2b at the front. Incidentally, in this specification, the front means the downstream direction in which the air sent by the blower 12 flows, and the rear means the upstream direction in which the air sent by the blower 12 flows. To do.

  As shown in the cross section of FIG. 1, the guide tube 3 has a cylindrical cup shape with a rear end having a bottom and a front end opened, and the bottom rear end is located on the rear side of the outer tube 2 and is opened. The outer cylinder 2 is disposed coaxially with the outer cylinder 2 so that the front end of the outer cylinder 2 is located on the front side of the outer cylinder 2. A first air passage A is formed between the outer peripheral surface of the guide tube 3 and the inner peripheral surface of the outer tube 2.

  The combustion cylinder 4 has a cylindrical shape with front and rear openings, and has a combustion air inlet 4a at the rear and a combustion gas outlet 4b at the front. The combustion cylinder 4 is arranged coaxially with the outer cylinder 2 in the outer cylinder 2 with the outer cylinder 2 aligned in the front-rear direction so that the combustion air inlet 4 a is located inside the guide cylinder 3. As a result, the combustion air inlet 4 a of the combustion cylinder 4 opens into the guide cylinder 3. A second air passage B is formed between the outer peripheral surface of the combustion cylinder 4 and the inner peripheral surface of the outer cylinder 2, and combustion air is formed between the outer peripheral surface of the combustion cylinder 4 and the inner peripheral surface of the guide cylinder 3. A passage C is formed. In this example, the outer cylinder 2, the guide cylinder 3, and the combustion cylinder 4 all have a cylindrical shape with a circular cross section, but the shape of these members is not limited to a cylindrical shape. Not too long. The outer cylinder 2, the guide cylinder 3, and the combustion cylinder 4 are not necessarily arranged coaxially. However, in order to form a flow of air and combustion gas that is not biased in the circumferential direction, the outer cylinder 2, the guide It is preferable that the three of the cylinder 3 and the combustion cylinder 4 are arranged coaxially.

  The burner 5 is disposed in the combustion cylinder 4 so that the flame is directed in front of the combustion cylinder 4, that is, in the direction toward the combustion gas outlet 4b. 5a is a jet port for fuel gas supplied from the fuel gas supply pipe 6, 5b is a flame holder having an air port through which combustion air is jetted, and 5c is a passage for combustion air. The burner 5 is not limited to the one shown in the figure, and any shape and structure may be used as long as it is supplied with combustion air and burns gaseous fuel such as city gas, propane gas, and natural gas. In some cases, a burner of a type in which liquid fuel is gaseous and mixed with air and burned may be used.

  The spark plug 7 and the flame detector 8 are disposed in the combustion cylinder 4 and are connected to the control device 9 wirelessly or by wire. A fuel gas source 10 that supplies fuel gas to the fuel gas supply pipe 6 is also connected to the control device 9. The diaphragm plate 11 has a flat donut shape, is attached to the front end portion of the outer cylinder 2, and functions as a flow path resistance of the second air passage B. In this example, the diaphragm plate 11 is attached to the outer cylinder 2 and protrudes inward from the outer cylinder 2 toward the combustion cylinder 4, but conversely, it is attached to the combustion cylinder 4 and extends from the combustion cylinder 4. You may make it protrude outside toward the outer cylinder 2. FIG.

  In the case of this example, the air blower 12 is comprised from the axial flow fans 12a and 12b connected by 2 steps | paragraphs, and is comprised separately from the hot air generator 1 for snow melting. The blower device 12 is detachably connected to the rear end of the outer cylinder 2 at its front end, that is, the air introduction port 2a. In use, the rear end of the blower device 12 is connected to an air intake port from the outside. Is done. As the blower 12, for example, a blower having a blower mechanism different from an axial blower such as a sirocco fan may be used. However, as in the present example, the axial blowers 12a and 12b are used as the blower 12. In such a case, a swirling flow is generated, and air taken in from the outside flows into the outer cylinder 2 while swirling, which is preferable. That is, when air taken in from the outside flows into the outer cylinder 2 while turning, snow particles and water droplets having a large mass flow on the relatively outer side in the outer cylinder 2 due to centrifugal force, and flow on the inner side in the outer cylinder 2. The air is less contaminated with snow particles and water droplets. Therefore, the direction of the flow of the air flowing inside thereof is reversed by the pressure difference between the second air passage and the guide cylinder 3 and guided into the guide cylinder 3, whereby snow particles and water droplets flow into the combustion cylinder 4. Can be prevented as much as possible. The axial fans 12a and 12b are not necessarily provided in two stages, and may be provided in one stage.

  Even when a blower having a blower mechanism different from an axial blower such as a sirocco fan is used as the blower 12, for example, a swirl flow in the outer cylinder 2 is obtained by using an air swirl blade (not shown). Can be generated. Such air swirl vanes are preferably mounted in the first air passage, for example, but may be on the front side of the outer cylinder 2 relative to the first air passage or may be mounted on the blower 12. In any case, by generating a swirling flow, large-sized snow particles and water droplets flow relatively outside the outer cylinder 2 due to centrifugal force, and the air flowing inside the outer cylinder 2 contains snow particles and water droplets. Since mixing is reduced, the traveling direction is reversed by the differential pressure, and snow particles and water droplets mixed in the air flowing into the guide cylinder 3 can be reduced and prevented as much as possible. Moreover, even when an axial blower is used as the blower 12, the swirl flow generated in the outer cylinder 2 is made stronger by attaching the air swirl blade described above, and snow particles, water droplets and air Can be separated more completely.

  Hereinafter, the operation of the hot air generator 1 for melting snow shown in FIG. 1 will be described with reference to FIG. FIG. 2 shows a state in which the air blower 12 shown in FIG. 1 is attached to the snow-melting hot air generator 1 shown in FIG. 1 and is connected to the air inlet 2a of the outer cylinder 2 at its front end. In FIG. 2, first, when the air blower 12 is activated, external air is sucked by the axial flow fans 12 a and 12 b and sent to the air inlet 2 a of the outer cylinder 2. The air sent to the air inlet 2a passes through the second air passage B from the first air passage A while turning and proceeds to the air outlet 2b of the outer cylinder 2, but the snow particles mixed in the air Since the mass of water and water droplets is large, they pass through the vicinity of the outside of the first air passage A and the second air passage B by centrifugal force, and relatively small snow particles and water droplets are inside the first air passage A and the second air passage B. Air with less contamination will flow.

  On the other hand, since the throttle plate 11 is provided as a flow path resistance at the front end portion of the outer cylinder 2, the internal pressure of the second air passage B rises and the pressure difference between the pressure in the guide cylinder 3 (guide cylinder) 3 is low pressure relative to the second air passage B). Due to this differential pressure, part of the air flowing in the vicinity of the combustion air passage C is sucked, and the sucked air reverses the traveling direction and flows into the guide cylinder 3 through the combustion air passage C. It will be. At this time, even if snow particles and water droplets are mixed in the air flowing in the vicinity of the combustion air passage C, since the snow particles and water droplets have large mass and large inertia, the difference between the second air passage B and the guide cylinder 3 is large. Depending on the pressure, the air travels in the second air passage B as it is without reversing the traveling direction, and flows out from the air outlet 2b of the outer cylinder 2 to the outside. In addition, the air sucked into the guide cylinder 3 by the differential pressure is air that flows inside the first air passage A and the second air passage B and is essentially free of snow particles and water droplets. The possibility of snow particles and water droplets flowing into the cylinder 3 is extremely low.

  When the operation of the air blower 12 becomes stable, the control device 9 operates to send fuel gas from the fuel gas source 10 to the burner 5 and to operate the spark plug 7 to ignite the burner 5. Further, the flame detector 8 detects whether or not the burner is in an ignited state. The high-temperature combustion gas generated by the ignited burner 5 travels through the combustion cylinder 4 and is mixed with the air that has passed through the second air passage B when it exits from the combustion gas outlet 4b, and becomes hot air. 2 flows out from the air outlet 2b. It goes without saying that the hot air that has flowed out is guided to an appropriate place by a duct or the like and used for melting snow.

  As described above, in the hot air generator 1 for snow melting of the present example, a large amount of air taken in from the outside by the blower 12 is partially used as combustion air, and the rest is a high temperature generated by the burner 5. However, only the air with a small mass reverses its traveling direction due to the differential pressure generated between the second air passage B and the guide tube 3. Snow particles and water droplets that flow into the guide tube 3 and have a large mass are configured to flow out from the air outlet 2b of the outer tube 2 as they are. For this reason, even if a part of the air taken in from the outside is used as combustion air, water may adhere to the spark plug 7 and the flame detector 9 of the burner 5 due to inevitably mixed snow particles and water droplets. Absent.

  Moreover, in the hot-air generator 1 for snow melting of this example, since the axial blowers 12a and 12b are used as the air blower 12, the air sent into the outer cylinder 2 turns into a swirl flow, and snow particles with large mass and The water droplets flow outside and the air flowing inside the guide tube 3 by reversing the direction of travel by the differential pressure contains very little snow particles or water droplets. For this reason, in combination with the reversal of the air flow direction due to the differential pressure generated between the second air passage B and the guide cylinder 3, snow particles and water droplets are mixed into the air flowing into the guide cylinder 3. This can be prevented very effectively.

  FIG. 3 is a partial cross-sectional view showing another example of the hot air generator for melting snow of the present invention, and shows a state where the blower 12 is attached to the hot air generator 1 for melting snow. The hot air generator 1 for snow melting of this example is different from the hot air generator 1 for snow melting shown in FIG. 1 in that a blower 13 is provided instead of the diaphragm plate 11. As shown in the figure, the blower 13 is provided in the guide cylinder 3 and has a function of sending air in the guide cylinder 3 to the combustion air inlet 4 a of the combustion cylinder 4.

  The operation of the hot air generator 1 for snow melting shown in FIG. 3 is basically the same as that of the hot air generator 1 for snow melting shown in FIG. 1, but the differential pressure between the second air passage B and the guide tube 3 is 2 It is not brought about by the throttle plate 11 that becomes the flow resistance of the air passage B, but is brought about by forcibly sending the air in the guide cylinder 3 into the combustion air inlet 4 a of the combustion cylinder 4 by the blower 13. Are different.

  Also in the hot air generator 1 for snow melting of this example, a part of the air flowing in the vicinity of the combustion air passage C is sucked by the differential pressure between the second air passage B and the guide cylinder 3, and the traveling direction , And flows into the guide tube 3 through the combustion air passage C. At this time, even if snow particles and water droplets are mixed in the air flowing in the vicinity of the combustion air passage C, since the snow particles and water droplets have large mass and large inertia, the difference between the second air passage B and the guide cylinder 3 is large. Depending on the pressure, the air travels in the second air passage B as it is without reversing the traveling direction, and flows out from the air outlet 2b of the outer cylinder 2 to the outside. In addition, the air sucked into the guide tube 3 by the differential pressure has snow particles and water droplets with large mass unevenly distributed outward due to the centrifugal force accompanying the swirling flow. There is less air.

  As described above, also in the hot air generating apparatus 1 for melting snow of this example, it is very effectively prevented that snow particles and water droplets are mixed in the air flowing into the guide tube 3, so that one of the air taken in from the outside is prevented. Even if the part is used as combustion air, there is a problem in that moisture adheres to the spark plug 7 and the flame detector 9 of the burner 5 due to inevitably mixed snow particles and water droplets, and the burner does not ignite. There is no.

  As a means for generating a differential pressure between the guide cylinder 3 and the second air passage B to make the guide cylinder 3 relatively low in pressure, the flow of the throttle portion 11 provided in the second air passage B or the like is reduced. Of course, the road resistance and the blower 13 provided in the guide tube 3 may be used in combination.

  FIG. 4 is a partial cross-sectional view showing still another example of the snow melting hot air generator of the present invention, and shows a state in which the blower 12 is attached to the snow melting hot air generator 1 as in FIG. 3. . In the hot air generator 1 for snow melting of this example, the guide tube 3 has an expanded portion 3a at the front tip, and the baffle plate 3b and the baffle plate 4c are provided in the combustion air passage C. And the point to which the burner 5 is a cone-shaped burner differs from the hot-air generator 1 for snow melting shown in FIG. Further, since the burner 5 is a cone-shaped burner and the inside of the cone becomes a combustion chamber, the spark plug 7 and the flame detector 8 are disposed inside the cone of the burner 5.

  As shown in FIG. 4, the expansion portion 3 a is an expansion portion that gradually expands as the front end of the guide tube 3 heads forward, and just pushes the front end of the guide tube 3 outward. It has a different shape. When the expanded portion 3a is present at the front end of the guide tube 3, the first air passage A formed between the outer peripheral surface of the guide tube 3 and the inner peripheral surface of the outer tube 2 is formed by the expanded portion 3a. The speed of the air passing through this narrow part is increased. As a result, the straightness of the snow particles and water droplets mixed in the air passing through the first air passage A is further increased, and the snow particles and water droplets are caused by the differential pressure between the guide tube 3 and the second air passage B. Without reversing the flow direction, the rate at which snow particles and water droplets mix into the air that flows out from the air outlet 2b of the outer cylinder 2 and flows into the guide cylinder 3 is further reduced.

  In addition, since the baffle plate 3b and the baffle plate 4c are provided in the combustion air passage C, some snow particles and water droplets are still mixed into the air guided in the guide cylinder 3 by reversing the flow direction. Even if this occurs, it collides with the baffle plates 3b and 4c and is trapped by the baffle plates 3b and 4c, so that it is possible to more completely prevent snow particles and water droplets from flowing into the guide tube 3.

  FIG. 5 is a partial cross-sectional view showing still another example of the hot air generator for melting snow according to the present invention. Similarly to FIGS. 3 and 4, the blower 12 is attached to the hot air generator 1 for melting snow. Show. The snow melting hot air generator 1 of this example is different from the snow melting hot air generator 1 shown in FIG. 4 in that the combustion air passage C is provided with a filter 14 instead of the baffle plate 3b and the baffle plate 4c. Is different.

  When such a filter 14 is attached to the combustion air passage C, it is assumed that some snow particles and water droplets are still mixed in the air guided in the guide cylinder 3 by reversing the flow direction. In addition, since it is removed by the filter 14, it is possible to more completely prevent snow particles and water droplets from flowing into the guide tube 3. The filter 14 only needs to prevent snow particles and water droplets from flowing into the guide tube 3, and any filter may be used as long as it can be prevented. For example, a line filter that removes moisture and particles ( Air filter), a mist filter that removes finer particles, or a combination of both.

  As described above, according to the hot air generator 1 for snow melting according to the present invention, even if snow particles and water droplets are mixed in the air taken from the outside, only the air is separated from the snow particles and water droplets to guide the air. In addition, since it can be caused to flow into the combustion cylinder 4 provided with the burner 5, moisture adheres to the spark plug 7 and the flame detector 8 of the burner 5 even when it is used during snowfall or particularly during snowstorms. Therefore, it is possible to reliably ignite the burner 5 and stably generate hot air necessary for melting snow.

  As described above, the hot air generator for melting snow according to the present invention reliably ignites the burner, which is a heat source, even when it is unavoidable to mix snow particles or water droplets in the air taken from outside, such as during snowfall or snowstorm. It is extremely effective for melting snow in snowfall areas. Therefore, the present invention has great industrial applicability.

DESCRIPTION OF SYMBOLS 1 Hot-air generator for snow melting 2 Outer cylinder 3 Guide cylinder 4 Combustion cylinder 5 Burner 6 Fuel gas supply pipe 7 Spark plug 8 Flame detector 9 Control apparatus 10 Fuel gas source 11 Throttle plate 12 Blower 13 Blower 14 Filter

Claims (10)

A hot air generator for melting snow comprising the following (1) to (6);
(1) An outer cylinder having an air inlet at the rear and an air outlet at the front,
(2) A guide tube whose bottom end is bottomed and whose front end is open, wherein the bottomed rear end is positioned on the rear side of the outer tube, and the open front end is the outer tube A guide cylinder which is disposed in the outer cylinder so as to be positioned on the front side of the outer cylinder and forms a first air passage between the inner cylinder and the inner peripheral surface of the outer cylinder,
(3) A combustion cylinder having a combustion air inlet at the rear and a combustion gas outlet at the front, wherein the combustion air inlet is located in the guide cylinder so as to be positioned in the guide cylinder. Combustion that is arranged with the outer cylinder aligned in the front-rear direction, forms a second air passage between the outer cylinder and the inner peripheral surface of the outer cylinder, and forms a combustion air passage between the outer cylinder and the inner peripheral surface of the guide cylinder Tube,
(4) A burner disposed in the combustion cylinder so that the generated flame is directed forward of the combustion cylinder;
(5) a spark plug and / or a flame detector disposed in the combustion cylinder, and
(6) Means for setting the pressure in the guide cylinder to a pressure lower than the pressure in the second air passage. The means for setting the pressure in the guide cylinder to be lower than the pressure in the second air passage is a flow resistance provided in the second air passage, or the air in the guide cylinder is introduced into the combustion air. The hot air generator for melting snow according to claim 1, wherein the blower is sent to the mouth or both of them. The hot air generator for melting snow according to claim 1 or 2, wherein a filter is provided in the combustion air passage. The hot air generator for melting snow according to any one of claims 1 to 3, wherein a baffle plate is provided in the combustion air passage. The hot air generator for melting snow according to any one of claims 1 to 4, further comprising an expanding portion that gradually expands as the front end of the guide tube moves forward. The hot air generator for melting snow according to any one of claims 1 to 5, wherein an air swirl vane for swirling the air flowing through the first air passage is provided in the first air passage. The hot air generator for melting snow according to any one of claims 1 to 6, further comprising a blower that feeds air toward the air inlet port behind the outer cylinder. The hot air generator for melting snow according to claim 7, wherein the blower is an axial blower. The hot air generator for melting snow according to claim 7 or 8, wherein the blower is detachably attached to the outer cylinder. The hot air generator for melting snow according to any one of claims 1 to 9, wherein the guide cylinder, the combustion cylinder, and the burner are integrally attached to the outer cylinder in a detachable manner.

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