Powder transport vehicle

Abstract

To provide a granule body transporting vehicle that prevents an outlet pipe from clogging due to the granule body, by preventing or suppressing occurrence of dew drops inside the outlet pipe.SOLUTION: A granule body transporting vehicle has a tank 5 loaded on a chassis 2 and loaded with the granule body therein, an outlet pipe 6 provided from inside the tank 5 to the outside of the tank 5, a compressed air supply part 16 supplying compressed air into the tank to discharge outside the tank 5 the granule body loaded in the tank 5 through the outlet pipe 6, and further, heating means 40 heating at least a part of the outlet pipe 6 inside the tank 5.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a powder transport vehicle that transports powder in a tank. [Background technology]

[0002] Conventionally, powder and granular material transport vehicles that transport powder and granular material loaded in a tank have been known. Some powder and granular material transport vehicles load the powder and granular material into the tank by pouring the powder and granular material into a manhole at the top of the tank, and then discharge the powder and granular material from a discharge pipe by sending compressed air from an air compressor into the tank. This type of powder and granular material transport vehicle is disclosed, for example, in Patent Documents 1 and 2.

[0003] The powder and granular material transport vehicles disclosed in Patent Documents 1 and 2 are equipped with a dehumidifying device that removes moisture from the air in the pipe connecting the air compressor and the tank to prevent condensation from forming inside the tank. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 4362100 [Patent Document 2] Patent No. 6781522 Summary of the Invention [Problem to be solved by the invention]

[0005] When powder and granular materials are discharged from a tank, the temperature of the air supplied from the air compressor to the tank drops, reducing the amount of saturated water vapor, making condensation more likely to occur inside the tank. Furthermore, when the highly humid air inside the tank is discharged through a discharge pipe that is cooler than the air inside the tank, a large amount of highly humid air comes into contact with the inside of the discharge pipe, resulting in more condensation inside the pipe than in other parts of the tank. When condensation occurs inside the discharge pipe, the powder and granular materials adhere to the condensation, gradually accumulating inside the pipe and potentially causing clogging.

[0006] Even if the air supplied to the tank is dehumidified using the techniques disclosed in Patent Documents 1 and 2, condensation may occur inside the discharge pipe depending on the outside temperature. Also, even if the air supplied to the tank is dehumidified, moisture in the powder and granular material itself may evaporate, increasing humidity, which may cause condensation inside the discharge pipe.

[0007] Therefore, an object of the present invention is to provide a powder / granular material transport vehicle that prevents or suppresses condensation from forming inside the discharge pipe, thereby preventing the discharge pipe from becoming clogged with powder / granular material. [Means for solving the problem]

[0008] A powdered or granular material transport vehicle according to one aspect of the present invention comprises a tank mounted on a chassis and loaded with powdered or granular material, a discharge pipe extending from the inside of the tank to the outside of the tank, a compressed air supply unit that supplies compressed air to the inside of the tank so that the powdered or granular material loaded inside the tank is discharged to the outside of the tank through the discharge pipe, and is characterized by comprising a heating means that heats at least a portion of the discharge pipe.

[0009] In a powder / granular material transport vehicle having such a configuration, the heating means heats at least a portion of the discharge pipe, thereby preventing or suppressing condensation inside the discharge pipe, and as a result, preventing the discharge pipe from being clogged with powder / granular material.

[0010] In a powder or granular material transport vehicle having the above-described configuration, it is desirable that the portion heated by the heating means is at least a part of the portion of the discharge pipe located inside the tank.

[0011] With a powder / granular material transport vehicle having the above-described configuration, the part of the discharge pipe that is located inside the tank, where condensation is likely to occur, can be heated, thereby effectively preventing or suppressing condensation from occurring inside the discharge pipe.

[0012] In a powder and granular material transport vehicle having the above configuration, it is desirable that the compressed air supply unit includes an air compressor, and the heating means has the air compressor included in the compressed air supply unit and a compressed air conduit that guides the compressed air supplied by the air compressor to the discharge pipe.

[0013] In a granular material transport vehicle having such a configuration, high-temperature compressed air generated by the air compressor is guided through the compressed air conduit to the discharge pipe, heating the discharge pipe, thereby preventing or suppressing condensation inside the discharge pipe. As a result, clogging of the discharge pipe with granular material can be prevented. Furthermore, compared to conventional cases in which a dehumidifier is installed on a granular material transport vehicle, this configuration has the advantages of eliminating the cost of a dehumidifier and minimizing the need to reduce the load weight of granular material by minimizing the increase in weight of the mounting device. Another advantage is that no space is required to install a dehumidifier on the granular material transport vehicle.

[0014] In a powder or granular material transport vehicle having the above configuration, the heating means may further have a discharge pipe cover that covers a portion of the discharge pipe and forms an air passage between the discharge pipe and the outer surface thereof, through which air passes, and the compressed air conduit may be connected to the air passage so that compressed air guided from the air compressor passes through the air passage.

[0015] In a powder / granular material transport vehicle having such a configuration, high-temperature compressed air generated by the air compressor is guided through the compressed air conduit into the air passage formed between the discharge pipe and the discharge pipe cover that covers part of the discharge pipe. Therefore, for example, by attaching a discharge pipe cover to a part of the discharge pipe that is prone to clogging with powder / granular material, the part can be heated intensively, preventing or suppressing the formation of condensation in that part, thereby preventing the entire discharge pipe from being clogged with powder / granular material.

[0016] In a powder and granular material transport vehicle having the above configuration, the discharge pipe may have a curved portion, and the discharge pipe cover may cover the curved portion of the discharge pipe and form the air passage between itself and the outer surface of the curved portion.

[0017] The bends in the discharge pipe are the parts of the discharge pipe that are particularly susceptible to clogging with powder and granular material. Therefore, by attaching a discharge pipe cover to the bends in the discharge pipe, the bends can be heated in a concentrated manner, and by preventing or suppressing condensation within the bends, the entire discharge pipe can be prevented from becoming clogged with powder and granular material.

[0018] In a powder or granular material transport vehicle having the above configuration, the air passage may include an outer air passage through which the compressed air flows along the radially outer side of the curved portion of the discharge pipe, and an inner air passage through which the compressed air flows along the radially inner side of the curved portion of the discharge pipe, and the compressed air conduit may be connected to the outer air passage, and the outer air passage and the inner air passage may be connected so that the compressed air supplied from the compressed air conduit passes through the outer air passage and then through the inner air passage.

[0019] The inner surface of the curved portion of the discharge pipe has a larger surface area on the radially outer side than on the radially inner side, so that more water droplets adhere to the radially outer side due to condensation. Furthermore, when powder or granular material is discharged through the discharge pipe, centrifugal force acts on the powder or granular material flowing through the curved portion of the discharge pipe, so that more powder or granular material adheres to the radially outer side than to the radially inner side. With a powder or granular material transport vehicle having the above-described configuration, the compressed air that flows along the radially outer side of the curved portion of the discharge pipe and exchanges heat with the discharge pipe flows along the radially inner side of the curved portion of the discharge pipe. Therefore, the radially outer side of the curved portion, where powder or granular material is likely to accumulate, can be heated to a higher temperature than the radially inner side, effectively preventing the curved portion of the discharge pipe from being clogged with powder or granular material.

[0020] In a powder or granular material transport vehicle having the above configuration, the compressed air conduit may be connected to the discharge pipe so as to direct compressed air directly into the discharge pipe, and the heating means may further have an on-off valve downstream of the connection point between the compressed air conduit and the discharge pipe for opening and closing the flow path in the discharge pipe.

[0021] With a powder / granular material transport vehicle having such a configuration, by introducing high-temperature compressed air generated by the air compressor into the discharge pipe through the compressed air conduit while the on-off valve that opens and closes the flow path in the discharge pipe is closed, the discharge pipe is heated before the powder / granular material is discharged through the discharge pipe, and condensation inside the discharge pipe can be prevented or suppressed. As a result, clogging of the discharge pipe with powder / granular material can be prevented. [Effects of the Invention]

[0022] According to the present invention, by preventing or suppressing condensation from occurring inside the discharge pipe, it is possible to prevent the discharge pipe from being clogged with powder or granular material. [Brief explanation of the drawings]

[0023] [Figure 1] 1 is a left side view of a powder / granular material transport vehicle according to an embodiment of the present invention. [Figure 2] FIG. 2 is a rear view of the powder / granular material transport vehicle according to the embodiment of the present invention. [Figure 3]1 is a plan view of a powder / granular material transport vehicle according to an embodiment of the present invention. [Figure 4] 1 is a piping diagram of a powder / granular material transport vehicle according to a first embodiment of the present invention. [Figure 5] FIG. 2 is a cross-sectional view of the tank to show the discharge pipe and discharge pipe cover in the first embodiment of the present invention. [Figure 6] FIG. 2 is a front view showing a discharge pipe and a discharge pipe cover in the first embodiment of the present invention. [Figure 7] FIG. 2 is a bottom view showing a discharge pipe and a discharge pipe cover in the first embodiment of the present invention. [Figure 8] FIG. 2 is a left side view showing a discharge pipe and a discharge pipe cover in the first embodiment of the present invention. [Figure 9] 7 is a cross-sectional view taken along the line AA in FIG. 6. [Figure 10] FIG. 4 is a piping diagram of a powder / granular material transport vehicle according to a second embodiment of the present invention. [Figure 11] FIG. 4 is a piping diagram of a powder / granular material transport vehicle according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0024] First Embodiment A powdery material transport vehicle according to a first embodiment of the present invention will be described below with reference to the drawings. As shown in Figs. 1 to 3, a powdery material transport vehicle 1 according to this embodiment has a travelable chassis 2 and a driver's cab 3. A subframe 4 is provided on the chassis 2. A tank 5, a discharge pipe 6, a discharge hose 7, etc. are provided on the subframe 4.

[0025] Powder and granular material are loaded inside tank 5. A manhole is provided on the top surface of tank 5 for pouring the powder and granular material into tank 5, and a manhole cover 8 for opening and closing the manhole is also provided. The powder and granular material transported by powder and granular material transport vehicle 1 is not limited to a specific one, but cement can be given as an example of powder and granular material that is likely to clog discharge pipe 6 due to condensation inside the discharge pipe 6.

[0026] As shown in FIG. 4, an air slide section 9 for fluidizing the powder or granular material is provided at the bottom of the tank 5. The air slide section 9 is composed of the bottom surface 5a of the tank 5 and a canvas 11. The canvas 11 is provided so as to form an air chamber 12 between the canvas 11 and the bottom surface 5a of the tank 5. Compressed air is supplied to the air chamber 12 by a compressed air supply section 16, which will be described later. The bottom surface 5a of the tank 5 is inclined downward toward a position overlapping with the upstream end 6a of the discharge pipe 6 when viewed from above. This inclination causes the powder or granular material to accumulate between the canvas 11 and the upstream end 6a of the discharge pipe 6, which opens downward. In this embodiment, the upstream end 6a of the discharge pipe 6 is located approximately in the center of the tank 5 when viewed from above.

[0027] The discharge pipe 6 is provided from a position near the bottom inside the tank 5 to the rear of one side of the vehicle outside the tank 5 in order to discharge the powder and granular material inside the tank 5 to the outside of the tank 5. Therefore, the discharge pipe 6 is made up of a portion disposed inside the tank 5 and a portion disposed outside the tank 5.

[0028] The discharge pipe 6 disposed outside the tank 5 is provided with an on-off valve 14 that opens and closes the flow path in the discharge pipe 6. The on-off valve 14 is, for example, a lever-operated butterfly valve.

[0029] A flexible discharge hose 7 is connected to the downstream side of the discharge pipe 6. The powder or granular material is discharged through the flexible discharge hose 7 to a desired location.

[0030] The powder / granular material transport vehicle 1 is provided with a compressed air supply unit 16 (see FIG. 4). The compressed air supply unit 16 supplies compressed air to the inside of the tank 5 so that the powder / granular material loaded inside the tank 5 is discharged to the outside of the tank 5 through the discharge pipe 6 and the discharge hose 7. The compressed air supply unit 16 is composed of an air compressor 17, an air filter 17a, a main pipe 18, valves provided on the main pipe 18, and the like.

[0031] The air compressor 17 is driven by a traveling engine (not shown) via a PTO. The air compressor 17 compresses air drawn in through an air filter 17a and discharges it from a discharge port. The temperature of the compressed air discharged from the discharge port of the air compressor 17 is higher (for example, about 100°C) than the temperature of the drawn air. For example, a screw-type air compressor, a swing-type air compressor, or the like can be used as the air compressor 17.

[0032] A main pipe 18 is connected to the discharge port of the air compressor 17. A plurality of tank branch pipes 21 branch off from the main pipe 18. The plurality of tank branch pipes 21 are each connected to the tank 5 so as to supply compressed air to the air chamber 12 in the tank 5. An air on-off valve 22 is provided midway in each tank branch pipe 21 to open and close the flow path within that pipe. A safety valve 15 is provided in the main pipe 18. A check valve 20 is provided in the main pipe 18 between the air compressor 17 and the safety valve 15. In addition, a check valve 23 is provided in the main pipe 18 downstream of the safety valve 15 and upstream of the air on-off valve 22.

[0033] Also provided is a discharge pipe 19 that connects the main pipe 18 and the discharge pipe 6. The upstream end of the discharge pipe 19 is connected to the main pipe 18 at a position between the check valve 23 and the safety valve 15. The downstream end of the discharge pipe 19 is connected to the discharge pipe 6 downstream of the on-off valve 14. As shown in Figure 4, an air on-off valve 24 that opens and closes the flow path in the discharge pipe 19 is provided midway along the discharge pipe 19, and a check valve 25 is provided downstream of that.

[0034] In addition, a heating branch pipe 28 for supplying high-temperature compressed air into a discharge pipe cover 42 (described later) is branched off from the discharge pipe 19. An air on-off valve 29 for opening and closing the flow path within the pipe is also provided midway along this heating branch pipe 28, and a check valve 30 is provided downstream of this.

[0035] Air vent valves 26 and 27 are provided at the front and rear of the tank 5, respectively. The air vent valve 26 is used to release residual pressure in the tank 5 to the atmosphere. The discharge pipe 19 is also provided with an air vent valve 27, which is used to release residual pressure therein to the atmosphere.

[0036] Next, a description will be given of a configuration for preventing or suppressing condensation from occurring inside the discharge pipe 6. The powder / granular material transport vehicle 1 is equipped with heating means 40 that heats a portion of the discharge pipe 6 located inside the tank 5 in order to prevent or suppress condensation from occurring inside the discharge pipe 6. In this embodiment, the heating means 40 is made up of an air compressor 17, a compressed air conduit 41, a discharge pipe cover 42, etc.

[0037] The compressed air conduit 41 guides the high-temperature compressed air generated by the air compressor 17 to the discharge pipe 6. In this embodiment, the compressed air conduit 41 is made up of the main pipe 18, a part of the discharge pipe 19, and the heating branch pipe 28.

[0038] 5, the discharge pipe cover 42 covers a portion of the discharge pipe 6 and forms an air passage 43 through which air passes between the discharge pipe cover 42 and the outer surface of the discharge pipe 6. In this embodiment, the discharge pipe cover 42 covers the bent portion 6b of the discharge pipe 6 and forms air passages 43A and 43B between the discharge pipe cover 42 and the bent portion 6b. The heating branch pipe 28 constituting the compressed air conduit 41 is connected to an air introduction hole 42a formed in the discharge pipe cover 42 and communicates with the air passage 43A inside the discharge pipe cover 42. The discharge pipe cover 42 also has an exhaust hole 42b that discharges the compressed air that has passed through the air passages 43A and 43B.

[0039] Specific examples of the discharge pipe cover 42 will be described in detail with reference to Figures 6 to 9. The discharge pipe cover 42 shown in these figures includes a cylindrical portion 421, lid portions 422 and 423, and partition plates 424 and 425.

[0040] The tubular portion 421 is disposed at a position away from the discharge pipe 6 so as to form air passages 43A and 43B between the tubular portion 421 and the discharge pipe 6. The tubular portion 421 is composed of an outer plate 421a, an inner plate 421b, and two side plates 421c. The tubular portion 421 has a rectangular cross section, and as shown in FIG. 6, has a curved shape that follows the curved portion 6b of the discharge pipe 6 as a whole.

[0041] The outer plate 421a is disposed radially outward of the curved portion 6b of the discharge pipe 6 and is made of a rectangular thin plate material bent so as to maintain a fixed distance from the curved portion 6b of the discharge pipe 6. The inner plate 421b is disposed radially inward of the curved portion 6b of the discharge pipe 6 and is made of a rectangular thin plate material bent so as to maintain a fixed distance from the curved portion 6b of the discharge pipe 6. As shown in Figures 6 and 7, the two side plates 421c are made of thin plate material formed into an arc shape according to the shape of the curved portion 6b of the discharge pipe 6. The two side plates 421c are joined by welding to the side edge of the inner peripheral surface of the outer plate 421a and the side edge of the outer peripheral surface of the inner plate 421b.

[0042] The lid portions 422, 423 close the openings between both ends of the tubular portion 421 and the discharge pipe 6. The lid portions 422, 423 are made of rectangular thin plates having a circular hole in the center with the same diameter as the discharge pipe 6. It is desirable that the lid portions 422, 423 be joined to the outer plate 421a, the inner plate 421b, and the side plate 421c by welding without any gaps.

[0043] The partition plates 424, 425 are joined by welding to the discharge pipe cover 42 and the discharge pipe 6, respectively, and divide the space between the discharge pipe cover 42 and the discharge pipe 6 into a radially outer air passage 43A (hereinafter also referred to as the "outer air passage 43A") and a radially inner air passage 43B (hereinafter also referred to as the "inner air passage 43B"). However, at one end side of the discharge pipe cover 42 (the upstream side of the discharge pipe 6), the partition plates 424, 425 and the lid portion 423 are spaced apart, and a communication portion 43C that connects the outer air passage 43A and the inner air passage 43B is formed. The partition plates 424, 425 are made of rectangular thin plates that are curved with the same radius of curvature as the center line of the curved portion 6b of the discharge pipe 6.

[0044] The heating branch pipe 28 (see FIG. 5), which constitutes a part of the compressed air conduit 41, is connected to an air inlet hole 42a formed in the cylindrical portion 421 of the discharge pipe cover 42 so as to supply compressed air to the other end side (downstream side of the discharge pipe 6) of the outer air passage 43A in the discharge pipe cover 42. In addition, an exhaust hole 42b formed in the cylindrical portion 421 of the discharge pipe cover 42 is connected to an outlet pipe 44 (see FIG. 5) which leads the compressed air that has passed through the air passage 43 into the air chamber 12.

[0045] Next, a case will be described in which the powder and granular material loaded in the tank 5 is discharged from the tank 5 in the powder and granular material transport vehicle 1. In the following description, the initial state is defined as a state in which the air compressor 17 is stopped, the on-off valve 14, the air on-off valves 24 and 29, and the air vent valve 26 are closed, and the air on-off valve 22 and the air vent valve 27 are open. Note that the initial state may also be a state in which the air on-off valve 29 is open.

[0046] From the initial state, the air compressor 17 is driven and the air on-off valve 29 provided on the heating branch pipe 28 is fully opened (if the air on-off valve 29 is open in the initial state, it is kept open).

[0047] When the air on-off valve 29 provided on the heating branch pipe 28 is opened, the high-temperature compressed air generated by the air compressor 17 is introduced into the air passages 43A and 43B provided between the discharge pipe cover 42 and the discharge pipe 6 along the direction indicated by the arrow in Figure 5 through the compressed air conduit 41 consisting of the main pipe 18, the discharge pipe pipe 19, and the heating branch pipe 28.

[0048] The high-temperature compressed air first flows through the outer air passage 43A, from the downstream side to the upstream side of the discharge pipe 6. Next, the flow is reversed at the end (communication portion 43C) of the discharge pipe cover 42, and flows through the inner air passage 43B, from the upstream side to the downstream side of the discharge pipe 6. At this time, the discharge pipe 6 is heated by the high-temperature air flowing through the outer air passage 43A and the inner air passage 43B. When the discharge pipe 6 is heated, condensation is less likely to occur on the inner surface of the discharge pipe 6, and powder and granular material is less likely to accumulate inside the discharge pipe 6. Furthermore, because the discharge pipe 6 is typically made of a metal material, when the bent portion 6b of the discharge pipe 6 is heated, the temperature of portions other than the bent portion 6b also rises due to heat conduction, making it less likely that condensation will occur on the inner surface of portions other than the bent portion 6b.

[0049] In this embodiment, the cross section of the discharge pipe cover 42 is rectangular rather than circular, so that air tends to stagnate and flow at a relatively slow speed at a corner 43a (see FIG. 9) of the air passage 43 that is located relatively far from the discharge pipe 6. The air at this corner 43a functions like a heat-retaining film, making it difficult to lower the temperature of the portion near the discharge pipe 6 where the flow speed is relatively fast.

[0050] Meanwhile, because the air on-off valve 22 provided on the tank branch pipe 21 is also open, compressed air generated by the air compressor 17 is supplied to the air chamber 12 in the tank 5. When compressed air is supplied to the air chamber 12, the powder and granular material loaded in the tank 5 is fluidized, and the pressure inside the tank 5 increases. As described with reference to Figure 5, compressed air that has passed through the air passage 43 and outlet pipe 44 in the discharge pipe cover 42 is also supplied to the air chamber 12.

[0051] Thereafter, when the pressure inside the tank 5 rises to a predetermined pressure, the on-off valve 14 provided on the discharge pipe 6 is opened, and the powder and granular material fluidized inside the tank 5 is discharged to the outside through the discharge pipe 6 and the discharge hose 7. If it is difficult to discharge the powder and granular material smoothly, such as when discharging the powder and granular material to a high place, the air on-off valve 24 provided on the discharge pipe piping 19 is also opened. In this way, compressed air is supplied directly to the discharge pipe 6, promoting flow in the discharge direction inside the discharge pipe 6 and allowing the powder and granular material to be discharged smoothly.

[0052] The powder / granular material transport vehicle 1 according to the first embodiment described above provides the following advantageous effects.

[0053] (1) In the powder / granular material transport vehicle 1 according to the first embodiment, the bent portion 6b of the discharge pipe 6 is heated using high-temperature compressed air generated by the air compressor 17, thereby preventing or suppressing condensation inside the bent portion 6b of the discharge pipe 6. As a result, clogging of the discharge pipe 6 with powder / granular material can be prevented. The bent portion 6b of the discharge pipe 6 is the portion where air flowing in from the upstream end 6a of the discharge pipe 6 first changes direction significantly and where powder / granular material first collides with the inner surface of the discharge pipe 6. Therefore, this portion of the discharge pipe 6 is particularly prone to accumulation of powder / granular material. Therefore, heating the bent portion 6b can efficiently prevent clogging of the inside of the discharge pipe 6 with powder / granular material. Note that the compressed air supplied from the air compressor 17 to the air chamber 12 expands beyond a certain level and its temperature drops. However, compressed air is introduced from the air compressor 17 into the air passage 43 inside the discharge pipe cover 42 before it has expanded beyond a certain level and its temperature has dropped. Therefore, the bent portion 6b of the discharge pipe 6 is heated to a high temperature.

[0054] In the above-described embodiment, the air on-off valve 22 provided on the tank branch pipe 21 is kept fully open when the powder or granular material in the tank 5 is being discharged, but it is also possible to reduce the opening of the air on-off valve 22 or close it to introduce more compressed air into the discharge pipe cover 42 through the compressed air conduit 41, thereby further heating the bent portion 6b of the discharge pipe 6. Since the temperature of the discharge pipe 6 is likely to drop when the powder or granular material in the tank 5 is being discharged to the outside, by further heating the discharge pipe 6 in this way, the temperature of the discharge pipe 6 can be maintained, and ultimately, clogging of the inside of the discharge pipe 6 with powder or granular material can be reliably prevented.

[0055] (2) The inner surface of the curved portion 6b of the discharge pipe 6 has a larger surface area on the radially outer side than on the radially inner side, so that more water droplets adhere to the curved portion 6b due to condensation on the radially outer side. Furthermore, when powder or granular material is discharged through the discharge pipe 6, centrifugal force acts on the powder or granular material flowing through the curved portion 6b of the discharge pipe 6, so that more powder or granular material adheres to the curved portion 6b than to the radially inner side. According to the powder or granular material transport vehicle 1 of the first embodiment, the compressed air that flows along the radially outer side of the curved portion 6b of the discharge pipe 6 and exchanges heat with the discharge pipe 6 flows along the radially inner side of the curved portion 6b of the discharge pipe 6. Therefore, the radially outer side of the curved portion 6b, where powder or granular material is likely to accumulate, can be heated to a higher temperature than the radially inner side, effectively preventing the curved portion 6b of the discharge pipe 6 from being clogged with powder or granular material.

[0056] (3) Furthermore, since the timing when condensation occurs inside the discharge pipe 6 and the timing when the air compressor 17 is driven to supply compressed air into the tank 5 overlap, the discharge pipe 6 can be heated using the high-temperature compressed air generated by the air compressor 17, and condensation can be prevented or suppressed from occurring inside the discharge pipe 6 without driving a device solely for preventing condensation.

[0057] (4) According to the powder and granular material transport vehicle 1 of the first embodiment, the portion of the discharge pipe 6 located inside the tank 5 is heated. However, since the upstream side of the discharge pipe 6 is more susceptible to condensation, heating the portion of the discharge pipe 6 where condensation is more likely to occur can effectively prevent or suppress condensation.

[0058] (5) The powder and granular material transport vehicle 1 according to the first embodiment has advantages such as eliminating the cost of the dehumidification device compared to the conventional case where a dehumidification device is installed on the powder and granular material transport vehicle, and hardly requiring a reduction in the load weight of the powder and granular material because the weight increase of the mounting device is suppressed.

[0059] Second Embodiment A powdered material transport vehicle according to a second embodiment of the present invention will be described below with reference to FIG. 10 . The powdered material transport vehicle 1A according to the second embodiment is different from the powdered material transport vehicle 1 according to the first embodiment in that it does not include the discharge pipe cover 42, and instead of the heating branch pipe 28 that branches off from the discharge pipe 19 and is connected to the discharge pipe cover 42, a heating branch pipe 28A is provided that branches off from the discharge pipe 19 and is connected to the discharge pipe 6 upstream of the on-off valve 14. The heating branch pipe 28A is provided to directly introduce high-temperature compressed air generated by the air compressor 17 into the discharge pipe 6. In the powdered material transport vehicle 1A according to the second embodiment, the heating branch pipe 28A is connected to a portion of the discharge pipe 6 outside the tank 5 near the tank 5, but the location to which the heating branch pipe 28A is connected is not limited thereto. For example, the heating branch pipe 28A may be connected to a bent portion 6b of the discharge pipe 6 inside the tank 5. When there are a plurality of bent portions 6b, the position where the heating branch pipe 28A is connected is preferably the bent portion located most upstream.

[0060] A case will be described in which the powder and granular material loaded in the tank 5 is discharged from the powder and granular material transport vehicle 1A configured as described above. In the following description, the initial state is defined as a state in which the air compressor 17 is stopped, the on-off valve 14, the air on-off valves 24 and 29, and the air vent valve 26 are closed, and the air on-off valve 22 and the air vent valve 27 are open. Note that the initial state may also be a state in which the air on-off valve 29 is open.

[0061] From the initial state, the air compressor 17 is driven, and the air on-off valve 29 provided on the heating branch pipe 28A is fully opened (if the air on-off valve 29 is open in the initial state, it is kept open).

[0062] When the air on-off valve 29 provided on the heating branch pipe 28A is opened, high-temperature compressed air generated by the air compressor 17 is introduced into the discharge pipe 6 through a compressed air conduit 41 made up of the main pipe 18, the discharge pipe 19, and the heating branch pipe 28A. The introduced high-temperature air flows in the direction indicated by the arrow in the discharge pipe 6 shown in Figure 10, and the upstream side of the position where the on-off valve 14 of the discharge pipe 6 is provided is heated. Then, by heating the discharge pipe 6, condensation is less likely to form on the inner surface of the discharge pipe 6.

[0063] Meanwhile, the air on-off valve 22 provided on the tank branch pipe 21 is also open, so that compressed air generated by the air compressor 17 is supplied to the air chamber 12 inside the tank 5. When compressed air is supplied to the air chamber 12, the powder and granular material loaded inside the tank 5 is fluidized, and the pressure inside the tank 5 increases.

[0064] Thereafter, when the pressure inside the tank 5 rises to a predetermined pressure, the on-off valve 14 provided on the discharge pipe 6 is opened. Then, the powder and granular material fluidized inside the tank 5 is discharged to the outside through the discharge pipe 6 and the discharge hose 7 in the direction indicated by the arrow inside the discharge pipe 6 shown in Figure 11. At this time, the discharge of the powder and granular material can be assisted by leaving the air on-off valve 29 open. To further assist the discharge of the powder and granular material, the air on-off valve 24 provided on the discharge pipe piping 19 may be opened.

[0065] In addition, if the powder or granular material flows backward through the heating branch pipe 28A while being discharged through the discharge pipe 6 and the discharge hose 7, the air on-off valve 29 provided on the heating branch pipe 28A may be closed and the air on-off valve 24 provided on the discharge pipe piping 19 may be opened to supply compressed air downstream of the on-off valve 14 of the discharge pipe 6.

[0066] The powder material transport vehicle 1A according to the second embodiment described above provides the following advantageous effects.

[0067] (1) According to the powder / granular material transport vehicle 1A of the second embodiment, the discharge pipe 6 is heated using high-temperature compressed air generated by the air compressor 17, thereby preventing or suppressing condensation inside the discharge pipe 6. As a result, clogging of the discharge pipe 6 with powder / granular material can be prevented. Note that the compressed air supplied from the air compressor 17 to the air chamber 12 expands beyond a certain level and drops in temperature, but the compressed air introduced from the air compressor 17 to the discharge pipe 6 has not yet expanded beyond the certain level and dropped in temperature. As a result, the discharge pipe 6 is heated to a high temperature.

[0068] (2) Furthermore, since the timing at which condensation occurs inside the discharge pipe 6 overlaps with the timing at which the air compressor 17 is driven to supply compressed air into the tank 5, the discharge pipe 6 can be heated using the high-temperature compressed air generated by the air compressor 17, and condensation can be prevented or suppressed from occurring inside the discharge pipe 6 without having to drive a device solely for preventing condensation.

[0069] (3) The powder and granular material transport vehicle 1A according to the second embodiment has advantages over the conventional case in which a dehumidifying device is installed on a powder and granular material transport vehicle, such as eliminating the cost of the dehumidifying device and minimizing the need to reduce the load weight of the powder and granular material because the weight increase of the mounting device is suppressed.

[0070] <Modification 1 of the First Embodiment> In the powder and granular material transport vehicle 1 of the first embodiment, a discharge pipe cover 42 is attached to the curved portion 6b of the discharge pipe 6 inside the tank 5, and the curved portion 6b is heated with high-temperature compressed air, but a discharge pipe cover may also be attached to other parts of the discharge pipe 6 inside the tank 5, or the entire discharge pipe 6 inside the tank 5, so that it can be heated.

[0071] <Modification 2 of the First Embodiment> In the powder / granular material transport vehicle 1 according to the first embodiment, the discharge pipe cover 42, the heating branch pipe 28, the air on-off valve 29, and the check valve 30 may be omitted, and an electric heater may be provided as heating means to cover the bent portion 6b or other portion of the discharge pipe 6 inside the tank 5, or the entire discharge pipe 6 inside the tank 5. In this case, it is desirable to turn on the switch of the electric heater before discharging the powder / granular material, and heat the discharge pipe 6 to prevent condensation from forming inside the discharge pipe 6 before the powder / granular material is discharged.

[0072] <Modification 3 of the First Embodiment> In the powder / granular material transport vehicle 1 according to the first embodiment, the cross section of the discharge pipe cover 42 is rectangular, but the cross section of the discharge pipe cover 42 may also be circular. In this case, the discharge pipe cover 42 is preferably arranged so that its cross section forms a concentric circle with respect to the discharge pipe 6. This makes the flow rate of the compressed air passing through the air passage 43 uniform regardless of the location in the air passage 43, allowing the discharge pipe 6 to be heated efficiently.

[0073] <Modification 1 of the above embodiment> In the above-described embodiment, an air slide type powder / granular material transport vehicle has been exemplified, but the invention according to this embodiment can also be applied to powder / granular material transport vehicles other than the air slide type. For example, the invention can be applied to an aeration (air agitation) type powder / granular material transport vehicle that collects powder / granular material at a discharge outlet by tilting the inside of the tank, an air slide type and aeration type powder / granular material transport vehicle, and a dump type powder / granular material transport vehicle.

[0074] <Modification 2 of the above embodiment> In the embodiment described above, a configuration in which the discharge pipe 6 inside the tank 5 is heated has been exemplified, but a configuration in which the discharge pipe 6 outside the tank 5 is heated may also be used. When powder or granular material is being discharged outside the tank 5 through the discharge pipe 6, the pressure inside the discharge pipe 6 and the discharge hose 7 gradually decreases as the pressure approaches the downstream end of the discharge hose 7, and becomes atmospheric pressure at the downstream end of the discharge hose 7. When the powder or granular material discharge operation is completed, the pressure inside the tank 5 and the downstream end of the discharge hose 7 decreases to atmospheric pressure. The greater the pressure drop inside the discharge pipe 6, the greater the temperature drop, so the pressure drop and temperature drop are greater in the portion of the discharge pipe 6 outside the tank 5 that is closest to the tank 5. Therefore, it is preferable to heat the portion close to the tank 5 where condensation is likely to occur.

[0075] <Modification 3 of the above embodiment> In the embodiment described above, the partition plates 424, 425 are provided to divide the ventilation path 43 in the exhaust pipe cover 42 into the outer ventilation path 43A and the inner ventilation path 43B. However, the ventilation path 43 may not be divided into the outer ventilation path 43A and the inner ventilation path 43B. Even with this configuration, the exhaust pipe 6 can be heated. [Explanation of symbols]

[0076] 1,1A Powder and granular material transport vehicle 2 chassis 5 Tank 6 Discharge pipe 6b Curved section 14 On-off valve 16 Compressed air supply unit 17 Air Compressor 18 Main piping 19 Piping for discharge pipe 28 Heating branch pipe 28A Branch Pipe 40 Heating means 41 Compressed air duct 42 Discharge pipe cover 43 Ventilation channel 43A Outer ventilation channel 43B Inner ventilation channel 44 Outlet piping

Claims

1. a tank mounted on the chassis and containing powder and granular material; a discharge pipe provided from the inside of the tank to the outside of the tank; a compressed air supply unit that supplies compressed air into the inside of the tank so that the powder and granular material loaded inside the tank is discharged to the outside of the tank through the discharge pipe; In a powder transport vehicle equipped with A powder and granular material transport vehicle comprising an electric heater for heating at least a portion of the portion of the discharge pipe located inside the tank.

2. In the powder and granular material transport vehicle described in claim 1, The discharge pipe has a bent portion, the electric heater heats the bent portion of the discharge pipe; A powder and granular material transport vehicle characterized by the above.

3. A tank mounted on a chassis and containing powder and granular material; a discharge pipe provided from the inside of the tank to the outside of the tank; a compressed air supply unit that supplies compressed air into the inside of the tank so that the powder and granular material loaded inside the tank is discharged to the outside of the tank through the discharge pipe; In a powder transport vehicle equipped with a heating means for heating at least a portion of the discharge pipe; the compressed air supply unit includes an air compressor; The heating means is the air compressor included in the compressed air supply unit; a compressed air conduit that guides the compressed air supplied by the air compressor to the discharge pipe; and The heating means is The exhaust pipe cover further includes a discharge pipe cover that covers a portion of the exhaust pipe and forms an air passage between the exhaust pipe and an outer surface thereof, through which air passes; The compressed air conduit is in communication with the air passage so that compressed air guided from the air compressor passes through the air passage. A powder and granular material transport vehicle characterized by the above.

4. The powder transport vehicle according to claim 3, The discharge pipe has a bent portion, The exhaust pipe cover covers the bent portion of the exhaust pipe and forms the air passage between the exhaust pipe cover and an outer surface of the bent portion. A powder and granular material transport vehicle characterized by the above.

5. The powder transport vehicle according to claim 4, The ventilation path is an outer air passage through which the compressed air flows along the radially outer side of the bent portion of the discharge pipe; an inner air passage through which the compressed air flows along a radially inner side of the bent portion of the discharge pipe; Including, the compressed air conduit communicates with the outer air passage; the outer air passage and the inner air passage are communicated with each other so that compressed air supplied from the compressed air conduit passes through the outer air passage and then through the inner air passage. A powder and granular material transport vehicle characterized by the above.

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