Steam jet spraying device for pulverizing and drying

Abstract

To provide a steam jet spraying device that can inject high-temperature gas through a high-temperature gas blower tube to a processing tank using a burner and a blower which are small-sized and inexpensive.SOLUTION: A steam jet spraying device comprises a steam spraying nozzle 10 and a high-temperature gas blower tube 11, supplies supersonic steam and high-temperature gas to a processing tank and pulverizes and dries raw materials in the processing tank, which is configured so that an axis line position L1 of a spraying port 16 of the steam spraying nozzle 10 is arranged closer to a blowing port of the high-temperature gas blower tube 11 than a central axis line C0 of an introducing tube 9 in a radial direction of the introducing tube 9 and so that ultrasonic steam sprayed from the steam spraying nozzle 10 exerts Coanda effect at a position close to the blowing port to offset pressure for pushing out the materials from the processing tank.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a steam jet injection device that injects supersonic steam and high-temperature gas into a treatment vessel to pulverize and dry raw materials in the treatment vessel. [Background technology]

[0002] Generally, as shown in FIG. 10, a steam jet injection device has a processing vessel 1 to which raw material is supplied, and a steam injection nozzle 3 and a high-temperature gas blower 4 are arranged via an injection pipe 2. The steam injection nozzle 3 injects supersonic steam into the injection pipe 2, and the high-temperature gas blower 4 blows high-temperature gas into the injection pipe 2 using a burner 5 and a blower 6. The supersonic steam and high-temperature gas are then injected into the processing vessel 1 as a supersonic saturated steam jet, pulverizing and drying the raw material within the processing vessel 1 (see, for example, Patent Document 1 below). Then, as shown in FIG. 11, the pulverized and dried raw material is introduced into a cyclone 8 via a conduit 7, where it is separated into processed material and steam by centrifugal force. Note that FIG. 11 shows the processing vessel 1, conduit 7, and cyclone 8, with the interior clearly visible through the cutaway portions.

[0003] Here, the steam injection nozzle 3 is configured to face the injection pipe 2 from the side so as to be coaxial with the central axis of the injection pipe 2, and supersonic steam is injected from the outside toward the axis inside the injection pipe 2. The high-temperature gas blower duct 4 is configured to face the injection pipe 2 from below so as to be approximately perpendicular to the central axis of the injection pipe 2, and high-temperature gas is blown into the injection pipe 2 from below to above in the radial direction of the injection pipe 2. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 3709880 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the steam jet injection device, due to the configuration of the treatment tank 1, conduit 7, and cyclone 8, the pressure inside the treatment tank 1 is slightly positive, so pressure is generated that tries to push the gas outward from inside the treatment tank 1 in the direction of the injection pipe 2, etc., and when supplying high-temperature gas from the high-temperature gas blower pipe 4 to the treatment tank 1, it was necessary to use a large and expensive burner 5 and blower 6 so that the gas could be blown in at a higher pressure than the internal pressure of the treatment tank 1.

[0006] SUMMARY OF THE INVENTION In view of the above circumstances, the present invention provides a steam jet injection device that can blow high-temperature gas into a treatment tank from a high-temperature gas blower pipe using a small, inexpensive burner or blower. [Means for solving the problem]

[0007] The present invention provides a steam jet injection device comprising a steam injection nozzle for injecting supersonic steam into an injection pipe in an axial direction, and a high-temperature gas blowing pipe for blowing high-temperature gas into the injection pipe from a radial direction, the device supplying the supersonic steam and the high-temperature gas from the injection pipe to a treatment tank, and pulverizing and drying raw materials in the treatment tank, an axis of the injection port of the steam injection nozzle is disposed closer to the blowing port of the high-temperature gas blowing pipe than the central axis of the injection pipe in the radial direction of the injection pipe; The supersonic steam jetted from the steam injection nozzle generates the Coanda effect at a position close to the air outlet, thereby offsetting the pressure that tends to push the steam out of the treatment tank.

[0008] In the steam jet injection device for pulverization and drying of the present invention, the supersonic steam injected from the steam injection nozzle can be configured to offset the pressure that tries to push the steam out of the treatment tank due to the Coanda effect, resulting in zero or negative pressure at the air outlet.

[0009] In the steam jet injection device for pulverization and drying of the present invention, the axial position of the injection port of the steam injection nozzle is preferably set in the range of more than 0 mm and not more than 40 mm from the blower port side with respect to the inner diameter of the injection pipe.

[0010] In the steam jet injection device for pulverization and drying of the present invention, the injection port of the steam injection nozzle may be formed into an ellipse or a rectangle when viewed from the axial direction so that supersonic steam is injected onto the entire surface of the high-temperature gas from the high-temperature gas blower pipe. [Effects of the Invention]

[0011] According to the steam jet injection device for pulverization and drying of the present invention, when supersonic steam is injected from the steam injection nozzle into the injection pipe, the Coanda effect offsets the pressure that tries to push the steam out of the treatment tank, so that high-temperature gas can be injected from the high-temperature gas blower pipe using a small, inexpensive burner or blower. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a conceptual diagram showing a first example of the configuration of a steam jet injection device for pulverization and drying according to the present invention. [Figure 2] 1 is a conceptual diagram showing a first example of the configuration of a steam jet injection device for pulverization and drying according to the present invention, including a steam injection nozzle, a high-temperature gas blower pipe, and an injection pipe. [Figure 3] FIG. 3 is a conceptual diagram showing a state in which supersonic steam is injected in the configuration of FIG. 2. [Figure 4] 1A and 1B are conceptual diagrams showing the front and side views of an example of the shape of the nozzle of a steam injection nozzle. [Figure 5] 10A and 10B are conceptual diagrams showing the front and side views of another example of the shape of the outlet of the steam injection nozzle. [Figure 6] 1 is a conceptual diagram showing the relationship between the shape of the nozzle of the steam injection nozzle and the diameter of the blowing port of the high-temperature gas blowing pipe. FIG. [Figure 7] FIG. 2 is a conceptual diagram showing a second example of the configuration of a steam jet injection device for pulverization and drying according to the present invention, which includes a steam injection nozzle, a high-temperature gas blower pipe, and an injection pipe. [Figure 8] FIG. 8 is a conceptual diagram showing a state in which supersonic steam is injected in the configuration of FIG. 7. [Figure 9] FIG. 10 is a conceptual diagram showing a third example of the configuration of the steam jet injection device for pulverization and drying of the present invention. [Figure 10] FIG. 1 is a conceptual diagram showing an example of the configuration of a conventional steam jet injection device for pulverization and drying. [Figure 11] FIG. 1 is a conceptual diagram showing an example of the configuration of a conventional steam jet injection device for pulverization and drying, including a treatment tank, a conduit, and a cyclone. DETAILED DESCRIPTION OF THE INVENTION

[0013] A first embodiment of the present invention will now be described with reference to the accompanying drawings.

[0014] FIG. 1 shows a conceptual diagram of a first example of the configuration of a steam jet injection device for pulverization and drying according to the present invention. The steam jet injection device for pulverization and drying includes a drum-shaped treatment vessel 1 consisting of a circular body 1a and side plates 1b on both sides. The treatment vessel 1 has a gas injection port 1c formed near the bottom end of the circular body 1a and a gas discharge port 1d formed at the center of one of the side plates 1b. A raw material supply port (not shown) is also formed at the lower end of the side plate 1b. A conduit 7 is connected to the gas discharge port 1d, which leads to a cyclone 8. A steam injection nozzle 10 and a high-temperature gas blower duct 11 are connected to the gas injection port 1c via an injection pipe 9. A raw material supply unit (not shown) is connected to the raw material supply port (not shown) so that raw materials such as dehydrated cake are supplied into the treatment vessel 1 from the side of the gas injection port 1c.

[0015] 2 and 3, the injection pipe 9 has a two-stage stepped configuration, with an upper pipe section 12 connected to the gas injection port 1c (see FIG. 1) and extending laterally, an inclined pipe section 13 inclined downward from the upper pipe section 12, and a lower pipe section 14 extending laterally from the inclined pipe section 13 and having a flange 14a at its end. The upper pipe section 12 of the injection pipe 9 has a central axis C0 parallel to the tangent line at the lowest end within the treatment tank 1, and has an air outlet 15 formed on its underside at an intermediate position. The lower pipe section 14 of the injection pipe 9 has a central axis C1 parallel to the central axis C0 of the upper pipe section 12, and is designed to accommodate a steam injection nozzle 10.

[0016] The steam injection nozzle 10 is configured to face the injection pipe 9 from the side, has an injection port 16 formed at its tip, and is disposed at its tip inside the lower pipe section 14 of the injection pipe 9, and is fixed to the injection pipe 9 via a flange 10a that can be connected to the lower pipe section 14. The steam injection nozzle 10 is also connected to steam generation equipment (not shown) through a steam supply pipe (not shown).

[0017] The position of the injection port 16 of the steam injection nozzle 10 is such that the axial position L1 of the injection port 16 is located closer to the outlet of the high-temperature gas blower pipe 11 than the central axis of the upper pipe section 12 in the vertical radial direction of the upper pipe section 12 due to the stepped shape of the injection pipe 9. Furthermore, the axial position L1 of the injection port 16 is set in a height range of more than 0 mm and not more than 40 mm from the lower surface of the inner circumference on the outlet side of the upper pipe section 12 with respect to the vertical inner diameter R1 of the upper pipe section 12, and more preferably in a height range of 5 mm to 20 mm. Here, the specific value of the axial position L1 of the injection port 16 is set to a height range of more than 0 mm and not more than 40 mm from the lower surface of the inner circumference on the air outlet side of the upper pipe section 12, particularly preferably around 5 mm, from the lower surface of the inner circumference on the air outlet side of the upper pipe section 12, with the upper and lower inner diameters of the upper pipe section 12 being 50 mm to 100 mm, under the condition that the injection pressure of the steam injection nozzle 10 is 0.2 MPa or more and 0.4 MPa.

[0018] 4 to 6, the shape of the injection port 16 of the steam injection nozzle 10 is formed into an ellipse (see FIG. 4) or a rectangle (see FIG. 5) when viewed from the axial direction so that the supersonic steam S collides with the high-temperature gas H from the blowing port 15 to cover the entire cross section of the high-temperature gas H (the entire surface of the high-temperature gas). Here, the shape of the injection port 16 is not limited to an ellipse or a rectangle as long as the supersonic steam S collides with the high-temperature gas H to cover the entire cross section, but an ellipse or a rectangle is preferable from the viewpoint of the injection shape.

[0019] 1 to 3, the high-temperature gas duct 11 extends from below toward the injection pipe 9 so as to be substantially perpendicular to the central axis C0 of the upper pipe portion 12, and an air duct 17 is disposed around the high-temperature gas duct 11. The high-temperature gas duct 11 and the air duct 17 form an inner and outer double duct, are connected to the air outlet 15 of the upper pipe portion 12, and are configured so as to be coaxial with the center line of the air outlet 15. The high-temperature gas duct 11 is bent downward and extends outward through the air duct 17, and a small burner 18 that generates high-temperature gas H is connected to the outer end of the high-temperature gas duct 11. A small blower 20 is connected to one end of the air duct 17 via a flexible hose 19. The burner 18 supplies high-temperature gas H, and the blower 20 blows room-temperature air, which cools the high-temperature gas blowing pipe 11 to protect it from high heat, and becomes warm air through heat exchange, which is then blown into the injection pipe 9 together with the high-temperature gas H. Here, the high-temperature gas blowing pipe 11 and the air blowing pipe 17 are configured to face the injection pipe 9 from below, but they may also be configured to face the injection pipe 9 from any other direction as long as they face the injection pipe 9 from the radial direction of the injection pipe 9.

[0020] The operation of the first embodiment of the present invention will be described.

[0021] When the raw material is pulverized and dried, the raw material is supplied to the treatment tank 1, while supersonic steam S is injected from the steam injection nozzle 10 into the injection pipe 9, and high-temperature gas H is blown into the injection pipe 9 from the high-temperature gas blower pipe 11.

[0022] At this time, the supersonic steam S injected from the outlet 16 of the steam injection nozzle 10 in the axial direction of the upper pipe section 12 passes through a height range of more than 0 mm and not more than 40 mm from the air outlet 15, causing the Coanda effect, and canceling out the pressure trying to push out from the treatment tank 1 in the direction toward the high-temperature gas blower pipe 11 (outward from the treatment tank 1), resulting in zero or negative pressure at the air outlet 15.

[0023] The high-temperature gas H sent from the high-temperature gas blowing pipe 11 to the upper pipe portion 12 can be supplied at zero or negative pressure at the blowing port 15, which is lower than the conventional pressure.

[0024] Here, the conditions such as the passage position and pressure of the supersonic vapor S are not particularly limited as long as they cancel out part of the pressure that tries to push out from the treatment tank 1 in the direction toward the high-temperature gas blower pipe 11 (outward from the treatment tank 1) due to the Coanda effect, but it is preferable to make the pressure zero or negative at the blower port 15. Furthermore, it is preferable that the zero or negative pressure at the blower port 15 is specifically in the range of -10 Pa or more and 0 Pa or less.

[0025] The supersonic steam S and high-temperature gas H are then injected into the treatment tank 1 as a supersonic saturated steam jet as shown in Figure 1, where the raw material is crushed and dried. The crushed and dried raw material is then introduced into the cyclone 8 via the conduit 7, where it is separated into the processed material and steam by centrifugal force.

[0026] As described above, the first example of the steam jet injection device for pulverization and drying comprises a steam injection nozzle 10 that injects supersonic steam S axially into the injection pipe 9, and a high-temperature gas blowing pipe 11 that blows high-temperature gas H into the injection pipe 9 from below (radially), and is configured so that the supersonic steam S and high-temperature gas H are supplied from the injection pipe 9 to the treatment tank 1, and the raw materials are pulverized and dried in the treatment tank 1, and the axial position L1 of the injection port 16 of the steam injection nozzle 10 is positioned radially of the injection pipe 9 closer to the blowing port of the high-temperature gas blowing pipe 11 than the central axis C0 of the injection pipe 9, and the supersonic steam S injected from the steam injection nozzle 10 generates a Coanda effect at a position closer to the blowing port, thereby offsetting the pressure that tries to push the steam S out of the treatment tank 1. In this way, when supersonic steam S is blown from the steam injection nozzle 10 into the injection pipe 9, the Coanda effect offsets the pressure that pushes the steam out of the treatment tank 1, so that high-temperature gas H can be blown from the high-temperature gas blower pipe 11 using a small, inexpensive burner 18 or blower 20.

[0027] Furthermore, in the first example of the steam jet injection device for pulverization and drying, the supersonic steam S injected from the steam injection nozzle 10 offsets the pressure that tries to push the steam out of the treatment tank 1 due to the Coanda effect, and when the pressure at the air outlet 15 becomes zero or negative, when the supersonic steam S is blown from the steam injection nozzle 10 into the injection pipe 9, the favorable Coanda effect appropriately offsets the pressure that tries to push the steam out of the treatment tank 1, so that high-temperature gas H can be easily blown in from the high-temperature gas blower pipe 11 using a small, inexpensive burner 18 or blower 20.

[0028] Furthermore, in the first example of the steam jet injection device for pulverization and drying, the axial position L1 of the injection port 16 of the steam injection nozzle 10 is the position through which the supersonic steam S passes, and when it is set in a height range of more than 0 mm and not more than 40 mm from the air outlet 15 relative to the inner diameter of the upper tube portion 12, a favorable Coanda effect is produced, and the high-temperature gas H can be easily blown in from the high-temperature gas blower tube 11 using a small, inexpensive burner 18 or blower 20. Furthermore, the axial position L1 of the injection port 16 is the position through which the supersonic steam S passes, and an even more favorable Coanda effect is produced when it is in a height range of 5 mm to 20 mm from the air outlet 15. On the other hand, if the axial position L1 of the injection port 16 is at the position where the supersonic steam S passes and is less than 5 mm above the air outlet 15, there is a possibility that the supersonic steam S from the steam injection nozzle 10 will enter the air outlet 15, and if the axial position L1 of the injection port 16 is at the position where the supersonic steam S passes and is more than 40 mm above the air outlet 15, there is a problem in that a suitable Coanda effect cannot be produced.

[0029] Furthermore, in the first example of the steam jet injection device for pulverization and drying, if the injection port 16 of the steam injection nozzle 10 is formed into an ellipse or rectangle when viewed from the axial direction so that supersonic steam is directed against the entire surface of the high-temperature gas from the high-temperature gas blowing pipe 11, the Coanda effect will offset the pressure trying to push the gas out of the treatment tank 1, and at the same time, the supersonic steam S will be directed against the entire high-temperature gas from the high-temperature gas blowing pipe 11, and will be injected into the treatment tank 1 as a supersonic saturated steam jet.

[0030] Furthermore, in the first example of the steam jet injection device for pulverization and drying, if the injection pipe 9 is arranged with two steps, one above the other, the axial position L1 of the injection port 16 can be changed and set using a conventional steam injection nozzle.

[0031] A second embodiment of the present invention will now be described with reference to the accompanying drawings.

[0032] 7 shows a second example of the configuration of the steam jet injection device for pulverization and drying of the present invention, and is a conceptual diagram showing the configuration of the steam injection nozzle, high-temperature gas blower pipe, and injection pipe. Here, the second example is a modification of the configuration of the steam injection nozzle and injection pipe of the first example, and the other configurations are the same as those of the first example.

[0033] The injection pipe 21 has a straight shape, is connected to the gas injection port 1c (see FIG. 1), extends laterally, and is provided with a flange 21a. The injection pipe 21 has a central axis C0 parallel to a tangent at the lowermost end in the treatment tank 1, and has an air outlet 22 formed on the lower surface at an intermediate position.

[0034] The steam injection nozzle 23 is configured to face the injection pipe 21 from the side, has an injection port 24 at its tip, and is disposed inside the injection pipe 21 at its tip, and is fixed to the injection pipe 21 via a flange 23a that can be connected to the injection pipe 21. The steam injection nozzle 23 has a smaller diameter than the steam injection nozzle 10 of the first example (see Figure 2).

[0035] The position of the injection port 24 of the steam injection nozzle 23 is such that the axial position L2 of the injection port 24 is located closer to the outlet of the high-temperature gas blower pipe 11 than the central axis C0 of the injection pipe 21 in the vertical radial direction of the injection pipe 21. The axial position L2 of the injection port 24 is set to a height range of more than 0 mm and not more than 40 mm, more preferably 5 mm or more and not more than 20 mm, from the lower surface of the inner circumference on the blower side of the upper pipe section 12 relative to the vertical inner diameter R2 of the upper pipe section 12 so as to be closer to the blower port when the injection pressure of the steam injection nozzle 23 is 0.2 MPa or more and 0.4 MPa or less. Here, the specific numerical value of the axial position L2 of the injection port 24 can be set to the same conditions as in the first example.

[0036] As in the first example, the shape of the outlet 24 of the steam injection nozzle 23 is formed as an ellipse (see FIG. 4) or a rectangle (see FIG. 5) when viewed from the axial direction so that the supersonic steam S collides with the high-temperature gas H from the blowing port to cover the entire cross section of the high-temperature gas H. Here, the shape of the outlet 24 is not limited to an ellipse or a rectangle as long as the supersonic steam S collides with the high-temperature gas H to cover the entire cross section of the high-temperature gas H, but an ellipse or a rectangle is preferable from the viewpoint of the injection shape.

[0037] The operation of the second embodiment of the present invention will be described.

[0038] When pulverizing and drying the raw materials, as in the first example, the raw materials are supplied to the treatment tank 1, and at the same time, as shown in Figure 8, supersonic steam S is injected from the steam injection nozzle 23 into the injection pipe 21, and high-temperature gas H is blown into the injection pipe 21 from the air outlet 22.

[0039] At this time, the supersonic steam S injected from the outlet 24 of the steam injection nozzle 23 in the axial direction of the upper tube section 12 passes through a height range of more than 0 mm and not more than 40 mm from the air outlet 22, causing the Coanda effect, counteracting the pressure trying to push out from the treatment tank 1 in the direction toward the high-temperature gas air outlet pipe (outward from the treatment tank 1), and making the pressure at the air outlet zero or negative.

[0040] The high-temperature gas H sent from the high-temperature gas blowing pipe to the upper pipe portion 12 can be supplied at zero or negative pressure at the blowing port 22, which is lower than the conventional pressure.

[0041] Here, the conditions such as the passage position and pressure of the supersonic vapor S are not particularly limited as long as they cancel out part of the pressure that tries to push out from the treatment tank 1 in the direction toward the high-temperature gas blower pipe (outward from the treatment tank 1) due to the Coanda effect, but it is preferable to make the pressure zero or negative at the blower port 22. Furthermore, it is preferable that the zero or negative pressure at the blower port 22 be specifically in the range of -10 Pa or more and 0 Pa or less.

[0042] The supersonic steam S and high-temperature gas H are then injected into the treatment tank 1 as a supersonic saturated steam jet as shown in Figure 1, where the raw material is crushed and dried. The crushed and dried raw material is then introduced into the cyclone 8 via the conduit 7, where it is separated into the processed material and steam by centrifugal force.

[0043] As described above, the steam jet injection device for pulverization and drying of the second embodiment can obtain the same effects as those of the first embodiment.

[0044] Furthermore, in the second example of the steam jet injection device for pulverization and drying, by using a straight injection pipe 21 and a small-diameter steam injection nozzle 23, a complex injection pipe 21 such as a stepped one (see Figures 1 to 3) is not required, and the axial position L2 of the injection port 24 of the steam injection nozzle 23 can be easily set.

[0045] A third embodiment of the present invention will now be described with reference to the accompanying drawings.

[0046] 9 shows a third example of the configuration of the steam jet injection device for pulverization and drying of the present invention, and is a conceptual diagram showing the configuration of the steam injection nozzle, high-temperature gas blower pipe, and injection pipe. Here, the third example has a modified configuration of the steam injection nozzle and injection pipe, but the other configurations are the same as those of the first example.

[0047] The injection pipe 25 has a straight shape, is connected to the gas injection port 1c (not shown), and extends laterally. The central axis of the injection pipe 25 is parallel to the tangent line at the lowermost end of the treatment tank 1.

[0048] The steam injection nozzle 26 faces the injection pipe 25 from the side, has an injection port 27 at its tip, and is disposed inside the injection pipe 25. The high-temperature gas blowing pipe 28 is tubular and positioned on the outer periphery of the steam injection nozzle 26, with an opening 29 at its tip, and is disposed so that its outer periphery is in contact with the inner periphery of the injection pipe 25. The steam injection nozzle 26 and the high-temperature gas blowing pipe 28 are coaxial with the central axis of the injection pipe 25, forming a double inner and outer pipe passage, and the pipe diameter is small so that the injection port 27 and opening 29 are narrow.

[0049] The operation of the third embodiment of the present invention will be described.

[0050] When pulverizing and drying the raw materials, as in the first example, the raw materials are supplied to the treatment tank 1, while supersonic steam S is injected from the steam injection nozzle 26 into the injection pipe 25, and high-temperature gas H is blown into the injection pipe 25 from the high-temperature gas blower pipe 28.

[0051] At this time, the supersonic steam S injected from the outlet 27 of the steam injection nozzle 26 in the axial direction of the injection pipe 25 passes near the opening 29 of the high-temperature gas blower pipe 28, causing the Coanda effect, which cancels out the pressure trying to push out from the treatment tank 1 in the direction toward the high-temperature gas blower pipe 28 (outward from the treatment tank 1), resulting in zero or negative pressure at the blower port.

[0052] The high-temperature gas H sent from the high-temperature gas blowing pipe 28 to the injection pipe 25 can be supplied at zero or negative pressure at the opening 29, which is lower than the conventional pressure.

[0053] The supersonic steam S and high-temperature gas H are then injected into the treatment tank 1 as a supersonic saturated steam jet as shown in Figure 1, where the raw material is crushed and dried. The crushed and dried raw material is then introduced into the cyclone 8 via the conduit 7, where it is separated into the processed material and steam by centrifugal force.

[0054] As described above, the steam jet injection device for pulverization and drying of the third embodiment can obtain the same effects as those of the first embodiment.

[0055] The steam jet injection device for pulverizing and drying of the present invention is not limited to the above-mentioned embodiment, and it goes without saying that various modifications can be made to the present invention without departing from the scope of the present invention. [Explanation of symbols]

[0056] 1 Treatment tank 1a Circular body 1b Side plate part 1c Gas inlet 1d Gas outlet 2 Injection pipe 3 Steam injection nozzle 4. High-temperature gas blast pipe 5 Burner 6 Blower 7 Conduit 8. Cyclone 9 Injection pipe 10 Steam injection nozzle 10a flange 11 High-temperature gas blast pipe 12 Upper pipe section 13 Inclined pipe section 14 Lower pipe section 14a flange 15 Air vent 16 Nozzle 17 Air duct 18 Burner 19 Flexible hose 20 Blower 21 Injection pipe 21a flange 22 Ventilation outlet 23 Steam injection nozzle 23a flange 24 Nozzle 25 Injection pipe 26 Steam injection nozzle 27 Nozzle 28 High-temperature gas blast pipe 29 Aperture S Supersonic Steam H hot gas C0 Central axis of the injection pipe (central axis of the upper pipe section) C1 Center axis of lower tube L1 steam injection nozzle axis position Axis position of L2 steam injection nozzle R1 inner diameter R2 inner diameter

Claims

1. A steam jet injection device comprising a steam injection nozzle that injects supersonic steam into an injection pipe in an axial direction, and a high-temperature gas blowing pipe that blows high-temperature gas into the injection pipe from a radial direction, wherein the supersonic steam and the high-temperature gas are supplied from the injection pipe to a treatment tank, and raw materials are pulverized and dried in the treatment tank, an axis of the injection port of the steam injection nozzle is disposed closer to the blowing port of the high-temperature gas blowing pipe than the central axis of the injection pipe in the radial direction of the injection pipe; A steam jet injection device for pulverization and drying, characterized in that the supersonic steam injected from the steam injection nozzle generates the Coanda effect at a position close to the air outlet, thereby offsetting the pressure that tries to push the steam out of the treatment tank.

2. 2. The steam jet injection device for pulverization and drying according to claim 1, characterized in that the supersonic steam injected from the steam injection nozzle is configured to offset the pressure that tries to push the steam out of the treatment tank by the Coanda effect, so that the pressure at the air outlet becomes zero or negative.

3. 3. A steam jet injection device for pulverization and drying according to claim 1, wherein the axial position of the injection port of the steam injection nozzle is set in a range of more than 0 mm and not more than 40 mm from the blower port side relative to the inner diameter of the injection pipe.

4. 3. The steam jet injection device for pulverization and drying according to claim 1, wherein the injection port of the steam injection nozzle is formed in an elliptical or rectangular shape when viewed from the axial direction so as to impinge supersonic steam onto the entire surface of the high-temperature gas from the high-temperature gas blower pipe.

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