JPH089206Y2 - Powder heating equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a powder heating device for heating powder, for example, stone powder, which is a raw material of an asphalt mixture.

[Prior Art] Asphalt mixture, which is a road pavement material, is manufactured by mixing a certain amount of aggregate, sand, stone powder, and molten asphalt, and is used for bridge surface pavement such as steel deck pavement and wear resistance in cold regions. In the goose asphalt mixture used, the amount of stone powder added is as large as 20 to 30%. Therefore, in order to maintain the asphalt mixture at an appropriate temperature, the stone powder is heated to an appropriate temperature and mixed. A rotary kiln type stone powder dryer is often used to heat the stone powder.

[Problems to be solved by the invention] However, the stone powder dryer requires a mechanism for rotating the drum and a dust collector such as a cyclone for capturing the stone powder scattered by the hot air passing through the drum, which makes the device expensive. Has become.

In view of the above points, the present invention has an object to provide a powder heating apparatus having a low initial cost by heating using a cyclone without using a stone powder dryer as a heating apparatus.

[Means for Solving the Problems] In order to achieve the above object, the present invention connects a suction duct to a suction portion of a cyclone for centrifugally separating powder from gas, and installs a burner at one end of the suction duct. While arranging,
A discharge duct is connected to the discharge part of the cyclone, an exhaust fan is arranged at one end of the discharge duct, and a supply chute of the powder supply device is exposed in the middle of the suction duct.

In addition, by combining multiple cyclones that centrifuge powder from gas, the end of the discharge duct connected to the discharge part of the previous cyclone is connected to the suction part of the latter cyclone, and the dust discharge part of the latter cyclone is connected to the former cyclone. A multi-stage cyclone is connected to the suction duct, a burner is arranged in the suction duct of the cyclone located in the first stage, and an exhaust fan is installed at the end of the discharge duct of the cyclone located in the final stage. And the supply chute of the powder supply device is faced in the middle of the suction duct.

[Operation] According to the powder heating apparatus of the present invention, the hot air generated by the burner is sent into the suction duct connected to the suction section of the cyclone, and the exhaust air is provided in the discharge duct on the discharge side of the cyclone. Suction with a fan to create a hot gas stream in the suction duct and cyclone. Then, when the powder is supplied from the supply chute of the powder supply device into the suction duct, the powder is brought into contact with the high temperature gas flow in the suction duct and is carried into the cyclone while being heated, and further inside the cyclone, the cyclone is discharged. It is heated to a predetermined temperature while rotating while descending while rotating on the inner peripheral wall thereof, and is dropped and accumulated in the lower dust discharge portion to be taken out of the system.

Also, when a plurality of cyclones are combined in multiple stages, hot air is sent from the first-stage suction duct and is sucked by the exhaust fan downstream to guide the hot air to each cyclone. Then, when the powder is supplied into the suction duct of the final stage from the supply chute of the powder supply device, the powder is carried into the cyclone of the final stage while being heated, and descends while swirling the inner peripheral wall of the cyclone, Drops and accumulates on the lower dust discharge part. Then, the deposited powder is dropped into the suction duct of the cyclone in the previous stage by natural fall, and is captured again by the cyclone in the previous stage while being heated while being carried by the gas flow as described above. The above operation is repeated for the number of cyclone steps to heat the powder to a predetermined temperature.

[Embodiment] An embodiment of the present invention will be described in detail below with reference to the drawings.

First, referring to FIG. 1, reference numeral 1 is a dryer for an asphalt plant, which rotatably tilts and supports a drum 2 having scraping blades around its inner circumference and has a burner 3 at one end. A hopper 4 and a cold hopper 6 having an exhaust flue 5 connected to the other end are arranged. An exhauster 7 for sucking the exhaust gas discharged from the drum 2 and a dust collector 8 for capturing scattered dust are disposed downstream of the exhaust flue 5. Reference numeral 9 denotes a conveyor for supplying aggregate into the drum 2. The aggregate supplied into the drum 2 by the conveyor 9 comes into contact with hot air sent by the burner 3 while rolling down in the drum 2. And heated to the desired temperature,
The hot hopper 4 is discharged from the lower discharge port.

Reference numeral 10 is a cyclone for heating and capturing stone powder, which is powder, and a suction duct 11 is connected in a cutting line direction to a suction portion above the cyclone, and a burner is provided at one end of the suction duct 11. Twelve are arranged. In addition, the suction duct 11
A supply chute 13 that puts stone powder into the duct in the middle of
Is connected to the inside of the duct from the supply chute 13 while cutting out an appropriate amount of stone powder supplied by a stone powder elevator 14 which is a powder supply device from a stone powder storage bin (not shown). It can be put in. A discharge duct 16 that discharges the hot air sent into the cyclone 10 is connected to the upper center of the cyclone 10, and the end of the discharge duct 16 is connected to the exhaust flue 5.
The hot air drawn out is sucked by the exhaust fan 7 and cyclone
The gas flow passing through 10 is maintained. Reference numerals 17 and 18 denote adjusting dampers arranged in the exhaust flue 5 and the discharge duct 16 and appropriately adjust the suction amount of hot air passing through the exhaust flue 5 and the discharge duct 16.

A discharge pipe 19 for discharging the stone powder that has fallen and deposited is attached to the dust discharge portion below the cyclone 10, and the amount of discharge of the stone powder is adjusted by a rotary valve 20 connected to the discharge pipe 19. A conveyer 21 is arranged below the discharge pipe 19 to convey the heated stone powder to the next step.

FIG. 2 shows a powder heating apparatus in which three cyclones are combined to form a three-stage structure. First stage cyclone
A suction duct 11a is connected to the suction portion of 10a, and a burner 7 is arranged at the end thereof. A suction duct 11b connected to the suction section of the second-stage cyclone 10b is connected to the discharge section above the center of the cyclone 10a, and a discharge section above the center of the second-stage cyclone 10b is connected to the third stage. A suction duct 11c connected to the suction portion of the eye cyclone 10c is connected. The discharge pipe 19c connected to the dust discharge portion under the third-stage cyclone 10c is connected to the middle of the suction duct 11b of the second-stage cyclone 10b with a rotary valve 20c interposed. Further, the discharge pipe 19b connected to the dust discharge portion under the second-stage cyclone 10b has the rotary valve 20b interposed and the suction duct 11a of the first-stage cyclone 10a.
Are connected in the middle of. Furthermore, the first stage cyclone 10
The discharge pipe 19a at the lower part of a faces the transfer conveyor 21 that transfers the heated stone powder to the next step with the rotary valve 20a interposed.

A discharge duct is connected to the discharge part at the center upper part of the third stage cyclone 10c, the end of which is connected to the exhaust flue 5, and the hot air is led out through the cyclones 10a, 10b, 10c one after another. Is being sucked by the blower 7.

Then, in the middle of the suction duct 11c of the cyclone 10c of the third stage, which is the final stage, a supply chute 13 for injecting stone powder
Is connected to the inside of the duct from the supply chute 13 while cutting out an appropriate amount of stone powder supplied by a stone powder elevator 14 which is a powder supply device from a stone powder storage bin (not shown). It can be put in.

When heating the stone powder with the powder heating device described with reference to FIG. 1, first, the burner 2 is burned to send hot air into the suction duct 11, and at the same time, the exhaust flue 5 and the discharge duct. The exhaust fan 7 is driven to suck the gas while adjusting the openings of the 16 adjusting dampers 17 and 18, and a high temperature gas flow passing through the cyclone 10 is formed. Then, the stone powder conveyed by the stone powder elevator 14 is transferred to the rotary valve.
It is supplied into the suction duct 11 of the cyclone 10 through a supply chute 13 while being cut out by a predetermined amount by 15. The stone powder supplied into the duct is brought into contact with the hot air and heated while being carried into the cyclone 10 at the downstream side, and further the cyclone 10
It is also heated while falling while turning along the inner peripheral wall. As a result, the stone powder captured by the cyclone 10 is heated to a predetermined temperature and accumulated in the lower dust discharge part,
A rotary valve 20 provided in 19 cuts out a lower conveyor 21 and conveys it to the next process.

Further, the powder heating device described with reference to FIG. 2 further aims to recover the heat of the hot air sent from the burner 12, and there is an opportunity to combine a plurality of cyclones in multiple stages to bring the stone powder into contact with the hot gas stream. Have many. In this device, the burner 12 is burnt to burn the first stage cyclone.
Hot air is sent into the suction duct 11a of 10a, and the hot air is blown into the cyclones 10a, 10b of the first, second and third stages,
Pass 10c one after another. Then, the stone powder to be heated is conveyed by the stone powder elevator 14, cut out by a predetermined amount by the rotary valve 15, and supplied from the supply chute 13 into the suction duct 11c of the cyclone 10c of the third stage. The stone powder supplied into the duct is first introduced into the third stage cyclone 10c and heated by the swirling flow, and then the cyclone 10c.
Deposit at the bottom. This stone powder is cut out by the rotary valve 20c and the suction duct 1 of the cyclone 10b in the second stage
It is thrown into 1b. The stone powder thrown into the suction duct 11b is introduced into the cyclone 10b, where it is further heated and then falls and accumulates in the lower part of the cyclone 10b. This stone powder is further cut out by the rotary valve 20b and
It is thrown into the suction duct 11a of the cyclone 10a at the stage,
It is heated in the cyclone 10a and heated up to a predetermined temperature. The stone powder accumulated in the lower part of the cyclone 10a is cut out by the rotary valve 20a, placed on the subordinate conveyor 21 and conveyed to the next step.

Although FIG. 2 shows an example in which cyclones are combined in three stages, the number of cyclones is not limited to this, and an appropriate number of cyclones may be combined in consideration of the heating set temperature of the powder and the like. Further, in the embodiment, the flue of the powder heating device and the flue of the dryer of the asphalt plant are combined, but the powder heating device may be installed independently without being combined.

[Effects of the Invention] As described above, according to the powder heating apparatus of the present invention, the powder is supplied into the cyclone suction duct and heated while being captured in the cyclone. In addition, it also serves as a dust collector and can reduce the cost of the device.

Moreover, since the chances of contact between the powder and the hot air can be increased by combining a plurality of cyclones, the heat recovery of the hot air can be further achieved and the powder can be heated to a high temperature.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an embodiment of the powder heating apparatus of the present invention, and FIG. 2 is a partially omitted explanatory view showing another embodiment of the present invention. 1 ... Asphalt plant dryer, 7 ... Air blower, 10, 10a, 10b, 10c ... Cyclone, 11, 11a, 11
b, 11c …… Suction duct, 12 …… Burner, 13 …… Supply chute, 14 …… Powder supply device (stone powder elevator), 15…
… Rotary valve, 16 …… Discharge duct

Claims (2)

[Scope of utility model registration request] 1. A suction duct is connected to a suction portion of a cyclone for centrifugally separating powder from gas, a burner is provided at one end of the suction duct, and a discharge duct is connected to a discharge portion of the cyclone. The powder heating device is characterized in that an air exhauster is arranged at one end of the discharge duct, and a supply chute of the powder supply device is exposed in the middle of the suction duct. 2. A combination of a plurality of cyclones for centrifugally separating powder from gas, the end of a discharge duct connected to the discharge part of the former cyclone is connected to the suction part of the latter cyclone, and the dust discharge part of the latter cyclone is connected. A multi-stage cyclone is constructed by connecting to the suction duct of the preceding cyclone, the burner is arranged in the suction duct of the cyclone located in the first stage, and the end of the discharge duct of the cyclone located in the final stage. The powder heating device is characterized in that an air exhauster is disposed in the air intake device, and a supply chute of the powder supply device is exposed in the middle of the suction duct.