JPS6023273B2 - rotary dryer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is characterized in that a crushing blade is attached to a rotary shaft to crush the material while transporting the material to be processed, in a drying space that forms a transfer path for the material to be processed and a high-temperature gas for drying. Drive can be rotated freely,
The present invention relates to a rotary drying device in which a flow path for supplying a cooling fluid to flow inside the rotary shaft is connected to the rotary shaft.

In the above device, in order to prevent the strength of the rotating shaft from decreasing due to heating by high-temperature gas, the rotating shaft is cooled by a flow of cooling fluid inside the rotating shaft. Even if the temperature inside is above the fog point,
As a result of the formation of a film around the rotating shaft as a result of gas transfer, the temperature at the circumferential part of the rotating shaft becomes below the dew point, forming a mist there, causing hydrogen sulfide to form in the dry operation gas or in the material to be treated. If corrosive components such as gas or hydrogen chloride gas are included, these corrosive components react with moisture generated by striped dew and turn into sulfuric acid, hydrochloric acid, etc., corroding and damaging the rotating shaft and reducing durability. In addition, due to the cooling structure for the rotating shaft, there is a problem in that the temperature in the drying space is lowered, resulting in unnecessary loss of thermal energy for drying. In view of the above points, it is an object of the present invention to make it possible to satisfactorily suppress both corrosion damage to the rotating shaft and loss of thermal energy for drying due to the cooling structure for the rotating shaft.

Next, embodiments of the present invention will be described in detail based on illustrative drawings.

A cylindrical body 2 for forming a drying space S with feeding blades 1 attached to the inner circumferential surface is provided to be freely driven and rotatable around a horizontal axis P, and one end of the cylindrical body 2 is provided with a cylindrical body 2 for forming a drying space S. The supply port 3 for the material to be treated is connected to the supply port 4 for drying high-temperature gas such as high-temperature exhaust gas from an incinerator, and the other end side of the cylinder body 2 is
A discharge port 5 for the material to be treated and a discharge port 6 for the high temperature gas are connected through a lotus, and a transfer path for the material to be treated and the high temperature gas is formed in the drying space S in a state in which the transfer direction is the same, and In the drying space S, there is a rotating shaft 7 which is parallel to the rotational axis P of the cylinder body 2 and is freely driven and rotatable around the deviated ball center Q.
At the same time, crushing blades 8 are attached to the rotating shaft 7 so as to be distributed in the longitudinal direction and in all directions around the circumference, and the supplied material to be treated is crushed and transferred as the cylinder body 2 rotates. However, the rotary drying apparatus is configured to carry out drying treatment by bringing high-temperature gases into contact with each other in parallel flow.

The rotary shaft 7 is formed into a cylindrical shaft, and a flow path R for supplying cooling fluid such as cooling water is connected to the rotary shaft 7, and the flow path R is connected to the rotary shaft 7 in the same direction as the processed material and the high-temperature gas. In this state, the cooling fluid is made to flow through the rotating shaft 7 to cool the rotating shaft 7 and avoid a decrease in strength due to heating of the high-temperature gas.

In the drying space S, the scale crushing blades 8 are arranged on the upstream side in the direction of transfer of high temperature gas from approximately the center in the longitudinal direction of the rotating shaft 7.
・A heat insulating member 9 is attached on the downstream side to form and cover a heat insulating space S between the outer circumferential surface of the rotating shaft 7 and to prevent rusting around the rotating shaft 7. It is structured as follows.

In addition, to show a numerical example of the temperature change of the gas and cooling fluid in the above embodiment, the temperature on the gas supply port 4 side is 600 to 7
When the temperature is 00℃, the temperature on the outlet 6 side is about 250~300qo.
On the other hand, when the supply side temperature of the cooling fluid is 20°C,
The outlet temperature was about 70°C.

FIG. 3 shows a modified example, in which a small-diameter cylinder 2b is placed inside a large cylinder 2a, a transfer path for gas and the material to be processed is formed between the two cylinders 2a and 2b, and a gas and material to be processed are transferred. The contact path is configured as a U-turn path to improve drying efficiency without increasing the size of the entire device, and the crushing blade 8
A heat insulating member 9 is attached to the rotary shaft 7 on which the ... is attached at a location facing the downstream side of the high temperature gas transfer path of the drying space S. The present invention can also be applied to a so-called co-current contact type rotary drying apparatus in which the direction of transfer of high-temperature gas and the direction of transfer of the material to be treated are opposite to each other. Any structure may be used as long as the rotating shaft 7 is covered with the heat insulating member 9 at a location facing the downstream side of the gas transfer path.

In summary, the present invention is characterized in that, in the above-mentioned rotary drying apparatus, the rotating shaft 7 is covered with a heat insulating member 9 at a portion of the drying space S facing the downstream side of the high temperature gas transfer path. .

In other words, after various considerations regarding the formation of fog around the circumference of the rotating shaft 7, we found that when the temperature of the drying gas is high, regardless of the formation of a film around the circumference of the rotating shaft 7 due to gas transfer, heat transfer Although the circumference of the rotating shaft 7 has reached the temperature above the Fushimi point, as the temperature decreases as the processed material dries, the rotating shaft 7
It was discovered that the temperature at the periphery of the drying gas becomes below the fog point, and dew condensation occurs on the downstream side in the direction of transport of the drying gas.Based on the above-mentioned results, we found that Since the rotating shaft 7 is covered with a heat insulating member 9 on the side, even if dew condensation occurs around the rotary koji 7 at a temperature below the dew point, the corrosive components contained in the gas or the processed material will come into contact with the moisture generated by the condensation. This can prevent corrosion damage to the rotating shaft 7, and since a part of the rotating shaft 7 is shielded from the high-temperature gas, it is possible to prevent the drying energy of the high-temperature gas from being taken away by the rotating shaft 7, thereby reducing the overall As a result, while cooling the rotating shaft 7, corrosion damage caused by this is suppressed, and the rotating shaft 7 is cooled.
In addition to improving the durability of the drying process, it has also been possible to improve the drying process performance by suppressing unnecessary loss of energy for drying high-temperature gas.

[Brief explanation of drawings]

1 is an overall vertical sectional view, FIG. 2 is a sectional view taken along the zero line in FIG. 1, and FIG. 3 is an overall partially cutaway side view showing a modified example. be. 7...Rotating shaft, 8...Crushing blade, 9.
...Insulation member, S...Drying space, R...
...Cooling fluid supply confluence channel. Figure 2 Figure 1 Figure 3

Claims (1)

[Scope of Claims] 1. A crushing blade 8 for crushing the workpiece while transporting the workpiece is attached to the rotating shaft 7 in the drying space S that forms a transfer path for the workpiece and the high-temperature gas for drying, respectively. The rotary drying device is a rotary drying device that is rotatably driven and has a flow path R that is connected to the rotary shaft 7 for supplying a cooling fluid that flows inside the rotary shaft 7, and is provided on the downstream side of the high temperature gas transfer path of the drying space S. A rotary drying device characterized in that the rotary shaft 7 is covered with a heat insulating member 9 at a facing location. 2. The apparatus according to claim 1, wherein the processing object transfer path and the high temperature gas transfer path are formed in the same transfer direction.