JPS6345670Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a rotary ventilation dryer equipped with a preheating section using indirect heating.

Structure of conventional example and its problems In conventional rotary aeration dryers, gas is brought into direct contact with the material to be dried supplied into the rotating drum, and drying is performed using the thermal energy of the gas. If the material to be dried has a high moisture content, it is difficult for the gas to pass through the material evenly, resulting in uneven drying.

Purpose of the invention An object of the present invention is to provide a rotary ventilation dryer equipped with a preheating section using indirect heating, which eliminates the above-mentioned conventional drawbacks.

Structure of the Invention In order to achieve the above object, the rotary ventilation dryer equipped with a preheating section by indirect heating of the present invention supplies the material to be dried to the upstream end of the rotating drum, and the rotation of the rotating drum and the inside In a rotary aerated dryer, the material to be dried is dried by the thermal energy of gas supplied to the rotary drum, and the product is taken out from the downstream end of the rotary drum. The central part and the downstream part are used as a drying part, a sealed double cylindrical body composed of an inner cylinder wall, an outer cylinder wall and a downstream end wall is arranged in the preheating part, and a louver is arranged in the drying part, A high-temperature gas supply port is provided to supply high-temperature gas into the double cylinder, and a nozzle is formed on the downstream end wall of the double cylinder toward the inside of the louver to supply medium-low temperature gas into the louver of the drying section. It is equipped with a medium- and low-temperature gas supply port.

According to this configuration, high-temperature gas is supplied into the double cylinder of the preheating section and sufficiently heats the double cylinder, and then enters the louver of the drying section from the nozzle and is mixed with the medium-low temperature gas, and the mixture is heated. The gas is ejected toward the center of the rotating drum.
Therefore, the high-moisture material to be dried supplied into the rotating drum is indirectly heated by conduction heat transfer in the preheating section.
Next, the product is directly heated by convection heat transfer in the drying section, and the dried product is taken out from the downstream end of the rotating drum in a predetermined manner.

In addition, when drying powdery materials using gas, drying by conduction heat transfer has generally been considered to be less efficient than drying by convection heat transfer, but as the moisture content of the material increases, the layer of material particles increases. The effective thermal conductivity increases rapidly, and indirect heating and drying by conductive heat transfer also works effectively. Using this phenomenon, high moisture materials can be efficiently preheated.

Embodiment and Operation An embodiment of the present invention will be described below with reference to FIGS. 1 to 5. 1 is a rotating drum that rotates in the direction of arrow A; 2 is an outlet hood that fits over the downstream end of the rotating drum 1, and has a product outlet 3, a defective product outlet 4, and an exhaust gas outlet 5; . Reference numeral 6 denotes a drying material inlet inserted into the upstream end of the rotating drum 1, and a screw feeder 7 is disposed therein.
The upstream part of the rotating drum 1 is a preheating part 8, and the central part and downstream part thereof are a drying part 9.
The preheating section 8 is provided with a sealed double cylindrical body 11 composed of an inner cylindrical wall 11A, an outer cylindrical wall 11B, and a downstream end wall 11C, and a louver 12 is provided in the drying section 9. There is. 13 is a large number of nozzles formed on the downstream end wall 11C toward the louver 12; 14 is a high-temperature gas supply port disposed across a section α facing the upstream end surface of the double cylindrical body 11; Reference numeral 15 denotes a medium and low temperature gas supply port disposed outside the high temperature gas supply port 14, which supplies medium and low temperature gas into the louver 12 through a gas passage 16 formed on the outside of the double cylindrical body 11. It is for the purpose of

Hereinafter, the effects of the above configuration will be explained. First, high-temperature gas of about 400° C., for example, is supplied from the high-temperature gas supply port 14 into the double cylindrical body 11 of the rotary drum 1 rotating in the direction of arrow A, and heats the double cylindrical body 11. Next, the double cylindrical body 11
The high temperature gas inside is ejected from the nozzle 13 into the louver 12. On the other hand, medium-low temperature gas is supplied into the louver 12 from the medium-low temperature gas supply port 15 through the gas passage 16 and mixed with the above-mentioned high temperature gas. In this state, the high-moisture material to be dried 17 (for example, coal) supplied into the material to be dried inlet 6 is transferred to the preheating section 8 in the rotating drum 1 by the screw feeder 7.
supply within. Then, the material to be dried 17 is indirectly heated by the highly heated inner cylinder wall 11A, and moisture is evaporated. Next, the material to be dried 17, which has been preheated and has a reduced moisture content, flows down into the drying section 9,
Here, the mixed gas blown up from the louver 12 passes through the object to be dried 17 and directly heats and dries it. Next, the dried material 17 that has been properly dried in the drying section 9 is sent into the outlet hood 2, the product is taken out from the product outlet 3, and the lumps are discharged as defective products from the defective product outlet 4. It is.

Effects of the Device As described above, according to the present invention, the material to be dried with a high moisture content is indirectly heated by conduction heat transfer in a double cylindrical body to evaporate moisture, so that in the drying section, the mixed gas is transferred to the material to be dried. It passes through the inside evenly and can be dried homogeneously, and uneven drying does not occur as in conventional methods. Further, in the drying section, the material to be dried is dried using a relatively low temperature mixed gas of medium-low temperature gas and high-temperature gas, so that the material to be dried does not undergo high-temperature deterioration. Since the high temperature gas used in the preheating section is reused in the drying section, thermal efficiency is good.

[Brief explanation of the drawing]

The figures show an embodiment of the present invention, in which Fig. 1 is a longitudinal cross-sectional view, Fig. 2 is a view taken in the direction of the - arrow in Fig. 1, Fig. 3 is a view taken in the - arrow direction of Fig. 1, and Fig. 4 is a view taken in the - 1, and FIG. 5 is a vertical sectional view of the main part. DESCRIPTION OF SYMBOLS 1...Rotating drum, 8...Preheating section, 9...Drying section, 11...Double cylindrical body, 11A...Inner cylinder wall, 1
1A...Outer cylinder wall, 11C...Downstream end wall, 12...
... Louver, 13 ... Nozzle, 14 ... High temperature gas supply port, 15 ... Medium and low temperature gas supply port, 17 ... Material to be dried.

Claims (1)

[Scope of utility model registration request] Supplying the material to be dried to the upstream end of the rotating drum,
In a rotary ventilation dryer, the material to be dried is dried by the rotation of the rotary drum and the thermal energy of the gas supplied therein, and the product is taken out from the downstream end of the rotary drum. The upstream part is used as a preheating part, the central part and the downstream part are used as a drying part, and the preheating part is provided with a sealed double cylindrical body composed of an inner cylinder wall, an outer cylinder wall, and a downstream end wall,
A louver is provided in the drying section, a high-temperature gas supply port is provided for supplying high-temperature gas into the double cylinder, and a nozzle is formed in the downstream end wall of the double cylinder toward the inside of the louver. A rotary ventilation dryer equipped with a preheating section by indirect heating, characterized in that a medium-low temperature gas supply port for supplying medium-low temperature gas is provided in the louver.