RU2031339C1 - Assembly for drying high-humid thermosensitive materials - Google Patents

Abstract

FIELD: drying of materials. SUBSTANCE: predrying chamber 3 is made in form of a pit and provided with heat exchange members 4 made in form of a frame with chains 5 attached to the frame; the chain are mounted for revolution. Basic drying chamber 6 has unit for preparing heat-transfer agent. The unit has heat generator 7 and shift chamber 8 placed at entrance of the chamber. Shift chamber is connected to recirculation circuit 9. EFFECT: improved efficiency. 2 cl, 2 dwg

Description

 The installation relates to devices for drying highly moist heat-sensitive materials and can be used for drying waste from various industries, such as the pulp and paper industry, in agriculture, etc.

 A known installation for drying highly moist heat-sensitive materials, comprising a heat-carrier preparation device connected in series, a mixing chamber connected to a pre-drying chamber, a main drying chamber, material loading and unloading units, a coolant recirculation line connecting the displacement chamber to the material unloading unit.

 This installation is the closest to the proposed invention.

 A disadvantage of the known technical solution is the low quality of the finished product.

 The purpose of the invention is the intensification of the drying process while improving the quality of the finished product.

 This goal is achieved by the fact that the pre-drying chamber is made of a shaft type and is equipped with heat-exchange elements in the form of a frame with circuits mounted on it, mounted for rotation, while the main drying chamber further comprises a heat carrier preparation device and a mixing chamber located at its input and connected to the recirculation line, as well as the fact that the mixing chamber installed in front of the preliminary drying chamber is provided with a lining, and the heat carrier preparation devices are made in de heat source.

 In FIG. 1 shows a general diagram of a plant for drying highly moist heat-sensitive materials; figure 2 - heat transfer element.

 The installation comprises a heat carrier preparation device in the form of a heat generator 1, a displacement chamber 2 with a lining connected to a shaft type chamber 3, a preliminary drying chamber with heat exchange elements 4 and chains 5 fixed thereon, a main drying chamber 6 (for example, a drum type), a preparation device heat carrier - heat generator 7, a bias chamber 8 located at the inlet of the main drying chamber 6 and connected to the recirculation line 9, a recirculation line 10 connected to the bias chamber 2, material loading units 11, 12, and site 13 p zgruzki material with the conveyor 14, the cyclone 15, the product discharge pipe 16 of the cyclone, the fan 17 and the exhauster 18, suction and discharge ducts 19 and 20, respectively, the duct 21 connecting the cyclone 15 from the main drying chamber 6, the material receiving hopper 22.

 Installation works as follows.

 Hot gases come from the heat generator 1 to the displacement chamber 2, where they are mixed with the vapor-gas mixture coming through the recirculation line 10 from the discharge duct 20, the heat carrier obtained in this way enters the shaft chamber 3 of the preliminary drying of the material, into which from the receiving hopper 22 through loading unit 11 feed is supplied to the heat exchange elements 4 rotating in the opposite direction with chains 5 fixed on them, on which the material is intensively dried in a heat stream carrier, as a result of which the temperature of the coolant decreases, and the vapor content in it increases. The drying process in the shaft type chamber 3 continues until there is free moisture in the material, after which it enters the chamber 6, for example, of the drum type, in which internal moisture is removed from the material. The drying mode in the chamber 6 is controlled by the amount and temperature of gases entering from the heat generator 7 into the displacement chamber 8, and by the amount of the vapor-gas mixture entering it through the recirculation line. The finished product from the main drying chamber 6 through the material unloading unit 13 is fed to the conveyor 14, while the vapor-gas mixture from the chamber 6 through the duct 21 is sent to the cyclone 15, where small particles of material are separated from it, which from the cyclone 15 through the material discharge pipe 16 enters the conveyor 14. The cleaned gas-vapor mixture of the exhaust fan 18 is sent to the discharge duct 20, from where it is thrown out or fed through the recirculation lines 9, 10 to the displacement chambers 2, 8.

 A feature of this invention is the separation of the processes of removal from the material of free and bound moisture.

Free moisture evaporates in the chamber 2 shaft type, and associated in the chamber 6, for example a drum dryer, and drying is carried out in a gas-vapor mixture with a small oxygen content. This is achieved due to the fact that combustion in heat generators occurs with a small coefficient of excess air (α = 2-3). The temperature of the gases at the outlet of the heat generator can reach 2000 ^° C, the oxygen content decreases by about half. When the vapor-gas mixture is introduced into the exhaust gases through the recirculation lines, the oxygen content decreases further, while the temperature of the coolant decreases and its heat capacity increases, due to the fact that the heat capacity of superheated steam is approximately two times that of the combustion products. A decrease in the oxygen content in the coolant sharply reduces the rate of oxidation processes, which helps to prevent the possibility of ignition of the material and increase the temperature of the coolant, and therefore, the intensity of the drying process without compromising the quality of the final product. Increasing the heat capacity of the coolant also allows you to speed up the drying process. As a result, the drying time is reduced by 2-3 times. Due to the decrease in the coefficient of excess air in the heat generators, the gas content in the gas-vapor mixture emitted into the atmosphere is significantly reduced, which reduces the power of the blowing equipment. The construction of the shaft displacement chamber, the hot gases of which are supplied in its lower part, and the mixing of gas-vapor mixture to them in the upper one, serves the same purpose.

 Due to the difference in the specific gravities of the gases and the gas-steam mixture, respectively, additional thrust arises in the mixing chamber and the vertical dryer, which reduces the pressure and power of the fan 17 and the smoke exhauster 18.

Claims (2)

 1. INSTALLATION FOR DRYING HIGH-MOISTURE THERMOSENSITIVE MATERIALS, comprising a heat carrier preparation device connected in series, a mixing chamber connected to a preliminary drying chamber, a main drying chamber, material loading and unloading units, a coolant recirculation line connecting the mixing chamber to the material unloading unit, characterized in that the pre-drying chamber is made of a shaft type and is equipped with heat-exchange elements in the form of a frame with chains mounted on it and installed with zhnosti rotation, the main drying chamber further comprises a heat carrier preparation device and a mixing chamber disposed at its inlet and connected to a recirculation line.  2. Installation according to claim 1, characterized in that the mixing chamber installed in front of the pre-drying chamber is provided with a lining, and the heat carrier preparation device is made in the form of a heat generator.

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