SU711326A1 - Tube furnace - Google Patents

Description

(54) TUBULAR OVEN

one

The invention relates to the technique of heating liquid and gaseous media and can be used in the gas, oil, petrochemical and chemical industries, especially for heating thermally unstable liquids.

The known tubular furnace, which provides heating of liquid and gaseous products, contains a firebox, radiant and convective chambers, inside of which is located a tubular food coil, which receives the heat of the combustion products of fuel 11.

The closest technical solution is a tubular furnace containing a furnace and a heat exchange chamber, in which heating elements are made in the form of vertically mounted cylinders with cooling walls and heat pipes, the upper end of which is located in the cavity of the cylinder and the lower end in the radiation chamber. Thermal pipes are filled with inorganic layers. A gaseous material is fed into a convection chamber, where it is heated by flue gases to 400-600 ° C. The heated material is directed to the heating elements in which it is in contact with the upper ends of the heat pipes, heating to the set temperatures 2.

The lack of a tubular furnace is the uneven heating of thermally unstable liquids, and the lack of equalization of the temperature regime in the heat removal zone with uneven heat generation of the heating source.

The purpose of the invention is to intensify heat exchange during the heating of thermally unstable liquids.

The goal is achieved by the fact that, in the proposed tube furnace, each heat pipe installed vertically is provided with an internal coaxial pipe plugged in the upper part, and each heating element is made in the form of two coaxial pipes with fittings for liquid inlet and outlet located in the upper part and placed in the annular space of the heat pipe.

The drawing shows a pipe furnace in cross section.

Claims (2)

The furnace tube contains a hollow body 1, along the axis of which the air colp is spaced. 37 duct 2. Air intake zhelzi 3 are placed around the perimeter of the housing. A recuperator 4 and a chimney 5 are located in the upper part of the furnace. The furnace 6 is placed on support 7 and is bounded below by a perforated bottom 8. Under the bottom is a mixing and distribution bpok 9 connected to the fan 10. The tubular coil 11 is designed as heating elements with vertically mounted heat pipes 12, covering the element from the outside, and heat pipes 13 fixed on top and placed coaxially in the cavity of the heating elements of the coil P. Each heating element also has a vertical Designed in the form of coaxial tubes, fitted in the upper part with nipples for inlet and outlet of the heated liquid. The heat-receiving ends of the pipes 12 are placed in a fluidized bed 14, and the heat transfer ends are brought inside the heat exchange chamber 15. The insulated duct 16 is designed to supply air to the furnace. To remove the combustion products, serve pipe 17 and channels 18 installed in the air collector located near the bottom of the heat exchange chamber 15. The furnace tube works as follows. Air is blown by the fan 10 through the heat exchanger 4 and through the air channel 2 is fed to the mixing and distribution unit 9, where it moves thoroughly with gas and through perforated plug 8 enters the furnace 6. The ignited gas-air mixture burns in the fluidized bed 14, while the solid particles of the fluidized bed are heated to 1200-1800 ° C and transferred to the warm (heat receptive) ends of heat pipes 12. The heat carrier, which is located in the lower part of heat pipes, evaporates, taking away the heat coming from the fluidized bed from the pipe wall. Heat carrier pairs rise to the back of the heat pipes 12, 13, condense on the surfaces in contact with the heated product, transferring the heat obtained in the furnace 6, carefully looking at the serpent II product from both sides. Combustion products leave through the smoke channel and the chimney 5. The counter-flow of air draws heat from the walls of the smoke channel. Another part of the combustion products flows through channel 18 into the cavity of chamber 1.5 and washing the recuperator plate 4 along the path and enters chimney 5. The presence of a soft heating mode leads to a significant decrease in the efficiency of the installation, since the temperature in the furnace reaches 1800 ° C and the temperature the heated product should not exceed 100 ° C, then a significant part of the heat is not used. In order to ensure the rational use of the high-temperature part of the flue gases and to increase the efficiency of the installation, a two-stage heating system for the air supplied to the furnace is generally provided. Flue gases washing the outside of the surface of the heat exchanger 4, heating its wall to a high temperature, provide pre-heating. With further movement along the annular channel 2, the air temperature will further increase, since there are no losses from the heated surfaces into the environment. As a result, the food coil 11 is enclosed in a space bounded by walls with a higher temperature than the working temperature of the coil 11 itself. Consequently, there are no heat losses from the surfaces of the coil 11, although heat transfer to the working surfaces cannot be reflected steam condensation temperature. Highly heated flue gases are used to heat the air supplied to the furnace and replace the lining to prevent heat loss from the coil surfaces P. Claims of the invention Tube furnace containing a furnace, a heat exchange chamber and vertical heating elements arranged therein, equipped with fittings for liquid inlet and outlet , and heat pipes, characterized in that, in order to intensify heat exchange during the heating of thermally unstable liquids, each heat pipe installed vertically, is supplied On the upper part of the inner, plugged-in top coaxial tube and each heating element are made in the form of two coaxial tubes with fittings for the inlet and outlet of the fluid, located in their upper part, and placed in the annular space of the heat pipe. Sources of information taken into account in the examination 1. Bakhshchi and C. Ts. A. Tube furnaces, M., GOSINTI, 1960. 2. USSR Author's Certificate No. 435433, cl. R 27 B 5/00, 1970.