RU2231713C1 - Tube furnace - Google Patents

Abstract

FIELD: tube furnaces for heating liquid and gaseous products for high-temperature processes, for example pyrolysis of hydrocarbon materials; petrochemical industry.

SUBSTANCE: proposed furnace is provided with gas acoustic double-stage burners which are mounted on radiating walls of fire box at pitch of 48 to 58 diameters of primary mixing chamber of acoustic gas burners.

EFFECT: enhanced operational reliability and efficiency due to smooth heating of radiating walls of fire box.

3 cl, 3 dwg

Description

The invention relates to burners of tube furnaces for burning liquid and gas products of high-temperature processes, for example, pyrolysis of hydrocarbon feedstocks and can be used in the oil, refining and petrochemical industries.

A known design of tubular furnaces with a vertical feed coil in a radiation chamber heated by injection burners / 1 /. A constructive disadvantage of these furnaces is that the ceramic bowl of the burners heated to 1250 ° C concentrates the heat radiation on the local sections of the coil, leads to overheating of the pipe metal, coking, and a premature stop for repairs.

Closest to the invention is a tube furnace / 2 /. It contains a housing with radiating walls on which acoustic gas burners are located perpendicular to the plane of the tubular coils. The raw material enters the coil and heats up to the required temperature due to radiation from the heated walls. The flame from the burners is laid on the masonry in the form of circles and creates a uniform temperature field on the radiating walls of the furnace.

The disadvantages of this furnace design are as follows:

- with fluctuations in the productivity of raw materials on the radiating walls of the furnace, the unevenness of the temperature field of the masonry of the furnace increases due to a change in the size of the burning disks of the air-fuel mixture, which negatively affects the material part of the furnace;

- when starting, stopping the furnace, burning coke due to reduced fuel consumption, there is a significant reduction in the size of the torches from the burners, smoke and volumetric combustion of the air-fuel mixture, leading to local overheating of the pipes of the raw material coils.

The technical result of the invention is to increase the reliability and efficiency of the furnace due to the uniform heating of the radiating walls of the furnace in a wide range of performance in raw materials and in different operating modes.

The technical result is achieved by the fact that in a tube furnace including a radiation chamber and a convection chamber, a vertical feed coil with fixation elements, acoustic gas burners, which are made of two-stage / 3 / and installed on the radiating walls of the furnace with a pitch of 48 ÷ 58 diameters of the primary mixing chamber of the acoustic gas burners, and clamps of tubular coils are applied, providing the required position of the pipes during the operational period.

Acoustic gas burners used in a tube furnace are protected by patent / 3 /.

In FIG. 1 shows a tube furnace; in FIG. 2 - section aa; in FIG. 3 - node A.

The furnace consists of a radiation chamber 1, a convection chamber 2, a vertical feed coil 3, with fixing elements 4 in the upper part and fixing elements 5, 7, 8 below the convection chamber; two-stage acoustic gas burners 6 having a primary mixing chamber are installed on the walls of the radiation chamber.

Tube furnace operates as follows.

The raw material enters the tubes of the convection chamber 2 and radiation 1, is heated to the required temperature from the red-hot walls of the radiation chamber 1 by two-stage acoustic gas burners 6. These two-stage acoustic gas burners provide flat burning of fuel in the form of hot disks, creating a uniform temperature field on the radiating walls of the furnace.

The inventive step of installing two-stage acoustic gas burners 48 ÷ 58 diameters of the primary mixing chamber of the burners is explained as follows.

The operation of two stages of acoustic gas burners provides a dense heat flux compared to single-stage acoustic gas burners. Combustion of fuel in two-stage acoustic gas burners occurs with a smaller diameter on the radiating walls. With a step of arrangement of burners over 58 diameters of the primary mixing chamber, the isothermal regime on the walls of the furnace is violated, since the temperature profile in the torch gradually decreases with distance from the burner to the periphery, this leads to uneven heating of the vertical feed coils. When the burner pitch is less than 48 diameters of the mixing chamber, burning disks of adjacent burners are superimposed, which leads to volumetric combustion of the air-fuel mixture, the thermal regime in the furnace is violated, which contributes to overheating of the material part of the furnace - coils, suspensions, etc.

The verticality of the pipes in the raw material coils is violated when they are heated during the operational period and cooled when the liver stops, and there is a longitudinal and transverse deformation.

In furnaces with a lower convection chamber, it is proposed to use the locks shown in FIG. 2. They are made in the form of pipes 5, guides 3, welded to the rolls, and plates 8, which prevent the longitudinal and transverse displacement of the pipes during temperature deformations.

In the upper part of the vertical raw material coils 3, it is proposed to use clamps in the form of hollow cylinders 4 attached to pipes between adjacent cams (Fig. 3).

Sources of information

1. Sharikhin V.V., Entus N.R., Konovalov A.A., Skorohod A.A. Tube furnaces for oil and gas refining and petrochemicals: - M., CMC, 2000, p.24.

2. A.S. 1712389 (USSR), Tube furnace / Aut. fig. V.V. Sharikhin, N.R. Entus, A.S. Pechnikov, V.K. Zizyukin, publ. in BI No. 6, 1992

3. RF patent 2059154, Gas burner / Auth. - V.V. Sharikhin, V.V. Stepanchuk, A.S. Pechnikov, A.S. Malinovsky, A.N. Kezin, Yu.V. Gusev, M.S. Gabutdinov publ. in BI No. 12, 1996

Claims (3)

1. A tube furnace including a radiation chamber and a convection chamber, a vertical feed coil with fixation elements, acoustic gas burners, characterized in that the acoustic gas burners having a primary mixing chamber are two-stage and are installed on the walls of the radiation chamber with a pitch of 48 ÷ 58 diameters primary mixing chamber of acoustic gas burners. 2. The tube furnace according to claim 1, characterized in that in the lower part of the raw coil there are used clamps in the form of pipes, guides and plates. 3. The tube furnace according to claim 2, characterized in that in the upper part of the raw coil there are used holders in the form of hollow cylinders attached to the pipes between adjacent rolls.

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