RU57746U1 - HEATING SECTIONAL FURNACE FOR SPEED HEATING - Google Patents

Abstract

The utility model relates to heating furnaces for heating billets and can be used in the metallurgical industry. The technical result of the utility model is to reduce specific fuel consumption, as well as increase the productivity of furnaces and increase their durability. The technical result is achieved by the fact that the furnace arch is solid using standard refractories and has no openings for smoke removal, and in between the zones, clamps are installed in the form of refractory partitions over the entire width of the furnace, and the burners are made high-speed and are staggered on both sides of the furnace above and below the level of heated billets.

Description

The utility model relates to heating furnaces for heating billets and can be used in the metallurgical industry.

Known heating furnace design Lengipromeza [1].

On this furnace burners are used flat flame, recuperators are made of metal, loop. Burners operate only on natural gas.

The disadvantage of such furnaces is low productivity and high fuel consumption, the durability of the furnace is not more than 1 year.

Known heating furnace with a walking hearth for heating metal products, comprising a housing, a arch walking under with movable and fixed beams, lined welding and languishing zones with torches and nozzles placed in the arch, arch partitions installed between the welding and languishing zones with end burners placed at an angle to the horizon for the formation of a gas stream [2].

The disadvantage of such heating furnaces is increased fuel consumption due to the uneven distribution of the pressure field over the working space of the furnace.

The closest technical solution to the proposed utility model is a sectional heating furnace used in a ball rolling shop at the Nizhny Tagil Metallurgical Combine [3].

In the known furnace design, each zone has an autonomous smoke removal system from the furnace, i.e. flue gases are removed independently from each zone of the furnace. The working space of the furnace has a poorly developed working surface and volume due to the insignificant cross-section, which does not allow to ensure complete combustion of the gas-air mixture in the working space. Incomplete combustion of the gas-air mixture in the working space leads to the removal of heat into the chimney path, which is emitted without benefit into the chimney flue, adversely affecting the lining of chimneys made of lightweight chamotte.

In addition, the repair of the upper structure of the furnace is very complicated and time-consuming. The upper structure has a low resistance, because flue gas temperature is very high.

The technical result of the utility model is to reduce specific fuel consumption, increase the productivity of furnaces and increase their durability.

The technical result is achieved in that the furnace containing the housing, under, heating elements, lined heating sections with burners located in the side walls and a smoke exhaust duct, while the furnace arch is suspended using standard refractories and has no openings for smoke removal, and in between between the zones, clamps are installed in the form of refractory partitions over the entire width of the furnace, the burners are used high-speed and they are staggered on both sides of the furnace above and below the level of the heated workpieces.

Figure 1 shows the proposed heating furnace high-speed heating.

The heating furnace consists of a housing 1, a continuous arch 2, a hearth 3, high-speed burners 4 and pinch 5, which are installed in the working space. The billets are transported through the furnace using the furnace roller table, the three-strand rollers of which are located in the vestibules at an angle of 82 ° to the longitudinal axis of the furnace with a pitch of 1170 mm. The furnace consists of 25 sections, which are divided into 4 independently adjustable zones. Combustion products are removed from the furnace’s working space sequentially from the discharge zones towards the posad zones, where the smoke box box is located with a cut-in chimney 6 and associated flue 7. To cut one of the 2 furnaces from the flue, slide valves 8 are installed.

Sectional heating furnace of high-speed heating is designed to heat round billets before rolling on a ball rolling mill, the speed of transportation of billets is 1.2-5.5 m / min ..

Each section of the furnace is a metal casing lined from the inside with a layer of high-alumina fireclay and a layer of chamotte lightweight.

Table number 1 Furnace Feature Furnace length mm 34692 Cross section, working space, mm 700 × 700

Thermal power (Kcal / hour) 14 × 10 Productivity (t / h) 18.8 Fuel coke oven gas, use of natural gas is possible Workpiece (mm): diameter, mm 80-125 length mm 3000-6000 Weight, kg 400-500 Material Carbon steel grades Recuperator one on two stoves Air heating temperature up to 400 ° C Type of burner high-speed Specific fuel consumption, kg ut / t 133

High-speed burners with a capacity of 20-85 nm ³ / h are installed on the furnaces. The burners are staggered on both sides of the furnace above and below the level of the heated workpieces. The furnaces are heated by coke oven gas with a calorific value of up to 4000 kcal / nm ³ , and it is also possible to use pure natural gas.

Combustion products are removed from the working space sequentially from the emission zones towards the posad zones, where the smoke box is located with the smoke of zone No. 1 embedded in it, the passage section of which corresponds to the cross-section of the hog for uninterrupted movement of combustion products through the furnace. The roof of the furnace is suspended using standard refractories of grades 88, 89, 90, 91.

This design of the furnace allows you to have temperature control completely for the entire zone, since the operation of the burner devices is united by one common working space of the furnace zone. To maintain pressure in the working space and ensure a stable hydraulic regime between the zones on the water-cooled beams, clamps are installed made in the form of refractory partitions over the entire width of the furnace.

The technical result of the proposed furnace design is achieved by:

1. Changes in the design of the furnace space, i.e. organization of the chimney from the discharge zone with the sequential transfer of combustion products through the entire working space of the furnace to the planting zone and transfer to the smoke collector, and then to the chimney.

This will significantly increase the use of flue gas heat.

2. Replacing the burners with high-speed ones provides an increase in the intensity of heating the billets, including due to an increase in temperature in the zone up to 1300 ° C, and, consequently, an increase in the radiation component of the masonry of the furnace.

3. The installation of clamps between the zones provides a stable hydraulic mode of the furnace during operation.

4. The arch of the furnace provides a good density of the structure, reduces heat loss. This design allows you to have high-quality temperature control completely over the entire zone and to exclude the effect of burners when improperly configured for the zone.

5. The new design of the working space is simple and maintainable, the resistance of the furnace is not less than 2 years.

The invention is new because There are no analogues from domestic and foreign sources of information.

Due to the fact that in the claimed design the temperature in the working room is increased compared to the prototype, this provides a more intense heating of metal products throughout the section.

A positive effect from the use of the inventive furnace design will be obtained due to the appearance of a new technical solution, which consists in the fact that the thermal energy of the flue gases with the new smoke removal system is used more efficiently.

Analysis of the thermal work data of the sectional furnace in comparison with the prototype showed that the installation of a suspended arch and vault clamps allowed to improve the technical and economic performance of the furnace.

The inventive utility model in comparison with the known technical solutions has the following advantages:

- due to a more complete use of flue gas heat, increasing temperatures in zones, increasing the radiation component, fuel savings of 7% are achieved;

- by increasing the intensity of heating the billets, the productivity of the furnace increases by 10%;

- maintenance costs are reduced, the overhaul period is increased by at least 2 years;

- significantly reduces material consumption due to the rejection of autonomous smoke removal, i.e. 12 chimneys are dismantled (in comparison with the prototype);

- improving the operating conditions of the furnace and the sanitary-kinetic conditions for the maintenance personnel by reducing heat generation in production facilities and reducing CO emissions into the atmosphere.

The experimental testing of the methodical furnace in the conditions of OAO Nizhny Tagil Metallurgical Plant confirms the industrial applicability of the utility model.

References

1. Metallurgical furnaces. Atlas. M. Metallurgy, 1987.

2. П - 2114185, С 21 Д 9 \ 00, F 27 В 13 \ 00, publ. in the bull. No. 18, 06/27/1998

3. Technical passport of a sectional furnace, MFM USSR, Chermetenergo, VNIIMT, 1965

Claims (3)

1. The sectional heating furnace of rapid heating, comprising a housing, a vault, a hearth with a roller table for transporting workpieces, a furnace zone with burners located in the side walls of the furnace and a smoke exhaust duct, characterized in that the furnace arch is made of solid standard grades of refractory materials and does not have intermediate openings for smoke removal. 2. The furnace according to claim 1, characterized in that the burners are of a high-speed type and are staggered on both sides of the furnace above and below the level of the heated workpieces. 3. The furnace according to claim 1, characterized in that between the zones of the furnace on water-cooled beams are clamped in the form of refractory partitions over the entire width of the furnace.