RU132172U1 - LINE GAS FURNACE OF LARGE PRODUCTIVITY FOR FIRING LUMBING MATERIAL - Google Patents

Abstract

1. High-performance shaft gas furnace for firing bulk material, comprising a lined shaft with heating, firing and cooling zones, an air-cooled beam with windows for supplying cooling air, located in the cooling zone, a gas distribution ceramic core located in the firing zone, made of refractory material on a bunch of self-propagating high-temperature synthesis (SHS) mortar 2-3 m higher than the upper tier of fuel-burning devices, including a supported base m to the air-cooled beam, a direct solid partition of two walls, separated by a temperature seam, and a wall element intersecting with it from two separate arched walls, each with one wing resting on the shaft lining, and the other wing entering into grooves made on two sides a partition with gaps for possible temperature deformations at the joints, made with heat channels with openings for gas outlet inside each specified wall, core and peripheral fuel burning devices installed in several tiers, characterized in that the lined shaft in cross section is elliptical in shape, the gas distribution core is additionally equipped with at least a second direct solid partition, each partition being supported by a base on a separate air-cooled beam with windows for supplying cooling air additionally located in the cooling zone in accordance with the number of additional solid partitions, all solid partitions are oriented

Description

The utility model relates to shaft gas furnaces for burning lump material, for example limestone, and can be used in ferrous and non-ferrous metallurgy, chemical, construction, soda and sugar industries.

It is known that for a uniform distribution of fuel, the cross section of the shaft can be round or ellipsoid, less often rectangular (http://lib.tr200.net/v.php?id=267191&sp=1).

It is known that to increase the cross-sectional area of the furnace, it is given an oval shape. With a large diameter, peripheral and central gas supply is carried out, and with an oval section of the shaft, only peripheral gas is supplied at two levels. (http://www.ntds.ru/statyi/025_shahtnye_pechi.pdf).

Known shaft kiln for calcining limestone, containing a lined shaft, external furnaces and a ceramic core, consisting of piers and a central pillar equipped with metal gas-cooled fixing beams. In the central column and the lining of the shaft of the furnace there are vertical grooves, which include piers with the possibility of free temperature deformation relative to the lining of the shaft and the central core column. The furnace also has a casing, water-cooled support beams under the core, the walls of which have channels communicating with the external furnaces, and communicating with the working space of the furnace through windows (patent RU No. 2194931, F27B 1/02, 2001).

This known device has several disadvantages. Metal gas-cooled fixation beams included in the core body (both piers and the central pillar) weaken it due to various temperature expansions of the metal and ceramics. The presence in the firing zone of water-cooled support beams under the core and, as a result, the loss of part of the heat in the firing zone of the furnace with cooling water requires a water cycle with chemical water treatment.

Known mine gas furnace for firing lump materials, including a lined shaft with heating, firing and cooling zones, containing an air-cooled beam with windows for supplying cooling air to the furnace space located in the cooling zone, core and peripheral fuel burning devices installed in two tiers, cross-shaped in cross section, a gas distribution core including piers with heat channels made inside each of them with openings for the exit of gases into the material layer, from of which two opposite walls are made in the form of arches, one wing resting on the lining of the shaft with a gap for possible temperature deformations at the joints, of the two other opposite walls separated by a temperature seam, made and placed with its base on an air-cooled beam, a cross-section with grooves in which each for their part, arches-shaped piers are located on the other wing, resting on a cross-beam with a gap for possible temperature deformations at the joints, while The core is made of refractory material on a special bond - self-propagating high-temperature synthesis of SHS mortar 2-3 m higher than the upper tier of fuel burning devices (patent RU No. 123507, F27B 1/00, С04В 2/12, 12/27/2012). Taken as a prototype.

However, this device has a drawback, namely:

- due to the fact that, according to practical and theoretical data, the best combustion of natural gas and, consequently, calcining of limestone takes place in shaft kilns at a distance of 0.8-1 m from the walls of the shaft, and further heat distribution> 1 m is hindered by the resistance of the bulk material and the temperature drops sharply, thereby producing poorly burnt pieces of material (I didn’t get it), (Filshin V.E., “Investigation of mine calcareous kilns.” - M .: “Chemistry”, 1964, 192 pp.), furnace productivity with a cross-shaped ceramic core cannot exceed amb 200-250 tons of lime per day, since the furnace shaft diameter can not be greater than 4.5 m on the above considerations. With a further increase in productivity and an increase in the diameter of the shaft of the furnace, the quality of the resulting lime decreases.

The task to be solved by this proposal is to increase the productivity of a mine gas furnace over 250 tons of finished product per day while maintaining its quality, by ensuring an even distribution of combustion products throughout the mine volume, eliminating arching, increasing the reliability and durability of the core. For this, changes were made to the design of the shaft gas furnace and modern masonry materials were used:

- based on the conditions for the distribution of the best combustion of 0.8-1 m from the walls of the mine to increase the cross-sectional area of the furnace, its shape is assumed to be ellipsoid in size on the small axis of not more than 3.6 meters, and on the major axis - the required size, provided that the distance between adjacent piers located along small axes, not more than 1.5 m, and from the extreme piers to the shaft lining - not more than 2 m;

- gas distribution core is made in the form of at least two direct solid partitions located along the minor axis of the ellipsoidal cross section of the shaft and the wall element intersecting with them, made of separate piers in the form of arches located along the major axis of the ellipsoidal cross section of the shaft;

- the gas distribution core is made 2-3 m higher than the upper tier of the fuel-burning devices made of refractory material on a special bond - self-propagating high-temperature synthesis of SHS-mortar;

- Optimized operation of fuel burning devices.

The technical result consists in increasing the productivity of a shaft gas furnace more than 250 tons of finished product per day while maintaining its quality, increasing the efficiency of the furnace, increasing the reliability and durability of the core, eliminating arch formation, increasing the life of the furnace between overhauls.

The essence of the utility model lies in the fact that in a large-scale shaft gas furnace for firing bulk material containing a lined shaft with heating, firing and cooling zones, an air-cooled beam with windows for supplying cooling air located in the cooling zone, a gas distribution ceramic core located in the firing zone made of refractory material on a special bunch of self-propagating high-temperature synthesis of SHS mortar 2-3 m above the level of the upper tier of fuel of fire-extinguishing devices, including a direct solid partition supported by a base on an air-cooled beam from two piers, separated by a temperature seam, and a wall element intersecting with it from two separate piers in the form of arches, each resting on one wing of the shaft lining, and the other wing entering into grooves made on two sides on a solid partition with gaps for possible temperature deformations at the joints, made with heat channels with openings for gas outlet inside each specified ostenka, core and peripheral fuel burning devices installed in several tiers, the peculiarity is that the lined shaft in cross section is made of ellipsoid shape, the gas distribution core is additionally equipped with at least a second straight solid partition, each of which is made based on a separate base air-cooled beam with windows for supplying cooling air, additionally placed in the cooling zone in accordance with the number of additional integral partitions However, all solid partitions are located oriented along the minor axis of the lined shaft, and the wall element intersecting with them is located along the major axis of the lined shaft, for this it is additionally equipped with at least one separate arch-shaped wall, each of which is solid inside and It is located between adjacent solid partitions with the incoming wings in the corresponding grooves made on them with gaps for possible temperature deformations at the joints. In addition, the gas distribution ceramic core can be made of refractory bricks. Also, gas distribution ceramic core can be made of refractory blocks. The peculiarity is that the fuel-burning devices are mainly installed in two tiers. As peripheral fuel combustion devices, diffusion gas burners can be used. But they can be used as peripheral fuel-burning devices for burners for complete gas combustion. It is desirable that the cross-sectional dimensions of the lined shaft along the minor axis are no more than 3.6 m, between adjacent solid partitions - no more than 1.5 m, between the lining of the mine and its corresponding solid partition - no more than 2 m. In the particular case, the gas distribution core includes two solid partitions, and the size of the lined shaft along the major axis of the cross section is 7.5 m.

The combination of these essential features allows you to get the specified technical result.

The implementation of the shaft gas furnace in the cross section of an ellipsoidal shape allows you to increase its volume, create optimal conditions for the uniform distribution of combustion products (0.8-1 m from the walls of the shaft). This leads to increased productivity while maintaining the quality of firing and the quality of the finished material.

The use of the gas distribution core of the proposed design allows to further increase the volume of the shaft, to ensure uniform distribution of combustion products throughout the volume of the shaft, and, therefore, increase the productivity of the furnace without reducing the quality of firing and the quality of the calcined material, and also increase the strength and stability of the core.

In the solution, new masonry technologies were used for the most intense and responsible furnace design - gas distribution core. The use in masonry for bonding refractory materials, such as bricks, blocks, of a well-known special bond - self-propagating high-temperature synthesis of SHS-mortar, increases mechanical strength and ensures reliability and durability of the structure. Performing a core on an ordinary bundle leads to its destruction in about a year. SHS-mortar welds (SHS-process) the refractory masonry with a ceramic weld, and the strength of the weld exceeds the strength of the material itself. This fact increases the strength of the masonry, prevents the loss of refractory material from the masonry and the formation of local burnout or overheating of the gas distribution core of the shaft furnace. The new bundle provides increased strength, resistance to deformation and thermal shock. This leads to an increase in the overhaul period, stabilizes the process, increases the degree of firing of bulk material. Moreover, the operational characteristics of a special ligament - SHS mortar are acquired in the process of operation, which ensures the manufacturability of its use as a masonry mortar.

Performing a gas distribution core 2-3 meters higher than the upper tier of the fuel burning devices ensures it is brought to a zone of lower temperatures, which eliminates arch formation and, therefore, increases the reliability and durability of the furnace as a whole.

Replacing peripheral fuel-burning devices from diffusion gas burners with full-gas burners similar to core burners, but with a lower power, eliminates the possibility of cakes and arched formation at high-temperature combustion sites. This ensures uniform burning of bulk material over the mine cross section by uniformly distributing the gas flow throughout the volume of the calcined material layer, which reduces the specific fuel consumption for calcination and increases the quality of the calcined material.

Thus, significantly increases the productivity of mine gas furnaces, their efficiency, provides a finished product of high quality.

The proposed solution is illustrated by drawings:

Figure 1 shows a shaft gas furnace for firing lump material, section aa in figure 3, a General view; figure 2 is a section bB in figure 3; figure 3 is a section bb in figure 1, a top view (cross section of the shaft).

A high-performance shaft gas furnace for burning lump material, such as limestone, contains a shaft 2 with a lining 3 enclosed in a casing 1. The lined shaft 2 has technological zones for heating (not shown), firing (not specified) and cooling (not specified) and transverse the section is made ellipsoidal (close to the shape of a rectangle with rounded corners). Mine 2 contains a gas distribution ceramic core 4, which is located in the firing zone. The core 4 includes at least two straight solid partitions 5 (their number depends on the productivity of the furnace), which are oriented oriented along the minor axis of the shaft 2, and a wall element intersecting with them from two separate walls 6, 7 and at least one separate wall 8, which are located along the major axis of the mine 2. For example, for a furnace with a productivity of 370-400 tons of lime per day, two solid partitions 5 are required, while the length of the furnace is 7.5 m along the major axis of the lining of the furnace shaft. Each solid partition 5 is made of two piers (not indicated), separated by a temperature seam, and is equipped with a separate air-cooled beam 9, on which it rests on its base. The number of air-cooled beams 9 (but at least two) corresponds to the number of solid partitions 5. Inside the solid partitions 5 and walls 6, 7, upper and lower fire channels 10 are made with openings 11 for the exit of combustion products into the material layer. All air-cooled beams 9 are located in the cooling zone and are made with a central cooling air supply unit and windows 12 through which cooling air is supplied into the space of the shaft 2. Each wall 8 is made solid inside and is located between adjacent solid partitions by incoming wings in grooves made on them. The piers 6, 7, 8 are made in the form of arches and enter with wings (not specified) into the corresponding grooves (not specified) located at the joints with a gap for possible temperature deformations. In this case, the walls 6, 7 are supported by one wing on the lining 3, the other on the corresponding solid partition 5, and each wall 8 is supported by the wings on the adjacent solid walls 5. Thus, in the gas distribution core 4, the walls 6, 7 and at least , one piers 8 are made in the form of arches and at least two solid partitions 5 of the piers separated by a temperature seam are made with a groove on each side and placed with their base on air-cooled beams 9. Based on the propagation conditions of the best burning (0.8-1 m from the walls of the shaft 2), it is desirable that the dimension along the small axis of the cross section of the lined shaft 2 be no more than 3.6 m, along the major axis - you can choose the necessary condition that the distance between adjacent solid partitions 5 is no more than 1, 5 m, and from the corresponding solid partition 5 to the edge of the lining 3 of the shaft of the furnace 2 - no more than 2 m. The shaft 2 is equipped with core and peripheral fuel-burning devices 13, 14, installed in several tiers, mainly in two tiers, and discharge devices 15. Gas distribution The core core 4 is made of refractory material, for example, refractory bricks, refractory blocks, on a special bundle of self-propagating high-temperature synthesis of SHS mortar 2-3 m above the upper tier of fuel-burning devices 13, 14. In particular, it is made of refractory brick on a bunch from SHS mortar (self-propagating high-temperature synthesis), manufactured by MAVR, Zhukovsky. As fuel-burning devices 13, burners for full or incomplete combustion of gas (remote furnaces) are used. As peripheral fuel-burning devices 14, diffusion burners can be used, which can also be replaced by burners for complete gas combustion with similar core burners (remote furnaces), but of lower power.

A shaft furnace with gas distribution core 4 operates as follows. Limestone coming from the furnace heating zone is distributed by core 4 into at least six sectors, where it is burned with fuel combustion products from core fuel-burning devices 13 through openings 11 of the flame channels 10 and peripheral fuel-burning devices 14. The temperature difference over the furnace cross section according to experimental data is 40-50 ° C, which allows to achieve a degree of firing of 96-98%.

Technical and economic benefits of the proposed technical solution are as follows:

- increased core strength and durability;

- increased reliability of the core and furnace in the complex;

- improved firing quality;

- reduced the possibility of arch formation, thereby increasing the trouble-free operation of the furnace as a whole;

- increased time between overhauls.

The utility model will increase the furnace productivity of more than 250 tons per day with maximum efficiency of the heat treatment process and high quality of the calcined material.

Claims (8)

1. High-performance shaft gas furnace for firing bulk material, comprising a lined shaft with heating, firing and cooling zones, an air-cooled beam with windows for supplying cooling air, located in the cooling zone, a gas distribution ceramic core located in the firing zone, made of refractory material on a bunch of self-propagating high-temperature synthesis (SHS) mortar 2-3 m higher than the upper tier of fuel-burning devices, including a supported base m to the air-cooled beam, a direct solid partition of two walls, separated by a temperature seam, and a wall element intersecting with it from two separate arched walls, each with one wing resting on the shaft lining, and the other wing entering into grooves made on two sides a partition with gaps for possible temperature deformations at the joints, made with heat channels with openings for gas outlet inside each specified wall, core and peripheral fuel burning devices installed in several tiers, characterized in that the lined shaft in cross section is elliptical in shape, the gas distribution core is additionally equipped with at least a second direct solid partition, each partition being supported by a base on a separate air-cooled beam with windows for supplying cooling air additionally located in the cooling zone in accordance with the number of additional solid partitions, all solid partitions are oriented along the minor axis of the lined shaft, and the wall element intersecting with them is located along the major axis of the lined shaft and is additionally equipped with at least one separate arch-shaped wall, each of which is solid inside and is located between adjacent solid partitions by incoming wings in the corresponding grooves made in them with gaps for possible temperature deformations at the joints. 2. The shaft gas furnace according to claim 1, characterized in that the gas distribution ceramic core is made of refractory brick. 3. Mine gas furnace according to claim 1, characterized in that the gas distribution ceramic core is made of refractory blocks. 4. Mine gas furnace according to claim 1, characterized in that the fuel burning devices are installed in two tiers. 5. A shaft gas furnace according to claim 1, characterized in that diffusion gas burners are used as peripheral fuel-burning devices. 6. Mine gas furnace according to claim 1, characterized in that as peripheral fuel burning devices used burners for complete gas combustion. 7. The shaft gas furnace according to claim 1, characterized in that the cross-sectional dimensions of the lined shaft along the minor axis are not more than 3.6 m, between adjacent solid partitions - not more than 1.5 m, between the lining of the shaft and its corresponding whole partition - no more than 2 m. 8. The shaft gas furnace according to claim 1, characterized in that the gas distribution core includes two solid partitions, while the size of the lined shaft along the major axis of the cross section is 7.5 m.

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