RU123126U1 - SHAFT FURNACE FOR FIRING BULK MATERIALS - Google Patents

Abstract

Shaft furnace for roasting lump materials, containing a lined shaft with heating, roasting and cooling zones, peripheral fuel combustion devices installed on the upper and lower tiers in the roasting zone, a gas distribution core with external core furnaces, a loading and unloading device and a smoke exhauster, characterized in that in the zone of loading lumpy material in the furnace shaft, a distributor is installed, made in the form of a steel hollow cylinder, equipped with a steel jacket coaxially installed from the outside, closed at the top and open at the bottom, while the upper part of the jacket is connected through a chimney with a smoke exhauster.

Description

The utility model relates to shaft furnaces for burning bulk materials, such as limestone, and can be used in ferrous and / or non-ferrous metallurgy, chemical and construction industries.

Known shaft kiln furnaces for burning lump material, containing a lined shaft with heating, firing and cooling zones, as well as a cross-shaped gas distribution ceramic core, inside which are made fire channels with openings for the exit of gases into the layer of calcined material. The furnace is equipped with peripheral smoke exhausts in the upper part of the furnace and a smoke exhaust beam located 1 m below the upper level of the material in the furnace. Peripheral burners and core furnaces installed on the upper and lower tiers are used as fuel burning devices (see Monastyrev A.V., Galiakhmetov RF Furnaces for the production of lime. Reference book. - Voronezh: Sources, 2011, p. 101-110).

A disadvantage of the known furnaces is the violation of their gas dynamics due to the uneven distribution of bulk material of different sizes over the cross section of the shaft of the furnace, which negatively affects the quality of firing and, therefore, the quality of the material obtained.

In this case, it is possible to destroy welds of the smoke exhaust beam by large pieces of material, and the selection of flue gases through peripheral smoke exhausts in the upper part of the furnace and through defects in the welds of the smoke exhaust beam also leads to unbalancing of gas flows in the furnace.

The closest analogue of the claimed utility model is a kiln for burning lumpy materials, containing from top to bottom along the vertical axis (xx) of the furnace, an input zone for the material, a suction device for exhaust gases, a preheating zone, one calcination zone, a burner, a cooling zone and a discharge zone moreover, it further comprises a post-calcination zone located between at least one calcination zone and a cooling zone and an additional suction device located between the post-calc zone nation and a cooling zone, for suction of cooling air after it is in contact with the calcined material and cooling the calcined material in the cooling zone, the additional suction device comprising a duct extending longitudinally along the axis (YY) of the furnace and provided with suction through holes communicating with an internal channel ending with a hole, and additionally a suction device is connected to a suction fan located on the outside of the furnace (with m RU 2413913 C2, 03/10/2011).

This device is taken as a prototype.

The disadvantages of the prototype include the implementation of the suction device for the exhaust gases in the form of a box and its location in the layer moving from top to bottom of the bulk material, which leads to constant increased mechanical stresses on this device and leads to the destruction of the welds and the device itself. Placing a suction device in a layer of heated material, where the temperature of the suction gases reaches 400-450 ° C, also leads to the destruction of the duct and chimneys.

Since the suction device is located in the zone of the heated material, the high-temperature suction gases supplied to the suction fan (smoke exhaust) must be cooled, diluting with outside air at least 2 times, which requires an increase in the power of the smoke exhaust. In addition, when loading material into the furnace, uneven distribution of lumpy material of various sizes along the furnace shaft cross section occurs, which leads to disruption of gas flows in the furnace and a decrease in the quality of material firing.

The task to which this utility model is directed is to improve the design of the shaft furnace and improve the quality of the resulting product.

The essence of the utility model lies in the fact that in a shaft furnace for burning bulk materials containing a lined shaft with heating, burning and cooling zones, peripheral fuel burning devices installed on the upper and lower tiers in the burning zone, a gas distribution core with external core furnaces, a loading and a discharge device and a smoke exhauster, a feature is that in the loading zone of lumpy material in the furnace shaft a distribution device is installed, made in the form of a steel hollow cylinder, with A steel jacket coaxially mounted on the outside, closed at the top and open at the bottom, with the upper part of the shirt communicated by means of a chimney with a smoke exhauster.

The proposed set of essential features allows to obtain the following technical result.

The installation in the loading zone of lumpy material in the furnace shaft of a switchgear made in the form of a steel hollow cylinder ensures uniform pouring and distribution of lumpy material of various sizes over the section of the furnace shaft, which positively affects the gas dynamics of the furnace, and therefore the quality of the final product.

Providing the switchgear with a steel jacket coaxially mounted on the outside, closed at the top and open at the bottom, the upper part of the jacket being connected by means of a chimney with a smoke exhaust, stabilizes the temperature field by uniformly exhausting the flue gases, and also eliminates the need for peripheral extraction of flue gases and a flue beam.

Figure 1 shows a vertical section of a shaft furnace; figure 2 - node 1 in figure 1; figure 3 is a section aa in figure 2.

A shaft kiln for firing lump materials contains a lined shaft 1 with heating zones 2, firing 3 and cooling of the finished product 4, a gas distribution core 5 with external core furnaces 6, 7, and a loading 8 and unloading device 9. In the firing zone 3, peripheral burners 10, 11 are installed, located at the upper and lower levels, respectively, and equipped with fuel supply lines 12, 13 and oxygen-containing gas supply 14, 15. The evacuation of flue gases from the mine 1 is carried out by means of a smoke exhauster 16 through a recuperator 17.

In the upper part of the shaft 1, in the loading zone, a switchgear 18 is installed, made in the form of a steel hollow cylinder, outside of which a steel jacket 19 is coaxially mounted, closed from above and open from below, while its upper part is communicated through a chimney 20 through a recuperator 17 with a smoke exhauster 16.

The bulk material is loaded into the funnel of the loading device 8 with a skip hoist 21.

The furnace operates as follows.

Bulk material to be fired, such as limestone, is loaded from the skip hoist 21 by means of the device 8 into the distribution device 18, from where it enters the heating zone 2.

From zone 2, where the calcined material is heated by the products of fuel combustion, the latter passes through the calcination zone 3 and enters the cooling zone of the finished product 4, from where it is unloaded by the device 9. After the finished product is unloaded by the unloading device 9, the material level in the furnace zone 2 decreases.

The device 18 maintains a constant amount of bulk material by loading it with the device 8. The gradual unloading of the material from the device 18 to zone 2 while lowering the level after unloading the finished product allows you to maintain the configuration of the material in the upper part of zone 2 in the form of a regular truncated cone.

Flue gases from the mine 1 are sucked out of the annular space between the device 18 and the jacket 19 of the exhaust fan 16 and through the chimney 20 enter the recuperator 17, where they are exchanged with air coming from the external environment, and then this air mixture is fed into the fuel burning devices 6, 7 , 10, 11.

The inventive utility model in comparison with the prototype provides a better process for obtaining the final product due to increased uniformity of distribution of bulk material of various sizes over the cross section of the furnace shaft, as well as stabilization of the temperature field due to the uniform suction of flue gases while simplifying the design of the smoke exhaust device.

Claims (1)

A shaft furnace for firing bulk materials, comprising a lined shaft with heating, firing and cooling zones, peripheral fuel burning devices installed on the upper and lower tiers in the burning zone, a gas distribution core with external core furnaces, a loading and unloading device, and a smoke exhauster, characterized in that in the loading zone of bulk material in the shaft of the furnace there is a switchgear made in the form of a steel hollow cylinder equipped with a steel coaxially mounted outside shirt, closed at the top and open at the bottom, with the upper part of the shirt communicated through a chimney with a smoke exhauster.