RU178166U1 - Direct-flow countercurrent regenerative furnace for calcining carbonate rocks - Google Patents

Abstract

The utility model relates to shaft furnaces for calcining carbonate rocks, mainly limestone, and can be used in metallurgical, construction, chemical, food and other industries where hydrated lime is used. The direct-flow countercurrent furnace for calcining carbonate rocks includes two round autonomous shafts, each of which consists of the lower part of the shaft with a conical vault of masonry and the upper part of the shaft entering its cavity to form an annular gas channel connected to the transitional gas channel between the shafts, having top vault of refractory bricks. In this case, the laying of the arch of the gas channel is overlapped in two layers obliquely to the vertical of the furnace at an angle α = 40-50 °, only of wedge-shaped refractory bricks supported by the lower part of the shafts and the arch of the transition channel, and the upper edge of the masonry is adjacent to the outer wall of the upper shafts with a gap of b = 5-10 mm, and the outer wall of the upper part of the shafts is made of wedge-shaped refractory bricks with anchors in the form of uniformly distributed metal plates attached to the metal body of the skirt of the upper shaft wall. The technical result is a simplification and increase in the resistance of the masonry of the arch and the lower part of the upper shaft is achieved through the use of conventional wedge refractory bricks and anchor plates, which does not require the use of complex shaped bricks and their laborious fitting during installation. 1 s.p. f-ly, 3 ill.

Description

The utility model relates to shaft furnaces for calcining carbonate rocks, mainly limestone, and can be used in metallurgical, construction, chemical, food and other industries where hydrated lime is used.

In the well-known double-shaft direct-flow counterflow furnaces with round shafts for calcining carbonate materials, in which the upper part of the shafts enters its lower part to form a gas ring channel, it is difficult to perform a vault horizontally located above the ring channel. For laying the vault, special shaped refractory bricks are required, the sizes of which are different for furnaces of different diameters. When laying bricks, accurate fitting and the use of special devices are necessary (see, for example, patent EP No. 2199717 C04B 2/12, F21B 1/02, published June 23, 2010).

So known direct-flow countercurrent regenerative kiln for firing carbonate materials with round shafts, which at the expansion site are interconnected by annular channels for the flow of flue gases from one shaft to another. The inner walls of the channels are formed by hollow air-cooled skirts lined from all sides with refractory material.

The lower part of the skirt has a hollow L-shaped protrusion facing the inside of the shaft and serves as a support for the lining. The internal cavity of the L-shaped protrusion is connected by nozzles to the pressure header of the cooling air supply. The nozzles are located between the wall of the bearing lining and the air-cooled skirt. Above the collector in the wall of the skirt there are openings for the exit of cooled air.

The implementation of the lower part of the skirt in the form of an L-shaped heel beam allows the use of a standard wedge brick for lining the inner walls, which is most resistant to contact with moving processed material having high temperature and chemical activity.

Above, the gas channels for the flow of flue gases from one mine to another have horizontal arches (ceilings), which are lined with special shaped bricks of complex shape, which increases the cost of the furnace (see USSR author's certificate No. 1719837 F27B 1/04, published March 15, 1992 .).

A direct-flow countercurrent regenerative kiln for calcining carbonate materials is also known, consisting of two round autonomous shafts, each of which contains a top for calcining and a bottom for cooling calcined lime parts. At the same time, the lower part of the shafts is 50% larger in diameter and covers the upper shafts along the outer surface with its horizontal arch (ceiling). In place of their corner junction in the horizontal arch, compensation nodes of deformations arising from the thermal heating of the inner walls of the mines are evenly mounted around the perimeter. The specified deformation node is a rather complex device, including the mechanism of deformation movement of the blocks and the blocks themselves, designed for thermal insulation of the mine shaft. Each shaped block of the arch has a very precise shape and is manufactured individually by the supplier factory, and their mutual adjustment presents a certain problem. This circumstance greatly complicates the process of forming and laying out the arches of the lower part of the mines, and therefore determines the complexity of the entire furnace design as a whole (see patent EP 2199718 С04В 2/12, F27B 1/14, op. 23.06.2010).

Closest to the claimed furnace in terms of technical nature, the problem to be solved and the result achieved is the analogue according to the patent of the Russian Federation No. 2301388 F27D 1/08 "Industrial furnace", published on 06/20/2007. This direct-flow countercurrent regenerative furnace contains two circular autonomous shafts (one not shown conventionally), each of which consists of the lower part of the shaft and the upper part of the shaft entering its cavity, with the formation of an annular channel covered with horizontal flat arch, lined with shaped bricks, connected to the transition between the mines by a gas channel having a vault. The upper lined mine, which enters the cavity of the lower part of the shaft, has a metal air-cooled skirt inside with outer edges bent in the lower part, onto which the lining is peeled off. The bottom metal skirt is protected by a ring cast from heat-resistant concrete. To prevent damage to the structure of shaped bricks in the outer convex refractory layer of the upper part of the shaft, which serves as the inner wall of the gas annular channel, resulting from thermal expansion, this layer is torn by four alignment zones composed of two concrete elements interconnected by a deformation seam. These concrete elements with a geometric closure are tightly connected along the perimeter with neighboring shaped bricks made in the form of a dumbbell, while the concrete elements are fixed to the metal body of the skirt using a large number of bifurcated concrete anchors.

Practice has shown that during operation, the masonry between concrete elements is extruded during expansion into the channel cavity. The problem of exact and complex individual fitting of shaped bricks of the horizontal vault of the gas ring channel of the furnace (as in other similarly designed furnaces) also remains. All this causes difficulties in the use of direct-flow counterflow regenerative furnaces with round shafts.

The problem of eliminating the disadvantages of the prototype is solved by creating the design of the furnace with masonry of the vault of the conical shape and using anchors in the form of plates to hold the external masonry of the upper part of the shaft, which is included in the cavity of the lower part of the shaft.

The technical result, which consists in simplifying the design of the furnace, is achieved due to the fact that the masonry of the arch of the annular channel is made obliquely to the vertical of the furnace at an angle α = 40-50 ° from wedge-shaped refractory bricks based on the lower part of the shafts and the arch of the transition channel, at least in two overlapping layers, and the upper edge of the masonry is adjacent to the wall of the upper shaft with a gap of b = 5-10 mm filled with plastic heat-insulating material, while the outer wall of the upper part of the shaft is also made of refractory bricks to inovidnoy standard form with anchors in the form of evenly distributed curved outside masonry metal plates attached to the metal case upper shaft.

Thus, the implementation of the arch of the gas annular channel of wedge-shaped bricks of a standard shape and the use of anchors to hold the external masonry of its inner wall allows you to exclude special shaped bricks individually selected for each furnace, simplify installation work and increase the resistance of refractory masonry.

The proposed utility model, “Direct-flow countercurrent regenerative kiln for calcining carbonate rocks”, is novel, since the combination of features of the utility model formula was not found in the information sources (see the information taken into account when filling out this application for a utility model).

The claimed utility model has an inventive step, since masonry of the arch of the annular channel obliquely in the furnace vertical at an angle α = 40 ° -50 ° in two overlapping layers is an unreasonable technical solution, which eliminates the individual selection of special shaped bricks for each furnace and simplifies installation work.

According to the utility model, design documentation has been developed and its use is foreseen in the construction of three furnaces at Tulachermet OJSC.

The essence of the utility model is illustrated by drawings, where in FIG. 1 shows a general diagram of a shaft furnace device; FIG. 2 shows a section along AA in FIG. 1, and in FIG. 3 shows a section through the transition between the shafts of the channel along BB in FIG. 1, and in FIG. 4 shows a section of the wall of the upper shaft with anchors BB in FIG. 2.

The direct-flow countercurrent regenerative furnace for calcining carbonate rocks includes two round shafts 1 and 2, each of which consists of the lower parts 3 and 4 of the mine with arches 5 and 6 of masonry and the upper part 7 and 8 of the mine entering their cavities with the formation of a gas an annular channel 9 connected to the transition between the shafts 1 and 2 of the gas channel 10 having a vault 11 of refractory brick on top. The masonry of the arches 5 and 6 of the annular channel 9 is made in two layers 12 and 13 with an overlap 14 and oblique to the vertical of the furnace at an angle α = 40-50 ° from refractory bricks 15 of a standard wedge-shaped shape with support on the surface 16 of the lower part of the shafts 3 and 4 and also on the arch 11 of the channel, and the upper edge 17 of the masonry is adjacent to the outer wall 18 of the upper shafts 7 and 8 with a gap b = 5-10 mm to eliminate the deformation of the arches 5 and 6. The indicated dimensions of the gap provide free movement during thermal expansion of the masonry of the arch annular channel relative to the masonry of its internal ste n, and with the given dimensions of the angle of inclination α = 40-50 °, the greatest strength of the brickwork of the arches 5 and 6 is ensured.

The upper parts 7 and 8 of each shaft 1 and 2 are suspended and fixed relative to the lower parts 3 and 4 using metal air-cooled skirts 19 and 20 with bent edges carrying lined walls 21 and 22.

To increase the durability of the outer walls 21 of the annular channel 9, it is provided that lamellar anchors 23 are rigidly attached to the skirts 19 and 20 along their entire contour, and to exclude the individual selection of shaped refractory bricks with a flat arch of the gas annular channel, mandatory for each mine, arches 5 and 6 are performed obliquely in two overlapping rows, which allows the use of conventional standard wedge-shaped refractory bricks. The heat-insulating layer 24 protects the mines from excessive heat loss. Bottom air-cooled metal skirts 19 and 20 protect the concrete rings 25, and to monitor the pollution of this ring in the side wall of the lower parts 3 and 4, inspection windows 26 and 27 are made. The annular channel 9 and the transition gas channel 10 are designed for overflow of flue gases from one mine to another. The shape of the annular channel 9 is not of fundamental importance, it is most important that its cross-sectional area ensures the normal flow of flue gases from one furnace to another.

Direct-flow countercurrent regenerative kiln for calcining carbonate rocks works as follows.

In the mines 1 and 2, alternating flow modes are alternately carried out by burning fuel and counterflow (removal of combustion products and cooling air from the calcined material). The flow of gas flows from one furnace to another occurs through an annular channel 9 and a transition gas channel 10.

The brickwork of the arches 5 and 6 overlapping 14 in two layers 12 and 13 laid obliquely at an angle α = 40-50 ° to the vertical axis of the mines significantly simplifies the design of the shaft furnace, since it eliminates the need to fit each shaped brick, which makes it possible to use ordinary standard wedge-shaped refractory bricks not only directly in the arches themselves, but also in the outer walls of the annular channel 9 of each mine 1 and 2. No changes in the movement of flue gas flows due to a change in the shape of the gas channel 9 should be expected if both Pechena sufficient total area of its passage section.

In general, the rest of the shaft furnace works in a standard way: when calcining lime in the first shaft, heat is prepared and removed in the second shaft, and then the process is carried out on the contrary, by switching the shafts.

The brickwork of the arches 5 and 6 of the annular channel obliquely at an angle α = 40-50 ° allows us to simplify the design of the furnace and use in its manufacture the usual standard wedge-shaped refractory bricks of domestic production, instead of expensive imported ones, thus making import substitution.

The gap b = 5-10 mm between the upper edge of the masonry of the arch of the annular channel and the outer wall of the upper shaft provides free movement of masonry vertically with thermal expansion, and filling it with plastic heat-insulating material prevents the penetration of dust in the flue gases into it and cementation.

Information taken into account when applying for a utility model:

1. USSR author's certificate No. 1589012 F17B 1/02, op. 08/30/1990

2. RF patent No. 2101636 F27B 1/02, op. 01/10/1998

3. RF patent No. 2353595 С04В 2/12, F27B 1/02, op. 04/27/2009

4. US Patent No. 3351685 F27B 1/00, op. 11/07/1967

5. US Patent No. 8673247 C04B 2/02, op. 03/18/2014

6. Patent EP 2199718 С04В 2/12, F27B 1/02, op. 06/23/2010

7. Patent EP 2199717 С04В 2/12, F27B 1/02, op. 06/23/2010

8. China Patent CN 102555077 B28D 1/22, op. 07/11/2012

9. US patent No. 5163831 F27D 1/00, op. November 17, 1992

10. US patent No. 3822989 F27B 1/02, op. 07/09/1974

11. Japanese Patent No. 2006060254 F27B 1/02, op. 02/26/2002

12. RF patent No. 2301388 F27D 1/08, op. 06/20/2007

13. USSR author's certificate No. 1719837 F27B 1/04, op. March 15, 1992

Claims (2)

1. Direct-flow countercurrent regenerative furnace for calcining carbonate rocks, consisting of two round autonomous shafts, each of which is made with the lower part and the upper part of the mine entering its cavity, with the formation of an annular gas channel, which is covered by a roof of refractory bricks, connected to the transition between the shafts of a gas channel having an arched vault of refractory bricks, characterized in that the masonry of the vault of the annular gas channel is made inclined to the vertical axis of the shafts at an angle α = 40-50 ° of refractory the wedge-shaped bricks stacked in stages the two layers overlap, with a support on the wall of the lower part of the shaft and set the transition duct and the upper edge of the annular channel adjacent to the arch masonry outer wall of the upper shaft with a gap b = 5-10 mm, filled with a plastic insulating material. 2. The furnace according to claim 1, characterized in that the masonry of the outer wall of the upper part of the mines is made of wedge-shaped refractory bricks with anchors in the form of uniformly distributed metal plates bent outside the masonry attached to the metal body of the skirt of the upper part of the mine.

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