RU101536U1 - HEAT EXCHANGE SYSTEM IN THE DRUM FURNACE - Google Patents

Abstract

 1. A drum furnace comprising a burner and a separation ring, characterized in that it further comprises heat exchange vanes installed along the furnace rings, which in the subsequent ring are shifted from the previous one by an angle of 10 to 30 °, the ring with heat exchange vanes closest to the burner distance from two to four diameters of the furnace from the nozzle of the burner, the separation ring is made in the form of a fill threshold located at a distance of three to seven diameters of the furnace from the nozzle of the burner, a height of 0.15-0.3 diameter of the furnace and a length of two threshold heights. ! 2. The drum furnace according to claim 1, characterized in that it further comprises a dusting device located between the heat exchanger blades and the overflow threshold.

Description

The system of heat exchangers in a rotary kiln relates to the construction of a rotary kiln for burning building material and can be used to produce materials obtained by burning in rotary kilns, for example expanded clay, magnesite, dolomite, etc.

It is known "INTERNAL HEAT EXCHANGE OF ROTATING FURNACES", according to the patent RU 2383836 from 12.26.2007, publ. 03/10/2010, IPC F27B 7/00, including heat exchange elements for mixing the material, while the heat exchange elements are made in the form of teeth with a triangle-shaped part protruding from the lining, the larger side of which is oriented in the opposite direction to the discharge end of the rotary kiln, and the angle between the larger side and adjacent to it is at least 45 °, and the heat exchange elements are located in sections in the heating zone of the material in the rotary kiln in parallel rows in a checkerboard pattern relative to each other neighboring areas.

The heat exchange elements of this device do not provide the required height of the material, which prevents the effects of thermal gases on the material during lifting and shedding from the heat exchange elements.

Also known is the "LIFT OF ROTARY FURNACE" according to the patent RU 2049971 from 12/10/1992, publ. 12/10/1995, IPC F27B 7/28, made of differently high refractory bricks forming a developed heat exchange surface, while it is made with metal tiles installed at the joints of differently high bricks, protruding above the surface of low bricks to a height of 0.5 to 1.5 height differences bricks.

Metal tiles at the joints of bricks, during long-term operation burn out, and which leads to the destruction of refractory bricks.

Also known as “ROTATING FURNACE” according to patent RU 2122695 from 06/11/1997, publ. 11.27.1998, IPC F27B 7/00, F27B 7/28, comprising a housing, a lining, consisting of ribbed and smooth sections, a burner, while the beginning of the section with a smooth lining is made at a distance of 30-55%, and the end is at a distance 80-90% of the total length of the furnace from the loading end.

However, the ribbed sections of the lining, due to temperature changes when moving from bottom to top in diameter, during rotation, are destroyed faster than smooth sections.

The closest in technical essence is the "Single-drum rotary kiln for claydite firing" by A. with. USSR 155432 dated 6.01.1962, publ. 1963, IPC Р27В 7/00, containing a burner and mounted, inside it, at the border of the zones of preparation of raw materials and firing, a dividing ring, with the passage opening area several times smaller than the furnace section.

The installed refractory separation ring, with the passage opening area four to five times smaller than the furnace section separating the firing zone from the raw material preparation zone, has a small passage section area, because of which the material does not pour over the separation ring, but moves in the opposite direction from the burner , as accumulated in the training zone.

The objective of the proposed technical solution is to increase the productivity of the furnace, reducing specific fuel consumption and improving the quality of the calcined material.

The problem is solved through the use of a system of heat exchangers in a drum furnace containing a burner and a separation ring, characterized in that the system further comprises rings installed along the furnace, heat exchange vanes, which in the next ring are shifted from 10 to 30 in relation to the previous one degrees; the ring closest to the burner with heat exchange vanes is located at a distance of two to four furnace diameters from the burner nozzle; the dividing ring is made in the form located at a distance of three to seven diameters of the furnace from the nozzle of the burner, overflow threshold, a height of 0.15-0.3 of the diameter of the furnace, and a length of two threshold heights; the system further comprises a dusting device located between the heat exchanger blades and the overflow threshold.

Equipping the system with additional rings installed along the furnace, heat-exchange vanes, shifted in the subsequent ring relative to the previous one, by an angle of 10 to 30 degrees, allows you to raise the material that goes along the furnace lining, from top to top, to the highest possible point along the diameter of the furnace, when falling with which there is compaction, reduction of the fraction, and improvement of the quality of the finished product, by improving the mixing of the material in the layer, increasing the area of influence of thermal gases on the material and heat transfer.

The location of the ring with heat exchanger blades closest to the burner, at a distance of two to four diameters of the furnace from the nozzle of the burner, allows the system to be used in drum furnaces of various diameters.

The implementation of the dividing ring in the form located at a distance of three to seven diameters of the furnace from the nozzle of the burner, overflow threshold, height 0.15-0.3 of the diameter of the furnace, and a length of two threshold heights, allows you to use the system in drum furnaces of various diameters, and accumulate heat, which reduces fuel consumption, increases the percentage of finished product and furnace productivity, and reduces the cost of the finished product.

The system of heat exchangers is installed in a drum furnace of any diameter and with various burner capacities, where it provides gas savings in the heat exchange blades, by moving the material on the walls of the blades and lifting into the gas stream, while the overflow threshold allows you to delay the increased flow of pulverized material, due to the fact that at the installation site of the filling threshold there is a narrowing of the diameter of the flue gas passage.

The system of heat exchange devices in a drum furnace is shown in the drawing where burner 1, housing 2, lining 3, heat exchange blades 4, dusting device 5, overflow threshold 6.

The system of heat exchangers in a drum furnace is as follows.

The drum kiln is inclined horizontally. The burner 1 is located at the lower end of the drum furnace, in the cooling zone.

Along the furnace, rings are installed heat-exchange vanes 4 in each ring contains several vanes 4. Heat-exchange vanes 4 in the next ring are shifted relative to the previous one, by an angle of 10 to 30 degrees.

Heat-exchange blades 4 are made of heat-resistant steel in the form of plates that withstand temperature differences between the upper and lower points along the diameter of the furnace drum without destruction, which ensures long-term operation of the furnace.

The closest ring to the burner with heat exchanger blades 4 is located at a distance of two to four diameters of the furnace from the nozzle of the burner.

Heat-exchange vanes 4 allow you to raise the material going along the lining 3 of the furnace, from bottom to top, to the highest possible point along the diameter of the furnace. When the material is in the upper part of the furnace, it is poured out from the heat exchanger blades 4, and there is a compaction, that is, a decrease in the fraction of the material upon falling. The presence of heat exchange blades 4 increases heat transfer, due to the increase in the area of influence of thermal gases on the material and the improvement of mixing of the material in the layer.

The dividing ring of the system is located inside the furnace and is made in the form located at a distance of three to seven diameters of the furnace from the nozzle of the burner, overflow threshold, a height of 0.15-0.3 of the diameter of the furnace, and a length of two threshold heights; The distance at which the system elements are located is selected depending on the power of the burner and the diameter of the furnace. A threshold height of less than 0.15 of the furnace diameter does not provide the necessary temperature difference between the zones and does not allow to accumulate a sufficient amount of heat from the burner. The threshold height of more than 0.3 of the diameter of the furnace prevents the normal movement of material from one zone to another.

The dusting device 5 is placed between the area with heat-exchange vanes 4 and the overflow threshold 6, which reduces dust extraction with exhaust gases of dusting material and dust generated when lifting and mixing the material with heat-exchange vanes 4, and ensures the supply of a special dusting powder to the drum furnace to increase the range swelling and reducing adhesion of the material,

The system of heat exchangers in a drum furnace operates as follows.

When the furnace rotates, the material moves along an inclined toward the burner 1. In the preparation area, the material is delayed by a fill threshold 6, for the time of removal, of chemically bound water from the material. When moving the material through the overflow threshold 6, it is dusted with the help of a dusting device 5. After which the layer of material falls onto the heat-exchange vanes 4, where the material is intensively mixed. Depending on the type of material, material swelling may occur in the area of the blades, for example, in the production of expanded clay.

Material firing occurs at temperatures of 950-1400 ° C, depending on the material being fired. Next is the cooling of the material.

The system of heat exchangers in the drum furnace provides gas savings in the area of the heat exchanger blades 4 due to the movement of material on the walls of the blades and the rise in the gas stream, which can lead to an increase in dust extraction, but the overflow threshold allows the dusty material to be retained as a result of setting the fill threshold, the diameter of the flue gas passage is narrowed, the fill threshold also allows you to accumulate heat, which reduces fuel consumption, increases the percentage of finished product and production productivity of the furnace, and reduces the cost of the finished product.

The technical effect is to increase the productivity of the furnace, reduce specific fuel consumption and improve the quality of the calcined material, through the use of a system of heat exchange devices in a drum furnace containing a burner and a spacer ring, characterized in that the system further comprises heat exchange vanes installed along the furnace rings which in the next ring are shifted relative to the previous one by an angle of 10 to 30 degrees; the ring closest to the burner with heat exchanger blades is located at a distance of two to four diameters of the furnace, from the nozzle of the burner; the dividing ring is made in the form located at a distance of three to seven diameters of the furnace from the nozzle of the burner, overflow threshold, a height of 0.15-0.3 of the diameter of the furnace, and a length of two threshold heights.

Claims (2)

1. A drum furnace comprising a burner and a separation ring, characterized in that it further comprises heat exchange vanes installed along the furnace rings, which in the subsequent ring are shifted from the previous one by an angle of 10 to 30 °, the ring with heat exchange vanes closest to the burner distance from two to four diameters of the furnace from the nozzle of the burner, the separation ring is made in the form of a fill threshold located at a distance of three to seven diameters of the furnace from the nozzle of the burner, a height of 0.15-0.3 diameter of the furnace and a length of two threshold heights. 2. The drum furnace according to claim 1, characterized in that it further comprises a dusting device located between the heat exchanger blades and the overflow threshold.