RU1784819C - Heat exchanger of rotating furnace - Google Patents

Abstract

Usage: in rotary kilns for the heat treatment of cement raw materials. SUMMARY OF THE INVENTION: A heat-exchange device of a rotary kiln comprises hollow elements with a variable cross section fixed on the inner surface of the housing, trapezoidal plates are fixed on the outer surface of each of them. Each hollow element is made in the form of a truncated pyramid and is located with a large base on the furnace body, with trapezoidal plates mounted sideways parallel to each other on the smaller base of the pyramid, and the large base of the trapezoid placed in opposite directions. 2 ill.

Description

with

WITH

FIELD OF THE INVENTION This invention relates to the construction of internal furnace furnaces for rotary kilns, for example rotary kilns for the heat treatment of cement raw materials.

Known heat exchangers containing fixed on the inner surface of the housing individual hollow elements 1 and 2.

A disadvantage of the known heat exchangers is their low thermal efficiency.

Closest to the proposed one is a heat exchange device comprising hollow elements fixed on the inner surface of the housing around the circumference with a variable cross section on the outer surface of each of

which fixed trapezoidal plate 3.

A disadvantage of the known heat-exchange device is the complexity of the design, large material consumption and relatively large geometric dimensions. In addition, laying of a special shaped lining is necessary at the site of the heat exchange device. Large geometrical dimensions, especially in height, do not allow the known heat exchanger to be placed on a high-temperature section of a rotary kiln - the most efficient from the point of view of heat engineering, due to their burnout.

In addition, it does not seem possible to carry out a compact arrangement of the elements, since this forms

Xi

00

00 -

about

high resistance to material movement.

A heat exchange device in the form of individual elements of a known design leads to the need for lining work between the elements, which greatly complicates the lining process and dramatically reduces its service life: in addition, special sizes of football bricks are required.

The structural form of the heat exchanger elements d5c is quite difficult to manufacture, many joints of elements of different thicknesses, slopes, transitions, etc.

All of the above factors in total reduce operational efficiency.

The purpose of the invention is to increase operational efficiency.

 The goal is achieved in that the heat exchanger of the rotary kiln, containing hollow elements with a variable cross section fixed on the inner surface of the casing, is trapezoidal in shape, each hollow element is made in the form of a truncated pyramid and is mounted on a large furnace base. moreover, the trapezoidal plates are installed sideways parallel to each other on the smaller base of the pyramid, and the large base of the trapezoid placed opposite opposite direction x.

In FIG. 1 shows a heat exchanger, general view; in FIG. 2 - a separate element.

In the inner cavity of the rotary kiln 1, hollow elements 2 are arranged around the circumference, with a variable cross section; each element is made in the form of a truncated pyramid. The smaller base 3 of the pyramid, on which trapezoidal plates 4 are placed parallel to each other, faces the internal cavity of the furnace. The greater than 5 and less than 6 sides of the trapezoid are located in mutually opposite directions. Hollow elements 2 are fixed to the furnace body 1 by bolts 7. Holes 9 are placed on the lateral surfaces of the pyramid 8.

Hollow elements on the inner surface are installed evenly with gaps between them.

The geometric dimensions of the truncated pyramid are selected from design considerations; dimensions of the rotary kiln body, segment size Material layer, etc. Pyramid height (from

larger to smaller base) is equal to the height of the lining, i.e. 0.045-0.035D. The lower limit is defined as the average value for a furnace with a case diameter of 3000 mm and lining thicknesses of 120 mm (0.04) and 160 mm (0.05).

Upper limit as average

for a furnace with a diameter of 5600 mm and a thickness

linings 180 mm (0.032) - 220 mm (0.039).

The area of the trapezoidal plates is equal to the area of the material segment in the installation area of the heat exchanger device and is 0.10-0.12 in the cross section of the furnace body. This represents 10-12% of the material filling of the furnace. With these

5 values of the area of the plates, the material does not linger on the installation site of the heat exchanger.

The heat exchanger is located in the internal cavity of the furnace so that it forms an angle of 27-30 ° between the edges of the plates and the direction of movement of the material along the slope, while excluding the wavy nature of the movement of the material and maintaining a constant speed of its movement.

5 The design of the element in the form of a truncated hexagonal pyramid ensures uniform expansion of the sides during operation, which eliminates the destruction of the element under the influence of thermal loads.

In addition, there are through holes on the sides to allow the material to be processed into the interior of the pyramid with the formation of an artificial lining layer.

When the rotary kiln body 1 rotates, the hollow elements 2; simultaneously performing the function of a lining and a heat exchange device, are immersed in a layer

0 material and give him part of the heat in the regenerative heat transfer mode. In addition, the material is the passage between the plates 4, located at an angle of 27-30 ° C to the direction of movement of the material along the slope,

5 is additionally mixed in the longitudinal direction, the multidirectional arrangement of the greater than 5 and less than 6 sides of the trapezoid contributes to additional mixing of the material in

0 transverse direction of material slope.

The ingress of material into the internal cavity of the element leads to its sticking and, consequently, heat loss to the environment is reduced, while the need for special footwork is eliminated.

The economic effect is achieved by reducing fuel consumption. Initial data

1. Furnace productivity - 72.0 t / h

2. The coefficient of use of calendar time - 0.85

3. Conditional fuel consumption:

basic version - 222 kg / t of clinker; developed version - 220 kg / t of clinker

4. The cost of 1 ton of standard fuel is 17.2 rubles.

Claims (1)

SUMMARY OF THE INVENTION A rotary kiln heat exchange apparatus comprising 5 0 the inner surface of the body is hollow elements with a variable cross section with trapezoidal plates on the outer surface of each of them, characterized in that, in order to increase operational efficiency, each hollow element is made in the form of a truncated pyramid and is located on a large base on the furnace body, and trapezoidal plates are installed the sides are parallel to one another on the smaller base of the pyramid and the large bases of the trapezoid are placed in opposite directions. Shig2