SU1546505A1 - Method of controlling the laying of wet pellets on bar grate - Google Patents

Abstract

This invention relates to the production of iron ore in ferrous metallurgy. The purpose of the invention is to increase productivity and improve the quality of the finished product. The method of controlling the loading of the raw pellet layer to the grate includes distributing the granules across the width of the kiln carts, measuring the temperature of the gases leaving the pellet layer, identifying areas with reduced (increased) gas permeability of the layer and, accordingly, increasing (decreasing) its height in these areas depending on the measured temperature The areas of the layer with reduced (increased) gas permeability are determined at the exit of the coolant from the layer during the initial period of its purging by measuring the temperature difference between adjacent elements of the layer, 40-80 times the average size of the piece apart from each other and increasing (decreasing) this difference in the corresponding area reduces (increases) the height of the layer by 1-3 times the average caliber of the piece.

Description

ate

The invention relates to the production of iron ore in ferrous metallurgy, namely the production of pellets on roasting conveyor machines.

The aim of the invention is to increase productivity and improve the quality of the finished product.

On the burning trolleys of the conveyor machine, the bed is loaded, then a layer of raw pellets is supplied and the carts are fed to the drying section with filtration of the heat carrier from the bottom up with a temperature of 300 ° C. The sensor installed in the drying section is a chromel-copel thermocouple -

continuously measures the average temperature of the waste gases from the layer (80 ° C). The sensors are installed at the beginning of the section at several points across the width of the carts at a distance of 100 mm from the layer surface. The distance between the sensors is 60 average gauge pieces (average diameter of the pellet), i.e. 720 mm (average diameter of the core is 12 mm). Under conditions of uniform loading, the difference in the sensor readings should not exceed 10 ° C. If due to the segregation of the pellets when laying the layer, the gas permeability of its sections becomes

with different and sensors will reach

difference 10 ° C

the height of the layer of the corresponding sections is reduced or increased by 2 medium caliber pieces by 1 ° C temperature difference, i.e. at a temperature difference of 10 ° C, the change in the height of the layer is 12 2 24 mm. If necessary, the correction is repeated and the specified difference is set close to zero.

Example 1. On the calcined bed planners of conveyor machines of type OK-306, they load the bed first, then the raw pellets. The carts are fed to the heat treatment zones of the machine, starting with its drying of the raw pellets by filtration through a layer from the bottom upwards of the coolant with a temperature of 400 ° C. A sensor installed in the first drying section (for example, a chromel-Kokel thermocouple) continuously measures the average temperature of the gases leaving the mountain drying section (80 ° C). In addition, in the first section, the temperature above the layer of the erupted pellets (at a distance of 100 mm from the layer surface) is measured at several points along the width of the kiln carts. Based on the indications of these thermocouples, the temperature difference between the coolant between the adjacent elements of the layer (located 720 mm apart from each other) is determined. For normal use of the roaster, this difference should be close to zero. In this case, the adjustment of the loading conditions of the raw pellets is not required. However, changes are possible, for example, in the formation conditions of the raw pellets, and their segregation begins on the machine. In this case, the temperature difference between the coolant between adjacent elements of the layer immediately begins to grow. Consequently, one of the sections (for example, right) has a reduced gas

0

five

0

five

0

five

permeability, the second (left) - increased. Upon reaching a temperature difference of 10 ° C, the laying of the layer of raw pellets is corrected. To do this, on the left side of the layer, its height is increased by 2 medium caliber pieces (by 10 ° C temperature difference of the heat carrier), and on the left side, respectively, it is lowered. The change in the height of the layer will be; 2л12 24 mm. After the indicated adjustment of the layer, the temperature difference of the heat transfer medium is again measured. If necessary, the correction is repeated and the specified difference is set close to zero.

After elimination of the unevenness of the process, the normal operation of the calcining conveyor machine continues.

The application of the invention ensures uniform heat treatment of the layer across the width of the kiln carts.

Claims (1)

Invention Formula A method for controlling the loading of a layer of raw pellets to the grate, including the distribution of granules across the width of the kiln carts, measuring the temperature of the gases leaving the pellet layer, changing the height of the layer is inversely proportional to the measured temperature, characterized in that, in order to increase productivity and improve the quality of the finished product, the temperature of the gases leaving the layer of pellets is measured in the initial period of the layer blowing, the temperature difference between the adjacent elements of the layer separated from each other is determined ug across the width of 40-80 average calibers of the piece, and for every 10 ° C increase (decrease) of this difference lower (increase) the height of the layer by 1-3 of the average caliber of the piece.