SU33849A1 - The device for burning cement raw mix in the sprayed state - Google Patents

Description

By means of the proposed device, it is intended to reduce the cost and simplify the process of burning the cement raw mix in a spray state.

In the schematic drawing of FIG. 1 shows a device in longitudinal section; and FIG. 2 is the same section along the line AB in FIG. one.

The apparatus for calcining the cement raw mix in a spray state consists of a shaft 7 with an oval-shaped cross section. The outer casing of the mine is made of hollow bricks; The inner wall 5 of the shaft, which is lining the furnace, is made of refractory bricks. Between the outer masonry and the lining there is an air annular gap 4, which is insulated from heat conduction. At the bottom, the mine space is closed by a cast-iron hollow funnel 5. The inner cavity of this funnel is always filled with circulating water. The top hole of the device is closed by a metal grate 36 installed in a metal frame 7 and receiving a vibratory movement from the electric motor 8 by means of cable 9. The sieve 36, like the diameter of the mine, has the same oval shape, but the area of the screen is slightly smaller than the area of the mine L Next, from the outside

Three dust-collecting chambers 70 adjoin the sides of the furnace. These chambers are folded independently, and c. Their upper parts are made of hollow brick with a corresponding refractory lining and in the lower parts, supporting their parts, are made of ordinary brick or stone. The transverse horizontal sections of these chambers are rectangular, slightly deviating from the square. At the bottom of the chamber are closed cast iron funnels. The first two funnels, hollow, have cavities 6 filled with circulating water, and a third, single-wall, without water cooling. On top of the chamber are covered with refractory vault / 2. The shaft 7 with the first chamber and further the chambers communicate with each other through the chimney openings J3 arranged in the longitudinal direction in a zigzag manner. Each chamber has cast-iron hollow dust-deflecting peaks J4, embedded with their ends into the longitudinal walls of the chambers. Internal cavities / 5 of these visors are connected in series with each other by air conduit iron pipes. The outside air enters the cavities of the visors through the receiving iron pipe / 7, passes successively through the cavities of all the visors and, heated, is supplied to two J8 fans

with iron pipes 19. Gases are sucked off by an exhauster 20 into chimney 21. Elevator 22 delivers dust 1d fuel from a coal mill through chute 23 to bunker 24, from where it is fed by feeder 25 and funnel 26 to injector 27. Injectors have two completely identical ones located in two planes x height of the furnace. To supply the pulverized fuel to the nozzle of the lower plane, a screw 28 is installed that receives fuel from the common feeder 25. Elevator 29 delivers ground marl mixture or ground clay mixture and limestone through chute 30 to a flat sieve vibrator 36. Oven funnel 5 and two first two funnels chambers remove finished products through automatic gateways 31 with counterweights 32 into auger 33. The funnel of the third chamber instead of the gateway has a simple gate for periodic descent from the hand of pulverized clinker.

An artificial flour mixture from marls or from clay and limestone receives a certain proportion of pulverized fuel or by grinding this fraction of fuel together with the marl mixture in raw mills, or in mixing silos from a coal mill, and the size of this fraction of fuel as a percentage of the total fuel, determined by the calculation for firing, varies depending on the type of artificial mixture and on the type of fuel itself in the range from 25 to 40%. Thus, 25–40% of pulverized fuel goes with the mixture and, accordingly, 75–60% is blown by two nozzles in their pure form. Optionally, the mixture should contain from 0.5% to 1% ground iron ore. The flour mixture enters a flat sieve with a vibration motion closed on top of the iron sheet (vibration can be carried out from both an electric motor and a pneumatic vibrator) so that the entire surface of the sieve is covered with a layer of flour mixture with a thickness of at least 20 millimeters. This layer protects against gas breakthroughs and shields radiant heat from losses through the top hole. The sieve itself is always uniformly cooled by the flour mixture passing through it. In addition, radiant heat is reflected significantly

degree cloud falling flour dust. The flour particles of the mixture that pass through the sieve initially fall down more or less freely, then, descending from the sieve to a distance equal to about half the sum of the axes of the furnace oval, they are closed with a flame of the upper nozzle and then the flame of the lower nozzle. The nozzle axes are approximately parallel to the greater axis of the furnace oval and moved apart to the gentle curves of the oval; along the height of the axis of the nozzles, they are arranged in such a way that the spiral turn of the lower torch is a continuation of the same turn of the upper torch. The turbulence is given for the purpose of more perfect combustion of fuel in a zone of lesser height, which results in a reduction in the overall height of the device and, secondly, in order to better mix the flour particles and lengthen the particle path, during which chemical reactions of calcination, sintering and, finally, melting, although theoretically, the reaction should have occurred almost instantaneously due to the smallest particle size. Despite the almost instantaneous reaction, it should still occur much more completely than in rotary, and even more so than in automatic shaft furnaces due to the smallest size of the mixture particles and uniformly high temperature, which together allows the mixture particles not only to evenly sinter, but, most importantly, fusing evenly (neither the first nor the second in rotary kilns can be achieved). The uniform sintering and melting create the necessary conditions for increasing the saturation coefficient (according to Kül) to the limits that guarantee the release of high-performance clinker without negative properties with respect to the constancy of volume. There can be no fear that the sintering particles of clinker may not get the proper ratios of the components, because the passage of the particles of the mixture in the form of the smallest lumps serves as a guarantee, since these lumps pass the sieve under some pressure of the mixture layer. on the sieve through the appropriately sized openings of it, and, secondly, the infinite number of collisions of these particles in the rings of the vortex flame. But,

if for some reason it happened to be known, in any case, MeihoH degrees, then these particles with inadequate composition of components, ultimately having a lower specific gravity, will be carried by gases into the second and third chamber W, from where the independent screw will depart as second-grade products in the form of Portland cement. The funnel of the furnace itself and the first chamber will collect clinker of high-acting cement of higher grades than from rotary kilns. The clinker should be obtained in the form of small grains, the largest size of which will exceed the poppy grain, which results in significant savings on grinding the clinker, which will be discussed below. The clinker particle will continue to fall swirling and, to a large extent, will pass in the immediate vicinity of the metal surface of the kiln funnel 5 and receive sufficient cooling from the water circulating in the funnel cavity. The process occurs in the reverse order than in modern rotary and shaft kilns, i.e., not towards the heat flux, but in its direction, which, according to the inventor, is the only correct one for roasting in the pulverized state. In view of the fact that the chemical process is very fast and very complete, the heat loss is minimized due to the maximum total surface of the flour particles; In addition, the presence of waste gas regeneration, the presence of sensitive regulating devices in the supply of raw meal by changing the frequency and amplitude of the vibrations of the sieve, in the supply of pulverized fuel and heated air, and finally, in the exhaust gas suction, supplement the maximum use of heat. Heated water in the funnels due to the cooled clinker should also be used for heating of service, residential and, to some extent, industrial premises. Taking into account the absence of the need to evaporate any moisture, the savings in fuel should be very high compared to rotary kilns. According to preliminary estimates by the inventor, the heat consumption per kilogram of clinker will decrease from 1200 to 800 calories. In other words, fuel consumption will decrease by more than 30% against rotary kilns.

The subject matter of the invention.

Claims (2)

1. A cement raw mix roasting device in an atomized state, characterized in that it consists of a mine / with a mobile sieve 36 over its top and with two nozzles set at different heights, feeding horizontal jets of pulverized fuel, to which the furnace is adjacent The dust-collecting chambers 10 communicating with each other, which, as well as the mine 7, are closed below with cast-iron funnels 5, have inclined visors 14 under the inlets 75. 2. In the device according to claim 1, use in the funnels 5 of the cavities b for cooling them with water, and in the visors of the 14-cavities 75 for conducting air, which then flows through the fans 18 to the nozzles.