SU698876A1 - Method of monitoring the speed of compact layer of loose material - Google Patents

Description

(54) METHOD FOR CONTROLLING THE VELOCITY OF THE MOTION OF THE DENSE LAYER MATERIAL

The invention relates to the field of pneumatic conveying of bulk materials and can be used in metallurgical, chemical, goptsevoy and other industrial areas, in particular, in the case of processing and release of materials from the mine sows, furnaces and other devices when exposed to a gas stream.

The empirical dependence of the mass flow rate of the flow of bulk material passing through the aperture with a flow of gas through the gas is known. The magnitude of the latter is calculated by dividing the pressure difference of the gas above the bed and the level of the outlet, determined experimentally, by the height of the column of material 1.

One of the main drawbacks of the method is its insensitivity to the case of countercurrent movement of the layer and the switch.

 The empirical content of the mass flow rate of the flow of bulk material is known, both in the case of passing and oncoming movement of gas and a layer, from the air; the pressure of the gas at the dynamically unstable arch above the convex hole. In this cnysae great

The pressure drop is determined by the difference in pressure of the gas at the level of the orifice and the surrounding atmosphere 2.

The disadvantages of the method are the necessity of simultaneously controlling the bed height and the gas pressure drop in it; the need for a perfect execution of settlement operations with measured parameters; the inapplicability of the method for the cases of bed movement under the influence of an oncoming gas flow in the form of high-speed jets, combined feeding of the pelvis; late measurement of the differential pressure and its distortion due to the transport delay in the layer and its damping action. In addition, the inconsistency of the porosity of the moving layer along its height leads to the determination of the rate of flow of materials from the hole.

The aim of the invention is to simplify and improve the accuracy, as well as to provide speed control during the jetting of gas.

Claims (2)

This nel is achieved by measuring the pressure drop of the gas at the outlet and the speed of the moving layer at the same time as the initial value of the current pressure for the device, as well as by the pressure level of the device. jump () 06 |) a: the 11th increase in pressure drop5 The pressure drop of gas at the outlet orifice, which includes the pressure drop1 at the dynamic-stable arch, directly at the rate of material outflow through the hole, and the investigator a layer with a motion speed. In connection with ETT1M, the measurement of the magnitude of the gas pressure drop at the outlet allows reducing the latency time of the monitoring system, increasing its accuracy and simpler in a constructive manner. FIG. 1 shows a scheme for controlling the speed of movement of a dense layer of bulk material; pas figs. 2 as a function of mass flow rate (Wt, kg / s) of flowable fraksdai material and 5-15 mm at different 1, 1x ways of introducing gas flow into the layer to mass flow rate (Wo, kg / s) of its gravitational release or value of current ratio gas differential pressure (D R, mm Aq.St) at the outlet orifice to its maximum value (DRL; mm W. of water) obtained at an integrated laboratory installation and industrial bunkers. The control circuit includes pulses, tubes 1 and 2 for sampling the gas pressure of the node and above the outlet hole The device 3 is connected, respectively, to the minus and 1 tusovy chambers of the differential pressure gauge 4 and the secondary self-pinging (regulating) device 5. In Fig. 2, the curves K, L, I and H depict the dependence of the relative flow rate of the material through the opening on the value of the relative pressure difference of the gas on the hole, respectively, in the counter-dosing of the gas stream, uniformly acting from below on the dynamically unstable arch; with the introduction of gas in the form of high-speed jets; combined with the movement of gas. From the graph (curves K, L, M, H) it is desirable that the increase in the value of 1 of the relative pressure difference of the gas corresponds to the decrease in the permeable flow rate of the material through the hole in Any gas supply method and does not depend on the physical and mechanical properties of the bulk material. Speed control is performed as follows. When setting up for each type of apparatus, in changing the size and method of inserting niinBoio popic oire.tselzhms K (msgrikgi giyna depending on the speed of outflow of granular material from the differential pressure of gas gas on the hole a. The flow rate of the Mial 1 through the outlet opening varies from the pool to the maximum possible value of the change in some cases of gas flow, and in others, the performance of the feeder at the optimum flow of gas. Then, the mass velocity (Wt, kg / s) of material outflow through the aperture is recalculated to the linear velocity (V. m / s) of the layer motion in the apparatus according to the formula: V - Wt F-7 where F - (outlet of the outlet, y - bulk density of the bulk material, KI / M. Finally, the HiKajfbi instrument 5 is measured and measured to measure the pressure drop of the gas to the linear velocity of the bed in the apparatus according to the measured dependence. Tachimistic, by the known value of its current pressure drop, the velocity bulk material. Formula of 1. The method of controlling the speed of the luiOTHoro layer of bulk material discharged through the hole when exposed to a gas stream, consisting in measuring the pressure drop of gas in the layer, characterized in that, in order to simplify and improve its accuracy, as well as to ensure the speed control when the jet gas flow, the measurement of the gas pressure drop is carried out at the outlet, and the velocity of the layer is determined by the ratio of the current value of the pressure drop to the maximum possible for a given pressure drop. Paraty. 2. The method according to claim 1, and u (and so that the hang is determined by the abrupt increase in pressure drop. Sources of information taken into account in the examination 1.Resnick. Wao Jndustr. And Engng. Chem. Fundament, 1966, v. 5. N 3,392-396. 2. Tsubanov A. G. to become O in the form of pressure drop over the flow of bulk material through a vertical channel. The Black Physics Journal, August 1.969, Home XVII, No. 2. p. 254-260, (prototype). Pfr.ax