SU1740937A1 - Pneumatic pump for injection of powdered materials into molten metal - Google Patents

Description

The gas entering the chamber from the openings of the channels 6 passes through the gap between the conical bottom 2 and the outer wall of the nozzle 5, then, reaching the top one except the nozzle, turns into the recess 8, from where it enters the material pipeline 3. A part of the gas passes through the material thickness and increases gas pressure in chamber 1.

When the gas pressure in the chamber increases to a value close to the gas pressure in connection 13 of the material pipeline, the powdery material begins to flow into the ejector 11 and then through connection 13 of the pipeline to liquid metal. After a predetermined amount of powdered material is injected into the liquid metal, gas supply to chamber 1 through pipeline 7 is closed, which leads to cessation of powder supply through connection 13 of the pipeline, but continue to supply gas through pipeline 12 and connection 13 of the pipeline, which prevents the lance from brewing with metal.

Then again, if necessary, it is possible to resume the injection of powdered materials into the liquid metal by resuming the gas supply to the chamber 1 through the pipeline 7.

The gas coming out of the channels 6 moves in the chamber 1 upwards to meet the material, it aerates it and carries it into the spherical recess 8, from where the mixture of gas and powder enters the input end 4 of the pipeline 3, the recess 8 is spherical, which reduces the resistance to movement gas powder mixture. Since the sphere radius of the recess 8 is made equal to 3–8 diameters of the material pipeline, the gas flow, moving up along the outer wall of the nozzle 5. well aerates the powder and affects the powder arch, destroying it.

When the sphere radius decreases to less than 3, or the sphere radius increases to greater than 8 diameters of the material pipeline, the arches of the powder are poorly destroyed.

Installing the bottom of the recess at a distance of 0.8-5.0 diameters of the material pipeline ensures the normal performance of the pneumopump.

If the bottom of the recess is located from the inlet end of the material pipeline at a distance less than 0.8 of the diameter of the material pipeline, the pump capacity decreases as among the powdered material there are

3 to 4 diameters are larger than particles, making it difficult to absorb powder. If the bottom of the recess is located from the inlet end of the pipeline to

distance greater than 5 diameters of the material pipeline, the inert gas freely captures the powder between the beginning and the end of the material pipeline, and the powder below the pipeline, the gas does not

captures.

PRI me R. In the proposed pneumosuperheater, in which, in separate experiments, the radii of the spherical groove and the distance were changed from a spherical groove to

the end of the pipeline, depending on the diameter of the pipeline in the boundary and beyond-limit ratios, were loaded with a frame-like material and were blown under the pressure of the gas carrier

0.45 MPa. In parallel, a known pneumosupercharger was manufactured and tested under identical conditions. The results of the experiments are presented in table. 1, where the numerator shows the intensity values (in kg / min),

and in the denominator, the specific intensities (in kg / m3 min) of powder blowing.

From the data in the table, it follows that the proposed ratios of dimensions of the pneumonagulator are characterized by the best indicators of powder blowing.

Thus, the use of the proposed pneumopump will allow for the uniform injection into the liquid metal of powdered materials prone to arching, due to the intensive destruction of these arches and good aeration of the powder, which increases the reliability of its operation.

Claims (1)

Invention Formula Pneumopump for injecting powdered materials into liquid metal, containing a cylindrical chamber with a truncated cone-shaped bottom, a material conduit, a nozzle installed at the bottom of the chamber coaxially under the inlet end of the material pipeline, a compressed gas supply line connected to the nozzle, characterized in that, in order to increase reliability, it is equipped with an ejector installed on the material pipeline at the chamber exit, and in the upper part of the nozzle a spherical recess is made, while the sphere radius is equal to (3-8) internal diameters of the pipeline, and the inlet end of the pipeline is set at a distance. (0,8-5) internal diameters of the material pipeline from the bottom of the recess.