SU1721441A1 - Device for measuring flow-rate of pulverulent medium - Google Patents

Abstract

The invention relates to instrumentation and can be used in the energy and other industries. The purpose of the invention is to increase the reliability of the device. The powdered medium enters the nozzle located in the pipeline, on the other hand, it receives air from an overpressure source, the level of powder in the nozzle, measured with a capacitive level gauge, is proportional to its flow rate. 2 hp f-ly, 2 ill.

Description

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The invention relates to instrumentation and can be used in the energy and other industries.

The purpose of the invention is to increase the reliability of the device.

FIG. 1 shows the device, a general view; in fig. 2 - implementation of the measuring pipeline.

The device contains a pipe 1 for a powdered medium, a transducer 2, a recording device 3, a measuring pipe 4, one end of which is connected to a source 5 of a stabilized overpressure, and the other 6 introduced into the pipe 1 for a powder medium contains two sensors 6.7 of a level meter powdered medium, the electrically conductive rod of the first of which is distributed over the cross section of the open end of the measuring pipe 4 and connected through the converter 2 to the first input of the multiplier 8 , and the conductive rod of the second is placed along the length of the measuring pipe 4 and connected through a parametric generator 9 to the second input of the multiplier 8.

The operation of the device is as follows.

The flow of the powder medium in pipeline 1 splits into two parts: the main one moves through the pipeline 1, and the other enters the output end of the measuring pipeline 4. The gas flow rate in the source of overpressure 5 is chosen so that the powder medium weighed by the velocity pressure of gas does not

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entered the measuring pipeline below the sensor 7 at the maximum measurable flow rate of the powder medium in the pipeline 1. The minimum measured flow in said pipeline corresponds to the minimum level of the powder medium entering the measurement pipeline 4.

The measurement process consists in balancing the velocity head of the powder-like medium in the measuring pipeline with the velocity head of the gas of the stabilized source of overpressure 5. This balance is performed at an average level of the sensor 7, the deviation of the level on one side characterizes the change in the flow rate of the powder medium, and the sensor 6 carries information (after converter 2) about the density of the powder medium in the pipe 4, and sensor 7 about the volume of its filling. The density information is used to eliminate the error from the separation of dust particles in the measuring conduit 4.

The sensors 6, 7 are connected to a parametric generator 9 and a converter 2, also containing a parametric generator, as long lines (i.e., their length is comparable with the wavelength of the high-frequency electromagnetic field generated by the parametric generator). The parametric generator is a high-frequency generator whose output parameters (amplitude, frequency) depend on the capacitive or inductive parameters of the load of sensor 6 or 7. In the process of entering the powdery medium into the measuring pipe 4, the particles are intensively mixed in the latter, but with minor changes the flow rate is carried out separation of particles (especially with the vertical placement of the pipeline 1 according to Fig. 1). introducing significant error into the measurements. To reduce the separation effect at the bottom of the measuring

Pipeline 4 (level gauge 7 in the cavity of the metering pipe) makes a hole that can be a slot. Through this hole (the diameter of which is about 0.05-0.1 of the diameter of the measuring pipeline) mass transfer of the cavities of the pipelines 1.4 takes place, which reduces the separation of large particles in the lower part of the pipeline 4.

With significant lengths of the latter along its length, several holes or a slit hole are made, for example, 0.8 times the length of the pipeline 4. The size of these holes must be at least 2-3 times larger than the maximum particle size of the powdered medium.

A reduction in the separation of particles is also carried out by performing a measuring conduit 4 over the length of the arrangement.

the level gauge of the sensor 7 is tapered from the open end. At the point of constriction, the gas velocity increases, which improves the mixing of particles in the cavity of the measuring pipeline.

The reliability of the device is increased by eliminating mobile sealing compounds, especially at high environmental temperatures.

Claims (2)

1. Device for measuring flow a powder medium comprising a flow sensor located in a pipeline, characterized in that, in order to increase reliability, the flow sensor is designed as a pipe turned with an open end against the medium flow, an overpressure source is connected to the pipe, and a conductive rod is located inside it, connected through a parametric generator with a recording device. 2. The device according to claim 1, of which is a series of holes at the bottom of the nozzle. 3, the Device in PP. 1, 2, that is, so that the nozzle is made expanding toward the open end. . . . .T „. tort FIG. one