SU139217A1 - The method of measuring the level and density of the fluidized bed - Google Patents

Description

There is a known method for measuring the level and density of a fluidized bed, based on differential pressure gauges with forced blowing of impulse lines.

However, this method has the disadvantages that the gas supplied to the blowing of the pulsed lines reacts, distorting and changing the material balance and the gas dynamics of the process in the apparatus.

The difference of the described method is that the level and weighted density are determined by the pressure value created in the measuring tubes lowered into the fluidized bed, by the upward flow of gas supplied to create the fluidized bed, which allows to automate the maintenance of the specified fluidized bed levels in the fluidized bed. devices and simplify measurements.

In the described method, the differential pressure meter is mounted vertically directly at the top of the apparatus and the instrument is remotely transmitted.

This makes it possible to drastically reduce the diameter and length of the cold part of the impulse lines extending vertically from the apparatus to the differential pressure meter, and the possibility of accumulation of condensate in the impulse lines is eliminated so as not to distort the instrument readings, as the condensate in the tube flows down into zone and evaporate.

The schematic drawing shows an example of a measurement of the level and density of a fluidized bed.

In the apparatus / filled with fluidized solid particles a tube 2 is immersed, the upper end of which is connected to the plus chamber 3 of the differential pressure gauge, and a coupling 4 is put on the lower open end, which is lowered to the bottom of the apparatus.

No. 139217-2, in order to compensate for the static pressure above the fluidized bed, a pressure is taken from the reactor cover, which is fed to the negative chamber 5 of the differential pressure gauge.

In the lower conical part of the apparatus /, where the distributor lattice 6 is located, gas or vapors of petroleum products are fed through pipe 7 to the reaction, as well as to create a fluidized bed.

The process of measuring the level proceeds as follows.

Gas or vapors of petroleum products entering the distribution grid 6 will simultaneously flow into the self-unloading tube 2 with the coupling 4, gradually accumulating in it. As gas or vapor accumulates in it, the pressure in the tube will gradually increase and, finally, will reach a pressure equal to the pressure of gases in the lower part of the apparatus.

Thus, the gas pressure in the pipe is the true value of the differential, that is, the level of the fluidized bed, equal to the depth of the tube in the fluidized bed, plus the pressure above the layer.

Using a differential pressure gauge, the pressure drop over the bed (minus line) and pressure at point M (positive line) determine the true value of the level of the fluidized bed.

Measurement of the weighted density of the fluidized bed, in contrast to the described level measurement method, is carried out by means of two tubes 2 and 5 lowered into the fluidized bed to a certain depth.

Subject invention

A method for measuring the level and density of a fluidized bed using piezometric tubes, characterized in that, in order to automate the maintenance of predetermined fluidized bed levels in apparatus and to simplify measurements, the level and weighted density are determined by the value of the pressure drop created in the fluidized tubes discharged into the fluidized bed bed, upward gas flow to create a fluidized bed.

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