SU769333A1 - Mass flowmeter - Google Patents

Description

(54) MASS FLOW METER

The invention relates to a measuring technique and can be used, in particular, to measure the mass flow of the solid phase, which is contained mainly in fine pulp, for example, at mining plants.

Known mass flow meter containing the volumetric flow sensor - the impeller, the density sensor and the computing device 1.

The disadvantage of this flow meter is the complexity of its design, due to the introduction of a separate density sensor with a converter into the measuring circuit. As a result, the reliability of the instrument and the accuracy of its readings are reduced. .

In the proposed flow meter, a density sensor is made in the interior of the radiation source with a receiving transducer, while the radiation source is placed inside the impeller shaft, made in the form of a collimator with holes, the impeller is placed in a chamber mounted on one side of the measuring pipeline, and its axis is perpendicular the axis of the pipeline, with the receiving transducer located on the other side of the measuring pipeline, opposite the flap.

FIG. 1 shows a flowmeter diagram; in fig. 2 - time diagram.

The flow meter contains a tangential impeller 7 mounted on a shaft 2, made in the form of a collimator with holes 3. Inside the shaft 2 a source of gamma radiation is placed. The impeller / ra is located in the housing 5, mounted into the wall of the measuring pipeline 6. On the opposite side of the pipeline 6 in the wall, the protective screen 7 with “hole 8 is fixed.

10 Against the aperture 8, a radiation detector 9 is placed, connected to an integrating - I1nten.simeter .10 and to a scaling device .M 1 //. At the entrance of the latter is installed the key 12 of the key scheme connected to

15 timer 13 and the output of the counting device //. The outputs of the intensimeter 10, the timer 13 m of the counting device are connected to the multiplying device 14, which has an output to the secondary receiver 15.

The flow meter operates in accordance with the timing diagram shown in FIG. 2, as follows.

Pulp flow, passage through the pipeline

25 6, rotates the impeller / s aal 2. At the time of aligning the holes 3 of the collimator with the hole 8 in the protective screen 7, the radiation intensity rises. This is noted by detector 9, the signals of which are converted by pulses with an intensity meter 10.

incoming in turn to the input of the multiplying device 14 with the following frequency proportional to the rotational speed of the impeller.

At time nt (see Fig. 2), timer 13 emits a pulse opening key 12, and pulses from the detector output 9 in an amount proportional to density arrive at the input of the scaling device // until time / when timer 13 is from- covers the key circuit 14, and further until the recalculator // capacity is filled at the moment tn, when the pulse from its output closes the key circuit 14 and the key 12. In such a way, the key circuit opens for a period (tn-t) when the secondary device 15 fixes intensity meter pulses 10, the frequency of which is proportional volumetric flow rate, and the amount recorded over a period of time (tn-mass flow rate of solid material.

Zero flow through solid material is observed when clean water flows through conduit 6 and when the time period for filling the container of the device // coincides with the time interval that is established for clean water using timer 13.

Such a technical solution allows, when there is one converter, to obtain information on two parameters — volume flow and density in accordance with the formula

B-- n-tiT

Q, C f

where QT is the consumption of solid material contained in the pulp; C is constant, depending on the cross section of the pipeline, its material and the energy of gamma quanta; B is constant, depending on the activity of the source;

T is the time of one revolution of the impeller.

The volume flow rate is determined by the frequency of the peaks of the radiation intensity,

proportional to the rotational speed of the impeller, which is generated by the intensity meter, and the density by the number of gamma quanta, which are calculated by the scaler for a certain period of time. The signals of the latter are converted by multiplying devices into units of mass flow. Thus, the flow meter contains one transmitter carrying information about

two parameters - volume flow and density. The presence of a rotating collimator with a plurality of holes increases the sensitivity of the flow meter, as it increases the frequency of the peaks of the radiation intensity and provides them a clearer fixation, because the radiation is collimated twice - with a collimator and a hole in the protective screen.

Formula U3

A mass flow meter that contains a section of the measuring pipeline with a volume meter and a density meter connected to a computing device located inside and n-its impeller is different from the fact that, in order to simplify the design and increase reliability, a density sensor is made in it in the form of a radiation source with a receiving transducer, while the radiation source is placed inside the shaft of the hcr, ylchatka, made in the form of a collimator with holes, and the impeller is placed in the chamber, The measuring pipeline is on one side, and its axis is installed perpendicular to the pipeline, with the receiving transducer located on the other side of the measuring pipeline, against the impeller.

The source of information taken into account in the examination:

45 1. USSR Author's Certificate No. 504088, cl. G 01 F 1/00, 1974 (prototype).

Fig 1

Claims (1)

Claim • A mass flow meter containing a section of the measuring pipeline with a volumetric flow meter impeller located inside it and a density meter connected to a computing device, characterized in that, in order to simplify the design and improve reliability, the density sensor is made in it in the form of a radiation source with a receiving transducer, while the radiation source is placed inside the impeller shaft, made in the form of a col35 limator with holes, and the impeller is placed in the chamber, is installed one side of the measuring pipeline, and its axis is perpendicular to the axis of the pipeline, and the receiving transducer is located on the other side of the measuring pipeline, against the impeller. Source of information taken into account during the examination: 45 1. Copyright certificate of the USSR No. 504088, cl. G 01 F 1/00, 1974 (prototype).