RU98116069A - ACTIVE PRESSURE SENSOR FOR FLOW METER - Google Patents

Claims (9)

1. The active pressure sensor for the flow meter, in particular for fluids containing solid impurities, made in the form of a tubular body with an inlet pipe (1), an output pipe (7) and sections located between these pipes with a gradually changing cross section, and having holes for pressure selection at successive points, the holes being distributed around the perimeter of the sections and surrounded on the outside of the tubular body by an averaging collector (11, 15, 19), characterized in that in the flow direction, after another, a diffuser section (3), a section with a maximum section (4) and a confuser section (6) are provided in the sensor, and that a cylindrical safety insert (22) having openings in its wall (23) is placed along the measurement section (21) , 24, 25). 2. The active pressure sensor according to claim 1, characterized in that the inner diameter of the inlet pipe (1) is equal to the inner diameter of the outlet pipe (7) and the outer diameter (d ₂ ) of the safety insert (22) and that the inner diameter (d) of the safety insert equal to the inner diameter of the pipeline (26, 27) into which the above-mentioned active pressure sensor is integrated.  3. The active pressure sensor according to paragraphs. 1 and / or 2, characterized in that the holes in the wall of the safety insert are longitudinal slots (23) that are parallel to the axis of the tubular body (27) or form an angle with cross-sectional planes other than 90 °.  4. The active pressure sensor according to paragraphs. 1 and / or 2, characterized in that the holes in the wall of the safety insert are transverse slots (24) located in the planes of the cross section oriented perpendicular to the axis of the tubular body, or forming a certain angle with these planes other than zero.  5. The active pressure sensor according to paragraphs. 1 and / or 2, characterized in that the holes in the wall of the safety insert are perforations, preferably round. 6. The active pressure sensor according to one or more of the preceding paragraphs, characterized in that in relation to the smallest size (b) of the hole in the insert wall, the condition is met:
d≅b <b ₁ ,
where d is the diameter of the holes for pressure selection (9, 13, 17) and
b ₁ - the minimum size of solid impurity particles carried away by the fluid flow. 7. The active pressure sensor according to one or more of the preceding paragraphs, characterized in that the length (l) of the portion of the safety insert (22) occupied by the openings in the wall satisfies the following conditions:
l≥l ₁ + l ₂ + l ₃ + l ₄ + l ₅ + 2d,
where l ₁ is the length of the section of the diffuser (3);
l ₂ - the length of the plot (4) with a maximum cross section;
l ₃ is the length of the confuser;
l ₄ - the distance between the plane (2) of the holes (9) for pressure selection at the inlet pipe (1) and the beginning of the diffuser section (3);
l ₅ - the distance between the plane (8) of the holes (17) for pressure selection at the outlet pipe (7) and the end of the confuser section (6).  8. The active pressure sensor according to one or more of the preceding paragraphs, characterized in that the holes in the wall (23; 24; 25) of the safety insert (22) are aligned with the holes for pressure selection (9; 17) at the inlet (1) and outlet (7) nozzles.  9. The active pressure sensor according to one or more of the preceding paragraphs, characterized in that the number of longitudinal slots (23) or perforations (25) in the safety insert (22) is equal to the number of holes (9; 17) for pressure collection at the inlet (1) and, accordingly, the outlet (7) nozzles or is an integer multiple of this number.