CS269521B1

CS269521B1 - Constant pneumatic resistance

Info

Publication number: CS269521B1
Application number: CS876026A
Authority: CS
Inventors: Vratislav Rndr Csc Balas; Milan Soukup
Original assignee: Balas Vratislav; Milan Soukup
Priority date: 1987-08-17
Filing date: 1987-08-17
Publication date: 1990-04-11
Also published as: CS602687A1

Abstract

Riešenie sa týká konštantného pneumatického odporu pře velký rozsah prietokov plynu. Podstatou riešenia sú pří ruby konštantného pneumatického odporu nesúce sieťku uchytenú v rámčeku tesnenom tesniacimi krúžkami sú vytvořené pneumatické kapacity s vývodmi do atmosféry, ohraničené vonkajšími hranami a vnútornými hranami, ktorých predlžené myslenie spojnice vytvárajú v ústiach pneumatického odporu rozširujúcich sa smerom k viacvrstvej sieťke, uhol 120 až 140 . Riešenie je možné využiť při snímaní výdychu u prístrojov určených na vyšetrovanie pl’úc.The solution concerns constant pneumatic resistance over a large range of gas flow rates. The essence of the solution is that pneumatic capacities with outlets to the atmosphere, bounded by outer edges and inner edges, whose elongated joints create an angle of 120 to 140 in the mouths of the pneumatic resistance expanding towards the multilayer mesh, are formed by the flanges of the constant pneumatic resistance carrying the mesh fixed in a frame sealed with sealing rings. The solution can be used when sensing exhalation in devices intended for lung examination.

Description

(57) The solution relates to a constant pneumatic resistance over a wide range of gas flow rates. The essence of the solution is flanges of constant pneumatic resistance carrying a mesh gripped in a frame sealed with sealing rings are created pneumatic capacities with outlets to the atmosphere, bounded by outer edges and inner edges, whose extended thinking of the connector creates in the mouths of pneumatic resistance extending towards the multilayer mesh, angle 120 to 140. The solution can be used for sensing exhalation in lung examination devices. 269 521 (11) (13) si (51) Int. Cl. 4 G 01 F 1/40

CS 269521 Bl CS 269 521 B1 1

The solution relates to a constant pneumatic resistance over a large range of gas flow rates with reduced aerodynamic noise, which can be used to measure instantaneous flow rates on the basis of the pressure loss measurement at this resistance.

[0004] In the meantime, known gas flow measurement methods based on the above principle use Fleisch tube resistance, where the gas stream is divided into a series of parallel laminar streams, or a Lilly tube, where a metal mesh is laid in the expanding portion of the pipe. A constant resistance value is achieved by shaping the expanding portion of the pipe.

The disadvantage of the Fleisch tube is the structural complexity, large dead space and narrower range of flow rates. On the other hand, the Lilly tube has the disadvantage of higher aerodynamic noise at higher gas flow rates.

These drawbacks are eliminated by a constant pneumatic opening formed from flanges carrying a multi-layered mesh. The essence of the solution is that pneumatic capacities with outlets are formed in the flanges of constant pneumatic resistance carrying the metal mesh held in the frame and sealed by the sealing rings. into the atmosphere, bounded by the outer edges and inner edges, whose extended thought lines form an angle of 120 ° to 140 ° in the pneumatic resistance mouths extending towards the multilayer mesh.

The constant pneumatic resistance according to the invention determines the dependence between pressure drop and air flow in the range of 0 to 15 l / s. with linearity 2% of reading. The fluctuation of the pressure drop by introducing capacity has reduced the approximate half of the capacity-free design. An example of a constant pneumatic resistance in a section is shown in the accompanying drawing.

The flanges 6 of the constant pneumatic resistor symmetrically positioned to the mesh 6 have pneumatic capacitances 6 provided with the outlets 6 into the atmosphere on the inner periphery. An imaginary extension of the connector between the outer edge 8 and the inner edge T_ produces a cone with an apex angle of 120 ° to 140 °. The mesh 6 fixed in the frame 6 is sealed by sealing rings 6 which simultaneously seal against the outer atmosphere.

The measured gas enters the resistor through the orifice 9 and through the mesh 2, a working pressure differential is created measured at the outlets 9 into the atmosphere. The magnitude of the pressure drop is due both to the density of the mesh 6 and to the size of the angle formed by the thought of extending the connecting edge of the outer edge 4 and the inner edge T, and ranges from 120 ° to 140 °.

The constant pneumatic resistance can be used with the advantages described above to measure instantaneous gas flow, for example, when sensing exhalation in lung examination devices.

Claims

OBJECT OF THE INVENTION

Constant pneumatic resistance formed from flanges carrying a multilayer mesh marked. by the fact that in the flanges (1) of the constant pneumatic resistance carrying the meshes (2) fixed in the frame (3) sealed by the sealing rings (4), pneumatic capacities (5) with outlets (8) to the atmosphere are formed, bounded by the outer edges (6). ) and inner edges (7), the elongated thought lines of which create an angle of 120 ° to 140 ° in the mouth (9) of the pneumatic resistance extending towards the multilayer mesh (2).