SU1688230A1 - Flow rate meter - Google Patents

Abstract

The invention relates to automation, in particular, direct action devices for controlling the flow of liquids and gases with varying pressure and density. The purpose of the invention is to stabilize the volumetric flow rate. The flow regulator includes a housing 1, the cavity of which is divided into a flow-through 2nd non-flowing 3 chamber with membrane 4 rigidly connected with a loading element - a float 5 k with a throttle element 6 unloaded and a load whose force is directed towards the opening of the throttling element. The regulator contains a transducer 8 of fluid flow into a dynamic pressure released on the membrane in a non-flowing chamber in the form of a force directed towards the closing of the throttling element. P. f-ly, 4 ill. (L with O5 00 00 INO with o

Description

g b FIG. /

The invention relates to automation 9, in particular, to devices for direct action for controlling the flow of liquids and gases with varying pressure and density,

The purpose of the invention is to stabilize the volumetric flow rate.

FIG. 1 shows the design of the flow regulator with the spring ya of FIG. 2, the same without the spring of FIG. 3.4 shows the corresponding Dependencies of the lifting force of the float body on the density of the medium L: F -Vp, volume G y and mass-f o. Gt expenditures, Indices 1.0.2 relate to minimum, nominal average) and maximum parameter values.

The flow regulator contains a cortex-iy 1, the cavity of which is divided into flow-through 2 and non-flowing 3 chambers by membrane 4, connected to a loading element made in the form of a gel 5, which is a float with a density less dense than the working environment. a two balanced balanced valve 6 is a throttling element, a dynamic fluid flow transducer, made in the form of a pressure tube 8 located in the inlet fitting 7 7, connected by a duct with the flow-through chamber 3 in the flow-through chamber 3, the cup 9 is fixed on the membrane to the bottom otrogo spring 10 rests, with the other end opirayuscha on plate 11 'fixed to the adjusting shto- e 12,

The flow regulator operates as follows.

The working medium comes from the inlet nozzle, 7 into the flow chamber 2 and the transducer — pressure tube 8 — into the non-flow chamber 3. The diaphragm 4 is acted upon by a dynamic pressure force balanced by the buoyant force 5, when the flow rate increases, the dynamic pressure increases 8. valve 6 is covered As the flow rate decreases, the dynamic pressure decreases and the valve opens.

The float 5, by pushing the medium by the medium, provides the force of the load F on the membrane 4 and is at the same time an element sensitive to changes in the density of the medium. With increasing media density

membrane increases in absolute value, as illustrated by the direct

F -Vp, (1),

where V is the volume of the float.

However, the weight of the float itself must be compensated by the force of the spring with a small stiffness with an open throttle element.

A change in the load on the membrane 4 causes a corresponding change.

bulk G

and mass G costs

five

l 20

five

0

35

40

45

50

Since the density of the medium and, consequently, the force of the load on the membrane often vary slightly, the regulators are made with unloaded double-seated valves, which allow to exclude the influence of static pressure on the flow rate.

In order to ensure a quick response of the regulator to a change in the density of the medium (to increase the dynamic accuracy of the adjustment), the float 5 is located in the flow chamber 2, since in the non-flowing chamber 3 a new value of the density of the medium is established with a significant delay.

The principle of the membrane regulator with a dynamic transducer is to stabilize the dynamic pressure of the fluid flow at such a level that the force released on the membrane 4, proportional to the dynamic pressure, is equal to the force F of the membrane load from the float 5 and the spring 10:

p-Pr-ts p.

- speed from reda in channel of dynamic converter j

- acceleration of free fall;

TH9f 2 (° 2 Dd + d2) The effective area of the membrane is the diameter of a Vis with a diameter of a rigid center d.

(2)

where v

yo

From (2) s

(3)

If the cross-sectional area of the channel of the dynamic converter is equal to w, then the volume flow rate, taking into account (3), will be expressed as

- -v - J

N p

(four)

v 2l.c GL-J

2g w2-2g

(eight)

a mass flow

Gm Gv P W V P

(five)

-one

The load force on the membrane 4 from the float 5, the weight of which is compensated by the spring 10E will be

F V-p,

where V is the volume of the float. Taking into account (4) and (6):

(6)

wJlsipl w, Up k „P P-fN S9f)

UV const

Thus, if the membrane load is formed by an ideal float (the weight of which is compensated by the spring force), then the load force is proportional to the density of the medium (6), and the regulator maintains a constant flow rate of the medium and ensures the volume flow invariance the flow rate varies linearly with the density of the medium (5).

Equation in expressions (2) and (6), taking into account (4) we get

one

t

 ///// х //////////////////// //,

The load force from the float 5 is determined from (2) and (4):

F and, o (-2v --Sjg

vp- p

2g w2

(9)

Claims (2)

1. The flow regulator, comprising a housing, the cavity of which is divided into flow and non-flowing chambers by a membrane connected to a balanced throttling element and a load element made in the form of a body located in the flow chamber, which is sensitive to a change in the density of the medium and whose force is directed towards the opening of the throttling element, and the flow converter of the medium into dynamic pressure, connected to the non-flowing chamber with the formation of a force directed towards the closing of the throttling electric This is due to the fact that, in order to stabilize the volumetric flow rate of the medium, the body is made with a density that is lower than the density of the medium. 2. The regulator according to claim 1, characterized in that the body is provided with a spring. Gvtm grnt Gmo By f, 0,2 6 ml FIG. J h Fm t