Opposing control vortex valve

Holder: Idem (7d) 74) Agent:

(54) Controlled vortex valve.

72) Invention by: Endre A. Mayer.

33) (32) (31

Conventional priority: Patent application filed in the United States of America on January 8, 1970, n. 1.504 in the name of Endre A. Mayer.

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The present invention relates to vortex control valves.

This type of valve, although very useful in many applications, has a number of drawbacks:

a) the characteristics of the pressure as a function of the flow rate do not allow great flexibility of application.

b) the negative resistance characteristics in logic fluid circuits, or else in power oscillators do not allow the use of current type vortex valves either.

c) The use of these valves as flow regulators when a common source of pressure is used as the control signal is very limited. These valves usually have at least one radial supply and one or more tangential control inputs. For optimal flow modulation, the radial supply pressure must be kept constant and the control pressure must be 1, 2 to 2 times higher for the minimum flow. If only one power source is available, a throttle must be placed in series in the flow circuit to obtain the required pressure drop between the supply and the control. This differential pressure across an orifice is maximum for the largest flow, while the efficient operation of a flow control valve requires opposite conditions.

To overcome these drawbacks, the present invention relates to a vortex valve controlled in opposition whose radial supply is eliminated and which has a tangential supply mounted in opposition to the control, the section of which relative to the nozzle of control provides the desired characteristic of the valve.

The invention will now be described by way of example and with reference to the attached drawing in which:

Fig. 1 is a diagram of a valve according to the invention;

Fig. 2 is an analytical representation;

Figs. 3 to 8 are statements of various characteristics;

Fig. 9 is a section through a valve according to the invention;

Figs. 10 and 11 are sections of the previous one respectively according to the references 10-10 and 11-11; and

Fig. 12 is_zan operating diagram of the previous flow regulator.

I

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Referring to FIG. 1, a vortex valve controlled in opposition 10 comprises a control input 12 and a supply inlet 14, both communicating with a vortex chamber 1 6 defined by a wall 1 7 and a central outlet orifice 18. As as can be seen, the fluid currents emitted by the inlets 12 and 14 are directed so as to produce the opposite vortices in the chamber 16, a resulting vortex being the consequence of this opposition.

The mathematical analysis of the operation of this valve 10 will be made below, by introducing a parameter defining a radial supply which, in the present invention, is zero. This analysis also uses an empirical variable W_not defining the relationship between the output flow W and the function of o

vortex ψ which is the angle of the velocity vector of the flow of the fluid with respect to the tangential direction. This function is determined experimentally for each valve configuration₀

Details concerning these calculations are recorded in the brochure published by the ASME / HDL Fluidics Symposium, Chicago, held May 1967, pages 233-250 of the article Advances in Fluidics under paragraph Analysis of vortex valves.

The following definitions are given: î A = flow section - outlet section

A, = section of the control port cl = flow section

Cd ^ = outlet coefficient Cd „, = flow coefficient of the control port = diameter of the vortex chamber = diameter of the outlet port

F. (_Σ) = flow function ¹ Ps g = gravitational constant k = ratio of specific heats 1 = length of the vortex chamber P_vsi = control pressure

P_g = supply pressure of the vortex chamber P ^ = ambient pressure R = constant of ideal gases T_vs = control gas temperature = gas temperature at inlet 12

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T_g = supply temperature

V_vs,, V_vs2 = control flow speeds

V_r = speed of the radial fluid outlet flow = tangential flow speed of the same

W_c1 »W_vs2 = mass order flow

W = mass outlet flow o

W_g = mass feed rate

W_M = sand dimension parameter linked to the flow f '= gas density ψ = angle of the flow speed with the tangential direction.

The flow W_Q is defined by:

P / P

W. = C_OJ Ao ^s C, f, ^v^{0 N d2} '(t.) ï / 2 ^{1 1}cp;

(1) or

1/2 (2), k - 1 and where:

k-1

1/2

- ^Pv

CT

1/2 (3) = 1 .00 (4) because

k.CT (5)

As a result of the conservation of the mass of the flow; the valve, we have: W_Q + W_vs2 through

4C

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00463 where W_s = O in this case. Using the equation of the orifice to calculate the first control flow, we find:

P ^Wcl = ^CDcl ^ATcl cl (^TcP

1/2 ^VS1 ^f1 cl

If P_VS?P_S (7) where and (Pg / Pjjj) are of the form given in equations (2) - (5), and

VI. = _Cd. A, cl cl cl

ÎU_c, f / (^TcP

1/2 if P_s^{? P}cl (8)

Similarly:

^Wc2 = ^CDc2 ^ATc2 c2

Tpi ^VS1 ^£i ' ^s (9) (^Tc2>

^ c2 or: W_c2 = -Cd_e2 AT_c2

1/2 qq Isa _Sip_s, p_c2 (10) (T_c2)

The respective flow sections are calculated as if these sections were circular.

^ATcl - $ - ^Dcl

AT_c2 = X ^Bc2

We also have T

v.

V₊ v_ = ^r A flM^Ps cl ^ cl g2 ^vc2

V_t = _1_ (w_r1 v_rl - w_g2 V ”o (11) (12) (13) (14) (15) (le)

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If there are significant opposite flow rates, this latter value of V ^. can surpass that of or of V_vs2 ° This cannot happen in a true vortex valve in which the tangential speed is higher, at the output at the tangential control input. Consequently, the value of is limited as follows:

.V ^ * Maximum (V_£1 , V ^) (17)

Control speeds are calculated based on the speed of sound and the Mach number:

cl cl (18) ^Vc2 ^{= CM}c2

09) where: C = Vg kr T c

(20)

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because :

(22)

L { ² (23) ^Pcl (" ⁺ V

The Mach number being limited to subsonic conditions by the relation:

Cl with k

CT (24)

Pcl

In reverse flow, if

P, &lt;P. ci s (25)

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00463 cl (26)

Μ 2 ^est calculated similarly with equations (22) to (26) but by replacing P_e1 by P_e2.

The value required to solve equation (1) is given by a set of measurements made on a valve of given geometry, as indicated in the article mentioned above.

These equations being nonlinear must be solved by an iterative method or by a computer.

The solutions of these equations are shown in Figs. 3 to 7. In this analysis P, j should be considered as the supply pressure and P_vs2 like control pressure.

Fig. 3 represents pressure curves as a function of the flow rate for equal supply and control diameters and different values ​​of these diameters, with a supply pressure of 3.5 kg / cm 2. These curves show that a maximum flow is obtained when Ρθ2 = P_vsi and that the vortex flow is zero.

For large control ports, their restrictive effect becomes negligible and the flow rate is almost entirely limited by the outlet port. These curves also show that the high pressure gain as a function of the flow rate is obtained for the values ​​of P_VS2 '9^υ^ are immediately below the value of P. This shows that the flow rate of the valve can be controlled by a pressure lower than the supply pressure, which is an important advantage of the present valve.

Figs. 4 and 5 show the unexpected effect of the variation of the section Ac ^ of the entry 12. In FIG. 4, for a supply pressure Pq of 3.5 kg / cm2, a pronounced negative characteristic occurs at the control orifice, the diameter of which can be chosen between 0.35 and 0.76 mm relative to the orifice the diameter of which can be 2.5 mm, while an extremely high gain can be obtained at the first orifice when its diameter is 1.50 mm.

Fig. 5 clearly shows other effects of a change in relative diameters. The curve corresponding to a control input with a diameter of 0.76 mm and a supply input of 0.88 mm shows that the high gain range of the curve has been moved to a corresponding point, at a pressure immediate / / less than 3.5 kg / cm2

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By increasing the diameter of the control input relative to the feed input, the same effect is created on a dextrorotatory vortex as if the diameter of the first input were reduced. In other words, a high gain range is introduced for a diameter of 1 mm from the control orifice, while a triple flow is obtained for a given control pressure corresponding to a diameter of 1.12 mm from the control port. This effect is also obtained by modifying the feed orifice compared to the previous one._In / the limits of this possibility, an analysis was made of a double outlet vortex valve, showing a slight negative resistance with a conventional radial supply, the result being shown in FIG. 6. The negative resistance is extremely marked, which is very favorable for the use of this type of valve as a fluid memory element.

These curves were recorded by supplying one of the control inputs with a pressure of 3.5 kg / cm2. Fig. 7 shows a family of curves recorded under different control pressures P_vs· This shows that the value of the command also acts on the shape of the pressure-flow characteristic, increasing the gains for an increase in the supply pressure until a negative resistance characteristic is created at the pressure of 3.5 kg / cm2.

Fig. 8 shows other curves recorded for a valve of similar proportion, but smaller.

Figd. 9 to 11 show a valve with opposite control input. We see, in Fig. 9, a valve body 20 associated with a body 22 to constitute a vortex chamber 24. The latter is supplied by a first fluid inlet 26 communicating with an annular passage 28 which sends the fluid into the chamber 24 by means of 4- tangential inputs 30. A second inlet 32 ​​sends fluid through a removable connector 34 formed in a central passage 36, by means of 4 channels 38 directed tangentially and opposite to the passage 30. An outlet is provided at 40.

In this arrangement, the sum of the areas of the passages

38, 30 is modified by replacing the fitting 34 with another fitting arranged in the passage 38.

Fig. 12 schematically illustrates the incorporation of this valve into a pressure regulating device. A pressure source 12 is connected to an inlet of a valve 44 at the same time

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2077536 time at the entry of a fluid amplifier 46 of the confined jet type. This regulator also includes a control device 48 producing an output signal which can indicate the pressure at the output 52. The signal emitted by the circuit breaker 48 is applied in the chamber of the amplifier which delivers a signal 50, which is at its turn applied to another opposite inlet of valve 44. The output 52 is connected to the use 54, the pressure of which is thus regulated to any desired value.

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