RU1796908C - Liquid metering device - Google Patents

Abstract

The invention relates to fluid dispensers and can be used in chemical and other industries. SUMMARY OF THE INVENTION: The supply-1 bone 1 is a constant-level tank with an outlet 3 in the bottom, under which there is a distribution element made in the form of a disk 4, having a chamfer on the lower side. the side walls 9 of which are parabolic profiled

Description

vysimbsy. In this case, the apex of the parabola (left side of the receiving tank) is located at the radius farthest from the center of the disk 4. The right wall is a mirror image of the left side with a central axis dividing the receiving capacitance into two equal halves. Given

an expression for determining the distance between the outlet 3 in the bottom of the supply tank 1 and the disk 4. The liquid enters the disk 4 and flows evenly through the container 8 to the consumer, the excess is removed through the drain hole 7. 2 sludge

/ The invention relates to dispensers for fluid media and can be used in the chemical and other industries: -.; Нб; ст., ... :: --...: х.: B,: .. о -... .. ; ..h: .-. ...; .-. -: Dispensers of liquids are known; supply tank, volumetric containers and put;

brazed distributor with valves, at the opening of which a dose is supplied

. in several devices at the same time, the main disadvantages of such systems are - 10 V: the dosage frequency, which is unacceptable for continuous technology.;. ::; processes, clogging of valves during the dosing of contaminated liquids and liquids with solid inclusions. 16 The dispenser is not very accurate; dosing on media with variable viscosity:. In addition, the dosing schedule cons.t-:; . It is rather complicated manually ...;: /: .. - - / ../ Closest to the expected, 20.; is a device; including supply and receiving containers, a swivel. a right-hand tube connected to the shaft of an electric motor, which sets it above one of the receiving tanks according to a preset 25.; our program I /; ..:: ..: y ,, ...; ..; .: In a known metering device; periodically dosing the liquid at which filling is carried out. . all the receiving containers are carried out not 30 at the same time, but for a certain interval ...,: time jumper; determined by quantity:

receiving tanks and the program, dosiro. which eliminates the possibility of using the dispenser under the conditions of technological 35-processes, where the dosing of the liquid should be carried out continuously in several. ; to devices at the same time. Besides,

. a change in the viscosity of the dosing medium causes a change in hydraulic losses 40 ... along the length of the guide tube, and, consequently, a change in the flow rate of the fluid per unit time with a constant dosage program at which the dose of fluid poured into 45, the capacitance is determined by the constant value of the length of time the turntable is located above the receiving tank. The use of a software device in the system introduces an additional error in the dosing process. All of the above reduces the accuracy of the airing and significantly reduces the scope of the dispensers. : -V,

The purpose of the invention is to increase the dosage rate with a change in the viscosity of the liquid, and to expand the scope of the dispensers ..; :. - :: y :: ...

The goal is achieved in that in a device for dispensing liquid media containing a supply and receiving containers and a directing element located L between them: according to the invention, the supply capacity is (p6 is a constant level with an outlet from the bottom, the distribution element is high. full in the form of a disk around which radial receiver containers are located, having concave lateral walls in the form of a double parabolum with an apex on the periphery of the device.In addition, to prevent disturbance of the flow structure, has a chamfer on the bottom side and is installed under the outlet opening of the supply tank at a distance L, determined from the Relation ratio g; .-, ...: „;; H :.: .--.; ;; L ( 2- Odav: h:; ,, L / -V / V:; V /;

where do is the diameter of the outlet of the supply tank.

A comparative analysis with the prototype shows that the inventive device is distinguished by a new embodiment of the receiving capacities of the guide element and the distance between it and the supply capacity. This allows us to conclude that the proposed device meets the criterion of novelty.

Comparison of the claimed solution, not only with the prototype, but also with other technical solutions in the technical field, did not allow them to identify features distinguishing the claimed solution from the prototype, which allows us to conclude that the criterion meets significant differences. ..: .- ...

In FIG. 1 shows a diagram of the proposed device, section; in FIG. 2, view. in the direction of arrow A in FIG. 1, .- ....

The device comprises a supply tank 1, with overflow 2 to maintain a constant hydrostatic pressure h above the metering calibrated hole 3, a distribution element in the form of a disk4 having a chamfer on the bottom side and mounted on the rod 5 under the hole 3 at a distance determined by the formula L (2-6) dQ. a drain tank 6 with a nozzle 7, receiving tanks 8 with side walls 9, and metering nozzles 10. The side walls 9 are profiled according to a parabolic dependence, where b is the thickness of the liquid layer in the dome, am is the distance between the side walls of the tank 8. In this case. the top of the parabola (left side of the receiving tank 8) is located at the radius farthest from the center of the disk A, i.e. near the wall of the drain tank 6. The right wall is a mirror image of the left side with a central axis dividing the receiving tank into two equal halves.

The device operates as follows ...

The dosed liquid is piped into the supply tank 1, Part of the liquid through the overflow 2 enters the drain tank b or the general feed system of the dispenser. Liquid medium with constant hydrostatic pressure h. maintained by overflow 2, is poured in the form of a compact stream through a calibrated hole 3 onto a distribution disk 4.

The liquid spreads along the distributor disk 4, the liquid is poured in the form of a dome into the receiving containers 8 and the drain tank 6. Through the metering nozzles 10, the liquid enters various points of the process simultaneously.

The number of receiving tanks can be practically unlimited, which makes it possible to dispense liquid media at several points of the technological process simultaneously in a wide range of costs without using a meter in vozostom (viscometer) and an automatic flow correction system,

 A part of the liquid that was not used during the dosing process, through the drain pipe 7, is supplied to the general feed system of the dispenser.

When dosing media with variable viscosity, a constant value of the dose of fluid per unit time is ensured for

due to the variable cross-section of the receiving containers 8, achieved by profiling the walls 9 according to a relationship taking into account the change in the layer thickness and the flight range of the liquid dome, as well as the liquid velocity in the layer. „...- ..y ...

To prove this, consider: section 1-1 in Fig. 1. The diameter of the dome of the liquid falling from the disk 4 is constant at a constant liquid velocity Vo from the calibrated hole 3 and. constant viscosity of the dosed liquid of c. In this case, the thickness of the liquid layer L in the dome in section 1-1 is unchanged, which can be determined when all other parameters of the dispenser are constant for the viscosity of the liquid medium

With a change in the viscosity of the dosed liquid, for example, its increase, the loss of fluid c-velocity by friction along the radius of the disk increases, which at a constant speed V0 leads to a thickening of the liquid layer b in the dome and a decrease in its diameter in the controlled section 1-1 due to a decrease the velocity of the fluid along the distribution disk 4. And, conversely, with a decrease in viscosity rj, the thickness of the layer, fluid b decreases, and the diameter of the dome in a controlled section increases.

Thus, if the side walls 9 of the receiving containers 8 are plane-parallel. are breathable, each value of the viscosity of the liquid with a constant width of its capture by the receiving tank will correspond to a certain flow rate of the liquid medium per unit time through the receiving tank, i.e. a change in the viscosity of the liquid causes a significant metering error.

Consider dosing.vz, 1 fluid with variable viscosity.

The liquid flows out of the calibrated hole 3 at a speed of V0 and then, spreading over the surface of the disk 4, merges from it in the form of a dome with a layer thickness in the dome equal to b.

Fluid velocity Vi in the dome

. ; vi Vo-l / g, .... v

where V2 - loss of fluid velocity due to friction with the surface of the distribution disk 4.

The loss of speed due to friction of the liquid on the surface of the distribution disk 4 is a function of the viscosity of the dosing medium C.

V2..f ($.

 With increasing viscosity r, the loss of velocity Va also increases due to an increase in the friction of the flowing fluid against the surface of the distribution disk 4..

On the other hand, the flight range of the dome in the horizontal plane after separation of the liquid from the sharp chamfer of the distribution disk 4, i.e. the flight range of the dome in the control section 1-1 (see Fig. 1) I, is a function of the fluid velocity Vt, in the dome layer :.

Vr

where H is the magnitude of the path of the control point of the dome from the moment of separation of the liquid from the chamfer of the distribution disk 4, to the horizontal section 1-1, with H corist; g is the acceleration of gravity. Or:

KVo-Va)

. .-. 9 . :: When the viscosity of the liquid is equal to tj «., The range of the dome in the plane 1-1 will be equal to: /;

Ik (Vo-V2k) Ј-5. .,:.: ,,, .- ,. ; V

rAeV2k f (J / ic); .; at,. :: .. V2k - loss4 of the fluid velocity on the distribution disk 4 with the viscosity of the dosed medium y. Moreover, the layer thickness

the liquid in the dome is bk .:

With an increase in the viscosity of the dosing medium, the range of the dome

ln (Vo-Vri)

Where

v 2n f (s ..-.:.

Van is the fluid velocity loss on the distribution disk 4 with the viscosity of the metering medium rjn. The thickness of the liquid layer in the dome at viscosity / n is equal to bn. :

Thus, with an increase in the viscosity of the liquid I tjn. I, the range of the dome in the horizontal plane 1-1 decreases t n I to I due to the fact that the loss of fluid velocity on the surface of the distribution disk increases I 1.

In this case, the thickness of the liquid layer in the dome increases I bn bk I.

For parallel parallel side walls 9 of the supply capacitance 8, at a distance between the side walls m-const, the liquid flow rates Gk and Gn, taken at a unit time, for different viscosities t) K and n are

a) the flow rate of the liquid through the receiving tank at a fluid viscosity equal to tjK

Gk (Vo-V2k) bk m

where Gk is the fluid flow rate per unit time; . :. :. :: - bk-thickness of the liquid layer in the dome: V2k - loss of fluid velocity on the distribution disk with the viscosity of the dosed medium

b) the flow rate of the liquid through the receiving tank with a fluid viscosity equal to rjn: Gn (Vo-V2n) bn m. where Gn is the fluid flow rate per unit time;. . ; . ..: / .. :: -. . . ..; ..-.-; - ... ... .. bn is the thickness of the liquid layer in the dome; Van - loss of fluid velocity on the distribution disk with the viscosity of the dosing medium IJnl

 The speed loss on the surface of the distribution disk V2 depending on the viscosity of the liquid is determined by methods accepted in hydraulics. At the same time, the range of the dome and the thickness of the liquid layer of the dome are measured.

A change in the viscosity of the dosed medium in the range of 3-5 cPs practically does not affect the rate of fluid outflow from the calibrated hole:

In this case, because bk bn. Thus, in the case when the walls of the receiving tank are plane-parallel (m const) when the viscosity of the liquid changes, the flow rate of the dosed medium per unit time through the receiving tank 8 also changes, which causes a metering error. This drawback is eliminated if the walls along the width of the receiving tank 8 are given a parabolic profile defined by the formula and ensuring equal flow rates through the receiving tank when dosing liquids with variable viscosity; h

Gi G2 ....

or

Gi g2

For viscosity values rjK and g) n, the dosed flow rates Gk and Gn for the case of profiled side walls - receiving tank:

(V0 - V2k) bk

(Vo - ya k) bn mn.

mK; .bn (Vo-V2n).

mn bK (V0-V2K)

where tk is the distance between the side walls of the receiving tank with the viscosity of the dosed liquid / k,

mn is the distance between the side walls of the receiving tank with the viscosity of the dosed medium

Vp is the rate of outflow of the dosed fluid from the calibrated Hole in the supply tank;

V2k-loss of fluid velocity on the distribution disk with the viscosity of the dosed medium

Van — fluid velocity loss on the distribution disk with tyn viscosity;

bk is the thickness of the liquid layer in the dome with the viscosity of the dosed medium%;

Bp is the thickness of the liquid layer in the dome with the viscosity of the dosed medium cp,.

When the side walls are made according to the given relative, they have a parabolic profile, giving the receiving tank a variable cross section. This causes, in combination with the structural design of the distribution element in the form of a disk with a sharp chamfer. On the lower side, the constant flow rate of the dosed liquid, regardless of its viscosity ,;

Claims (1)

The claims A device for dispensing a liquid, comprising a supply and receiving containers and a distribution element located between them, moreover, in order to increase the accuracy of dosing when the viscosity of the liquid changes, the supply container is made in the form of a constant tank level with outlet in the bottom, distribution element The execution of the disk 4 with a chamfer and its placement at a distance h under the outlet 3 equal to (2-6) d0 prevents the violation of the flow structure. As shown by experimental studies, when h 2do occurs, a jet spray is observed when falling onto disc 4. Only in the specified interval has an undisturbed structure thanks laminar fluid motion of a established character. The presence of a chamfer prevents leakage of liquid under the disk, the sticking of solid inclusions on its lateral surface, i.e. also prevents violation of the flow structure in the section of movement to the receiving tanks. As a result, quality is achieved; subsidizing liquids at several points; technological process at the same time in a wide range of flow rates, including shovels, and the accuracy of the dosing is not affected by the change in the viscosity of the dosed medium. All this is significant. expands the scope of dispensers. made in the form of a bevel with a chamfer on the lower side, around which there are radially placed receiving tanks, a horizontal section of which is made with symmetrical concave side walls in the form of half-parabolas, the vertices of which are located on the periphery of the device, the distance L between the outlet capacity and the disk is selected from the ratio L. (2-6) d0, where do is the diameter of the outlet of the capacity. .. 1796908 / l Type A  fi.p xy