Venturi Tube

Abstract

The invention is directed to a Venturi tube comprising: a cylindrical tube, wherein a first cone and a second cone are arranged. The first cone and the second cone are configured so that their bases face each other and are separated by a gap. A suction tube has an inlet and an outlet. The inlet is located outside of the cylindrical tube and the outlet is located between the first base and second base, i.e., the gap between the first base and the second base. The Venturi tube of this structure serving as a gas-liquid mixer will have higher gas solubility. The Venturi tube of this structure has a shorter length than traditional ones while processing the same amount of liquid and thus requires lower manufacturing cost.

Claims

1. A Venturi tube, comprising: a cylindrical tube having a tube diameter, a fluid-in end, and a fluid-out end; a first cone having a first base and a first opening angle, the first cone is concentrically positioned in the cylindrical tube with its first base facing away from the fluid-in end; a second cone having a second base and a second opening angle, the second cone being concentrically positioned in the cylindrical tube with the second base being spaced apart from the first base for a distance, the second base having a base diameter equal to that of the first base and smaller than the tube diameter; and a suction tube having an inlet and an outlet, the inlet being located out of the cylindrical tube and the outlet being located between the first base and second base.

2. The Venturi tube according to claim 1, wherein the first opening angle is greater than the second opening angle.

3. The Venturi tube according to claim 2, wherein the second cone is truncated and the cylindrical tube is adapted to the truncated cone to shorten its length.

4. The Venturi tube according to claim 2, wherein the outlet is located between the centers of the first base and second base.

5. The Venturi tube according to claim 3, wherein the outlet is located between the centers of the first base and second base.

6. The Venturi tube according to claim 5, wherein the distance between the first base and the second base is 1 mm to 3 mm.

7. The Venturi tube according to claim 5, wherein the diameter of the first base is 0.5 mm to 2 mm less than that of the cylindrical tube.

8. The Venturi tube according to claim 6, wherein the diameter of the first base is 0.5 mm to 2 mm less than that of the cylindrical tube.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] FIG. 1 shows a traditional Venturi tube.

[0016] FIG. 2 shows a Venturi tube of the present invention.

DETAILED DESCRIPTION

[0017] FIG. 2 shows a Venturi tube 1 of the present invention. The Venturi tube 1 comprises a cylindrical tube 10 having a fluid-in end 12 and a fluid-out end 14 with corresponding pressure P.sub.fi′ and P.sub.ho′, respectively.

[0018] The Venturi tube 1 further comprises a first cone 20 and a second cone 30. The first cone 20 has a first base 22 and a first opening angle θ.sub.1 and the second cone 30 has a second base 32 and a second opening angle θ.sub.2. The first cone 20 is concentrically positioned in the cylindrical tube 10 with its first base 22 facing away from the fluid-in end 12. The first opening angle θ.sub.1 is greater than the second opening angle θ.sub.2. The second cone 30 is concentrically positioned in the cylindrical tube 10 with the second base 32 being spaced apart from the first base 22 for a distance D.sub.c. In the embodiments, the distance D.sub.c is 1 mm to 3 mm. The second base 32 has a base diameter D.sub.b equal to that of the first base 22 and smaller than the tube diameter D.sub.t. Accordingly, the gap R.sub.g between the bases 22, 32 and the cylindrical tube 10 is:

[00002]$R_g=\left(D_t-D_b\right)/2$

[0019] In the embodiments, the base diameter D.sub.b is 0.5 mm to 2 mm smaller than tube diameter D.sub.t. The gap R.sub.g then is 0.25 mm to 1 mm.

[0020] The Venturi tube 1 further comprises a suction tube 40. The suction tube 40 has an inlet 42 and an outlet 44. The inlet 42 is located outside of the cylindrical tube 10 and the outlet 44 is located between the first base 22 and second base 32. In an embodiment, the outlet 44 is located between the centers of the first base 22 and second base 32 in order to distribute the sucked gas more evenly in the fluid passing through the Venturi tube 1.

[0021] In one embodiment, the second cone 30 can be truncated. The length of a truncated cone is shorter than a cone without truncation if the opening angle and base are the same. The cylindrical tube 10 can be adapted to the truncated cone to have a reduced length. Therefore, a Venturi tube 1 with a truncated second cone 30 will be shorter in length and thus be lighter and take up less space.

[0022] Referring to FIG. 2, it can be understood that cross-section of the fluid passageway formed between the cylindrical tube 10 and the first cone 20 and second cone 30 in the Venturi tube 1 is a ring shape. Along axis Z, the cross-sectional area of the fluid passageway gradually decreases from the fluid-in end 12 and reaches the minimum at the point where the first base 22 or the second base 32 is located, and then gradually increases toward the fluid-out end 14. As a result, the fluid speed is slower at the fluid-in end 12 and at the fluid-out end 14 and is fastest at the first base 22 and the second base 32, where the fluid passageway has a minimum cross-sectional area. According to Bernoulli's principle, the pressure is a minimum at the point where the fluid speed is the fastest, that is, at the location where the cross-sectional area of the fluid passageway is a minimum.

[0023] The outlet 44 of the suction tube 40 is arranged between the centers of the first base 22 and second base 32, that is, the location where the cross-sectional area is a minimum. Gas is sucked from the outlet 44 to this location through the tube 40.

[0024] As liquid flows through the Venturi tube 1, gas is sucked out from the outlet 44 and forms bubbles. The volume and the pressure of these bubbles are assumed to be V.sub.a′ and P.sub.a, respectively, when the bubbles leave the outlet 44. The volume V.sub.a′ is associated with the distance D.sub.c between the first base 22 and the second base 32. As the bubbles continue to flow along the Venturi tube, the bubbles will shrink to volume V.sub.c′ due to pressure increasing from P.sub.a′ to P.sub.fo′. When the bubble size is smaller, the gas solubility is higher. Due to the geometric shape of the second cone 30, liquid flowing through the Venturi tube creates a pressure gradient that pulls these small bubbles toward the surface of the second cone 30, that is, toward the central axis Z of the stream. Bubbles flowing around the central axis Z of the stream will have more chance to contact the fluid. As a result, gas dissolution rate will be higher than in the traditional Venturi tube 100, wherein bubbles flow away from the central axis Z.

[0025] In the Venturi tube of the present invention, the passageway through which the fluid flows is of a ring-shape. A ring-shaped passageway has a larger effective cross-sectional area as compared with a throat in a traditional Venturi tube, and thus has a higher flow rate. Consequently, the size of the Venturi tube can be significantly reduced.

[0026] As compared with a traditional Venturi tube, the present invention can be smaller. In addition, the Venturi tube of the present invention produces smaller bubbles and thus will have a higher gas dissolution rate.

[0027] It should be appreciated by those skilled in this art that the above embodiment is intended to be illustrative, not restrictive. Thus, additional modifications and improvements of the present invention are possible without departing from the concepts as described.