GB2191420A

GB2191420A - Apparatus for removing gases from liquid fluids

Info

Publication number: GB2191420A
Application number: GB08614430A
Authority: GB
Inventors: Leonid Mikhailovich Sedlov; Gennady Yakovlevich Kamashev; Alexandr Mikhailovich Dunaev; Frid Saidovich Valeev; Nikolai Vladimirovi Merzlyakov; Egor Alexandrovich Kokh
Original assignee: KZ NI TEKNOLOGICHESKY I PI KHI; UDMURTSKY G UNI IM 50 LETIA SS
Current assignee: KZ NI TEKNOLOGICHESKY I PI KHI; UDMURTSKY G UNI IM 50 LETIA SS
Priority date: 1986-06-11
Filing date: 1986-06-13
Publication date: 1987-12-16
Also published as: GB8614430D0; DE3619908A1; DE3619908C2

Abstract

The apparatus comprises a vessel (1) having an inlet hole (2) for admitting incoming liquid fluid (3) and an outlet hole (4) for discharging the degassed fluid (3), a plurality of vertical baffles (13) arranged in succession inside the vessel (1) and spaced from a bottom (10), and an acoustic transducer (17); each vertical baffle (13) in succession from the inlet hole (2) being spaced from the bottom (10) at a distance which is less than that of the preceding baffle (13), whereas the acoustic transducer (17) is provided before each of the baffles (13) except the last in succession. <IMAGE>

Description

SPECIFICATION Apparatus for removing gases from liquid fluids This invention relates to equipment associated with separating liquid and gaseous fluids in a range of industrial processes, and more particularly to apparatus for removing gases from liquid fluids.

The invention can find application in producing materials for the motion picture industry and photography to remove fine and superfine bubbles of free and partially dissolved gases from highly viscous (more than 300 centipoises) photographic emulsions and magnetic lacquers.

In addition, the invention can be used for processing plastic materials and in the production of synthetic fibers, for fabricating articles from glass, ceramics and porcelain, as well as in oil refining, paper production, clarification of wines, for making medicinal preparations, and reducing the corrosive property of liquid process fluids in the heat power industry.

It is known that the presence of gases in a liquid fluid entail the formation of cavities, pores, pits and other flaws in finished articles. In other instances gases present in the liquid fluid promote corrosion.

There is known a method and apparatus for continuous untrasonic degassing a stream of a liquid fluid as exemplified in U.S. Patent No. 3,284,991.

In the apparatus described in the U.S. Patent No. 3,284,991 gases are removed from a liquid fluid, such as a 50% aqueous solution of caustic soda, in a rectangular vessel having an inlet hole for admitting the initial liquid fluid disposed in the upper portion of a side wall of the vessel, an outlet hole for discharging the degassed liquid fluid arranged in the lower portion of a side wall adjacent the bottom of the vessel, and drain pipes for evacuating the liberated gases.

The vessel accommodates a plurality of vertical baffle plates arranged in succession one after another and spaced from the bottom to ensure the passage of the flow of liquid fluid in a direction from the inlet hole to the outlet hole along the bottom of the vessel.

The vessel is provided with an acoustic transducer secured to its bottom and serving to generate sonic waves in the stream of liquid fluid resulting in the formation of gas bubbles.

Due to the fact that the vertical baffle plates are spaced at equal distances from the bottom and extend from one side wall of the vessel to another to contact with these side walls, these baffles form with the side walls of the vessel a plurality of degassing zones filled with the liquid fluid which is continuously in contact with the flow of liquid fluid passing under the ends of the vertical baffle plates. Gas bubbles formed by sonic waves generated by the acoustic transducer are caused to occupy these degassing zones. In the degassing zones the gas bubbles are retained by the vertical baffle plates, accumulate close to the plates, float to the surface of the liquid fluid, and flop.

However, because the intensity of sound waves induced in the liquid fluid by the acoustic transducer weakens in all directions to the periphery, the process of formation of gas bubbles, their coalescence and ascent to the surface is non-uniform through the flow of liquid fluid.

Therefore, gas bubbles fail to ascend in the degassing zones formed in the vessel by the vertical baffle plates in succession from the inlet hole, and thereby the vertical baffle plates spaced at equal distances from the bottom of the vessel fail to ensure complete evacuation of gases from the liquid fluid.

The provision in the apparatus of the acoustic transducer connected to the bottom to extend under all the vertical baffle plates and serving to generate sound waves in the liquid fluid being degassed results in that in the liquid fluid confined between the vertical baffle plate which is the last in succession from the inlet hole and the side wall of the vessel the dissolved gas present in the liquid fluid liberates to form new gas bubbles in the fluid escaping from the outlet hole.

Also, the arrangement of the acoustic transducer under all the baffle plates results in that the sound vibrations act on the gas bubbles through the entire travel path of the liquid fluid in the apparatus. Therewith, the liquid fluid may have areas at the nodal points of standing waves, whereto gas bubbles tend to rush from the upper and lower levels of the liquid and where these gas bubbles are retained by sound vibrations through the length of travel of the flow of liquid fluid. Only large-size bubbles are capable of floating upwards.

The spacing of the vertical baffles in the apparatus according to the U.S. Patent No.

3,284,991 at a distance equal to a multiple of an odd number of quater wavelengths of sound waves in the liquid fluid results in that the zones where gas bubbles tend to accumulate occupy the level of the ends of the vertical baffle plates or below, whereby the gas bubbles pass the vertical baffles even at a minimum distance from the baffles to the bottom of A/4.

The arrangement of the vertical baffle plates transversely to the flow of liquid fluid causes flow swirls at the ends of the baffles, whereby the gas bubbles are captured from the upper layers of the liquid fluid to pass under the ends of the vertical baffles.

In view of the aforedescribed, the spacing of the vertical baffle plates at equal distances from the bottom of the vessel, and the provision of a single acoustic transducer under all the vertical baffles is disadvantageous in that the apparatus fails to remove gases from liquids having a viscosity greater than 300 centipoises, since the rate of ascent of gas bubbles in such liquids reduces markedly, and the bubbles are entrained by the viscous forces of the liquid flow to the outlet from the vessel rather than be raised to the height of the vertical baffle plates.

It is a major object of the present invention to provide an apparatus capable of thoroughly removing gases from a stream of highly viscous liquid fluids.

The essence of the invention resides in that in an apparatus for removing gases from a stream of a liquid fluid comprising a vessel having an inlet hole for admitting the initial liquid fluid, an outlet hole for discharging the degassed liquid fluid, and drain pipes for evacuating gases from the apparatus, a plurality of vertical baffles arranged inside the vessel in succession one after another and spaced from a bottom of the vessel to allow the passage of the liquid fluid along the bottom of the vessel from the inlet hole to the outlet hole, and an acoustic transducer affixed to the bottom of the vessel and serving to induce sound waves therein, according to the invention, each vertical baffle in succession from the inlet hole is spaced from the bottom of the vessel at a distance which is less than that of the preceding baffle, whereas at least one acoustic transducer is provided before each of the vertical baffle except the last one in succession.

The provision of at least one acoustic transducer before each vertical baffle except the last one in succession from the inlet hole results in that any single gas bubble formed initially at a minimum distance from the surface of the acoustic transducer is raised by sound vibrations generated by the acoustic transducer in the liquid fluid to a greater height.

Even if any single gas bubble ascends above the first acoustic transducer in succession from the inlet hole to an insufficient height to be therefore entrained by the viscous forces of the flow of liquid fluid to the space above the next successive acoustic transducer, it is raised here to a greater height than above the first acoustic transducer.

The arrangement of the vertical baffles so that each such baffle is spaced from the bottom of the vessel at a distance smaller than that of the preceding baffle causes any single gas bubble to eventually rise to a height exceeding the distance at which the corresponding baffle is spaced from the bottom of the vessel.

In addition, newly formed gas bubbles are added to those already present in the liquid fluid conveyed above each acoustic transducer, the bubbles tending to expand in size, coalesce, decelerate, stop, and be pushed upwards, where they are eventually retained by the vertical baffles, after which the bubbles rise to the surface of the liquid fluid and flop.

In case at some portion of the vessel bottom gas bubbles fail to expand to the necessary size and rise to a height at which they can be retained by the vertical baffle, the bubbles are entrained by the viscous forces of the liquid fluid to a space above the successive acoustic transducer, where sound waves make them coalesce with the newly formed gas bubbles and ascent to a sufficient height.

By virtue of the fact that each successive vertical baffle is spaced from the bottom of the vessel at a distance smaller than that of the preceding baffle, the section through which the flow of liquid fluid passes under the ends of the baffles is reduced as each successive vertical baffle is spaced closer to the bottom of the vessel, whereas the amount of liquid fluid flowing through the thus reducing sections remains invariable. This in turn causes an increase in the flow speed of the liquid flow as it passes under the end of every successive vertical baffle. According to the Bernoulli law, an increase in liquid flow speed results in a reduction in its pressure, which promotes the formation of new bubbles and their escape from the liquid fluid.Because of the provision of the acoustic transducer before each vertical baffle except the last one in succession, no new bubbles are formed in the liquid fluid before the last baffle in succession from the inlet hole, whereas the distance between the two last vertical baffles in succession from the inlet hole is such that event the finest gas bubbles formed by the sound waves generated by the last successive acoustic transducer are reliably retained by the last baffle in succession from the inlet hole.

Preferably, each vertical baffle in succession from the inlet hole is spaced from the bottom of the vessel at a distance which is less by a factor of 0.05-0. 1 than the distance at which the preceding baffle is spaced from the bottom of the vessel.

Arranging each vertical baffle in succession from the inlet hole at a distance from the bottom of the vessel smaller than by a factor of 0.05 as compared with the distance at which the preceding baffle is spaced from the bottom requires a greater number of the vertical partitions and acoustic transducers before such partitions to be employed to eventually result in reduced efficiency of the apparatus. In addition, a greater number of the acoustic transducers requires more electric power to be consumed during operation of the apparatus.

Conversely, spacing of each successive vertical baffle from the bottom of the vessel at a distance greater than by a factor of 0.1 as compared with the distance at which the preceding baffle is spaced from the bottom entails the use of a lesser number of vertical baffles and acoustic transducers before them, which likewise results in reduced efficiency of the apparatus.

Such an arrangement is accompanied by considerable swirling of the flow of liquid fluid at the ends of the vertical baffles in succession from the inlet hole, whereby the gas bubbles are entrained from the upper layers of the liquid fluid and forced under these baffles.

Advisably, the vertical baffles are provided with a means for adjusting their position in the vertical plane to optimize the operation of the apparatus; that is in response to the viscosity of the liquid fluid being processed to change its rate of flow by adjusting the sectional area through which the flow of liquid fluid passes under the ends of the vertical baffles, thus attaining the desired degree of degassing.

It is also advisable to affix the acoustic transducer provided before each vertical baffle to the bottom of the vessel through an element fabricated from a sound-damping material, the portion of the vessel bottom before the last baffle in succession from the inlet hole being preferably also fabricated from a sound-damping material.

As a result, sound vibrations generated by the acoustic transducers are transmitted to the flow of liquid fluid more completely along the vertical axis of symmetry of the vertical baffles, because transmission of sound vibrations to the bottom of the vessel in a direction substantially downstream of the flow of liquid fluid facilitating the movement of gas bubbles in this direction is obviated.

Thanks to connecting the acoustic transducers to the bottom of the vessel through the sounddamping elements, the adverse effect of interference between the acoustic transducers through the bottom of the vessel is prevented to ensure a more efficient operation of each such transducer. Another attending advantage of fabricating the portion of the bottom before the last successive baffle from a sound-damping material resides in a failure of new gas bubbles to form in the space before the oultet hole.

Preferably, the vertical baffles are rectangular in shape to be accommodated between the side walls of the rectangular vessel in front of the inlet hole transversely to the flow of liquid fluid, whereas the acoustic transducer provided before each baffle is disposed so that a sound wave of the maximum intensity it generates would be transmitted to the flow of liquid flow passing through a section coinciding with the vertical axis of symmetry of the baffle.

Thanks to that the intensity of sound vibrations induced in the central portion of the flow of liquid fluid above the center of the acoustic transducer is greater than the intensity of sound vibrations induced above the periphery of the transducer, the sound vibrations of the maximum intensity act on the gas bubbles present in the central portion of the liquid flow moving at a higher speed. Since the liquid fluid is conveyed through the vessel of rectangular shape, the flow of liquid fluid assumes substantially the same cross-sectional configuration. Assuming the fact that the intensity of sound vibrations induced in the liquid fluid by the acoustic transducer is distributed symmetrically from the center of the acoustic transducer toward its periphery, the sound vibrations are likewise distributed uniformly along the rectangular section of the flow of liquid fluid.In consequence, the desired degree of degassing is attained thanks to the uniform removal of gases from the liquid fluid lengthwise of and transversely to the flow.

By virtue of the fact that the direction of the sound wave of the maximum intensity generated by the acoustic transducer coincides with the vertical axis of symmetry of the baffle, these sound vibrations act on the flow of liquid fluid perpendicularly to make the travel path of gas bubbles deviate from the horizontal to a greater upward angle, whereby they tend to float up to the surface of the liquid fluid and flop at a faster rate.

Advisably, the means for adjusting the position assumed by the vertical baffles in the vertical plane includes a tube received by the inlet hole, a float, and a system of levers, one of which levers carries the vertical baffles and is rigidly connected to the cover plate of the vessel, whereas the other lever is pivotably connected to the tube and to the float, the two levers being interconnected by a third lever.

The provision in the proposed apparatus of the means for controlling the movement of the vertical baffles in the vertical plane makes it possible to ue the apparatus for reliably removing gas bubbles from a liquid fluid delivered at changing flow rate.

Advantageously, the apparatus is provided with a set of microswitches attached to the lever carrying the vertical baffles and electrically connected to every acoustic transducer except the first in succession from the inlet hole through a switchboard unit ensuring alternate energization of the acoustic transducers.

When the lever moves upwards the set of microswitches is energized, an electric signal is fed from the set of microswitches to the switchboard unit, which in turn alternately energizes the acoustic transducers, the number of transducers energized in this manner being such as to ensure the required degree of degassing. The number of vertical baffles carried by the lever and the number of acoustic transducers provided before the baffles is normally preselected so as to vary the flow rate of the liquid fluid within a wide range. On the other hand, when the lever carrying the vertical baffles moves downwards, the set of microswitches will act through the switchboard unit to deenergize the acoustic transducers.Every acoustic transducer may be thus deenergized except one closest to the inlet hole to prevent idle operation of the transducers, if a sufficient degree of degassing of the diminishing flow of liquid fluid is guaranteed.

Favourably, the proposed apparatus comprises several intercommunicating vessels arranged in succession one after another with each successive vessel arranged above the preceding vessel at a height equal to:

where p,=density of the liquid fluid; p2=density of air; R=radius of gas bubbles; =intensity of sound vibrations; a=absorption factor; S0 initial distance between the gas bubble and thesurface of the acoustic transducer; 1= surface length of the acoustic transducer; 11=viscosity of the liquid fluid; vo=flow speed of the liquid fluid; Re=Reynolds number; C=velocity of sound in the liquid fluid; e=base of natural logarithm;; 0.7=margin constant allowing for the fluctuations in the parameters of the sound wave field and liquid fluid; the last vertical baffle in succession from the inlet hole for admitting the liquid fluid in each vessel having an aperture of rectangular shape at the level of the bottom of the successive vessel downstream of the flow of liquid fluid.

Due to that each successive vessel is arranged at a height h above the preceding vessel, the flow of liquid fluid passing under the ends of the vertical baffles is evacuated through the outlet hole provided in the side wall of each vessel to make the apparatus operate more efficiently.

The provision of the vertical baffles with rectangular apertures at the level of the bottom of the successive vessel downstream of the flow of liquid fluid ensures separation of the flow of liquid fluid passing through each vessel at the height h; that is the upper layers of the liquid fluid containing gas bubbles are separated and conveyed to the next successive vessel for further degassing. Therewith, the height h at which each successive vessel downstream of the flow of liquid fluid is arranged above the preceding vessel and at which the rectangular apertures are provided in the vertical baffles is determined by the height to which a gas bubble initially resting at the minimum distance SO from the surface of the acoustic transducer ascends, this height being calculated from the equation of forces acting on the gas bubble in a sound wave field.

In this manner the flow of liquid fluid free of gas bubbles will pass under the ends of the vertical baffles to escape through the outlet hole provided in each vessel substantially below the height h, which ensures guaranteed degassing of the liquid fluid and improves the operation efficiency of the apparatus.

Preferably, provided between the two adjacent vessels is a pick-up for monitoring the amount of gas bubbles in the liquid fluid electrically connected to the acoustic transducers in the vessel next after the pick-up through a switchboard unit providing successive energization of the acoustic transducers in each vessel downstream of the flow of liquid fluid.

The provision of a pick-up for monitoring the amount of gas bubbles in the liquid fluid between the adjacent vessels prevents idle operation of the acoustic transducers in the vessel after the pick-up downstream of the liquid fluid. When the liquid fluid conveyed to the vessel after the pick-up carries a negligeable amount of gas bubbles, the pick-up issues a signal to the switchboard unit, which successively energizes the acoustic transducers in each vessel downstream of the flow of liquid fluid; gas bubble removal being carried out in each successive vessel downstream of the flow of liquid fluid exclusively by virtue of diminishing height at which the vertical baffles are spaced from the bottom of the vessels.

Advantageously, the apparatus is provided with an additional vertical baffle wall inside a cylindrical vessel and fashioned as a spiral having a center coaxial with the center of the inlet hole to form a helical passage of invariable cross-section in which there are disposed substantially transversely to the direction of the flow of liquid fluid vertical rectangular baffle plates, whereas arranged coaxially with the inlet hole is an acoustic transducer, a sound wave of the maximum intensity it generates coinciding with the axis of symmetry of the inlet hole, the acoustic transducer provided before each rectangular baffle plate being disposed so that a sound wave of the maximum intensity it generates is transmitted to the flow of liquid fluid passing through a section coinciding with the vertical axis of symmetry of the vertical baffle plate.

Thanks to that the intensity of sound vibrations induced in the central portion of the flow of liquid fluid passing through the inlet hole above the center of the acoustic transducer is more substantial than that generated above the periphery of the flow, gas bubbles travelling at a higher speed are acted upon by sound vibrations of a greater magnitude. Coincidence of the sound wave of the maximum intensity generated by the acoustic transducer with the axis of symmetry of the inlet hole of the vessel results in that the sound vibrations act in a direction opposite to the travel path of the liquid fluid.

Therefore, deceleration of the gas bubbles, as well as their coalescence and evacuation from the degassing zone confined by the first coil of the vertical spiral baffle wall connected to the bottom of the vessel is more pronounced than in the case of the previously described modifications of the proposed apparatus.

The flow of liquid fluid vonveyed along the helical passage formed by the subsequent coils of the additional baffle wall connected to the bottom and the side wall of the cylindrical vessel is substantially rectangular in cross-section. The arrangement in the helical passage transversely to the flow of liquid fluid of the vertical rectangular baffle plates, and the provision of an acoustic transducer before each such baffle plate generating a sound wave of the maximum intensity exertable on the flow of fluid passing through a section coinciding with the vertical axis of symmetry of the baffle plate ensure uniform distribution of sound vibrations about the rectangular cross-section of the flow. In consequence, such an arrangement provides uniform removal of gas bubbles from the flow of liquid fluid both lengthwise and transversely of the flow direction.

The additional baffle wall forming a helical passage causes the flow of liquid fluid to move therealong from the inlet hole to the outlet hole about a spiral. From the degassing zone confined by the first coil of the helical passage and the first vertical rectangular baffle plate from the inlet hole the flow is conveyed through all the degassing zones formed by the coils of the additional baffle wall, side wall of the vessel and vertical rectangular baffle plates above each of the acoustic transducers provided before each vertical rectangular baffle plate except the last one in succession from the inlet hole.

In view of the aforedescribed, the thus extended travel path of the liquid fluid inside the apparatus causes a longer time of exposure of the liquid fluid to the action of sound vibrations, which ensures a high degree of degassing liquid fluids of up to 300 centipoises in viscosity.

Another advantage of this modification of the proposed apparatus includes its small overall dimensions, which saves production floor area.

Preferably, the ends of the vertical rectangular baffles facing the bottom of the vessel have an outline transversely to the flow of liquid fluid arched about a curve substantially conforming to the curve of the distribution of intensity of sound vibrations induced in the liquid fluid by the acoustic transducers provided before each such vertical rectangular baffle.

This configuration of the ends of the vertical rectangular baffles makes it possible to convey above the part of the acoustic transducer generating more intensive sound oscillations a larger amount of the liquid fluid to thereby increase the efficiency of the apparatus and ensure a required degree of degassing.

Alternatively, the vertical baffles can be cylindrical in shape to be arranged transversely to the flow of liquid fluid in a cylindrical vessel coaxially with one another and with respect to the inlet hole. Arranged in line with the inlet hole is an acoustic transducer generating a sound wave of the maximum intensity which is aligned with the axis of symmetry of the inlet hole. The acoustic transducer can be so arranged before each cylindrical baffle that a sound wave of the maximum intensity it generates would be transmitted to the flow of liquid fluid passing through a section coinciding with the vertical axis of symmetry of the baffle.

Due to that the intensity of sound vibrations induced in the central part of the flow of liquid fluid admitted through the inlet hole above the center of the acoustic transducer is higher than the intensity of sound vibrations generated in the periphery of the flow, gas bubbles present in the central part of the flow and moving at a higher speed are acted upon by sound vibrations of a greater magnitude. Because the sound wave of the maximum intensity generated by the acoustic transducer aligns with the axis of symmetry of the inlet hole, the action of these sound vibrations is directed oppositely to the direction of the flow of liquid fluid admitted to the inlet hole.

The above arrangement facilitates deceleration of the gas bubbles, their coalescence and evacuation from the degassing zone confined by the first cylindrical baffle.

Since the vertical cylindrical baffles are disposed coaxially between themselves and with respect to the inlet hole, the flow of liquid fluid admitted to the vessel is conveyed from the inlet hole to the outlet hole along the bottom of this vessel spreading in all directions, after which it tends to move circumferentially along the side wall of the cylindrical vessel in a zone confined by the vertical cylindrical baffle which is the last in succession from the inlet hole and the side wall of the vessel. The acoustic transducer provided before each vertical cylindrical baffle generates sound vibrations in a continuously reducing volume of the liquid fluid confined by the baffles.As a consequence, due to that the circumferential length of the end of each vertical baffle in succession from the inlet hole increases, the sectional flow area for the liquid fluid running away from the inlet hole is reduced in a more pronounced manner than in the previously described modifications of the apparatus, this being so not only because each vertical cylindrical baffle more remote from the inlet hole is brought closer to the bottom of the vessel, but also due to an increase in the area of the degassing zone confined by each such baffle.

In addition, the arrangement of the acoustic transducer before each vertical cylindrical baffle so that a sound wave of the maximum intensity it generates is transmitted to the flow of liquid fluid along the vertical axis of symmetry of the baffle in every direction results in that the intensity of sound vibrations induced in the flow by the acoustic transducer is distributed uniformly across the flow of liquid fluid thus enabling to carry out a uniform removal of gas bubbles from the liquid fluid. Also, the sound vibrations are transmitted perpendicularly to the travel path of the gas bubbles in the flow of liquid fluid, whereby the travel path of the gas bubbles is deviated from the horizontal to a certain upward angle.

In view of the foregoing, the proposed apparatus is so constructed as to enable removing gas bubbles from a flow of liquid fluid of small sectional area, and to carry out degassing of especially viscous liquids, such as quartz glass.

Advisably, the apparatus is provided with a means for controlling the movement of the vertical baffles in the vertical plane, this means including a tube received by the inlet hole for admitting the initial liquid fluid, a sleeve capable of axial displacement on the tube, and levers pivotably secured at the end of the sleeve, carrying the vertical baffles attached with a degree of freedom thereon, and movably connected to the cover plate of the vessel.

The pivotal connection of the levers carrying the vertical baffles to the end of the sleeve capable of axial movement on the tube, and the movable connection of the levers to the cover plate of the vessel provide for the movement of the baffles in the vertical plane as the sleeve is axially displaced. It is important to note that each vertical cylindrical baffle in succession from the inlet hole is moved at a distance substantially less than that of the preceding baffle, whereas the difference in the height to which the first and last baffles are elevated from the bottom of the vessel ensures equality in the values of the sectional areas between the ends of the vertical baffles and the bottom of the vessel.If this condition is not conformed with, advantageous effect of each baffle in succession from the inlet hole is diminished, because the liquid fluid tends to spread from the inlet hole in a progressively thinner layer, and therefore can pass below the ends of the successive vertical baffles.

The movement of the vertical cylindrical baffles in the vertical plane to a different height from the bottom of the vessel makes it possible to control the flow rate of the liquid fluid being processed when switching to liquids of varying viscosity, which ensures the required degree of degassing a wide range of liquids.

The invention will now be described in greater detail with reference to various specific embodiments thereof taken in conjunction with the accompanying drawings, in which: Figure 1 is a longitudinal sectional view of an apparatus for removing gases from a stream of a liquid fluid according to the invention; Figure 2 is a section taken along the line Il-Il in Fig. 1; Figure 3 is an expanded view of the section A in Fig. 1; Figure 4 is a longitudinal sectional view of a modified form of the proposed apparatus provided with a means for controlling the movement of the vertical baffle plates of rectangular shape; Figure 5 is a longitudinal sectional view of another modification of the proposed apparatus having several vessels of rectangular shape; Figure 6 is a partial view taken along the arrow B in Fig. 5; Figure 7 is an expanded view of the section C in Fig. 5;; Figure 8 is a longitudinal sectional view of one more modification of the proposed apparatus provided with a vertical baffle wall in the form of a spiral; Figure 9 is a section taken along the line IX-IX in Fig. 8; Figure 10 is a longitudinal sectional view of a modified form of the apparatus in which the vertical baffle walls are cylindrical; Figure 11 is a section taken along the line Xl-XI in Fig. 10; and Figure 12 is a longitudinal sectional view of yet one more modified form of the apparatus according to the invention provided with a means for controlling the movement of cylindrical vertical baffle walls.

The proposed apparatus for removing gases from a stream of liquid fluids with reference to Figs. 1, 2 and 3 comprises a vessel 1 having an inlet hole 2 for admitting an incoming liquid fluid 3, and an outlet hole 4 for discharging the liquid fluid 3 free of gas bubbles 5.

The vessel 1 is defined by side walls 6, 7, 8, 9 (Fig. 2) and a bottom wall 10 (Fig. 1), and has a cover plate 11 with drain pipes 12.

The inlet hole 2 for admitting the liquid fluid 3 is arranged in the cover plate 11 in proximity to the side wall 6. The outlet hole 4 for discharging the treated liquid 3 is disposed in the lower part of the side wall 7 adjacent the bottom wall 10 of the vessel 1.

The vessel 1 accommodates in the space from the side wall 8 to the side wall 9 a successive arrangement of vertical baffle plates 13.

These vertical baffle plates 13 (Fig. 1) define therebetween treatment zones 14 occupied with the liquid fluid 3.

The vertically arranged baffle plates 13 can be moved vertically inside the vessel 1.

Ends 15 of the vertical baffle plates 13 are spaced from the bottom 10 a distance L (Fig. 3) to allow the passage of the liquid fluid 3 in a direction indicated by the arrow D that is from the inlet hole 2 toward the outlet hole 4 along the bottom 10 of the vessel 1.

According to one feature of the present invention, each vertical baffle plate 13 (Fig. 1) in succession from the inlet hole 2 is spaced from the bottom 10 of the vessel 1 at a distance which is less than that of the preceding baffle plate, i.e., L1 > L2 > L3 > L4.

A portion 16 of the bottom 10 of the vessel 1 before the last successive baffle plate 13 from the inlet hole 2 is made of a sound-damping material.

Provided before each vertical baffle plate 13 exept the last one in succession is an acoustic transducer 17 secured to the bottom 10 of the vessel 1 through an element 18 (Fig. 3) made of a sound-damping material and serving to induce sound vibrations in the zones 14 (Fig. 1) to cause the gas bubbles 5 to ascent toward a surface 19 of the liquid fluid 3.

According to the invention, in a modified form of the apparatus illustrated in Figs. 1, 2 and 3 the vessel 1 is of rectangular configuration with substantially rectangular vertical baffle plates 13 (Fig. 1) arranged between its side walls 8 and 9 (Fig. 2) in front of the inlet hole 2. The acoustic transducer 17 is arranted before each vertical baffle plate 13 so that the sound wave of maximum intensity it induces is transmitted to the flow of liquid fluid 3 passing in a section coinciding with the vertical axis of symmetry of the baffle plate 13 in a direction indicated by the arrow B (Fig. 3) from the inlet hole 2 (Fig. 1) to the outlet hole 4.

Referring now to Fig. 4 of the drawings, the modification of the apparatus it represents has a means for controlling the movement of the vertical baffle plates 13 in a vertical plane, this means including a tube 20 received by the inlet hole 2 for admitting the liquid fluid 3 of the vessel 1, and a system of levers 21, 22 and 23. One lever 23 of this system is adapted to carry the vertical baffle plates 13 and is affixed to the cover plate 11 of the vessel 1, whereas the other lever 21 is pivotably connected to the tube 20. The levers 21 and 23 are interconnected by a lever 22. Also, the means for controlling the movement of the baffle plates 13 comprises a float 24 pivotably connected to the lever 21.The apparatus shown in Fig. 4 is provided with a set of microswitches 25 attached to the lever 23 carrying the vertical baffles 13 and electrically wired to all the acoustic transducers 17 exept one adjacent the inlet hole 2 through a switchboard unit 26 acting to alternately energize the acoustic transducers 17.

With reference to a modification of the apparatus illustrated in Figs. 5, 6 and 7, two vessels 1 are provided communicable with each other and arranged successively one after another, the second vessel 1 resting above the first one at a height determined by the following equation:

where p,=density of the liquid fluid 3; p2=density of air; R=radius of gas bubbles 5; tO=intensity of sound vibrations; a=absorption factor; So initial distance between the gas bubble 5 and the surface of the acoustic transducer 17; I=surface length of the acoustic transducer 17; 7l=viscosity of the liquid fluid 3; vo=flow speed of the liquid fluid 3; Re=Reynolds number; C=velocity of sound in the liquid fluid 3; and e=base of natural logarithm 0.7 = margin constant allowing for fluctuations in the parameters of the sound field and liquid fluid; The vertical baffle plate 13 which is the last in sequence from the inlet hole 2 in each vessel 1 has an aperture 27 (Fig. 6) of rectangular configuration arranged at the level of the bottom 10 (Fig. 5) of the last vessel 1 in succession downstream of the flow of liquid fluid 3. Any number of vessels 1 can be employed depending on the desired production output.

In addition, according to another feature of the present invention, in the apparatus represented in Figs. 5 and 7 there is provided between the adjacent vessels 1 a pick-up 28 for monitoring the amount of gas bubbles 5 in the liquid fluid 3. The pick-up 28 is electrically connected to the acoustic transducers 17 of the vessel 1 (Fig. 5) extending after the pick-up 28 (Fig. 7) downstream of the flow of the liquid fluid 3 through a switchboard unit 29 which successively energizes the acoustic transducers 17 in each vessel 1 in the direction of the flow of liquid fluid 3.

Turning now to Figs. 8 and 9 of the accompanying drawings, a modified form of the proposed apparatus comprises a vessel 30 of cylindrical configuration having an inlet hole 31 for admitting initial liquid fluid 32 and an outlet hole 33 for discharging the liquid fluid 32 free of gas bubbles. The cylindrical vessel 30 is defined by a side wall 35 and a bottom wall 36, and has a cover plate 37 accommodating drain pipes 38.

The vessel 30 accommodates an additional vertical baffle wall 39 fashioned as a spiral having a center arranged in line with the center of the inlet hole 31 to form with the bottom 36 and side wall 35 of the vessel 30 a helical passage of invariable cross-section. The inlet hole 31 for admitting the initial liquid fluid 32 is disposed in the cover plate 37 in line with the symmetry axis of the vessel 30. The outlet hole 33 for discharging the liquid fluid 32 free of gas bubbles 34 is arranged at the end of the helical passage in the bottom 36 of the vessel 30.

Arranged in succession transversely to the flow of the liquid fluid 32 (having a viscosity greater than 300 centipoises) in the helical passage are vertical baffle plates 40 of substantially rectangular shape.

The first coil of the vertical wall 39 connected to the bottom 36 of the vessel 30 starts from the inlet hole 31, and forms a degassing zone 41 (Fig. 9) occupied by the liquid fluid 32 (Fig. 8).

The successively unwrapping from the inlet hole 31 coils of the vertical wall 39, as well as the vertical baffle plates 40 and side wall 35 of the vessel 30 define degassing zones 42 (Fig. 9) occupied by the liquid fluid 32.

Ends 43 (Fig. 8) of the vertical baffle plates 40 are spaced at a certain distance from the bottom 36 to allow the passage of the liquid fluid 32 in a direction from the inlet hole 31 to the outlet hole 32 along the bottom 36 of the vessel 30.

According to the invention, each successive vertical baffle plate 40 remote from the inlet hole 31 is spaced from the bottom 36 of the vessel 30 at a distance which is smaller than that of the preceding baffle 40, i.e., M1 > M2 > M3 > M4; > M5 A portion 44 of the bottom 36 of the vessel 30 adjacent the last vertical baffle plate 40 in succession from the inlet hole 31 is fabricated from a sound-damping material.

Arranged coaxially to the inlet hole 31 in the vessel 30 is an acoustic transducer 45 which induces sonic waves in the degassing zone 41 (Fig. 9) for the gas bubbles 34 (Fig. 8) to rise to a surface 46 of the liquid fluid 32. Therewith, a sound wave of the maximum intensity induced by the acoustic transducer 45 coincides with the symmetry axis of the inlet hole 31.

Accommodated in the zones 42 (Fig. 9) before each of the vertical baffle plates 40 except the last one in succession are acoustic transducers 47 for the sound waves of the maximum intensity they generate to be transmitted to the flow of liquid fluid 32 (Fig. 8) passing through a section coinciding with the vertical axis of symmetry of the vertical plates 40 in a direction (as indicated in Fig. 9 by the arrow F) from the inlet hole 31 (Fig. 8) to the outlet hole 33.

The acoustic transducers 45 and 47 are affixed to the bottom 36 of the vessel 30 through elements 48 made of a sound-damping material.

In the apparatuses represented in Figs. 1 to 9 the end 15 (Figs. 1 to 7) and end 43 (Figs. 8 and 9) of each rectangular vertical baffle plate 13 and 40, respectively, facing the bottom 10 or 36 of the vessel 1 or 30 are arched transversely to the flow of the liquid fluid 3 or 32 about a curve substantially conforming to the curve of the distribution of intensity of the sonic waves generated in the liquid fluid 3 or 32 by the acoustic transducer 17 or 45 provided before each such baffle 13 or 40.

An alternative arrangement of the proposed apparatus with reference to Figs. 10 and 11 comprises a vessel 49 (Fig. 10) of substantially cylindrical shape formed by a side wall 50 and bottom 51 and having an inlet hole 52 for admitting initial liquid fluid 53, and an outlet hole 54 for discharging the liquid fluid 53 free of gas bubbles 55.

The vessel 49 has a cover plate 56 which is provided with drain pipes 57 and accommodates the inlet hole 52 disposed coaxially to the axis of symmetry of the vessel 49. The outlet hole 54 (Fig. 11) has the form of a slot in the lower portion of the side wall 50 (Fig. 10) adjacent the bottom 51 of the vessel 49.

Arranged transversely to the flow of fluid 53 in the vessel 49 are coaxial vertical baffle walls 58 of cylindrical shape. The vertical cylindrical baffle wall 58 which is the first in succession from the inlet hole 52 forms a degassing zone 59 occupied by the liquid fluid 53. The other cylindrical vertical walls 58 remote from the inlet hole 52 form therebetween and with the side wall 50 of the vessel 49 degassing zones 60 filled with the liquid fluid 53. The area of these zones 59 and 60 is determined by the circumference of the end 61 of the vertical cylindrical baffle wall 58.

The vertical baffle walls 58 are so arranged in the vessel 49 as to be capable of displacement in the vertical plane.

The ends 61 of the vertical baffle walls 58 are spaced from the bottom 51 a certain distance to allow the passage of the fluid 53 in a direction from the inlet hole 52 to the outlet hole 54 along the bottom 51 of the vessel 49.

According to the invention, each successive vertical baffle wall 58 remote from the inlet hole 52 is spaced from the bottom 51 of the vessel 49 at a distance which is smaller than that of the preceding wall 58, i.e., N1 > N2 > N3.

A portion 62 of the bottom 51 of the vessel 49 adjacent the last vertical baffle wall 58 in succession from the inlet hole 52 is fabricated from a sound-damping material.

Arranged coaxially to the inlet hole 52 is an acoustic transducer 63 for a sound wave of the maximum intensity it generates to coincide with the axis of symmetry of the inlet hole 52 and make the gas bubbles 55 float upwards to a surface 64 of the liquid fluid 53 in the degassing zone 59.

Arranged before each vertical baffle wall 58 except the last one in succession is an acoustic transducer 65 (Fig. 11) for a sound wave of the maximum intensity it generates to be transmitted to the flow of liquid fluid 53 (Fig. 10) along the vertical axis of symmetry of the baffle wall 58.

The acoustic transducers 63 and 65 are affixed to the bottom 51 of the vessel 49 through elements 66 fabricated from a sound-damping material.

A modification of the proposed apparatus shown in Fig. 12 has a means for controlling the movement of the vertical baffle walls 58 in the vertical plane. This means includes a tube 67 received by the inlet hole 52 for admitting the liquid fluid 53 of the vessel 49, a sleeve 68 capable of axial travel on the tube 67, and levers 69 pivotably secured at one end of the sleeve 68, carrying the vertical baffle walls 58 freely suspended thereon, and movably connected to the cover plate 56 of the vessel 49.

Another end of the sleeve 68 extends through a thrust washer 70 to the cover plate 56 of the vessel 49. An adjusting nut 71 with a lock nut 72 are threadingly arranged on this end of the sleeve 68. Attached to the cover plate 56 of the vessel 49 is a scale 73 provided with a pointer 74 rigidly connected to the sleeve 68.

The vertical walls 58 are suspended on rods 75 in slots 76 of the levers 69 by means of a pin attachment 77.

Arms of the levers 69 are movably connected to the cover plate 56 of the vessel 49 by means of supports 78.

Arranged in the space after the vertical baffle wall 58 which is the last in succession from the inlet hole 52 is a pick-up 79 for monitoring the level of the liquid fluid 53. This pick-up is electrically connected to a valve 80 provided in the tube 67 and serving to stop the flow of incoming liquid fluid 53.

The apparatus for removing gases from a stream of liquid fluids according to the present invention operates in the following manner.

The initial liquid fluid 3 is admitted to the vessel 1 of rectangular shape formed by the side walls 6, 7, 8, 9 (Fig. 2) and bottom 10 (Fig. 1) through the inlet hole 2 provided in the cover plate 11 adjacent the side wall 6 to spread along the bottom 10 in a direction (indicated by the arrow D) from the inlet hole 2 to the outlet hole 4 disposed at the lower portion of the side wall 7 adjacent the bottom 10. The liquid fluid 3 then tends to fill the vessel 1 to a height exceeding the distance L1, L2, L3, L4 between the bottom 10 and the ends 15 of the vertical baffle plates 13 extending from the side wall 8 (Fig. 2) to the side wall 9 of the vessel 1 (Fig.

1) and arranged in succession from the inlet hole 2 (Fig. 2). The flow of liquid fluid 3 is conveyed successively through the degassing zones 14 defined by the vertical baffles 13 to be subjected to the effect of sound vibrations induced by the acoustic transducers 17 provided before each such vertical baffle 13 except the last one in succession.

Therewith, a single gas bubble 5 spaced initially at a distance So from the surface of the acoustic transducer 17 is acted upon by the sound vibrations generated by the acoustic transducer 17 to make it float upwards to a height calculatable by the equation of forces exerted on such a gas bubble in a sonic wave field.

Even if the single gas bubble 5 is caused to rise above the first transducer 17 in succession from the inlet hole 2 to an insufficient hight, it is bound to be entrained subsequently by the viscous forces of the flow of liquid fluid 3 to the space above the next successive acoustic transducer 17, where it is raised to a height exceeding the previously attained one.

The liquid fluid 3 flows from one degassing zone 14 to the next under the ends 15 of the vertical baffle plates 13 each of which is spaced from the bottom 10 of the vessel 1 at the distance L1, L2, b, L4 progressively diminishing as compared with the preceding baffle plate 13, whereby any single gas bubble 5 is most likely to finally ascend to a height exceeding the distance L1, L2, L3, L4 from the corresponding baffle plate 13 to bottom 10 of the vessel 1.

Also, the passage of the liquid fluid 3 over each successive acoustic transducer 17 causes the formation of new gas bubbles 5 in addition to those already present in the fluid 3, this process being accompanied by expansion of the gas bubbles in size, vigorous coalescence, deceleration, stop and ascent to be retained by the vertical baffles 13. The gas bubbles 5 eventually rise to the surface 19 of the liquid fluid 3 to flop and be evacuated from the vessel 1 through the drain pipes 12.

Even if at some section of the bottom 10 of the vessel 1 the gas bubbles 5 fail to coalesce, expand and rise to a height equal to the distance L1, L2, b, L4, where they are retained by the vertical baffle 13, these bubbles are entrained by the viscous forces of the flow of fluid 3 to the space above the next acoustic transducer 17 to coalesce under the action of sound waves with the newly formed gas bubbles 5, whereby they are raised to a height equal to the distance L1, L2, b, L4 retained by the vertical baffle 13, floated to the surface 19 of the liquid fluid 3, and evacuated through the drain pipes 12.

Because the sectional area through which the flow of liquid fluid 3 moves under the ends 15 of the vertical baffle plates 13 tends to diminish as each successive vertical baffle plate 13 is suspended closer to the bottom of the vessel 1, while the amount of liquid fluid 13 passing through these areas remains invariable, the flow speed of the liquid fluid 3 progressively increases as it runs under each next end 15 of the baffle 13 in succession. According to the Bernoulli law, an increase in the speed of flow of the liquid fluid 3 passing through varying sectional areas causes reduction in the pressure of this fluid 3, which promotes the formation of new gas bubbles 5 and their escape from the liquid fluid 3.

During the passage of the liquid fluid 3 under the ends 15 of the vertical baffle plates 13 each one of which is spaced from the bottom 10 of the vessel 1 at a distance L2 which is less than by a factor of 0.05 as compared with the distance L1 of the preceding vertical baffle plate 13 nearer the inlet hole 2, the difference in the flow area for the liquid fluid 3 under the ends 15 of these baffles 13 results in a negligeable increase in the speed and pressure differential in the flow of liquid fluid 3 and consequently inefficient removal of the gas bubbles 5 from the fluid 3.

Conversely, when the liquid fluid 3 flows under the ends 15 of the vertical baffle plates 13 each of which is spaced from the bottom 10 of the vessel 1 at a distance L, which is more than by a factor of 0.1 as compared with the distance L2 of the successive vertical baffle plate 13 remote from the inlet hole 2, the difference in the flow area for the liquid fluid 3 running under the ends 15 of the vertical baffles tends to cause substantial swirls in the flow of fluid 3 under the ends 15 of the vertical baffle plates 15, whereby the gas bubbles 5 are entrained from the upper layers of the liquid fluid 3 for the flow of such fluid to force the bubbles under the vertical baffle plates 13.

During the passage of the flow of liquid fluid 3 in the vessel 1 of rectangular configuration through the degassing zones 14 above the acoustic trasducers 17 from the inlet hole 2 to the outlet hole 4 the flow is also caused to assume a rectangular cross-section, and sound vibrations are transmitted to the flow with an intensity uniformly distributed from the central part thereof to the periphery in a direction substantially transverse to the flow direction of the liquid fluid 3. This ensures uniform removal of the gas bubbles 5 from the flow of liquid fluid 3 along its travel path, which in the end guarantees reliable degassing of the liquid fluid 3.

In addition, when the flow of liquid fluid 3 moves under the ends 15 of the baffles 13 facing the bottom 10 of the vessel 1 and shaped transversely to the flow of liquid fluid 3 about a curve substantially conforming to the curve of intensity distribution of sound vibrations induced in the liquid fluid 3 by the acoustic transducer 17, the section of the flow in the vertical plane changes. As a result, within a unit space of time a greater amount of the liquid fluid 3 is conveyed above the central portion of the acoustic transducer 17 where sound vibrations of the maximum intensity are generated than above the peripheral portion thereof, whereby the appartus operates more efficiently.

Also, the sound vibrations induced by the acoustic transducers 17 act perpendicularly to the direction of the flow of liquid fluid 3 in the degassing zones 14 to cause a deviation in the travel path of the gas bubbles 5 from the horizontal to an ascending angle, whereby the bubbles 5 float faster to the surface 19 of the liquid fluid 3 and flop for the gas they liberate to be evacuated from the vessel 1 through the drainpipes 12.

In addition, the sound vibrations generated in the degassing zones 14 by the acoustic transducers 17 are transmitted to the flow of liquid fluid 3 more completely along the vertical axis of symmetry of the vertical baffle plates 13, since the transmission of the sound vibrations to the bottom 10 of the vessel 1 in the direction of the flow of liquid fluid 3 preventing deceleration of the gas bubbles 5 in this direction is impossible due to attaching the acoustic transducers 17 to the bottom 10 of the vessel 1 through the elements 18 made of a sound-damping material.

No new gas bubbles are formed in the liquid fluid 3 flowing above the portion 16 of the bottom 10 fabricated from a sound damping material and disposed before the vertical baffle plate 13 which is the last in succession from the inlet hole 2. Gas bubbles 5 generated by the last acoustic transducer 17 in succession from the inlet hole 2 are completely retained by the vertical baffle plate 13 which is the last in succession from the inlet hole 2 by virtue of its arrangement at a sufficient distance from the preceding baffle plate 13.

The flow of liquid fluid 3 escapes from the vessel 1 through the outlet hole 4 completely free of the gas bubbles 5, since now new gas bubbles 5 are produced in the degassing zone 14 before the last baffle 13 thanks to the absence of the acoustic transducer 17 before this last baffle 13.

As the level of the surface 19 of the liquid fluid 3 in the vessel 1 decreases, the float 24 (Fig.

4) goes down to actuate the lever 21 pivotably connected to the float 24. Because one arm of the lever 21 is pivotably secured to the tube 20 received by the inlet hole 2 of the vessel 1, and the other arm thereof is pivotably connected to the lever 22, the lever 21 is caused to be lowered to move the lever 22 downwards. Thanks to the pivotal connection of the lever 22 to the lever 23 carrying the vertical baffle plates 13, these plates 13 start their downward travel to reduce the flow area for the liquid fluid 3 conveyed under the ends 15 of the vertical baffles 13.

In view of the aforedescribed, with the thus reducing flow rate of the fluid 3 sound vibrations are induced by the acoustic transducers 17 in a flow of such fluid 3 of smaller sectional area to more efficiently remove the gas bubbles 5 therefrom.

As the flow rate of the liquid fluid 3 increases, each successive vertical baffle plate 13 furthest from the inlet hole 2 is raised to a height or distance L1, L2, Ls, L4 which is less than that of the preceding baffle plate 13, since the lever 23 carrying these vertical baffles 13 is connected by one end thereof to the cover plate 11 of the vessel 1. This enhances the difference in the sectional areas of the flow of liquid fluid 3 running under the ends 15 of the vertical baffles 13 to result in a progressively increasing difference in the flow speed of the liquid fluid 3 through these sections and in a more pronounced pressure difference in the flow causing accelerated removal of gas bubbles 5 from the liquid fluid 3.As the level of the surface 19 of the liquid fluid 3 rises and moves the lever 23 upwards, the set of microswitches 25 is closed for an electric signal to be applied to the switchboard 26 and alternately energize the acioustic transducers 17; the number of acoustic transducers 17 thus energized being such as to ensure complete removal of the gas bubbles 5 from the liquid fluid 3.

A decrease in the level of the liquid fluid 3 causes the downward movement of the lever 23 carrying the vertical baffle plates 13 to again trigger the set of microswitches 25 for the switchboard 26 to deenergize the acoustic transducers 17, which affords to obviate idle operation of the acoustic transducers 17 when guaranteed degassing of the diminishing flow of liquid fluid 3 is ensured.

When the liquid fluid to be degassed is conveyed through an apparatus comprising several interconnected vessels 1 arranged one after another so that each successive vessel 1 is above the preceding one at a distance or height h, the flow of fluid 3 passing under the ends of the vertical baffle plates 13 escapes through the outlet hole 4 in the side wall 7 of each vessel 1 to result in improved degassing efficiency of the apparatus.

Therewith, the flow of liquid fluid 3 conveyed through each vessel 1 is divided at the height h by the apertures 27 of rectangular shape made in the vertical baffle plates 13 at the level of the bottom 10 of the successive vessel 1 downstream of the flow of liquid fluid 3, which makes it possible to separate the upper layers of the liquid fluid 3 containing the gas bubbles 5 and convey them to the next vessel 1 in succession for carrying out a further degassing process.

In this manner the flow of liquid fluid 3 free from gases will pass under the ends 15 of the vertical baffle plates 13 to leave each vessel 1 substantially below the height h from the outlet hole 4 and thus ensure guaranteed degassing and operation efficiency.

During the transfer of the liquid fluid 3 from one vessel 1 to the next the amount of gas bubbles 5 in the flow is monitored by the pick-up 28 provided between the adjacent vessels 1.

If the liquid fluid 3 being treated contains gas bubbles 5 in abundance, the pick-up 28 issues a signal to the switchboard 29 to successively deenergize the acoustic transducers 17 in each vessel 1 downstream of the flow of fluid 3 for the degassing process to proceed in each successive vessel 1 exclusively by virtue of the reduction in the height at which the vertical baffles 13 are suspended.

In another modified form of the proposed apparatus the liquid fluid 32 (Fig. 8) is admitted through the inlet hole 31 in the cover plate 37 disposed in line with the axis of symmetry of the vessel 30 to be conveyed along a passage of invariable cross-section formed by the side wall 35 of the cylindrical vessel 30 and the additional vertical baffle wall 39 having the form of a spiral centered with the inlet hole 31 and connected to the bottom 36 of the vessel 30. In the course of travel the flow of liquid fluid 32 passes through the degassing zone 41 formed by the first coil of the vertical wall 39 above the acoustic transducer 45 aligned with the axis of the inlet hole 31 of the vessel 30.

Due to the fact that the central part of the flow of liquid fluid 32 passing in the degassing zone 41 over the center of the acoustic transducer 45 is acted upon by sound vibrations of greater intensity as compared with the rest of the flow, the gas bubbles 34 moving in the central portion of the flow of liquid fluid 32 at a higher velocity are decelerated more effectively by the action of the sound vibrations. Therewith, the process taking place in the liquid fluid 32 occupying the degassing zone 41 is accompanied by the formation of more gas bubbles 34, expansion of the bubbles in size, vigorous coalescence, deceleration and floating up to be retained by the first coil of the vertical spiral baffle wall 39, after which the bubbles rise to the surface 46 of the fluid 32, flop, and the gas they liberate is evacuated from the vessel 30 through the drain pipes 38.

In addition, thanks to that the flow of liquid fluid 32 admitted through the inlet hole 31 of the vessel 30 is acted upon by sound vibrations generated by the acoustic transducer 45 arranged coaxially with the inlet hole 31 in a direction counter to the direction of the flow of liquid fluid 32, the gas bubbles 34 are decelerated, stopped, raised to the surface 46 of the fluid 32, removed from the degassing zone 41, and evacuated from the vessel 30 through the drain pipes 38 in a more efficient manner.

The sound vibrations generated in the degassing zone 41 by the acoustic transducer 45 are transmitted to the flow of liquid fluid 32 more efficiently without losses, since no sound vibrations are imparted to the bottom 36 of the vessel 30 thanks to the connection of the acoustic transducer 46 to the bottom 36 through the sound-damping element 48.

The liquid fluid flows further to the degassing zones 42 defined by the side wall 35 of the cylindrical vessel 30, successive coils of the verical baffle wall 39 and rectangular baffle plates 40 transverse to the flow of liquid fluid 32. The liquid fluid 32 is conveyed from one degassing zone 42 to another under the ends 43 of the vertical baffle plates 40 each of which is spaced at a distance (M1 > M2; > M3;> M4#M5) from the bottom 36 less than that of the preceding baffle 40 in succession from the inlet hole 31; the flow of liquid fluid 32 being subjected to sound vibrations induced by the acoustic transducers 47 secured before each vertical baffle plate 40 except the last one in succession for a sound wave of the maximum intensity to be transmitted to the flow of liquid fluid 32 passing through a section coinciding with the vertical axis of symmetry of the baffle plate 40.

Therewith, any single gas bubble 34 is caused to ascend by the sound vibrations induced by the acoustic transducer 47 substantially in the same manner as described with reference to the description of operation of the previous modified form of the apparatus according to the invention.

Newly formed gas bubbles 34 are added to those already present in the liquid fluid 32 passing over each successive acoustic transducer 47 to be evacuated from the vessel 30 in a manner similar to what has been described with reference to the previous modification of the apparatus.

As a result of the progressive reduction in the flow area sections through which the fluid 32 passes under the ends 43 of the vertical baffles 40, as they are successively spaced closer to the bottom 36 of the vessel 35, the process of formation of new gas bubbles 34 and their removal from the fluid 32 is accelerated.

When the liquid fluid 32 is conveyed under the ends 43 of the vertical baffle plates 40 each of which is spaced from the bottom 36 of the vessel 30 at a distance less than by a factor of 0.05 or greater than by a factor of 0.1 compared with the distance from the bottom 36 of the next baffle plate 40 in succession from the inlet hole 31, the difference in the flow areas under the ends 43 of the vertical baffle plates 40 through which the liquid fluid 32 is conveyed is such as to result in gas bubbles behaviour described in greater detail with reference to the operation of the previous modification of the apparatus.

During the movement of the liquid fluid 32 along the helical passage of invariable cross-section through the degassing zones 42 above the acoustic transducers 47 adapted to transmit a sound wave of the maximum intensity to the flow of fluid 32 passing in a section coinciding with the vertical axis of symmetry of the rectangular baffle plate 40 in a direction (as indicated by the arrow C in Fig. 9) from the inlet hole 31 to the outlet hole 33, this flow of fluid 32 also assumes a substantially rectangular cross-section, whereby the sound vibrations generated in the flow of fluid 32 by the acoustic transducers 47 are distributed with uniform intensity transversely to the flow of the liquid fluid 32 to attain the effect of generally uniform removal of gas bubbles 34, as described with reference to the manner in which the previous modification of the proposed apparatus operates.

In addition, because sound vibrations generated by the acoustic transducers 47 in the degassing zones 42 are imparted substantially perpendicularly to the flow of liquid fluid 32, the travel path of the gas bubbles 34 departs to an even greater upward angle from the horizontal, whereby the ascent of the bubbles to the surface 46 of the liquid fluid 32 and eventual evacuation of the gas they contain through the drain pipes 38 is accelerated.

In the course of movement of the flow of liquid fluid 32 under the vertical rectangular baffle plates 40 having the ends 43 facing the bottom 36 of the vessel 30 arched transversely to the flow of liquid fluid about a curve substantially conforming to the curve of intensity distribution of the sound vibrations induced in the liquid fluid 32 by the acoustic transducer 47, the crosssection of the flow of fluid 32 changes to result in increased efficiency of the apparatus as described with reference to the previously disclosed modification of the apparatus.

Also, sound vibrations induced in the degassing zones 42 by the acoustic transducers 47 are transmitted more completely along the vertical axis of symmetry of the vertical baffles 40, as has been described with reference to the previous modification of the apparatus, thanks to affixing these acoustic transducers 47 to the bottom 36 of the vessel 30 through the elements 48 made of a sound damping material.

Thanks to the provision of the helical passage of invariatable cross-section, the liquid fluid 32 has to travel a more extensive distance to result in that this fluid tends to dwell in the degassing zones 42 and be subjected to sound vibrations induced by the transducer 47 for a longer space of time. This in turn affords to reduce the overall dimensions of the apparatus and save production floor areas, while ensuring reliable removal of gas from the liquid fluid 32.

No new gas bubbles 34 are formed in the liquid fluid 32 passing over the portion 44 of the bottom 36 made of a sound-damping material. Gas bubbles 34 formed by the last acoustic transducer 47 in succession from the inlet hole 31 are retained by the vertical baffle plate 40 which is the last in the succession of such plates from the inlet hole 31 thanks to that this baffle plate 40 is spaced at a sufficiently large distance from the preceding baffle plate 40.

When discharged from the outlet hole 33, the liquid fluid 32 is free of gas bubbles 34 thanks to the lack of the acoustic transducer 47 before the last vertical baffle plate 40 in succession from the inlet hole 31, as is the case with the previously described modified form of the proposed apparatus.

As to one more alternative modification of the apparatus represented in Fig. 10, the liquid fluid 53 is admitted through the inlet hole 52 in the cover plate 56 arranged in line with the axis of symmetry to the cylindrical vessel 49 to be conveyed to the degassing zone 59 defined by the cylindrical baffle wall 58 which is the first from the inlet hole 52 and coaxial with the inlet hole 52, where the fluid 53 is subjected to the action of sound vibrations generated by the acoustic transducer 63 also disposed coaxially with the inlet hole 52 of the vessel 49.

The central part of the flow of liquid fluid 53 passing through the degassing zone 59 above the acoustic transducer 63 is subjected to sound waves of higher intensity than the rest of the flow, which results in an effect generally described with respect to previous modifications.

Newly formed gas bubbles 55 in the degassing zone 59 are added to those already present in the liquid fluid 53, the gas bubbles tending to expand in size, coalesce, decelerate, stop, and move upwards to be retained by the vertical baffle wall 58 first in succession from the inlet hole 52. The gas bubbles 55 are then floated to the surface 64 of the fluid 53, and flop for the gas they deliver to be evacuated from the vessel 49 through the drain pipes 57.

The incoming flow of liquid fluid 53 admitted through the inlet hole 52 of the vessel 49 is acted upon by sound vibrations induced by the acoustic transducer 63 coaxial with the inlet hole 52 in a direction counter to the flow of fluid 53 resulting in an effect described with respect to the previous modification of the proposed apparatus.

The sound vibrations generated in the degassing zone 59 by the acoustic transducer 63 are transmitted to the flow of liquid fluid 53 more completely without accompanying losses thanks to the connection of the acoustic transducer 63 to the bottom 51 of the vessel 49 through a sound-damping element 66.

The liquid fluid is then conveyed to the degassing zones 60 formed by the side wall 50 of the cylindrical vertical vessel 49 and cylindrical vertical baffle walls 58 arranged coaxially relative to the inlet hole 52. From one degassing zon 60 to the next the flow of fluid 53 passes under the ends 61 of the vertical walls 58, each such wall 58 being spaced from the bottom 51 of the vessel 49 at a distance (N1#N2 > N3) substantially shorter than that of the preceding wall 58 in succession from the inlet hole 52.The liquid fluids 53 flowing in the thus described manner is subjected to the action of sound vibrations induced by the acoustic transducers 65 provided before each vertical wall 58 so that a sound wave of the maximum intensity the transducer 65 generates is transmitted to the flow of liquid fluid 53 passing in a section coinciding with the vertical axis of symmetry of the vertical baffle wall 58.

Therewith, any single gas bubble 55 present in the fluid 53 tends to move upwards when sound vibrations generated by the acoustic transducers 65 are imparted thereto in much the same manner as has been described with reference to the previously discussed modifications of the proposed apparatus.

Newly formed gas bubbles 55 are added to the bubbles already present in the liquid fluid 53 passing over each successive acoustic transducer 65, this process being accompanied by expansion of the bubbles in size, vigorous coalescence, deceleration and a subsequent upward movement of the bubbles for the gas they carry to escape through the drain pipes as described heretofore.

Thanks to that the vertical cylindrical baffle walls 58 are disposed coaxially between them selves and relative to the inlet hole 52, the fluid 53 flows from the inlet hole 52 to the outlet hole 54 along the bottom 51 of the vessel 49 by spreading in all directions.

In this modification of the apparatus the sectional flow area of the fluid 53 as it departs from the inlet hole 52 diminishes in a more pronounced way than in the previously described modifications due to that each vertical baffle wall 58 in succession from the inlet hole 52 is spaced more closely to the bottom of the vessel 50, and also due to an increase in the area of each degassing zone 60 in succession from the inlet hole 52 determined by the circumference of the ends 61 of the vertical baffle walls 58 facing the bottom 51.

The passage of the flow of liquid fluid 53 below the vertical baffle walls 58 is prevented by the equality of sectional areas under the ends 61 of each vertical baffle wall 58.

Because the section through which the liquid fluid 53 flows under the ends 61 of the vertical baffle walls 58 is diminished as each of successive baffle wall 58 is brought closer to the bottom of the vessel, new gas bubbles 55 are formed and removed from the fluid 53 at an accelerated rate.

During the passage of the flow of liquid fluid 53 under the ends 61 of the vertical baffle walls 58 each of which is spaced from the bottom 51 of the vessel 49 at a distance which is less than by a factor of 0.05 compared with the next successive baffle wall 58 or greater than by a factor of 0.1 compared with the distance from the bottom of the preceding vertical baffle wall 58 from the inlet hole 52, the difference in Che flow area of the liquid fluid 53 under the ends 61 of the vertical baffle walls 58 results in the removal of the gas bubbles substantially as described with reference to the previous modifications of the proposed apparatus.

When the flow of liquid fluid 53 moves through the degassig zones 60 above the acoustic transducers 65 arranged so that a sound wave of the maximum intensity is transmitted to the liquid fluid 53 flowing in a section coinciding with the vertical axis of symmetry of the vertical baffle walls 58 in every direction, the sound vibrations induced therein by the transducers 65 is distributed with uniform intensity across the flow of liquid fluid 53, whereby a uniform gas removal effect is attained as described with respect to the earlier described modifications of the proposed apparatus.

In addition, the liquid fluid 53 flowing through the degassing zones 60 is subjected to sound vibrations induced by the acoustic transducers 65 substantially perpendicularly to the flow, whereby the travel path of the gas bubbles 55 is deviated from the horizontal to a greater upward angle to accelerate their ascent to the surface 64 of the fluid 53 and eventual evacuation of the gas they contain through the drain pipes 57.

Further, sound vibrations induced in the degassing zones 60 by the transducers 65 are transmitted more completely along the vertical axis of symmetry of the vertical baffle walls 58, as in the case of the previously described modified forms of the apparatus, thanks to attaching the acoustic transducers 65 to the bottom 51 of the vessel 49 through the elements 66 fabricated from a sound-damping material.

No new gas bubbles 55 are formed in the liquid fluid 53 flowing through the zone 60 between the two last successive vertical baffle walls 58 from the inlet hole 52 due to the absence of the acoustic transducer 65 before the last successive vertical wall 58, and also thanks to that the portion 62 of the bottom 51 before the last baffle wall 58 is made of a sound-damping material.

The gas bubbles 55 formed by the last acoustic transducer 65 from the inlet hole 52 are retained by the last vertical baffle wall 58 in succession from the inlet hole 52 thanks to its arrangement at a sufficient distance from the preceding baffle wall 58.

The passage of the flow of liquid fluid 53 below the vertical buffle wulls 58 is prevented by the equality of sectional areas under the ends 61, facing the bottom 51, of each vertical wall 58.

In the degassing zone 60 between the last vertical baffle wall 58 in succession from the inlet hole 52 and the side wall 50 of the vessel 49 the liquid fluid 53 flows about a circumference along the side wall 50 of the vessel 49 toward the outlet hole 54 to escape therefrom free of gas bubbles 55.

In view of the foregoing, the proposed apparatus is so constructed as to remove gas bubbles 55 from a flow of especially viscous liquid fluid 53, such as quartz glass, and attain a high degree of degassing.

In order to adjust the apparatus for degassing the liquid fluid 53 of a different viscosity, use is made of the adjusting nut 71 to move the sleeve 68 fitted on the tube 67 received by the inlet hole 52 to its lowest position, one end of which sleeve 68 extends through the thrust washer 70 from the cover plate 56 of the vessel 49. The apparatus is then put in operation and, while monitoring the amount of gas bubbles 55 in the flow of liquid fluid 53, the nut 71 is rotated to gradually lift the sleeve 68. Since the lower end of the sleeve 68 has pivotably secured thereto arms of the levers 69 carrying the vertical baffle walls 58, whereas the other arms of the levers 69 are movably connected to the cover plate 56 of the vessel 49 by means of the supports 78, then as the sleeve 68 lifts the vertical baffle walls 58 suspended freely by the rods 75 in the grooves of the levers 69 through the pin attachment 77 start to rise thus increasing the flow section for the liquid fluid 53 passing under the ends 61 of the vertical baffle walls 58.

Therewith, each successive cylindrical vertical baffle wall 58 more remote from the inlet hole 52 moves a distance substantially shorter than the preceding baffle wall 58 thus providing a difference in section areas for the flow of the liquid fluid 53 to result in the effect described in detail with reference to the previous modification of the proposed apparatus.

The vertical baffle walls 58 are lifted by the sleeve 68 until an increase in the flow rate of the liquid fluid 53 through the apparatus results in a less through removal of gas bubbles 55 from the fluid, and the difference in the height to which the first and last vertical baffle walls 58 in succession from the inlet hole 52 ensures an equality of section areas for the flow of liquid fluid 53 under the ends 61 of the first and last vertical baffle walls 58 in succession from the inlet hole 52. At this stage the adjustment procedure is considered finished, and the nut 71 is locked by the lock nut 72. The height at which the sleeve 68 rests on the tube 67 with respect to the bottom 51 of the vessel 49 is marked by the scale 73 secured on the cover plate 56 and having the pointer 74 rigidly connected to the sleeve 68. When processing the liquid fluid 53 to which the apparatus was previously adjusted, the sleeve 67 is set to a definite height without preadjustment. During variations in the rate of flow of the liquid fluid 53 delivered to the apparatus the level of this fluid in the degassing zone 60 formed by the last vertical baffle wall 58 in succession from the inlet hole 52 and the side wall 50 of the vessel 49 is monitored by the pick-up 79 arranged in this zone 60 and electrically connected to the valve 80 provided in the tube 67. If the level of the liquid fluid 53 reduces below the end face 61 of the last vertical baffle wall 58 in succession from the inlet hole 52, the valve 80 stops the flow of liquid fluid 53 delivered through the tube 67.

Claims

1. An apparatus for removing gases from a stream of a liquid fluid comprising a vessel having an inlet hole for admitting the incoming liquid fluid, and an outlet hole for discharging the degassed liquid fluid, and provided with drain pipes for evacuating liberated gases from the apparatus, a plurality of vertical baffles secured in the vessel in succession one after another and spaced from a bottom of the vessel to allow the passage of the flow of liquid fluid along the bottom from the inlet hole to the outlet hole, each such vertical baffle in succession from the inlet hole being spaced from the bottom of the vessel at a distance which is less than that of the preceding baffle, arranged before each such vertical baffle except the last one in succession is at least one acoustic transducer affixed to the bottom of the vessel and serving to generate sound waves therein.

2. An apparatus as claimed in claim 1, in which each vertical baffle in succession from the inlet hole for admitting the liquid fluid is spaced from the bottom of the vessel at a distance which is smaller by a factor of 0.05 to 0.1 than the distance at which the preceding baffle is spaced from the bottom of the vessel.

3. An apparatus as claimed in claim 1, in which the baffles are provided with a means for controlling their movement in the vertical plane.

4. An apparatus as claimed in claim 1, in which the acoustic transducer provided before each vertical baffle is affixed to the bottom of the vessel through elements made of a sound-damping material, a portion of the bottom of the vessel before the last vertical baffle in succession from the inlet hole for admitting the liquid fluid being also made of a sound-damping material.

5. An apparatus as claimed in claim 1, in which the vertical baffles are of rectangular configuration and disposed inside the vessel of rectangular shape between its side walls in front of the inlet hole for admitting the liquid fluid transversely to the travel path of the liquid fluid, the acoustic transducer provided before each baffle being arranged so that a sound wave of the maximum intensity it generates is transmitted to the flow of liquid fluid passing through a section coinciding with the vertical axis of symmetry of the vertical baffle.

6. An apparatus as claimed in claims 3, 5, in which the means for controlling the movement of the vertical baffles in the vertical plane comprises a tube received by the inlet hole for admitting the incoming liquid fluid, a float, and a system of levers, one of which levers carries the vertical baffles and is rigidly connected to a cover plate of the vessel, whereas the other lever is pivotably connected to the tube and to the float, these levers being interconnected by a third lever.

7. An apparatus as claimed in claim 6, in which there is provided a set of microswitches secured on the lever carrying the vertical baffles and electrically connected to each acoustic transducer except one which is the first in succession from the inlet hole for admitting the liquid fluid through a switchboard unit providing their alternate energization.

8. An apparatus as claimed in claim 5, in which there are provided several intercommunicating vessels arranged in succession one after another with each successive vessel arranged above the preceding vessel at a height equal to:

where p,=density of the liquid fluid; p2=density of air; R=radius of the gas bubbles; =intensity of sound vibrations; a=absorption factor; S0 initial distance between the gas bubble and the surface of the acoustic transducer; vo=flow speed of the liquid fluid; 1= surface length of the acoustic transducer; 11=viscosity of the liquid fluid; Re=Reynolds number; C=velocity of sound in liquid fluid; and e=base of natural logarithm; 0.7=margin constant allowing for fluctuations in the parameters of the sound field and liquid fluid; and the vertical baffle which is the last in succession from the inlet hole for admitting the liquid fluid having an aperture of rectangular shape arranged at the level of the bottom of the successive vessel downstream of the flow of liquid fluid.

9. An apparatus as claimed in claim 8, in which provided between the adjacent vessels is a pick-up for monitoring the amount of gas bubbles in the liquid fluid electrically connected to the acoustic transducers of the vessel in succession after the pick-up through a switchboard unit ensuring alternate energization of the acoustic transducers in each vessel downstream of the flow of liquid fluid.

10. An apparatus as claimed in claim 1, in which inside a cylindrical vessel there is provided an additional vertical spirally-shaped baffle wall having a center aligned with the center of the inlet hole for admitting the liquid fluid to form a helical passage of invariable cross-section which has secured therein substantially transversely to the flow of liquid fluid a plurality of vertical rectangular baffles whereas arranged coaxially with the inlet hole for admitting the liquid fluid is an acoustic transducer generating a sound wave of the maximum intensity coinciding with the axis of symmetry of the inlet hole, an acoustic transducer provided before each vertical rectangular baffle being arranged so that a sound wave of the maximum intensity it generates is transmitted to the flow of liquid fluid passing through a section coinciding with the vertical axis of symmetry of the vertical rectangular baffle.

11. An apparatus as claimed in any of the preceding claims 5 or 10, in which an end of each vertical rectangular baffle facing the bottom of the vessel is shaped archwise transversely to the flow of the liquid fluid about a curve substantially conforming to the curve of intensity of sound waves induced in the liquid fluid by the acoustic transducer provided before each such baffle.

12. An apparatus as claimed in claim 1, in which the vertical baffles are cylindrical in shape arranged transversely to the flow of liquid fluid in a cylindrical vessel coaxially between themselves and relative to the inlet hole for admitting the liquid fluid, also arranged coaxially to the inlet hole is an acoustic transducer generating a sound wave of the maximum intensity coinciding with the axis of symmetry of this inlet hole, whereas further provided before each vertical baffle is an acoustic transducer arranged so that a sound wave of the maximum intensity it generates is transmitted to the flow of liquid fluid passing through a section coinciding with the vertical axis of symmetry of the vertical baffle.

13. An apparatus as claimed in any of the preceding claims 3 or 12, in which there is provided a means for controlling the movement of the vertical baffles in the vertical plane which includes a tube received by the inlet hole for admitting the liquid fluid, a sleeve secured on the tube so as to be capable of axial displacement, and levers carrying the vertical baffles freely secured thereon, these levers being pivotably attached to one end of the sleeve and movably connected to the cover plate of the vessel.

14. An apparatus as claimed in claims 1 to 13 and embodied substantially as described in the description and represented in the accompanying drawings.