Pumps – One fluid pumped by contact or entrainment with another – Jet
Reexamination Certificate
1999-12-17
2001-11-06
Tyler, Cheryl J. (Department: 3746)
Pumps
One fluid pumped by contact or entrainment with another
Jet
C417S198000
Reexamination Certificate
active
06312230
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention pertains to the field of jet technology, primarily to liquid-gas jet apparatuses for evacuation of gaseous mediums.
A liquid-gas jet apparatus is known, which has a nozzle, a receiving chamber and a cylindrical mixing chamber (see, Sokolov E. Y. & Zinger N. M., “Jet apparatuses” book, Moscow, “Energoatomizdat” Publishing house, 1989, page 213).
Such liquid-gas jet apparatuses allow evacuation of various gaseous mediums. However, the efficiency factor of these jet apparatuses is low, therefore the range of their application is limited.
The closest analogue of the jet apparatus described in the present invention is a liquid-gas jet apparatus, comprising a nozzle and a mixing chamber composed of an inlet convergent section and an outlet cylindrical section (see, Sokolov E. Y. & Zinger N. M., “Jet Apparatuses” book, Moscow, “Energoatomizdat” Publishing house, 1989, page 254).
The given jet apparatuses are widely used as air-ejecting devices of steam turbine units. One of the main advantages of the employment of liquid-gas apparatuses in condensers of modem modular steam turbines is the possibility starting the turbine unit without feeding steam from an outside source. But these apparatuses also have a relatively low efficiency factor.
SUMMARY OF THE INVENTION
The objective of the present invention is to increase the efficiency factor of the liquid-gas jet apparatus.
The objective is attained as follows: a liquid-gas jet apparatus, having a nozzle and a mixing chamber composed of a convergent inlet section and a cylindrical outlet section, has a ratio of the surface area of the minimal cross-section of the mixing chamber to the surface area of the inlet cross-section of the mixing chamber that ranges from 0.005 to 0.392. At the same time, the ruling line of a conical surface forming the convergent section of the mixing chamber or the tangents to each point of a curved surface forming the convergent section of the mixing chamber are inclined to the axis of said chamber at an angle of between 30′ and 10°.
The convergent section of the mixing chamber can be formed by a conical surface or it can be formed by a curved surface smoothly turning into a surface of the cylindrical outlet section of the mixing chamber. The jet apparatus can also be furnished with a guide confessor mouth installed at the entrance of the inlet section of the mixing chamber and with a diffuser installed at the outlet of the cylindrical section of the mixing chamber.
There is another variant embodiment of the apparatus wherein the liquid-gas jet apparatus comprises a nozzle and a mixing chamber converging in the flow direction. In this apparatus, the ratio of the surface area of the minimal cross-section of the convergent mixing chamber to the surface area of the inlet cross-section of this mixing chamber ranges from 0.005 to 0.392 and the inclination of the ruling line of a conical surface of the convergent mixing chamber or the angle is of inclination of the tangents to each point of a curved surface of the mixing chamber to the axis of the mixing chamber is from 30′ to 10°.
The convergent mixing chamber can be formed by a conical surface or by a curved surface. An outlet section of the mixing chamber formed by a curved surface can smoothly turn into a cylindrical surface.
Experimental research has shown, that the correlation of the dimensions of the mixing chamber exerts a significant influence on the performance of the liquid-gas jet apparatus. One series of experiments were carried out with the liquid-gas jet apparatuses whose mixing chambers have convergent inlet sections formed by a curved surface or by a conical surface. In addition to the convergent inlet sections the mixing chambers of the apparatuses tested under this first experimental program were always tested with the embodiment having cylindrical outlet sections. Another series of tests were carried out with the liquid-gas jet apparatuses having entirely convergent mixing chambers, i.e. mixing chambers without the cylindrical outlet section. Some of these apparatuses were furnished with a diffuser. In the latter case, the entirely convergent mixing chamber turned or transitioned directly into the diffuser in the zone of the minimal cross-section of the mixing chamber.
It was determined that, regardless of the embodiment of the liquid-gas jet apparatus, the correlation of the dimensions of the convergent inlet section of the mixing chamber (or the correlation of the dimensions of the entirely convergent mixing chamber) has a vital importance for the proper formation of a gas-liquid mixture in the mixing chamber, where generation of the mixed gas-liquid flow starts and comes to the end.
During the research it was also determined that energy losses during the mixing of an evacuated gaseous medium and an ejecting liquid medium are minimal when the ratio of the surface area of the minimal cross-section of the mixing chamber (in case the mixing chamber has a cylindrical outlet section the minimal cross-section of the mixing chamber is a cross-section of its cylindrical outlet section) to the surface area of the inlet cross-section of the mixing chamber ranges from 0.005 to 0.392 and when the angle of inclination of the ruling line of a conical surface forming the convergent section of the mixing chamber to the axis of the mixing chamber or the angle of inclination of the tangents to each point of a curved surface forming the convergent section of the mixing chamber to the axis of the mixing chamber is from 30′ to 10°.
It turned out that when the mixing chamber of the liquid-gas jet apparatus does not have the cylindrical outlet section, i.e. when the mixing chamber as a whole converges in the flow direction, the optimal correlation between the mixing chamber dimensions remains the same. In other words, the ratio of the surface area of the minimal cross-section of the mixing chamber to the surface area of the inlet cross-section of the mixing chamber must be from 0.005 to 0.392 and the angle of inclination of the ruling line of a conical surface forming the convergent mixing chamber to the axis of the mixing chamber or the angle of inclination of the tangents to each point of a curved surface forming the convergent mixing chamber to the axis of the mixing chamber must be from 30′ to 10°.
Nevertheless, an embodiment of the entirely convergent mixing chamber is also possible, wherein the end of the curve forming the mixing chamber surface smoothly turns or transitions into a cylindrical surface. This is expedient if some processes occur in the gas-liquid flow inside the mixing chamber in addition to the mixing process. Such processes are, for example, partial condensation of a gaseous component of the gas-liquid mixture in a motive liquid, being accompanied by conversion of the gas-liquid flow into a supersonic flow regime with subsequent deceleration of the flow in a pressure jump (the exact location of the jump can not be determined in the given case).
Thus, based on the assumption of the above mentioned correlation of dimensions and geometry, the described mixing chambers having a convergent inlet section and a cylindrical outlet section or the entirely convergent mixing chambers provide a resolution of the objective stated in the invention, i.e. liquid-gas jet apparatuses realized in accordance with the introduced conditions have an increased efficiency factor. It is necessary to note that the discovered optimal correlations of the dimensions are applicable for both single-nozzle and multi-nozzle liquid-gas jet apparatuses.
REFERENCES:
patent: 2582069 (1952-01-01), Rose
patent: 3625820 (1971-12-01), Gluntz et al.
patent: 4842777 (1989-06-01), Lamort
patent: 5087175 (1992-02-01), Raizman et al.
patent: 5628623 (1997-05-01), Skaggs
patent: 2016262 (1994-07-01), None
patent: 985462 (1982-12-01), None
patent: 1483106 (1989-05-01), None
Sokolov E.Y., Zinger N.M., “Jet apparatuses” book, 1989, USSR, Moscow, “Energoatomizdat” Publishing house, pp. 213, 254.
Oathout Mark A.
Petroukhine Evgueni D.
Tyler Cheryl J.
LandOfFree
Liquid-gas jet apparatus variants does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Liquid-gas jet apparatus variants, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Liquid-gas jet apparatus variants will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2605624