RU2123619C1 - Steam-and-liquid jet device with pressure of liquid across outlet exceeding pressure of working steam - Google Patents

Abstract

FIELD: production of heated liquid with pressure exceeding pressure of working flow. SUBSTANCE: jet device includes body housing steam nozzle. Body is divided along pass of working medium into intake chamber, transition diffuser and mixing chamber. Area of minimum cross-section (f_n)_m of steam nozzle exceeds area of minimum cross-section (f_c)_m of mixing chamber. Relation of values of mentioned areas lies within limits 1.1 ≤(f_n)_m/(f_c)_m≤ 3.7. Two other versions of realization of jet device differ from the described one by relation of values of specified areas lying within limits 4 ≤(f_n)_m/(f_c)_m< 10 and 12 ≤(f_n)_m/(f_c)_m≤ 20. EFFECT: possibility of production of heated liquid flowing from outlet of jet device with pressure exceeding pressure of working flow. 3 cl, 1 dwg

Description

 The invention relates to inkjet technology and can be used to obtain a heated liquid with a pressure exceeding the pressure of the working stream at the outlet of the vapor-liquid jet device (PJSA).

Known PZhSA, containing a housing with a steam nozzle located inside it with an expanding output part (Laval nozzle), and the housing in the direction of the working medium is divided into a receiving chamber, a transition diffuser and a mixing chamber [1]. According to [1] when the ratio of the outlet diameter (d _c ) _{o of the} expanding part of the nozzle to the diameter (d _k ) _{m of} the mixing chamber is equal to (d _c ) _o / (d _k ) _m = 1.1 - 1.7, the maximum efficiency is ensured jet pump with a pressure at its outlet exceeding the pressure of the working stream.

Known PZhSA, containing a housing with a Laval nozzle placed inside it, and the housing in the direction of the working medium is divided into a receiving chamber, a transition diffuser and a mixing chamber [2]. According to [2], a similar result [1] is achieved when the ratio of the minimum cross-sectional area (f _c ) _{m of the} steam nozzle to the minimum cross-sectional area (f _c ) _{m of} the mixing chamber lies within (f _c ) _m / (f _k ) _m = 3.75 - 4.

Known PZhSA containing the housing with a tapering steam nozzle located inside it, and the housing in the direction of the working medium is divided into a receiving chamber, a transition diffuser and a mixing chamber [3]. According to [3], a similar result [1] and [2] is achieved with the relations: the annular cross-sectional area f _{s, ks} between the outer surface of the output end of the steam nozzle and the inner surface of the input end of the mixing chamber to the minimum cross-sectional area (f _to ) _{m of the} camera mixing within f _{s, ks} / (f _k ) _m = 3.25 - 3.75, the area of the minimum (in this case, output) cross section (f _c ) _{m of the} steam nozzle to the area of the minimum cross section (f _k ) _{m of the} chamber mixing within (f _c ) _m / (f _k ) _m = 10 - 12 and the outer circumference ( l _c ) _{n of the} outlet end of the nozzle to the circumference (l _kc ) _{m of the} minimum cross section of the mixing chamber in the range 3.75 - 4.25.

 The objective of the invention is to provide reliable conditions for obtaining fluid pressure at the exit of the PZhSA greater than the pressure of the working vapor.

This problem is solved due to the fact that in a vapor-liquid jet apparatus containing a housing with a steam nozzle located inside it, the housing being divided into a receiving chamber, a transition diffuser and a mixing chamber along the working medium, and the minimum cross-sectional area (f _c ) _m the steam nozzle exceeds the minimum cross-sectional area (f _k ) _{m of} the mixing chamber, according to the invention, the ratio of the values of these areas lies within 1.1 ≤ (f _c ) _m / (f _k ) _m ≤ 3.7; 4 ≤ (f _c ) _m / (f _k ) _m <10; 12 <(f _c ) _m / (f _c ) _m ≤ 20.

According to the results of theoretical and experimental studies of the authors of the present invention, the only condition for receiving the liquid pressure (p _{w) O} outlet PZHSA greater than the pressure of the motive steam (p _{n) Rin} is excess area (f _{c) m} minimum cross-section of the steam nozzles above the square (f _k ) _{m of the} minimum cross section of the mixing chamber, i.e. the implementation of the ejector, subject to the ratio (f _c ) _m / (f _to ) _m > 1.

To confirm this conclusion, the following is a table of calculated values of the maximum ejection coefficients (U) _m and pressure (P _in ) of the _output liquid (water) at the PZhSA outlet for various values of the ratio of diameters and cross sections at the characteristic points of the nozzle and mixing chamber of the ejector, as well as the product ( U) _m • (P _f ) _o , characterizing the efficiency of the ejector. Moreover, in the first series of calculations, at constant values of (d _s ) _m and (d _to ) _m, (d _s ) _out changed, that is, the authors' statement [1] was checked about the decisive influence of the ratio (d _s ) _out / (d _to ) _m on the pressure at the outlet of the ejector and its effectiveness. In the second series of calculations, (d _c ) _o remained unchanged, which implies the constancy of the ratio (d _c ) _o / (d _k ) _m , and the ratio (f _c ) _m / (f _k ) _m changed due to the variation of (f _c ) _m The following parameters of steam and water before PZhSA were adopted: pressure and temperature of the steam (p _p ) _in = 1.02 MPa, (t _p ) _in = 179 ^o C, pressure and temperature of the ejected water (P _w ) _in = 0.102 MPa, ( t _g ) _out = 20 ^o C. The diameter of the inlet section of the mixing chamber was taken equal to (d _k ) _in = 50 mm.

As can be seen from the table, the change (d _s ) _out (series 1) slightly affects the water pressure at the PZhSA outlet and its efficiency, while the change (d _c ) _m (series 2) affects these indicators to a large extent, and the water pressure at the PZhSA outlet, it is in this case that it can exceed the working vapor pressure. The table also shows that the only condition for such an excess is the ratio (f _c ) _m / (f _k ) _m > 1. The additional restrictions on this ratio introduced in [2] and [3] seem unreasonable in this regard. Based on this conclusion, the applicant claims the indicated ratio in the ranges not covered by the inventions [2] and [3] (any of them can be chosen as a prototype).

 The drawing schematically shows the proposed PZhSA in longitudinal section.

PZhSA contains a housing 1 with a steam nozzle 2 located inside it (in this case, a Laval nozzle) with diameters of a narrow section (d _s ) _m and an output section (d _s ) _out , and the housing 1 is divided into a receiving chamber 3 in the direction of the working medium transition diffuser 4 and mixing chamber 5, and the minimum cross-sectional area (f _c ) _{m of the} steam nozzle exceeds the minimum cross-sectional area (f _c ) _{m of} the mixing chamber, i.e. the ratio (f _s ) _m / (f _k ) _m > 1 is observed. The inlet section of the nozzle 2 inside the housing 1 is connected to the supply steam line 6, and the annular space between the housing 1 and the nozzle 2 is connected to the ejected liquid supply pipe 7.

 The operation of the PZhSA is as follows: the working steam is supplied through the steam line 6 to the nozzle 2, wherefrom, at a supersonic speed, through the transition diffuser 4, condensing in the mixture with the ejected liquid, it enters the mixing chamber, and the pressure at the outlet of the PZhSA under these conditions exceeds the pressure of the working steam at the entrance to the nozzle 2.

Sources of information
1. USSR author's certificate N 1281761, F 04 F 5/24, 1985.

 2. US Patent N 5029535, F 23 D 11/00, 1991.

 3. British patent N 898171, F 05 D, 1962.

Claims (3)

1. A vapor-liquid jet apparatus comprising a housing with a steam nozzle disposed inside it, the housing being divided into a receiving chamber, a transition diffuser and a mixing chamber along the working medium, and the minimum cross-sectional area (f _c ) _{m of the} steam nozzle is larger than the minimum cross-sectional area (f _k ) _m mixing chamber, characterized in that the ratio of the values of these areas lies within 1.1 ≤ (f _c ) _m / (f _k ) _m ≤ 3.7. 2. A vapor-liquid jet apparatus comprising a housing with a steam nozzle located inside it, the housing being divided into a receiving chamber, a transition diffuser and a mixing chamber along the working medium, and the minimum cross-sectional area (f _c ) _{m of the} steam nozzle exceeds the minimum cross-sectional area (d _to ) _m mixing chamber, characterized in that the ratio of the values of these areas lies within 4 ≤ (f _c ) _m / (f _to ) _m <10. 3. A vapor-liquid inkjet apparatus comprising a housing with a steam nozzle disposed inside it, the housing being divided into a receiving chamber, a transition diffuser and a mixing chamber as the fluid travels, and the minimum cross-sectional area (f _c ) _{m of the} steam nozzle exceeds the minimum cross-sectional area (f _k ) _m mixing chamber, characterized in that the ratio of the values of these areas lies within 12 <(f _c ) _m / (f _k ) _m ≤ 20.

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