RU1806295C - Gas ejector - Google Patents

Abstract

The invention relates to inkjet technology and can be used for pumping various media. In a gas ejector containing an active nozzle, a mixing chamber with a diffuser, a coaxially mounted screw blade insert, the leading edges of the blades of which are made stepwise, the leading edges of the blades of a smaller diameter are located inside the active nozzle, and more damet. pa — outside the nozzle and intersect the nozzle exit edge, the inner edges of the blades are located on the axis of the ejector, the front and rear edges of the blades of a larger diameter are made of a variable radius increasing from the nozzle, each blade of a step of a larger diameter has at least two cuts directed from axis of the ejector to the wall of the mixing chamber. the minimum radius of each subsequent section is greater than the corresponding minimum radius of the previous section, the sections of the blades behind each of the sections are smoothly bent the direction of the spin along the line passing through the point of the beginning of the cut. The use of the invention in condensing units of steam turbines, as well as in other branches of technology, makes it possible to reduce energy costs for servicing them by increasing the KP / J of the ejector by intensifying the process of mixing active and passive media in the displacement chamber, and also reducing the size of the latter without significantly complicating the design . 4 s.p. f-ly, 5 ill. to with

Description

The invention relates to inkjet technology and can be used in pumping various media.

. The purpose of the invention is to increase efficiency and reduce size.

In FIG. T is a longitudinal section of the ejector; in FIG. 2 is a section AA in FIG. 1; in FIG. 3 - fragment; blade and nozzle; in FIG. 4 is a section AA in FIG. 1; in FIG. 5 -: section AA in FIG. 1,

In a gas ejector containing an active nozzle 1, a mixing chamber 2 with a diffuser 3, a coaxially mounted screw blade insert 4, front edges 5

the blades of which are made stepwise, while the leading edges of the 5 blades of smaller diameter b are located inside the active nozzle 1, and the larger diameter of 7 is VNV: nozzle 1 and intersect the outlet edge of the nozzle 1, the inner edges of the 8 blades are located on the axis of the ejector, the front 5 and rear 9 the edges of the blades of larger diameter 7 are made of variable radius increasing from the nozzle t, each blade of the step of larger diameter 7 has at least two cuts (Fig. 3), directed from the axis of the ejector to the wall of the mixing chamber 2, radii each th point

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the cut lines increase simultaneously with their removal from the exit section of the nozzle 1, the minimum radius of each subsequent section is greater than the corresponding minimum radius of the previous section (), the minimum radius of the first section located closer to the nozzle 1 is equal to or greater than the radius r of the nozzle 1 in its output section, sections of 10 blades b (Fig. 2) behind each of the cuts are smoothly bent in the direction of twist along the line passing through the point of the cut (Figs. 1,2,3).

Moreover, all points of each bend line 11 of the sections of the blades 6 behind each of the sections can be equidistant from the axis of the ejector (Fig. 1, 3); each point of the bend line, more distant from the point of the beginning of the cut a or a (Fig. 3), can be more distant from the axis of the ejector; the surfaces of the bent parts 10 of the blades 6 in the peripheral part can form cylindrical surfaces 12 (Fig. 4), coaxial to the mixing chamber 2; cylindrical sections 12 of the bent parts of the blades b can be closed between each other (Fig. 5).

Gas ejector works as follows.

At the exit from the nozzle 1, the peripheral layers of the active medium due to the acting centrifugal forces arising from the twisting of the specified medium in a screw blade insert 4 located partially in the nozzle 1, move along the concave surface of each blade 7 simultaneously along the axis of the ejector and in the direction from the axis the latter to the wall of the mixing chamber 2 (Fig. 3), while interacting outside the cylindrical surface described by the radius r of the outlet section of the nozzle 1 with a passive medium.

Due to the fact that the particles of the active medium outside the specified cylindrical surface of radius r move towards the diffuser along a curved path, the surface area of each blade of larger diameter 7 is reduced due to the front 5 and rear 9 edges of the blades of larger diameter 7 of variable radius increasing from nozzle 1. which leads to a decrease in resistance to movement of passive and active media. This eliminates the premature swirling of the passive medium, i.e. prior to the interaction with the active medium, the twisting of the active medium at the axis of the ejector at the outlet of insert 4 is also eliminated, which in this zone does not contribute to improving the quality of interaction of the two media, but creates additional resistance

the movement of the medium and the energy consumption for its twisting.

The execution of each blade step of a larger diameter of 7 with at least

two or more cuts (Fig. 1, 2, 3), directed from the axis of the ejector to the wall of the mixing chamber 2, allows these blades to be made in the shape of a fan (in the cross section of the insert) and thereby

0 using the action of centrifugal forces caused in the flow of the active medium when the latter swirls, without increasing the surface of the specified blade 7, to provide a more uniform distribution of the active medium in the volume enclosed between adjacent blades 7, due to the fact that the active medium as it moves in the insert to the diffuser is distributed over the cut parts of the specified blade 7, and

0 thereby ensure, not surface mixing of the active and passive media, but their volumetric mixing and, accordingly, significantly increase the efficiency of the ejector and reduce its size, and make 5 cuts so that the radius of each point of the cut line increases simultaneously with its removal from the exit section of the nozzle 1 , leads to an additional increase in efficiency due to a decrease in hydraulic

0 resistance to the movement of the medium. -Distances And and 2 (Fig. 3) from the output section of the nozzle 1 to points ai and aa, respectively, i.e. the start points of cuts are determined from the conditions for achieving maximum efficiency and depend

5 on the size of the exit section of the nozzle and the characteristics of the ejector.

Bending can be performed so that all points of each bending line of the sections of the blades behind, each of the cuts are equidistant from the axis of the ejector, or each point of the bending line that is farther from the point of start of the cut is farther from the axis of the ejector and are determined from Efficiency. Peripheral shape selection

5th part 12 of each blade 7, which may be cylindrical (Fig. 4), coaxial to the mixing chamber 2, or one in which the cylindrical sections 12 of the bent parts of the blades 7 are closed to each other

0 (Fig. 5) is determined by the conditions for providing maximum efficiency. The indicated forms of the peripheral part 12 of each blade improve the conditions for the interaction of the two media by imparting a flow directed from the insert 5 along the axis of the ejector.

The choice of the geometry of the screw blade insert and its size depends on the characteristics of the ejector in the nominal (design) mode of its operation and they are chosen as

so that the maximum possible ejector efficiency is achieved.

The use of the claimed invention in condensing units of steam turbines, as well as in other branches of technology, makes it possible to reduce energy costs for servicing them by increasing the efficiency of the ejector by intensifying the process of mixing active and passive media in the mixing chamber, and also reducing the size of the latter without significantly complicating the design .

Formula of the invention.

Claims (5)

1. A gas ejector containing an active nozzle, a mixing chamber with a diffuser, a coaxially mounted screw blade insert, the leading edges of the blades of which are made stepwise, while the leading edges of the blades of a smaller diameter are located inside the active nozzle and of a larger diameter outside the nozzle and intersect the nozzle exit edge, the inner edges of the blades are located on the axis of the ejector, characterized in that, in order to increase the efficiency and reduce the size, the front and rear edges of the larger blades are made variable The radius, uvelichivayuschegos from the nozzle, each vane stage of greater diameter has at least at least two sections, directed from the axis of the ejector to the wall of the mixing chamber, the radii of each point of the cut line increase simultaneously with their distance from the exit section of the nozzle, the minimum radius of each subsequent section is greater than the corresponding minimum radius of the previous section, the minimum radius of the first section located closer to the nozzle is equal to or greater than the radius of the nozzle in its output section, the sections of the blades behind each of the sections are smoothly bent in the direction of swirl along the line / passing through the start point of the cut. 2. The ejector according to claim 1, characterized in that all points of each bending line of the blade portions behind each of the cuts are equidistant from the axis of the ejector. 3. The ejector according to claim 1, characterized in that each point of the bend line is more distant from the cut start point, more distant from the axis of the ejector. 4. The ejector according to paragraphs. 1-3, characterized in that the surfaces of the bent parts of the blades in the peripheral part form cylindrical surfaces coaxial with the mixing chamber. 5. An ejector according to claims 1-4, characterized in that the cylindrical sections of the bent parts of the blades are closed to each other. Figure 2