SU1453285A1 - Apparatus for investigating phase transition of liquid drops in gas flows - Google Patents

Abstract

The invention relates to physical studies and can be used to study the parameters of liquid droplets in a gas stream, in particular to study the processes of phase transformations of droplets. The purpose of the invention is to increase the informativeness of research. The device contains a working section in the form of a diffuser, a system for stabilizing and decelerating the gas flow, and a profiled braking grid placed in the working section and equipped with a mechanism for moving it along the height of the working section. The grid is equipped with at least three radial slots located around the circumference, which makes it possible to divide the gas flow into several sectors, in each of which the test drops are placed. Moving the grid along the height of the working section allows one to achieve interaction of the drops with each other, which makes it possible to investigate their phase transitions directly in the gas stream. 1 hp f-ly, 1 ill. i (L

Description

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The invention relates to physical research and can be used to study the parameters of an apel liquid in a gas stream, in adherence to study the processes of phase transformations of droplets.

The purpose of the invention is to increase the research inormativ

In the drawing; The scheme of construction is presented.

The device includes a housing 1 with an erectly located channel 2, which is centered on the axis of channel 2 on the upper part of the channel 17 for extinguishing the flow of the supplied section of the conf de rest of the network of channel 2 interconnected to a stable flow of the thin wall package. 2 m channel upper end

The end of the housing is mounted on a cylinder with a gap

The nozzle 3 has an internal conical shape and forms a working section 4, which is a channel 2 diffuser. Concentric nozzle 3 on the upper 20 end of the body an external nozzle 5 is mounted with an inner diameter larger than the nozzle 3, resulting in an annular between the nozzles gap. 6, Nozzles 3 and 5 25 are made of a transparent material with a high purity of processing their surfaces. On the diametrically opposite sections of the walls of both nozzles, there are made narrow through slots 7, in which flat brackets B are placed, located radially relative to the axis of channel 2 and rigidly fixed in outer 9 and inner 10 movable bushes, which are placed on outer lateral the surfaces of the nozzles 3 and 5 covering the slots 7. The sleeve 9 through the stop sleeve 11 and the fluoroplastic nut 13 rests on the adjusting nut 13 Q screwed on the nozzles 5.

In the working section 4 perpendicular to the axis of the channel there is a profiled braking mesh 14, fixed at the ends of the brackets B. dd There is a gap 15 between the edge of the mesh 14 and the inner surface of the nozzle 3. The mesh 14 is provided with four radial slots around the circumference and width of which Q is equal to the maximum mesh size. The adjusting nut 13 provides the ability to move the grid 14 along the height of the working section 4. In this case, the movable sleeves .9 and 10 ensure the overlap of the slots 7 o

In front of the channel 2 diffuser, there is a braking wire mesh 16 "

Profiled 14 is made of steel with a thickness of 0.5 mm. and 18 are made. with a diameter of 0.2 m cells the size is connected to the device with the capabilities of the register flow and with drops of liquid

P device

at once "

It is carried out with a gas for alignment. When passing through the fusor 17, the grids 19 and the grids 16 d with laminar flow, it enters the gap, it acquires a rate to prevent flow to the wall

During the movement of 4 channels 2, the gas encounters the sparse grid 14 with a grid of 14 and the character of the distribution of the flow decreases. In zones to slots in the net, all the waste is increased at once. With the removal, the difference in magnitude decreases in standing, the value of metric cuts in the grid,

Set post regulation

The lower part of the channel 2 is equipped with a confusor 17 to quench the turbulence of the feed gas stream. In the minimum cross section of the confuser 17, a braking grid 18 is placed. In the middle part of the channel 2 between the grids 16 and 18, a gas flow distribution stabilizer is installed, made in the form of a package of thin-walled tubes that fill the entire space of the channel 2, 17 and the upper end of the stabilizer 9 through holes 20 communicate with

gap cavity

The profiled braking mesh 14 is made of 0.2 mm thick stainless steel sheet with a hole diameter of 0.5 mm. The braking grids 16 and 18 are made of braided wire with a diameter of 0.2 mm, with rectangular cells of mm size. Case 1 is connected to the gas supply system. The device may be equipped with means for registering parameters, gas flow and means of observing fluid droplets.

The device works as follows:

The device is purged with temperature equalization gas. When the gas flow of the confuser 17, the grid 18, the stabilizer 19 and the grid 16 passes, its movement becomes laminar, while part of the gas enters the gap 6, and the nozzles 3 acquire the gas temperature, which leads to the exclusion of heat transfer from the flow to the wall of the nozzle 3.

When moving along the working section 4 of channel 2, the gas stream encounters a shaped retard grid 14 on its way. When the grid 14 and annular gap 15 flow, the pattern of distribution of local flow velocities over its cross section changes. In the zones of the annular gap 15 and the slots in the grid 14, the local velocities increase, thus dividing the entire flow into several sectors. With the removal of the flow from the grid 14, the difference in the values of the local velocities decreases and at a certain distance, depending on the average value of the flow velocity and the geometric dimensions of the gap 5 and the slots in the grid, disappears.

Set a constant gas flow rate. By means of the adjusting nut 13, the grid 14 is transposed to a position in which the eshora of local flow velocities forms a paraboloid of rotation with protrusions-partitions in the areas of the slots. The necessary data (gas consumption, depending on the drop size, grid location) is obtained in the calibration process of the device „

Using a syringe, droplets are introduced into the flow paths, each placed in the corresponding sector. The grid 14 is then moved to a position in which the protrusions-partitions are removed. When this drops get the opportunity to interact with each other.

-The device makes it possible to study

in a gas flow, comprising a transparent housing with a vertical channel, the working section of which, located in the upper part of the channel, is in the form of a diffuser, a system for braking and stabilizing the flow, and a profiled braking grid located in the working section of the channel with an annular gap, characterized in that , in order to increase the informativeness of research, it is equipped with a mechanism for moving the profiled mesh along the height of the working section, and the mesh has at least three circumferential radial slots width equal to the maximum mesh size. 2. The device according to claim 1, about t l and

to give phase transformations of droplets as 2 o

The section of the diffuser is coaxially mounted with a hollow cylindrical nozzle of a transparent material, the inner diameter of which is greater than the outer diameter of the diffuser 25, with the gap between the walls of the diffuser and the nozzle in its lower part communicating with the channel.

Claims (1)

by changing the temperature of the gas stream, and by introducing into the stream drops of various sizes and in different thermal states. Invention Formula 1, Device for the study of phase transformations of liquid droplets I t f