RU1777950C - Regular distributing packing - Google Patents

Abstract

Scope: it is used in heat and mass transfer apparatus for sorption, distillation, distillation, and gas purification processes in the chemical, food, oil and gas processing industries. The essence of the invention lies in the fact that in the nozzle, consisting of identical, vertically mounted sheets, each sheet in the upper part has large corrugations, in the middle part there are rectangular holes with upwardly curved notches, and in the lower part there are elongated holes with serrated upper edges, and the width of the teeth is less than the width of the notches. The horizontal projections of the protrusions of the large corrugations of adjacent sheets have a gap of 1.0-1.5 mm. The edges of the nozzle sheets have cutouts deflecting the liquid toward the middle of the sheets. In the spaces between the horizontal rows of toothed openings there may be sections with a small corrugation 3-4 mm high. The surface of the nozzle is hydrophilized. 4 C.p. f-ls, 10 ill.

Description

The invention relates to the design of regular contact devices and can be used in apparatuses for controlling heat and mass transfer processes in a gas-liquid system, such as sorption, distillation, rectification, and gas purification, allowing heat and mass transfer to be intensified due to a more uniform distribution of liquid over the cross section of the apparatus and eliminating leakage, channeling and bypassing of liquids

The aim of the invention is to increase the uniformity of distribution and eliminate channelization and bypassing of the liquid in a wide range of irrigation densities by preventing the failure of the irrigation liquid, crushing large jets into smaller ones and spreading small jets while the liquid flows on both sides of the sheets. Figure 1 shows a fragment of the nozzle package, front view; figure 2 is the same side view; Fig. 3 is a diagram for capturing corrugations freely falling between sheets of large drops of liquid; Fig. 4 is the same for small drops; figure 5 - diagram of the crushing of large jets into smaller ones; Fig. 6 is a diagram of the spreading of small jets of liquid in a perforated area with serrated holes; Fig. 7 is a front view of a lower portion of a sheet with additional corrugations between horizontal rows of gear openings; in Fig. 8 is the same side view, in Fig. 9 is a diagram for improving the spreading of liquid X | XI X |

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sti on the corrugations of the corrugation: in Fig, 10 - the same, in the troughs.

The distribution regular nozzle consists of vertical sheets 1 of the same shape, having three sections in height: upper, middle and lower with structural elements different in purpose and design. The upper portion contains horizontally directed corrugations 2 and 3, protruding in different directions from the plane of the sheet to a height sufficient to trap freely falling jets and drops of liquid.

The middle section, intended for dividing large jets into smaller ones, contains rectangular openings 5 on three sides, along the upper edges of which grooves 4 and 6 are formed from these holes and openings are arranged in horizontal rows in pairs in a checkerboard pattern . The distance between the holes in the horizontal rows is equal to the width of the holes. In each horizontal row, the notches are bent to one side, in adjacent rows to the opposite. The incisions bent upwards must not deviate from the sheet plane by more than half the gap between the sheets.

The edges of the sheets are provided with cutouts 7.

The lower section contains horizontally stitched horizontal rows of rectangular openings 8 with serrated upper edges. The width of the teeth 9 of the holes 8 is equal to the width of the webs 10 between the teeth and the horizontal distance between the holes 8. The number of down-hanging teeth in the holes should be even. In this case, with the staggered arrangement of the holes, the tooth of the upper holes is located above the jumpers of the teeth of the lower holes and the most complete spreading of the liquid across the width of the sheets is ensured.

The surface of the sheets of the nozzle must be well wetted by the working fluid, for this it is subjected to special treatment, for example, it is hydrophilized, notched, rolled, covered with a layer of fine-grained, well-wettable material forming a network of microcapillary channels for spreading the liquid.

The nozzle is designed to increase the uniformity of the distribution of fluid after irrigation, as well as to equalize the disturbed uniformity of fluid flow along the height of the apparatus due to the hydrodynamic interaction of flows and design flaws of the working nozzle.

the uniform distribution of fluid, the nozzle is installed under the irrigation device, and to remove the transverse unevenness of the fluid flow, the distribution nozzle is installed periodically between the work packages every 2-5 m of the apparatus height.

The equalization of the uniformity of the fluid flow in each individual package on the charge takes place only in the direction of the sheets, i.e. along their width in both directions.

The upper section of each sheet is corrugated with horizontally directed corrugations. Below it is the middle

5, a section filled with rectangular notched holes with upright elements bent upwards on the upper side of the holes in different directions relative to the sheet plane, located

0 horizontal rows in pairs in a checkerboard pattern. The lower portion is perforated by horizontally elongated rectangular holes with serrated upper edges, the width of the teeth being

5 is equal to the distance between them and less than the width of the slotted elements located horizontally at a distance equal to the width of the teeth.

In order to reduce hydraulic resistance, horizontally directed corrugations of the upper corrugated section have a Z-shape, and horizontal projections of the corners of the corrugations of the corrugations of adjacent sheets have a gap of 1.0-1.5 mm. ,

5In order to prevent dripping

liquids at the edges of the sheets, the latter provided with cutouts or other structural elements deflecting the liquid to the middle of the sheets.

0 In order to improve the spreading of small jets on the surface, sheets, between the horizontal rows of holes with serrated edges, horizontal Z-shaped corrugations with a height of corrugations equal to

5 3-4 mm

In order to improve the distribution of liquid at the level of microflows, the surface of the nozzle is hydrophilized, has a small notch or knurling, or is coated

0 with a layer of finely cellular, well-wettable material, forming a network of microcapillary channels that facilitate fluid spreading.

Known features include individually applicable structural elements: corrugations, perforated elements, sharp holes, hydrophilizing surface treatment.

In order to equalize the uniformity of flows over the cross section of the apparatus, i.e. in two mutually perpendicular cross-sectional directions, it is necessary to use two nozzle packs, placing them one on the other cross on the cross.

The nozzle can operate under counterflow conditions in film-film fluid flow and emulsification conditions, under flow conditions with downward and upward fluid flow. With upward flow, the nozzle must be turned upside down.

When operating under counterflow or downward flow conditions, fluid is supplied to the nozzle from above from the corrugated portion and moves along the sheets. The corrugated portion serves to prevent a dip and completely trap free-falling jets and liquid droplets. To achieve this, there is no need to use a large number of corrugations: it is sufficient to use a Z-shaped section with two protruding vertices of the corrugations 2 and 3 alternately on one and the other sides relative to the plane of the sheet. Reducing the number of corrugations to two helps to reduce the hydraulic resistance and height of the nozzle.

The liquid dip, which is to be captured by the corrugated portion of the sheet, consists of large and small drops.

We consider large droplets having an average diameter greater than 1.0-1.5 mm. They have a sufficiently large inertia, expressed in the fact that when flying near the peaks of the protruding corrugations, they practically do not change the direction of their movement. To catch such drops, the gap between the horizontal projection of the corrugated vertices should not exceed the size of these drops, i.e. 1.0-1.5 mm. Span in a narrow gap equal to the size of the droplet, the droplet touches the surface of the corrugation and, due to the forces of surface adhesion, settles on the surface and is flattened into the film.

Small droplets having a diameter of less than 1 mm have a lower inertia and, spanning in the gap between the corrugated vertices, deviate together with the gas flow, change direction and inevitably fall on the surface of the nozzle sheets. To capture them, there is no need to reduce the gap between the corrugation peaks and, accordingly, increase the hydraulic resistance of the nozzle.

After the corrugated section, the liquid flows to the middle section, containing rectangular openings 5 and bent rectangular upward angles

slotted elements 4 and 6, used to break large jets of liquid into smaller ones. The scheme of crushing large fluid flows into smaller ones is shown in

figure 5.

The horizontal rows of the perforated elements 4 and 6 are arranged one above the other in pairs, and the pairs of the perforated elements are arranged in a checkerboard pattern. In each

In a pair of rows, the grooved elements located one above the other are rejected in different directions. In the next pair of rows, the grooves are located under the jumpers between the grooves of the neighboring pair. Such an arrangement

5 cuts ensures uniform crushing of large fluid flows on both sides of the sheet.

A large drop of liquid falling on a leaf is indicated by three directional

5 downward by the arrows in the upper left of Fig. 5, it moves at high speed and, having met on its way an upward notch 4 of the upper row, is divided into two streams flowing along the right and field sides of the notch. The encounter on the way of the hole of the second from the top row (the cut-outs of these holes are bent to the back of the sheet), the large flow practically does not deform (although some of the liquid flows to

0 the back of the sheet) and continues to flow downward at an angle down to meet the horizontally shifted notches of the second pair of horizontal rows. On these cuts, a subsequent division of the flows into smaller ones takes place.

Since the probability of liquid jets falling on both sides of the sheet is the same, it is therefore necessary to ensure the same conditions for their crushing on both

0 sheet surfaces. This requirement is fulfilled only when the distance between the perforated elements in horizontal rows is equal to the width of the perforated elements. Failure to do so5 impairs the uniform distribution of the liquid.

The process of dividing large jets, it is advisable to repeat 3-5 times depending on the degree of irregularity of the irrigation feed

0 and the distance between the feed points of large jets (i.e., the number of pairs of rows is 3-5). The crushing of large jets on the back of the sheet is carried out similarly. After a three-to-ten-fold division,

5, large jets turn into smaller ones, lose their kinetic energy, and for their further spreading it is already necessary to use other, smaller and softer structural elements affecting the flow.

Such elements are checkerboard-shaped elongated horizontal holes 8 with serrated upper edges. The spreading of liquid in the lower portion of the toothed hole sheet is shown in Fig. 6. Low-inert trickles of liquid falling on the gear holes flow around the jumper 10 teeth. They flow onto the right and left tooth from the bridge and form separate drops on these teeth x. When the droplets have reached a sufficient size, they come off the teeth, fly in free space to the lower edge of the hole and fall on its lower edges, while they are partially flattened and divided into two parts flowing down on both sides of the sheet (front and back). Since a jumper 10 is located in the underlying rows of holes under each tooth 9, vertically flowing liquid flows around the teeth jumpers and is divided into two parts on each row of holes. Multiple fission of small jets leads to a fairly uniform distribution of the liquid. The smaller width of the elements of the serrated holes compared to the width of the slotted elements of the middle sections of the sheet contributes to a finer distribution of the liquid on the surface of the nozzle.

The most uniform fluid division is achieved when the width of the teeth of the gear openings is equal to the width of the bridges between the teeth. In this case, a symmetrical spreading of the liquid in both directions is achieved without causing transverse and longitudinal unevenness.

The flow pattern of the elementary fluid flow in the lower portion of the pad is shown in Fig. 6, top right. The flow to the jumper of the tooth at the upper hole is divided into two parts, in the second from the top of the hole into three parts, in the third into four parts, and so on until a uniform distribution over the entire width of the sheet.

Attention should be paid to the fact that the described fluid movement on the gear holes occurs only in the case of small low-inertia fluid flows. Large fluid flows have a high kinetic energy and flow down the toothed holes vertically downward, practically without interacting with them, and are not divided into smaller flows. Therefore, the use of serrated holes for even distribution of liquid is effective only after preliminary crushing of large

jets into smaller ones with the help of upwardly expanded notching elements.

Taking into account that the lower section of the sheet with serrated holes gets already

pre-distributed liquid; it is advisable to take the number of rows of serrated holes within five to seven. A further increase in their number practically does not lead to an increase in the positive effect.

The number of rows of toothed holes, as well as the number of pairs of rows of bent slotted elements, should be determined based on the degree of unevenness of the feed

5 irrigation. The nozzle height depends on the number of rows of distribution elements

A uniform distribution of the entire liquid across the width of the sheets is achieved after

0 That, when the spreading flows of liquid repeatedly overlap each other.

Repeatedly dividing the liquid on the perforated elements and the tooth x of the holes can ultimately lead to the flow of part of the liquid to the edges of the sheets. To avoid this undesirable phenomenon, the edges of the sheets are provided with cutouts 7 or other structural elements deflecting fluid flows to the middle of the sheets. Such elements may include grooved elements bent at an angle downward, cutouts with a bend of the upper part, special redistribution bars, inserts and other elements. It is important that they do not lead to

excessive increase in hydraulic

resistance and design complexity.

At the bottom of the sheets for rejection

flowing on the edge of the liquid to the central

0 parts of the sheets used oblique slices 11, made in the upper edges of the toothed holes.

Further improvement in the distribution of small jets of liquid in the lower section

5 sheets with horizontal rows of toothed holes can be achieved by making Z-shaped horizontal corrugations 13 between horizontal rows of holes - see Fig. 7.8 - with corrugations 3-4

0 mm During the flow of liquid over the protrusions and troughs of the corrugated portion, an additional distribution of fluid in the transverse direction occurs. This phenomenon is caused by the influence of surface tension forces and the hydrodynamic interaction of gas and liquid flows. During the flow around the protrusion of the corrugation - see Fig. E - the liquid flow changes its direction of motion and slows down, which leads to its thickening. Under dynamic

the pressure of the gas stream and the wetting forces, the thickened part of the jets partially spreads in the transverse direction and behind the corrugation the stream flows down with a wider front.

Additional transverse spreading of the liquid also occurs in the internal channels 14 of the corrugations - see Fig. 10. The main influence in this case is exerted by capillary forces causing the liquid to spread inside the grooves, which can conditionally be considered as capillary channels. The liquid to spread inside the corrugation grooves increases the width of the streams. Thus, the corrugation of the bottom of the sheets contributes to an improvement in the distribution of the liquid.

Since the spreading of liquid in the corrugated areas is mainly caused by capillary forces, the size of the corrugations should not exceed the sphere of action of these forces, i.e. should be within the linear value of the capillary constant, the value of which for ordinary working fluids does not exceed 3-4 mm. Small height allows to improve the uniform distribution of the fluid without a significant increase in hydraulic resistance.

To improve the distribution of liquid at the level of microflows, the nozzle surface is hydrophilized, subjected to additional machining, for example, by knurling or notching, or a well-wettable auxiliary material is applied to it, for example, a layer of fine-grained silica sand, a layer of activated carbon, fabric, metal mesh, etc. This helps to wet the surface with a microfilm of a liquid, along which a larger flow of liquid flows well.

An important advantage of the nozzle is that, while providing good distribution ability, it simultaneously has high heat and mass transfer characteristics. With a low hydraulic resistance in this nozzle, efficient turbulization of the interacting flows is achieved, leading to the activation of the interphase transfer process. The nozzle contains practically no structural elements that would not be involved in creating conditions for close contact of gas and liquid flows.

The effectiveness of the use of the nozzle in each case depends on the degree of unevenness of the fluid flow that was in the apparatus prior to its use.

The nozzle is easy to manufacture and can be obtained by stamping or rolling flat sheets with subsequent bending of the perforated elements.

Claims (4)

SUMMARY OF THE INVENTION 1. Distribution Regular Nozzle Consisting of Equal Spaced Parallel Equal Spacing 0 vertical sheets with corrugations, perforations and perforations, characterized in that, in order to increase the uniformity of distribution and eliminate channel formation and bypassing the liquid in a wide range of irrigation densities while maintaining low hydraulic resistance by preventing the failure of the irrigation liquid, crushing large jets into smaller and smaller jets with the simultaneous flow of liquid on both sides of the sheets, the upper section of each sheet is corrugated with horizontally directed corrugations In the middle, the middle section has rectangular cut holes with upright elements bent upwards on the upper side of the holes in different directions relative to the sheet plane, arranged horizontally in pairs in a checkerboard pattern, and the lower section is perforated horizontally elongated angular holes with serrated upper edges, while the width of the teeth is equal to the distance between them and less 5 are the widths of the slotted elements located horizontally at a distance equal to their width. 2. Nozzle according to claim 1, characterized in that, in order to reduce hydraulic 0 resistances, horizontally directed corrugations of the upper section are Z-shaped. 3. A nozzle according to claims 1 and 2, characterized in that, in order to prevent liquid from flowing at the edges of the sheets, the latter are provided with cutouts. 4. The nozzle according to claims 1 to 3, characterized in that, in order to improve the spreading of small jets on the surface of the sheets, 0 is equipped with horizontal Z-shaped corrugations installed between horizontal rows of holes with serrated edges, 5, Nozzle according to claims 1-4. breaking 5 so that, in order to improve the distribution of liquid at the level of microflows, the surface of the nozzle is hydrophilized, or has a small notch or knurling, or covered with a layer of finely cellular, well wettable material. # "2 / g  W x x D v  %  m / rv v    ,   b) s, N N - vv N "about CC, "about "J-e FIG. 7 FIG. 9 .Jr Fig. U