Heat and mass transfer device of apparatus

Abstract

FIELD: heat and mass exchangers.SUBSTANCE: present invention relates to contact devices intended for carrying out heat and mass exchange processes in heterogeneous gas (steam) – liquid systems, and can be used in the chemical, food and related industries. A heat and mass transfer device of an apparatus is proposed, which includes a cylindrical body, a collector in the form of a central pipe with a central partition for feeding and removing a coolant into channels formed by vertically installed contact plates, which are combined in pairs into heat exchange modules, packed mass and heat exchange elements, placed in the space between the heat exchange modules. The central pipe-collector with a partition in the middle is made in the form of two adjacent coaxial vortex chambers. The lower vortex chamber has a tube for inlet of a coolant from outside the apparatus body, and the upper one has a tube for outlet of a coolant outside the apparatus body, and both tubes are cut in tangentially. The lower vortex chamber is provided with a blind bottom, and the upper one - with a blind cover. The heat exchange modules, formed by paired contact plates, form two thermal tiers: lower and upper; the modules of the lower tier evenly alternate with the modules of the upper tier around the circumference. The heat exchange modules in the middle part of the device overlap each other in height.EFFECT: simplifying the design and ensuring a more uniform and efficient thermal regime of the entire volume of the mass-exchange packing in the apparatus.1 cl, 5 dwg

Description

[0001] The invention relates to contact devices designed for mass-heat exchange processes in heterogeneous gas (vapor)-liquid systems. The device is used to ensure optimal thermal conditions in the mass-transfer packing of a column apparatus. The device is most effective in sorption and chemisorption processes, as well as rectification and desorption processes accompanied by thermal effects, when it is necessary to maintain the required temperature.

[0002] A “Mass exchange apparatus” is known [1], which contains a housing in which two or more heat and mass exchange blocks are vertically installed one after the other along its longitudinal axis, each block is formed from elements that are corrugated or flat spiral walls welded in pairs along the upper and lower ends, and the elements are welded together along the side ends and adjoin each other, forming internal spiral-shaped slotted channels for the passage of one medium in a radial-spiral direction and external spiral-shaped slotted channels for the passage of another medium in the direction along the axis of the apparatus.Each block has internal and external cavities isolated from each other. The internal cavity, for the passage of the coolant in a radial-spiral direction, is bounded by the cylindrical body of the apparatus, a cylindrical shell installed coaxially along the axis of the apparatus, and end annular baffles. It includes internal spiral-shaped slotted channels connected to the coolant inlet and outlet pipes. The external cavity, for the passage of mass-transfer media in a direction along the axis of the apparatus, is bounded by the cylindrical body of the apparatus and baffles installed horizontally between adjacent blocks along the height of the apparatus. It includes external spiral-shaped slotted channels connected to the upper and lower portions of the external cavity. A separator and drip separator are installed in the lower portion of the external cavity of each block for separating gas from liquid exiting the external spiral-shaped slotted channels.A distribution device is installed in the upper part of the outer cavity of each block to uniformly distribute the downward-flowing liquid over the surfaces of the spiral-shaped walls of the outer spiral-shaped slotted channels. Furthermore, the lower part of the outer cavity of each block is connected by a channel to the upper part of the outer cavity of the adjacent block installed above for the passage of gas into the upper part of the outer cavity of the adjacent block installed above. The lower part of the outer cavity of each block installed above is connected by pipes to the upper part of the outer cavity of the adjacent block installed below for the transfer of liquid to the distribution device installed below. The lower part of the outer cavity of each block is connected to a pipe for the discharge of a portion of the liquid (fraction) from the apparatus.

[0003] The disadvantages of this device are its significant complexity, problems with tightness during its long-term operation and high hydraulic resistance.

[0004] A "Heat and mass transfer device" is known [2], comprising a cylindrical body, collectors for the removal and supply of coolant into a channel formed by vertically installed contact pairs of plates, adjacent pairs of plates form gas-liquid channels, in each of which perforated corrugated heat-conducting elements are installed, characterized in that the collector is made in the form of a central pipe, the plates are combined in pairs into heat exchange modules and are installed with an eccentricity in relation to the radius so that one of the walls is tangent to the collector. The heat exchange modules have rounded upper and lower edges. The coolant is fed into the collector vertically from above or from below. The coolant is fed into the heat exchange modules and removed through pipes that are installed tangentially on the collector. The collector has a blind horizontal partition dividing it into two parts: supply and discharge.The central collector pipe of the unit can account for up to 20% of the heat exchange surface of the modules. However, the inlet and outlet sections of the collector contain stagnant zones, which increase with the height of the heat exchange modules. The height of each stagnant zone is approximately 1 / 2 of the heat exchange module's height. The coolant in the stagnant zone is practically motionless, which reduces the intensity of heat transfer to the wall, so these zones are practically not involved in heat exchange.

[0005] A "Heat and mass transfer device of the apparatus" is known [3], comprising a cylindrical body, a collector in the form of a central pipe with a central partition for the removal and supply of a coolant into channels formed by vertically installed contact pairs of plates, adjacent pairs of plates form gas-liquid channels, in each of which perforated corrugated heat-conducting elements are installed, wherein the plates are combined in pairs into heat-exchange modules having rounded upper and lower edges, and are installed with an eccentricity with respect to the radius so that one of the walls is tangent to the collector. The device is distinguished in that swirlers in the form of a spiral winding are installed in the central pipe, and feed inserts in the form of pipes having a gap with the central partition are installed in the upper and lower supply nozzles.

[0006] Using pipe inserts in the corresponding fittings located at the bottom and top of the unit allows for spatial separation of the coolant supply and discharge zones, eliminating stagnation. A spiral-wound swirler inside the central pipe creates a channel for coolant flow, increasing its velocity and creating turbulence.

[0007] The purpose of the device [3] is to ensure optimal thermal conditions in the mass-exchange packing of the column apparatus.

[0008] The device operates as follows. The gas phase is fed from above or below, distributing it in gas-liquid channels between the modules. The liquid phase is fed from above (or below), distributing it among the heat and mass transfer elements of the packing. The phases contact each other on their surfaces, where mass transfer occurs. A coolant is fed into the channels inside the modules. Thus, heat transfer occurs on the module surfaces (walls). The heat-conducting elements of the mass-transfer (corrugated) packing also participate in the heat transfer process.

[0009] According to the authors [3], the technical result of the invention is an increase in heat transfer intensity by up to 20%, as well as the overall efficiency of the device. The known device consists of four heat exchange modules connected in parallel.

[0010] This device was chosen as a prototype, as it is the closest in technical essence and the achieved result.

[0011] The known device[3] has the following disadvantages:

[0012] firstly, the increased complexity and metal consumption of the device, which is associated with the use of additional elements;

[0013] secondly, there is increased hydraulic resistance to the passage of the coolant, since inside the collector it moves along a narrow, long and complex trajectory;

[0014] Thirdly, the presence of problematic volumes in the collector pipe, both in the supply and discharge parts, from which the removal of the coolant when the device is stopped is difficult;

[0015] Fourth, there is a disruption in the temperature distribution within the layers of the mass-transfer packing, which ensures efficient mass transfer in the apparatus. The required temperature at the apparatus's periphery is achieved only near the heat-exchange modules. In the space between them, at the apparatus's periphery, the thermal effect is weak because the heat-exchange modules are too far apart. Here, heat supply and removal are insufficient. This reduces the efficiency of the mass-transfer process in the apparatus.

[0016] The proposed technical solution is aimed at eliminating the above mentioned shortcomings.

[0017] The problem that the proposed invention is aimed at solving is to increase the efficiency of a heat and mass transfer device.

[0018] The technical result consists in simplifying the design and ensuring a more uniform and efficient thermal regime of the entire volume of the mass-exchange packing in the apparatus.

[0019] The technical result is achieved in a heat and mass transfer device comprising a cylindrical housing, a collector in the form of a central pipe with a central baffle for supplying and discharging a coolant into channels formed by vertically installed contact plates, which are combined in pairs into heat exchange modules, closed at the ends and installed eccentrically with respect to the radius, so that one of the plates (the outer one) is tangent to the collector, and the other (the inner one) is parallel to it. Packed heat and mass transfer elements are located in the space between the heat exchange modules. The device is characterized in that the central pipe-collector with a baffle in the middle is designed as two adjacent coaxial vortex chambers, which are intended for the input and output of the coolant, wherein the lower vortex chamber has a tube for inlet of the coolant from outside the device body, and the upper one has a tube for output of the coolant outside the device body.Both tubes are inserted tangentially. The lower vortex chamber has a solid bottom, and the upper one has a solid cover. Heat exchange modules, formed by paired contact plates, form two thermal tiers: lower and upper. Moreover, the modules of the lower and upper tiers, when viewed from above, alternate evenly around the circumference, i.e., all modules are arranged at equal angles.

[0020] The coolant inlet into the heat exchange modules of the lower tier is made from the lower vortex chamber above the bottom of the lower vortex chamber, and the outlet is above the central partition.

[0021] The coolant inlet to the upper-tier heat exchange modules is located from the lower swirl chamber under the central partition, and the outlet is located under the upper swirl chamber cover. Thus, the heat exchange modules in the middle section of the unit overlap each other in height.

[0022] Using vortex chambers as coolant supply and discharge devices creates a rotating flow in the lower and upper chambers. This, along with the uniform coolant supply to the heat exchange modules, ensures good heat transfer to the collector wall in the lower and upper vortex chambers.

[0023] The arrangement of heat exchange modules in two tiers, alternating circumferentially, ensures a more uniform distribution of heat exchange modules across the apparatus' cross-section. This results in more efficient heat supply and removal to the mass-transfer packing elements and a more uniform temperature distribution throughout its volume, thereby improving conditions for the mass-transfer process.

[0024] The proposed device connects twice as many heat exchange modules in parallel as the prototype. With equal coolant flow rates, this and the coolant supply to the heat exchange modules using the lower and upper vortex chambers reduces hydraulic resistance and eliminates stagnant zones without the need for additional structural elements.

[0025] The heat and mass exchange device is shown schematically in the drawings:

[0026] Fig. 1 - general view;

[0027] Fig. 2 - top view;

[0028] Fig. 3 shows a section along B - B (without packing elements);

[0029] Fig. 4 shows a section along B - B (without packing elements);

[0030] Fig. 5 shows an isometric view of the device (without the grate and packing elements).

[0031] The following designations are used in the description and in the drawings: 1 - apparatus body, 2 - distribution manifold; 3 - partition; 4 - heat exchange module; 5 - outer plate of the module; 6 - inner plate of the module; 7 - mass and heat exchange packing; 8 lower vortex chamber; 9 - upper vortex chamber; 10, 11 - coolant inlet and outlet tubes; 12 - bottom of the lower vortex chamber; 13 - cover of the upper vortex chamber; 14 - lower tier heating modules; 15 - upper tier heating modules; 16 - coolant inlet into the lower tier module; 17 - coolant outlet from the lower tier module; 18 - coolant inlet into the upper tier module; 19 - coolant outlet from the upper tier module; 20 - support grate.

[0032] The heat and mass transfer device is installed in the cylindrical body 1 of the column apparatus. It includes: a collector 2 in the form of a central pipe with a central partition 3 for feeding and removing the coolant into channels formed by vertically installed contact plates, which are combined in pairs into heat exchange modules 4. Modules 4 are closed at the ends and are installed eccentrically with respect to the radius so that one of the plates (external) 5 is tangent to the collector 2, and the other (internal) 6 is parallel to the plate 5. Packed mass and heat transfer elements 7 are placed in the space between the heat exchange modules. The device is characterized in that the central collector pipe 2 with a partition 3 in the middle is made in the form of two adjacent coaxial vortex chambers 8 and 9, which are intended for the input and output of the coolant.The lower swirl chamber 8 has a tube 10 for introducing the coolant from outside the apparatus's casing 1, and the upper chamber 9 has a tube 11 for removing the coolant from the apparatus's casing 1. Both tubes 10 and 11 are inserted tangentially. The lower swirl chamber 8 is equipped with a blind bottom 12, and the upper chamber 9 has a blind cover 13. Heat exchange modules, formed by paired contact plates, form two thermal tiers: lower 14 and upper 15. The modules of the lower and upper tiers alternate evenly around the circumference, i.e., all modules are arranged at equal angles.

[0033] The coolant inlet 16 from the lower swirl chamber to the lower-tier heat exchange modules 14 is located above the bottom of the lower swirl chamber, and the outlet 17 is located above the central partition. The coolant inlet 18 from the lower swirl chamber 8 to the upper-tier heat exchange modules 15 is located under the central partition 3, and the outlet 19 is located under the cover 13 of the upper swirl chamber 9. Thus, the heat exchange modules in the middle part of the device overlap each other in height.

[0034] The heat and mass exchange device rests in the housing 1 on the grate 20. The mass and heat exchange packing 7 also lies on the grate 20.

[0035] If necessary, one or more of these heat and mass transfer devices can be installed in the column apparatus along the height.

[0036] The device operates as follows. The gas phase is fed from below, distributing in gas-liquid channels between modules 14 of the lower and upper tiers 15. The liquid phase is fed from above, distributing over the surface of the housing 1, collector 2, heat and mass transfer modules 4, and mass and heat transfer packed elements 7.

[0037] The phases contact at their surfaces, where mass transfer occurs. A coolant (H / N - water, cooling liquid, or steam) is fed into the channels inside modules 4. Its purpose is to ensure optimal thermal conditions in packing 7 on the mass transfer surface.

[0038] The device's nozzle 7 can operate in both film and flooded modes. The use of a vortex chamber manifold eliminates stagnant zones and intensifies heat transfer by rotating and increasing the coolant velocity.

[0039] In the drawings shown, the direction of coolant rotation in the lower swirl chamber 8 (see Figs. 2 and 5) is clockwise. This is facilitated by the insertion point of tube 10 and the tangential placement of the coolant inlets to the heat exchange modules of the lower 14 and upper 15 tiers. The direction of coolant rotation in the upper swirl chamber 9 (see Figs. 2 and 5) is counterclockwise. This is facilitated by the insertion point of tube 11 and the tangential placement of the outlets from the heat exchange modules of the lower 14 and upper 15 tiers.

[0040] The rotation mode in the lower and upper vortex chambers ensures high heat transfer from the coolant. The heat exchange modules of the lower 14th and upper 15th tiers are connected to the collector 2 in such a way that stagnant zones in the collector are eliminated. The lower 14th and upper 15th tiers are connected in parallel, which reduces the resistance of the device to the coolant flow.

[0041] When the device is stopped for repair, the coolant can be drained from the device through pipes 10 and 11.

[0042] For example, let's compare the effective heat exchange surface and coolant resistance for the prototype (option A) and the proposed solution (option B). For both, we'll assume the following: column body diameter D = 1 m; collector diameter d = 0.2 m; and packed bed height H = 1 m.

[0043] For option A: Number of heat exchange modules n = 4 pcs. Heat exchange modules are placed at 90°. Heat exchange surface of the collector -F к = 0.63 m 2 . Height of heat exchange module -H м = 1.0 m. Heat exchange surface of one heat exchange module -F м = 0.77 m 2 The total heat exchange surface for the prototype will be F А = 3.7 m 2 .

[0044] For option B: Number of heat exchange modules n = 8 pcs. Heat exchange modules are placed at 45°. Heat exchange surface of the collector -F к = 0.63 m2 The height of one heat exchange module is H м = 0.6 m. Heat exchange surface of one heat exchange module -F м = 0.47 m 2 The total heat exchange surface for the declared one will be F Б = 4.4 m 2 . RatioF Б / F А = 1.19, i.e., along with an increase in the uniformity of placement, the heat exchange surface of option B is somewhat larger.

[0045] The hydraulic resistance of the coolant depends on its trajectory, the size of the device, and the speed of the coolant in the channels. Calculations have shown that if, with equal coolant flow rates for option A, the resistance of the coolant P А take as 100%, then for option B the resistance P БThe efficiency will be 32–39%. This will ensure energy savings when supplying the coolant to the device. And due to the increased heat exchange surface and uniform heat supply (removal) throughout the packing volume, the overall mass transfer efficiency will be higher than that of the prototype.

[0046] The above information confirms the achievement of the technical result and the possibility of increasing the efficiency of the heat and mass transfer device.

[0047] List of references

[0048] 1. Russian Federation Patent 2647029 C1, cl. B01D 3 / 28, Mass exchange apparatus / Astanovsky D.L., Astanovsky L.Z., Astanovskaya O.V., Kustov P.V., Rosenstein V.A.; Applicant - Astanovsky D.L. - published 13.03.2018, Bulletin No. 8.

[0049] 2. Patent RF 2 806 946 C1, cl. B01D 3 / 28, Heat and mass transfer device / Bukharov D.M., Stepykin A.V., Sidyagin A.A.; Applicant - R.E. Alekseev NSTU. - published 08.11.2023, Bulletin No. 31.

[0050] 3. Patent RF 2 847848 C1, class. B01D 3 / 28, Heat-mass exchange device with vortex / Sidyagin AA, Bukharov DM, Stepykin AV, Tutanina EM, Goryunov NS; Applicant - NGTU them. R.E. Alekseeva. - published. 10 / 15 / 2025, Bull. No. 29 - Prototype.

Claims

A heat and mass exchange device of an apparatus, including a cylindrical body, a collector in the form of a central pipe with a central partition for feeding and removing a coolant into channels formed by vertically installed contact plates, which are combined in pairs into heat exchange modules, closed at the ends and installed with an eccentricity in relation to the radius so that one of the plates - the outer one - is tangent to the collector, and the other - the inner one - is parallel to it, packed mass and heat exchange elements, placed in the space between the heat exchange modules, characterized in that the central pipe-collector with a partition in the middle is made in the form of two adjacent coaxial vortex chambers, which are intended for the input and output of a coolant, wherein the lower vortex chamber has a tube for inlet of a coolant from outside the apparatus body, and the upper one - a tube for output of a coolant outside the apparatus body and both tubes are cut in tangentially;the lower swirl chamber is provided with a blind bottom, and the upper one - with a blind cover; heat exchange modules, formed by paired contact plates, form two thermal tiers: lower and upper; the modules of the lower tier alternate evenly around the circumference with the modules of the upper tier; the inlet of the coolant from the lower swirl chamber to the heat exchange modules of the lower tier is made above the bottom of the lower swirl chamber, and the outlet is above the central partition; the inlet of the coolant from the lower swirl chamber to the heat exchange modules of the upper tier is made under the central partition, and the outlet is under the cover of the upper swirl chamber, so that the heat exchange modules in the middle part of the device overlap each other in height.

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