RU2623252C1 - Foam mass-transfer and heat exchange unit - Google Patents

Abstract

FIELD: heating system.

SUBSTANCE: foam mass-transfer and heat exchange unit is proposed, it comprises a body with gas inlet and outlet nozzles and a working fluid inlet; a group of lattices horizontally installed inside the body at its height, dividing the inner cavity of the body into sublattice and superlattice zones; a vertical closed partition installed inside the body coaxially with it, forming an annular channel between it and the cavity body for draining the working fluid. Lattices are fixed along the perimeter of the inner surface of the partition, and the upper end of the partition is located above the upper grid and serves as its overflow threshold; a gas supply pipe having a rectilinear portion extending vertically downward along the axis of the housing through all the lattices; a spray separator located in the superlattice zone, a discharge chamber of the working fluid with a branch pipe for the discharge of the spent working fluid. In the sublattice zone, a heat exchange surface is provided in the cavity formed by the lower lattice and the partition, with inlets and discharge tubes of the coolant located outside the body, and the lower end of the partition is located below the heat exchange surface; in addition, a temperature sensor is built into the drain chamber of the working fluid, and a coolant flow controller, controlled by signals from the temperature sensor.

EFFECT: treat gas heat energy utilisation control with a pure coolant directly in the foam unit.

2 cl, 1 dwg

Description

The invention relates to devices for mass transfer and heat transfer processes, including for the purification of air and industrial gases from solid, liquid and gaseous components, and can be used in chemical, petrochemical, metallurgical and other industries during technological processes and to solve environmental problems method of liquid washing gases.

Foam devices are widely used for gas purification, heat transfer and mass transfer.

Known foam gas scrubber according to patent RU 2316382 C1, IPC 6 B01D 47/02, 2006, comprising a housing, a tangential nozzle for supplying contaminated air and a vertical cylindrical contact-exhaust pipe mounted coaxially with the housing, the lower end of which is placed inside the housing and provided with a blade twist connected to the lower part of the housing, the twist made with at least three trapezoidal blades curved in a spiral of Archimedes, and a moisture separator is installed in the upper part of the contact-exhaust pipe a dish-shaped body above which a pipe is placed for the outlet of purified air; it is provided that, as the apparatus operates, the spent working fluid is removed and replaced with fresh working fluid; the level of the working fluid is maintained by means of a float regulator installed in the lower part of the apparatus.

The disadvantages of the known technical solutions are as follows:

- design complexity;

- the principle of operation of the apparatus is based on injection and imparting rotational movement of the working fluid by a flow of swirling processed air; therefore, in off-design modes (for example, when the flow rate of the processed air is reduced), the efficiency of the apparatus is significantly reduced;

- the apparatus does not provide for the possibility of mass transfer processes with the supply and / or removal of heat.

Also known is a device for cleaning dusty hot gases and heat recovery according to patent RU No. 2253504 C1, IPC 6 B01D 47/04, 2004, comprising a housing with a collection of working fluid and nozzles for supplying and discharging the treated gas and working fluid, a droplet eliminator and, at least two stages of gas cleaning, located one below the other, each of which includes a nozzle of elongated elements fixed in the housing, a distribution grid located under the nozzle and a supply device located under the distribution grid working fluid with openings oriented along the gas flow; the housing at the junction of two stages has external pockets for collecting heated working fluid, pockets of an upstream stage are connected to a device for supplying working fluid to a lower stage, and an additional device for supplying working fluid connected to a pressure pipeline is installed under the lower stage; heated working fluid is diverted for further use as a coolant from the pockets of the lower section, and fresh working fluid is supplied to the device for supplying the working fluid of the upper stage.

The disadvantages of the known technical solutions:

- design complexity;

- since the heated working fluid discharged from the apparatus is contaminated with various components extracted from the gas being treated, its further use as a heat carrier is significantly limited;

- the device does not provide for the possibility of carrying out mass transfer processes while maintaining the optimum process temperature during the generation or absorption of heat.

The closest analogue of the claimed invention, adopted as a prototype, is a gas purifier according to patent RU No. 2079344 C1, IPC 6 B01D 47/04, 1995, containing a housing with gas and liquid inlet and outlet nozzles, a group of gratings, horizontally installed inside the housing by its height with the separation of the internal cavity of the housing into the sublattice and sublattice zones, a vertical closed partition installed inside the housing coaxially with it with the formation of a fluid drain chamber, gratings between it and the body of the cavity and fixed along the perimeter of the inner surface of the partition, the upper end of the partition is located above the upper grate and serves as its overflow threshold, and the lower end of the partition is located below the lower grate, a gas supply pipe having a straight section extending vertically along the axis of the housing through all the gratings, a spray separator placed in over the lattice zone, and a chamber for draining the working fluid,

This unit has the following disadvantages:

- not provided for the utilization of heat taken by the working fluid during the cleaning of hot gases;

- it is not envisaged to maintain the temperature regime that is optimal for the separation of gases and harmful components, in particular, during exothermic and endothermic mass transfer processes;

- not provided for separate removal from the apparatus of the spent working fluid and the separated solid sediment (sludge).

The objective of the invention is the provision of heat recovery of the processed hot gases with a clean coolant directly in the foam apparatus.

The objective of the invention is also to provide the possibility of supply or removal of heat to the working fluid during the flow in the apparatus of respectively endothermic or exothermic mass transfer processes with the release of harmful components or substances intended for further use from the treated gases.

The objective of the invention is also to provide the possibility of maintaining in the apparatus an optimal temperature for the ongoing mass transfer processes.

The objective of the invention is also to provide the possibility of separate output from the apparatus of a solid sludge (sludge) and spent working fluid containing gaseous and liquid components extracted from the treated gases.

The tasks are solved in that in a foam mass transfer and heat exchange apparatus, comprising: a housing with gas inlet and outlet nozzles and a working fluid inlet nozzle; a group of gratings horizontally mounted inside the casing along its height with the division of the internal cavity of the casing into sublattice and sublattice zones; a vertical closed partition installed inside the casing coaxially with it with the formation of an annular channel for draining the working fluid between it and the casing, moreover, the gratings are fixed along the perimeter of the inner surface of the partition, and the upper end of the partition is located above the upper grate and serves as its overflow threshold; a gas supply pipe having a straight portion extending vertically down along the axis of the housing through all the grilles; spray separator located in the superlattice zone; attached to the bottom of the body and made mainly in the form of a tilted cone bottom with a pipe outlet of the spent working fluid, forming together with the bottom of the body the chamber for draining the working fluid; in the sublattice zone in the cavity formed by the lower lattice and the partition, a heat exchange surface is installed with coolant inlet and outlet pipes located outside the casing, and the lower end of the partition is located below the heat exchange surface.

In addition, in order to maintain the temperature optimum in the apparatus for mass flow processes occurring in it, a temperature sensor is built into the drain of the working fluid, and a flow rate regulator is installed on the supply line to the heat transfer surface, controlled by signals from the temperature sensor, which allows you to maintain the required fluid temperature.

In addition, if the apparatus is designed to purify gases from precipitated solid particles, it is additionally equipped with a nozzle with a discharge device for removing sludge located at the bottom of the chamber for discharging the working fluid, and the outlet pipe for the outlet of the spent working fluid is set above the maximum level of sludge accumulating in the bottom parts of the apparatus.

Below the invention is illustrated by a specific example of its implementation and the accompanying drawing, which shows the proposed foam apparatus, a longitudinal section.

Foam mass transfer and heat exchange apparatus contains:

- housing 1 with nozzles of the input 2 and output 3 of the gas and the nozzle of the input 4 of the working fluid;

- a group of lattices 5 horizontally mounted inside the housing 1 by its height with the separation of the internal cavity of the housing into the sublattice A and the sublattice B of the zone;

- a vertical closed partition 6 installed inside the housing 1 coaxially with it with the formation between it and the housing 1 of an annular channel 7 for draining the working fluid, and the lattice 5 is fixed along the perimeter of the inner surface of the partition 6, the upper end of the partition 6 is located above the upper lattice 5 and serves its overflow threshold;

- gas supply pipe 8 having a straight section extending vertically down along the axis of the housing 1 through all the grilles 5;

- a spray separator 9 located in the superlattice zone B above the fluid inlet section;

- attached to the lower part of the housing 1 and made mainly in the form of a tilted cone bottom 10 with a pipe 11 for the outlet of the spent working fluid, forming together with the lower part of the housing 1 the chamber B discharge of the working fluid;

- heat transfer surface 12 installed in the sublattice zone A in the cavity formed by the lower lattice 5 and the partition 6, with nozzles for the supply 13 and heat transfer 14 placed outside the housing 1, and the lower end of the partition 6 is located below the heat exchange surface 12.

If the apparatus is designed to clean gases from precipitated solid particles, it is additionally equipped with a nozzle 15 located at the bottom of the bottom 10 and an unloading device 16 for removing sludge, and the nozzle 11 for discharging the spent working fluid is installed above the maximum level of sludge accumulating in the lower part of the apparatus .

In order to maintain the temperature regime in the apparatus that is optimal for the mass transfer processes occurring in it, a temperature sensor 17 is built into the chamber for draining the working fluid, and a flow rate regulator 18 is installed on the supply line to the heat transfer surface 12, which is controlled by signals from the temperature sensor 17.

The device can be used during various processes, among which the following should be indicated:

- for cleaning and cooling hot (for example, flue) gases, which allows not only to remove harmful components from gases discharged into the environment, but also to utilize the heat of hot gases;

- for carrying out mass transfer processes in various industries and for separating vapors of low-boiling liquids (for example, gasoline and various solvents) from the air to ensure the optimum temperature regime of the process, for which, during endothermic reactions, a high-temperature coolant is supplied to the heat exchange surface, so that the working fluid is heated, and in exothermic reactions - low-temperature coolant, which allows you to cool the working fluid and to remove the heat released during the reaction;

- for the absorption of hydrogen by liquid petroleum feedstock during its hydrogenation treatment;

- for carrying out processes of humidification or dehumidification of gases, for example, in installations for the production of electricity from hydrocarbons in electrochemical generators with fuel cells.

Depending on the composition of the gases to be cleaned and the type of trapped components, water, oil, kerosene, nitric acid, etc. can be used as a working fluid.

As a heat carrier, it is preferable to use liquids (water; ethylene glycol and other liquids), as well as air and gaseous products of the main industries having a temperature that ensures the fulfillment of the task (supply or removal of heat to the ongoing process).

The device operates as follows.

Before starting work, the apparatus is filled with a working fluid at a level above the lower grill 6, and a heat carrier is supplied through the internal cavity of the heat exchange surface 12 through the pipe 13, which is then removed from the heat exchange surface 12 through the pipe 14.

The processed gases enter through the pipe 2 and pipe 8 into the sublattice cavity A, capture the working fluid and rises up through the grids 5 inside the partition 6, washing the heat exchange surface 12 and forming a highly turbulent gas-liquid mixture in the form of a mobile unstable foam, in which gases and other heat and mass transfer are purified processes. This ensures good phase contact between the working fluid and gases (as well as between the working fluid and solid particles, if present in the gases). On the upper grill 5, the foam flows through the threshold formed by the upper end of the septum 6, and enters the annular channel 7, where it collapses. The gas phase rises and enters the superlattice zone B, where, after passing through the spray separator 9, it is discharged from the apparatus through the nozzle 3, and the working fluid flows through the annular channel 7 into the liquid discharge chamber B. Continuous circulation of the working fluid is ensured thanks to the kinetic energy of the processed gas stream.

If gases having a high temperature are cleaned in the apparatus, then a coolant is supplied to the heat exchange surface 12, which, flowing through the heat exchange surface 12, is heated, taking away heat from the working fluid circulating in the apparatus, which ensures utilization of the heat of hot gases.

If mass transfer processes are realized in the apparatus, then, depending on the nature of the proceeding reaction — endothermic or exothermic — a high-temperature or a low-temperature coolant is supplied respectively to the heat-exchange surface 12. In this case, the controller 18, based on the signals from the temperature sensor 17, supports the flow rate of the coolant supplied to the heat exchange surface 12, which ensures the maintenance of the required temperature of the working fluid, and therefore, optimal for the temperature conditions in the apparatus.

In a similar way, humidification or dehumidification of the process gases is provided.

As necessary (for regeneration of the working fluid or for the allocation of captured useful components), the spent working fluid is removed from the apparatus through the pipe 11, and the required amount of fresh working fluid replacing it is supplied through the pipe 4.

If solid particles are precipitated from the gases being processed, which settle in the lower part of the chamber B to discharge the working fluid, then, as the sediment (sludge) accumulates, it is periodically removed from the apparatus through the pipe 15 using an unloading device 16.

The proposed foam apparatus has, in comparison with known technical solutions, including a prototype, the following advantages:

- provides the utilization of the heat of the processed hot gases without the use of additional heat exchangers;

- Utilization of the heat of hot gases and its transportation for further use is carried out by a clean coolant that does not come into contact with contaminated media;

- if mass transfer processes occur in the apparatus, accompanied by absorption or evolution of reaction heat, then, depending on the nature of the reaction, controlled by circulation of a high-temperature or low-temperature coolant through the heat-exchange surface, the optimum temperature regime is maintained;

- provides separate removal from the apparatus of the spent working fluid and solid sediments.

Claims (2)

1. Foam mass transfer and heat exchange apparatus, comprising a housing with gas inlet and outlet pipes and a working fluid inlet pipe; a group of gratings horizontally mounted inside the casing along its height with the division of the internal cavity of the casing into sublattice and sublattice zones; a vertical closed partition installed inside the housing coaxially with it with the formation of a cavity of an annular channel for draining the working fluid between it and the housing, the gratings being fixed along the perimeter of the inner surface of the septum, and the upper end of the septum located above the upper grating and serves as its overflow threshold; a gas supply pipe having a straight portion extending vertically down along the axis of the housing through all the grilles; a spray separator located in the superlattice zone, a chamber for draining the working fluid with a nozzle for withdrawing the spent working fluid, and in the sublattice zone in the cavity formed by the lower grill and the partition, a heat exchange surface with coolant inlet and outlet pipes located outside the housing, and the lower end of the partition it is located below the heat exchange surface, in addition, a temperature sensor is built into the draining chamber of the working fluid, and on the supply line of the coolant to the heat exchange surface getting coolant flow regulator controlled by signals from the temperature sensor. 2. The apparatus according to claim 1, characterized in that a nozzle with an unloading device for removing sludge is additionally placed in the lower part of the bottom, and a nozzle for discharging the spent working fluid is installed above the maximum level of sludge accumulating in the lower part of the apparatus.

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