DE10048516B4 - Device for heat and mass exchanges - Google Patents

Abstract

Device (1) for heat and mass transfer processes, which take place between gaseous media, such as air, and liquid or bulk-like media in direct exchange,
which is based on a fluidization of the liquid or bulk-like media, consisting of a housing (2) with a liquid or bulk material-like medium (4) therein, which has a resting mirror (9), and one above the resting mirror (9) located Free space (11),
from pipelines (6/7/12/14/15) for feeding a gaseous medium into the housing (2),
the supply being effected above the resting mirror (9) and from at least one opening (5/33/18) in the housing (2) for discharging the treated gaseous medium, in which housing (2) the pipelines (6/7/12 / 14/15) have a plurality of outlet openings (8) for distributing the gaseous medium, the outlet openings (8) are arranged in a horizontally extending plane, and
In operation, the gaseous medium is blown from this plane into the liquid or bulk-like medium (4),
so that ...

Description

The The invention relates to a device for heat and mass exchanges and Method according to the preambles of claims 12, 15, 16 and 17.

As in DE 198 06 700 A1 described, it is known to drain a moist saturated air from the washing and to clean the air by cooling and condensation of water vapor. However, further measures are needed to achieve faster cooling of the moist air.

A condensate chamber ( 5 ) for cooling vapors is in DE 51687 A described. Here, measures are required to achieve a uniform distribution of Wrasens in the liquid and an early onset of volume production.

An arrangement for drying dishes by cooling air in direct contact with fresh water is in DE 40 37 367 A1 described. The escape of the air into the large space above the water slows down the speed of the arrangement shown and further measures are necessary to improve the heat and mass transfer operations in the arrangement shown.

A Further treatment of air takes place in the so-called air-washers. After the prospectus of the company Venta-Luftwäscher the air is moistened surfaces passed by. Whereby for a saturation the air through a wash or a warming the air further action required are.

A method for thermal treatment of a material layer is in CH 644 683 A described. Here, the bulk material-like material layer is fluidized under implementation of various heat and mass transfer processes. In the arrangement shown here, measures are required, for example, to treat a liquid material layer or to treat, for example, steam with heat transfers from the material layer to the gaseous medium.

Other typical facilities for the treatment of air currents are air heaters. For a heating of a flow rate of 140 l / min. in a heater Leister (Switzerland) recommends its Type 700 high pressure blower type ROBUST, around the flow losses in the air heater to overcome by a static pressure of 80 mbar. For the treatment of such amounts of air in household appliances further measures required are.

Out From the above process it can be seen that in the treatment of air streams further Improvements are necessary. Additionally, in processes that already good mass transfer processes enable, the big one Space requirement in the treatment of small amounts of air disadvantageous.

From the DE 40 23 060 A1 a process for the cooling of process gases is known, wherein the process gases are guided here by a central overflow shaft of a fluidized bed against a cooled product upwards. In this case, the cooling of the gaseous medium above the fluidized bed, which is formed by a bulk-like medium, realized with this product according to the exchange principle of direct current.

From the DE 197 38 033 A1 a device for receiving buoyant growth bodies in a ventilated chamber is known, wherein the ventilation device is designed as an injector for the release of oxygen. In this case, a liquid medium and floatable growth bodies are moved within a housing of the flow of waste water and a small amount of oxygen as a gaseous volume.

Out DE 34 39 600 C2 describes a process for the production of gas from carbonaceous solids, with a desulfurization of the gases by a mass transfer in a fluidized bed of sulfur-binding, cooled material. In this case, the gaseous medium is cooled with impurities in a fluidized bed of a bulk material according to the cross-flow principle and cleaned.

From the DE 695 12 942 T2 For example, a method of making silver-palladium powder by aerosol decomposition is known. Wherein the aerosol is dispersed in a carrier gas. In this case, the aerosol as a solid medium with a gaseous medium as a carrier gas through a heated reactor after the same current principle led.

at the above Method with a heat and mass transfer is given an apparatus construction, which is in height or in the area expands. For are the technical implementation of the exchange processes longer distances and a corresponding space required. This is the execution of the exchanges in the technical equipment associated with the problem that certain operations are not Completely expire and / or the implementation of the space not available is.

task The invention is therefore now the treatment of a gaseous medium in contact with liquid or bulk-like To enable media in the way that yourself the desired exchanges between the media in small units.

According to the invention This object is achieved by the device according to claim 1 and with the method the claims 12, 15, 16 and 17 solved. Further embodiments of the invention are in the claims 2-11 and 13-14 solved.

About fluid beds is known to the inventor that at Bulk goods like Common salt and a grain distribution similar to an evaporator salt, at a fluidized level of 10 cm between the air (for fluidization) and the bulk material above the Fluidized bed in the exhaust air given a temperature and mass transfer can be. Mass transfer means that the locally exiting exhaust air accordingly the local vapor pressure over the salt saturated with water vapor is.

It is further known that in such a fluidized bed good heat transfer between heating / cooling surfaces and the fluidized bulk material are feasible.

to solution of tasks of heat and mass transfer in the household and commercial sector are compared with industrial Processes for reasons of space small apparatus (facilities) can be used.

In Such fluid bed-like Apparatus can the above-known exchanges in products with small grain fractions and small flow velocities and be implemented according to small layer heights. there can the outflow speed be a multiple of the actual fluidization speed.

Example:

at an open area in the nozzles of a total of 2% of the floor area of the fluidized bed The exit speed is 50 times higher.

To For example, the gaseous medium used for fluidization, such as air, of above over a nozzle system in the fine bulk, distributed by area, be blown. By the distribution of the air and the rising Freeboard freeboard, the bulk material is fluidized and covered the outlet openings acting from above e.g. For the air.

Different ways of distributing air are associated with 1 to 5 described. It is also known that in a channel-like housing liquid media, such as water to be fluidized in the same manner as the bulk material similar media.

• – kein Verstopfen der Austrittsöffnungen,
• – kein Eindringen von Flüssigkeit in das Verteilrohr,
• – kurze Ansprechzeit zum Aufbau des Fließbettes,
• – geringer Energiebedarf für die Fluidisierung.

It is advantageous in this case to arrange the individual nozzles or outlet openings in the distributor of the gas so that they are arranged in the non-fluidized state outside the product bed. Advantage:

• - no clogging of the outlet openings,
• No penetration of liquid into the distributor tube,
• - short response time to build up the fluidized bed,
• - low energy requirement for fluidization.

there is the lateral extent of the fluidized bed by a channel-like casing and the height the layer is limited by the existing freeboard.

In this case, the gaseous medium before exiting the freeboard in a separator for Dust or one to be cleaned for dripping. In the same way is given with the device according to claim 1, the possibility of gaseous air over a saline solution, eg relatively aufzusättigen to 70% and at the same time to leave aerosols of this solution in the exiting gas.

The Invention will be explained in more detail with reference to the drawing. This shows:

1 Device for the treatment of gaseous media,

2 Device with a round channel cross section,

3 Device with a rectangular channel cross-section

4 Device for heating air and

5 Device for multi-stage treatments.

In 1 is a treatment facility 1 shown suitable for gaseous media. A canal-like housing 2 is on its bottom 3 open and stuck in a liquid or bulk-like medium 4 , This case 2 has an outlet opening in the flow direction 5 for gases.

About a pipeline 6 becomes the gaseous medium or air for treatment in the medium 4 fed, the purpose of this via a manifold 7 by means of outlet openings 8th on the medium 4 is blown.

These outlet openings are at the beginning of a gas production above the medium 4 , With the use of fluidization, for example, the medium of water, the resting mirror rises 9 to the level 10 the fluidized layer. From the level 10 the fluidized layer up to the height of the outlet nozzle 5 there is a free space 11 , In this free space 11 the flow may settle and droplets or solids are retained in the free space. Conversely, it is possible by increasing the volume of gas supplied, for example, to increase the droplet content in the treated exhaust air.

The gas outlet openings 8th are preferably directed downward to the contact time of the gas with the medium 4 extend and simultaneously positively influence the required layer height and the energy requirement for fluidization. The required pressure for the gas transport can be generated via a conveyor eg a fan.

• – Inhalation von Dampfanteilen aus einer (im Kochtopf) erwärmten Flüssigkeit;
• – Inhalation eines mit Tröpfchen angereicherten Gases über einer Salzlösung;
• – Befeuchtung von Raumluft durch eine Wäsche der Luft in einer Wasservorlage. Der Waschprozeß kann z.B. durch die Zugabe von Oxidationsmittels intensiviert werden.
• – Entstauben von kleinen Produktschüttungen.

In the 1 shown device can be used advantageously for the following needs:

• - inhalation of vapor content from a (heated in a saucepan) heated liquid;
• Inhalation of a droplet-enriched gas over a saline solution;
• - Humidification of room air by washing the air in a water mask. The washing process can be intensified, for example, by the addition of oxidizing agent.
• - Dusting of small product fillets.

Next is in 1 over an axis 12 another possibility of piping, suitable for gaseous media, shown. Such a conduit can be used advantageously, for example, for the condensation of vapors on the liquid present in dishwashers.

Now to the description of the device with a round case in 2 , In the case 2 are 2 represented different pipe guides for the distribution of the gas, the separation of which schematically over a central axis 13 he follows. In the left picture becomes a pipeline 14 to different distribution pipes 15 connected, through which the gaseous medium is to escape. In contrast, on the other, right side is a distribution over radial feed lines 16 shown.

3 shows an embodiment of the device in a rectangular housing 2 , With the pipeline 6 and the manifold 7 corresponds to the representation of a plan view of the representation in 1 , The treated gaseous medium flows in this case between the housing 2 and the manifold 7 up.

A further embodiment of the invention with a rectangular housing in the form of an air heater is in connection with 4 described. Here is a case 17 facing the front with one outlet opening 18 for gases and a bottom plate 19 shown. In the case 17 is a heating element 20 arranged, which has a connection 21 can be electrically heated. This heating element 20 may initially be partially covered with a fluidizable medium. The supply of air or other medium to be heated can be done via vertically aligned nozzles (rows) 24 and 25. Depending on the task and the desired state of the heated air, can be used as a fliudisable medium 23 a liquid (case A) or a dry good (case B) can be used.

Case A: fluidization of water

• – Erzeugung von Heißdampf zum Befeuchten und Aufheizen von kaltem Geschirr,
• – Anfeuchten von Pils- oder Weizenbiergläsern,
• – Zusätzlicher Betrieb als Durchlauferhitzer zur Erwärmung von Spülwasser,
• – Luftbefeuchter für erwärmte Luft z.B. bei Klimaanlagen in Fahrzeugen.

With the onset of air delivery, the liquid level across the heating element 20 to a level 26 be raised. According to the heating power and the resulting temperature in the liquid, the air is heated in the fluidizing layer and saturated with water vapor. The heat flow is from the heating element into the liquid fluidized bed and from there into the air; the mass transfer from the liquid fluidized bed by evaporation in the exhaust air. By increasing the speed, even droplets can get into the exhaust air. The following options are possible for the use of the device according to the case A:

• Generation of superheated steam for humidifying and heating cold dishes,
• - moistening Pils or wheat beer glasses,
• - additional operation as instantaneous water heater for heating rinse water,
• - Humidifier for heated air eg for air conditioning systems in vehicles.

Case B: Fluidization a dry good

• – Erzeugung von Trocknungsluft für das Geschirr.
• – Abkühlung der Heizelemente und gleichzeitige Kühlung des Geschirres nach der Trocknung.

In this case, a certain grain fraction of a limestone CaCO3, for example 0.1 to 0.3 mm, or other granules can be fluidized as bulk material. The fluidization of the bulk material around the heating element 20 causes an increase in the heat transfer coefficient to the bulk material and a better heat transfer to the air. In the fluidized layer height of 3 cm to 4 cm, an air flow can be heated from ambient to over 200 ° C as needed. At the same time a thermal insulation of the hot heating element with respect to the environment is achieved by the surrounding product layer. Such an air heater can be extended both in length and in width by the incorporation of further heating elements for the treatment of larger volume flows. For the use of the device after the case B, there are the following possibilities:

• - Production of drying air for the dishes.
• - Cooling of the heating elements and simultaneous cooling of the dishes after drying.

5 shows a device 22 in which in a 2-stage wash a gas stream in a fluidized layer 2 levels 27 and 28 can be treated. The function of this device 22 is described using a liquid as a fluidizable medium.

The way of the air leads in this case of an entrance 29 in a subsequent distributor. From there, a distribution takes place in the fluidized layer of the plane 27 , Via an outlet 30 the air comes to a fan 31 which can be connected via a pipeline in the open air. From this fan, the air of an inlet opening 32 a distributor to a fluidized layer in the plane 28 are fed and then flows through the freeboard about it in an outlet 33 the device 22 ,

The path of a liquid to be cooled leads via an infeed 34 to the upper level 28 , With the specification of overflow weirs 35 and underflow weirs 36 is shown that the levels 28 and 27 can be flowed through in a plug-like flow. About an overflow 37 The height of the static layer can be determined after an underflow weir. A gas outlet from this overflow is by installing a condensate pot 39 in the subsequent liquid line 38 prevented. From the lower level 27 The liquid can also have an overflow 40 with subsequent condensation pot 41 flow away. From there it can be a reservoir 42 be supplied for cooled liquid.

The device 22 can be used advantageously as a cooling tower. Due to the arrangement of the fan shown 31 will soundproof the levels 27 and 28 reached and the sound emission from the fan 31 the outside becomes in the levels 27 and 28 insulated.

The gas is in this case conducted in countercurrent to the downflowing liquid. It is still possible to get a gas first in the upper level 27 suck on and then on one of the upper level 27 suck in and then via a fan of the lower level 28 supply. This is then in relation realized on a downflowing liquid a direct current.

For the implementation of Gas-liquid reactions The above device has the advantage that a reaction process in the Test tube expires with a gas, in a scale-up to a larger semi-technical and commercial investment transferable is. This is e.g. in the oxidation of NOx in exhaust gases in a scrubbing liquid with H2O2 advantageous.

The Blowing a gas into a test tube can also be done this way be implemented in commercial facilities. Where the fluidized bed technology has the advantage that one from a semi-technical execution the Transfer operating data to a commercial facility.

Further, it is possible to heat the fluidized layer via a heating element, inductively or by heat radiation partially or as a whole. Example: Air heaters air flow 50 l / min initial temperature 20 ° C final temperature 200 ° C Heat and power 161 watts Floor space (10 × 2.5) cm Heater surface 34 cm ² with 2 pages (2.2 × 8) cm / side bulk quartz sand

1

treatment facility

2

casing

3

bottom

4

liquid or bulk-like medium

5

outlet opening

6

pipeline

7

distributor

8th

outlet openings

9

calm mirror

10

level the fluidized layer

11

Freeboard / space

12

vent line

13

central axis

14

pipeline

15

manifolds

16

supply lines

17

casing

18

outlet opening

19

baseplate

20

heating element

21

electrical Connection

22

contraption

23

fliudisierbares medium

24

nozzle rows

25

nozzle rows

26

level the liquid

27

level

28

level

29

entry

30

outlet opening

31

fan

32

inlet opening

33

outlet

34

feed for liquid

35

Overflow weir

36

Underflow weir

37

overflow

38

pipeline

39

steam trap

40

overflow

41

steam trap

42

reservoir

Claims (17)

Contraption ( 1 ) for heat and mass transfer processes, which take place between gaseous media, such as air, and liquid or bulk-like media in direct exchange, which is based on a fluidization of the liquid or bulk-like media, consisting of a housing ( 2 ) with a liquid or bulk-like medium ( 4 ) in it, which is a resting mirror ( 9 ), and one above the resting mirror ( 9 ) free space ( 11 ), of pipelines ( 6 / 7 / 12 / 14 / 15 ) for a supply of a gaseous medium in the housing ( 2 ), wherein the supply above the resting mirror ( 9 ) and at least one opening ( 5 / 33 / 18 ) in the housing ( 2 ) for discharging the treated gaseous medium, wherein in the housing ( 2 ) the pipelines ( 6 / 7 / 12 / 14 / 15 ) a plurality of outlet openings ( 8th ) for distributing the gaseous medium, the outlet openings ( 8th ) are arranged in a horizontally extending plane and in operation from this plane from the gaseous medium into the liquid or bulk medium ( 4 ) is blown, so that thereby above the resting mirror ( 9 ) a fluidized layer is formed and this fluidized layer of gaseous medium and liquid or bulk-like medium ( 4 ) around the outlet openings ( 8th ) is formed. Apparatus according to claim 1, characterized in that the gaseous media through downwardly directed outlet openings ( 8th ) are blown into the liquid or bulk-like media. Device according to claim 1, characterized in that the housing ( 2 ) is formed without bottom and in operation in a liquid ( 4 ) or into bulk material-like media. Device according to claim 1, characterized in that that heat transfer body in the liquid or bulk-like Medium for an exchange with the gaseous Medium are arranged. Device according to claim 1, characterized in that that by means of the heat transfer body, the layer chilled becomes. Apparatus according to claim 1, characterized in that by means of the heat transfer body ( 20 ) Heat is transferred into the fluidized layer. Device according to claim 1, characterized in that that a radiant heat source over the layer for warming of the gaseous Medium is arranged. Apparatus according to claim 1, characterized in that with an overflow (weir) ( 37 ) the amount of fluidized medium is regulated. Device according to claim 1, characterized in that that as a liquid Medium water is used. Device according to claim 1, characterized in that that as a bulk-like Medium product fractions of products treatable in fluidized beds be used. Device according to claim 1, characterized in that that as a bulk-like Medium granules find use. A method using the apparatus of claim 1 for generating inhalable moist vapors over a heated liquid, comprising: a gas delivery device and a channel-like housing ( 2 ) and at least one gas-carrying pipe management ( 6 / 7 ) for the supply and distribution of air, characterized in that - the channel-like housing ( 2 ) is immersed in the liquid, - the fluid is fluidized within the housing and - the humid air can be inhaled. Method according to claim 12, characterized in that that the droplet content in the air by the increase the subsidized Air quantity is increased. Process according to claim 12 and for wetting of glasses e.g. in a beverage outlet, by characterized in that the moist, heated air in the glasses before their filling is blown. Method using the device according to claim 1, for cooling a water vapor-containing air over a colder liquid, comprising: a gas delivery device and a channel-like housing ( 2 ) and at least one gas-carrying pipeline ( 6 / 7 ) for the supply and distribution of air over the liquid, characterized in that - the air is blown onto the liquid, - the liquid within the housing ( 2 ) is fluidized and - the exhaust air is discharged from the free space above the liquid. Method using the device according to claim 1, for generating hot air, comprising: a gas delivery device, a housing ( 17 ) for receiving a bulk material, an electric heating ( 20 ) for the bulk material and at least one gas-carrying pipe for the supply and distribution of air, characterized in that - the air is blown onto the bulk material, - the bulk material is fluidized and - the heat is transferred from the bulk material to the air. Method using a device according to Claim 1, for a multi-stage treatment of gases and liquids, consisting of: - one Gas conveyor and at least 2 levels for receiving a fluidizable fluid, - such as gas-bearing Piping for the supply and distribution of air over the liquids, characterized, that - the Gas conveyor in the flow direction is installed between both levels, - the liquid on one level the sucked gas is fluidized and - the liquid on another Level through that of the gas conveyor incoming gas is fluidized.