DE102007017750B4 - Apparatus and method for filtering and humidifying air - Google Patents

Abstract

Method for filtering and humidifying air, comprising the method steps - coarse filtration of solid particles to 10 microns - atomizing and / or spraying a hydrogen peroxide (H2O2) -containing disinfecting solution in the air stream to be cleaned and humidified, wherein the hydrogen peroxide-containing disinfecting solution before and / or during atomization / spraying is heated by waste heat of the electronics of the device used, - mixing of air flow and spray of hydrogen peroxide solution - decomposition of hydrogen peroxide under free radical formation in the air-mist stream - catalytic conversion of unreacted hydrogen peroxide contained in the air stream until complete decomposition of the hydrogen peroxide ,

Description

The invention relates to a filter system for ad- and absorption of impurities in gases and gas mixtures, in particular from the air polluting particles, gases, toxins, viruses and bacteria.

A broadband filter system is from the DE 10 2004 027 354 A1 known.

This modular and multivalent broadband filtration system has both a purely mechanical separation effect and chemical and antimicrobial effects against nanodisperse air pollutants, while at the same time registering and regulating monitoring of the system's load level. In particular, superoxidation systems, fine filters with heating, ionization grid, catalysts, nonwoven webs of stabilizer fiber and carbon fiber and sensors for control are used.

Such filters, which are used for superoxidation disinfectant solutions based on hydrogen peroxide (H ₂ O ₂ ), have the disadvantage that hydrogen peroxide (H ₂ O ₂ ) is released into the air and the vapors strongly corrosive to the skin and mucous membranes, especially the eyes and the respiratory tract.

That from the WO 02/077537 A1 known air cleaning method provides to carry the cleaning liquid within the cleaning device in a circle. The cleaning liquid is introduced via a directed against the rising air flow injection nozzle in the air stream and collected at the bottom of the cleaning column. In the air inlet an inlet filter is installed, with which larger particles of the size 10 to 100 μm are filtered out of the air stream.

The cleaning liquid may be a hydrogen peroxide-containing solution. In addition, the cleaning solution may contain a catalyst which serves to increase and maintain the activity of the hydrogen peroxide-containing solution in the cleaning device.

In the exit area of the device, built-in filters such as, for example, an electrostatic precipitator, also in combination with a cooling device or dehumidifiers, ensure that detergent residues in the air condense out and are retained there. Thus, the discharged purified air from a technical point of view is almost, if not completely dry.

From the DE 10 2006 036 476 A1 a device for purifying air and a method for sterilizing the filter unit used in this case is known. In this case, a vaporous and / or liquid sterilizing agent is introduced into the filter unit and / or into at least one filter layer. Subsequently, the sterilizing agent is activated by means of a gaseous medium having a temperature above an activation temperature of the sterilizing agent, wherein the gaseous medium is heated by means of the heating device provided inside the filter unit. The sterilizing agent used is H ₂ O ₂ and / or the gaseous medium air.

The DE 694 22 095 T3 describes the disinfecting of surfaces with a phosphonic acid-containing hydrogen peroxide solution.

From the WO 2006/031957 A1 Further, there is known a flash-vapor-management system which provides a constant flow of vaporized hydrogen peroxide or other antimicrobial compounds for rapid sterilization of large enclosures such as rooms or buildings.

The method comprises pumping a carrier gas through a conduit into the space provided therefor and heating and dehumidifying the first carrier gas. A liquid antimicrobial compound is vaporized in an evaporator.

A heater block is maintained at the vaporization temperature of the antimicrobial compound. The liquid antimicrobial compound is fed downstream of the heating block into a regulated second carrier gas stream.

The antimicrobial compound is metered into an internal passage of the heating block to be vaporized there. The antimicrobial steam is then fed upstream of the dedicated room area into a mixing zone in the duct. The first carrier gas stream flows from the channel entrance upstream of the mixing zone into the line channel and then into the mixing zone to receive the antimicrobial compound and the second carrier stream to be transported from there through a channel exit into the space space provided without the first Carrier gas stream is passed through the evaporator.

Ultimately, should still on the US 8 007 717 B2 which describes a method and apparatus for decontaminating a region with a gaseous or vaporous decontaminant (vaporized hydrogen peroxide) without dehumidification. The saturation concentration of the decontamination agent within the Region is monitored and the concentration of decontaminant in the region is controlled to prevent condensation of the decontaminant. Germ number reduction is monitored continuously during a decontamination phase to achieve the successful completion of the decontamination process in accordance with the given germ count reduction.

Building on the possibilities of broadband filter systems, which have both purely mechanical separation effects and adsorption options for chemical and microbiological contaminants, it is an object of the invention to provide a filter system that can reliably ensure the supply of rooms with safe and clean air. At the same time the air should be moistened.

This object is achieved with the method claim 1 and the device claim 11, advantageous embodiments are the subject of the dependent claims.

• – Grobfiltration von Feststoffpartikeln bis 10 μm
• – Vernebeln und/oder Versprühen einer Wasserstoffperoxid(H₂O₂)-haltigen Desinfektionslösung in den zu reinigenden und zu befeuchtenden Luftstrom, wobei
• – die Desinfektionslösung vor dem und/oder beim Vernebeln/Versprühen durch Abwärme der Elektronik der eingesetzten Vorrichtung erwärmt wird,
• – Vermischen von Luftstrom und Sprühnebel der Wasserstoffperoxidlösung
• – Zerfall des H₂O₂ unter Radikalbildung im Luft-Nebel-Strom katalytische Umsetzung des im Luftstrom enthaltenen nicht abreagierten Wasserstoffperoxids bis zum vollständigen Zerfall des Wasserstoffperoxids.

The method according to the invention for filtering air, preferably room air, comprises the method steps

• - Coarse filtration of solid particles up to 10 microns
• - Nebulising and / or spraying a hydrogen peroxide (H ₂ O ₂ ) -containing disinfecting solution in the air stream to be cleaned and humidified, wherein
• The disinfecting solution is heated before and / or during atomization / spraying by waste heat from the electronics of the device used,
• - Mixing of air flow and spray of hydrogen peroxide solution
• - Decay of H ₂ O ₂ with formation of radical in the air-mist stream catalytic conversion of the unreacted hydrogen peroxide contained in the air stream until complete decomposition of the hydrogen peroxide.

These process steps are preferably realized in the following order: coarse filtration, atomization of a hydrogen peroxide (H ₂ O ₂ ) -containing disinfectant solution, mixing of air flow and aqueous H ₂ O ₂ mist and catalytic conversion.

The H ₂ O ₂ -containing disinfectant is an aqueous H ₂ O ₂ solution with up to 2-4 vol .-% H ₂ O ₂ , preferably 3 vol .-% H ₂ O ₂ , which preferably contains a fruit acid, wherein the Fruit acid is added as a stabilizer of the aqueous H ₂ O ₂ solution.

Further, procedurally, it is provided in an embodiment that the air flow and / or the humidity of the air-mist stream in the catalyst is adjustable and controllable, so that a sufficient liquid film for the Schadstoffadsorption on the acting as a catalyst carrier foam is present.

The humidity of the air-mist flow should preferably be adjustable by switching the fan on and off and / or by switching the nebulizer on and off.

Furthermore, it is advantageously provided that the components which are deposited on the housing inner wall or on the inner surfaces of the components through which an air-mist mixture flows are precipitated and run off from there, and fed to the nebulizer.

An apparatus for carrying out the method for air purification and humidification, which comprises in a flowing of the air to be purified housing at least one coarse filter for particles, a fan and a nebulizer or sprayer for a disinfecting solution which contains hydrogen peroxide (H ₂ O ₂ ) as an ingredient and nebulized or sprayed the air to be filtered is admixed, is improved to the effect that in the air flow to the nebulizer or sprayer an air-mist mixer is arranged downstream and arranged before exiting the housing at least one of the entire mixture through foam layer is, wherein the foam layer contains platinum or platinum metal or copper as a catalyst and the Durchströmdicke and / or structure of the foam layer is dimensioned so that H ₂ O _{2 has} completely disintegrated until it exits the housing.

In a preferred embodiment, the nebuliser used is an ultrasonic nebuliser with a piezoelectric generator in the gigahertz range, wherein the nebulizer has a nebulising basin. The nebulizer of the nebulizer is controlled controlled disinfectant solution from a arranged on or in the housing storage container.

It has proven to be advantageous if the disinfectant solution is slightly heated during misting. For this purpose, advantageously, the waste heat of the power transistor of the piezoelectric can be used.

For mixing the air stream and the atomized disinfectant solution, a funnel-shaped mixer is preferably used whose small funnel opening is located above the nebulizer basin and whose lateral surface has openings for the entry of flowing air into the funnel interior. The openings in the lateral surface of the funnel-shaped mixer are preferably formed as longitudinal slots. This shape of the mixer has the advantage in vertical construction that after the mixer precipitating or otherwise dripping water or water is brought together with disinfectant solution through the funnel, passed into the nebulising basin and here again atomized. A float in the mist basin prevents too much disinfectant solution from being delivered and overflowing.

Instead of a funnel-shaped body, a prismatic body inclined in the direction of the nebulising basin, preferably with a triangular or trapezoidal cross-section, can also be used with lateral slots and open at the top, or a combination of both forms.

Both in terms of the collection of dripping water and the good mixing of the air to be cleaned with the disinfecting solution is provided in an advantageous further embodiment that the funnel or the prismatic body is sealed in the flow direction to the openings with its outer periphery relative to the housing.

The open-pore or reticulated foam layer is a foam, preferably a plastic foam, in particular a polyurethane foam containing platinum or platinum metal or copper and / or coated with platinum, a platinum metal or copper as a catalyst, preferably by evaporation or dipping. The residence time and contact time of the air flowing through the foam air mist flow in the foam and with the catalyst surface is such that unreacted H ₂ O _{2 is} fully implemented until it leaves the housing. The porosity and the surface structure of the foam is preferably designed for optimum function such that the foam has optimum contact between the reaction products of H ₂ O ₂ and the pollutants of the air and the catalyst surface. Preferably, the foam is designed such that turbulent flow prevails in the foam. Of decisive influence on the formation of a turbulent flow is the roughness of the foam inner surface or the roughness of the catalyst surface, wherein the roughness of the surface for generating a turbulent flow is preferably high.

The foam layer may consist of several foam layers with one or more intermediate nonwovens with a fine-pored structure for capturing microbiological contaminants. Microbiological contaminants are in particular fungi, fungal spores or bacteria (killed or alive).

The web preferably has properties of a depth filter for retaining microbiological contaminants, especially for sterile filtration of air, and may also be downstream of the foam layers.

In addition to a disc or plate-shaped design of the foam layer or the foam layers is also provided that they are cup-shaped, wherein the air-mist stream enters the pot through the pot opening. Pot-shaped includes a conical or truncated pyramidal or hemispherical one.

A further advantageous embodiment provides that the foam layer contains at least one moisture sensor whose measurement result is usable for controlling the supply of disinfectant solution to the nebulizer and / or for controlling the nebulizer, in particular the piezoelectric agent, in order to always ensure a sufficient liquid film on the foam ,

The disinfecting liquid is provided in an advantageous embodiment in a bottle which is insertable into the housing and which has an opening at the top and bottom.

The above opening is closed with a gas diffusion cap, so that gas which escapes during transport due to decomposition can escape. At the same time, this cap is used to air in the removal of disinfecting liquid.

The removal takes place via the second opening, preferably arranged at the bottom, which is closed with a cap with a septum. The removal of the disinfecting liquid via a trocar in an inflow to the nebulizer.

The trocar is preferably coupled to a flap (closure) of the housing, such that after insertion of the bottle, the flap closes the insertion, in this movement, the trocar pierces the septum and thus the disinfectant solution can flow towards nebulizer.

Furthermore, it is advantageous if the pressure in the supply line to the nebulizer tank is measured and used as an output signal for a fill level indicator of the bottle. This has special significance insofar as a dry run of the nebulizer should be avoided (danger of destruction).

In a further advantageous embodiment it is provided that the nebulizer has a leakage protection, so that z. B. when the device falls over no exit of the disinfectant solution is possible.

An embodiment of the invention is shown in the drawing. Show it:

1 the device in vertical construction above,

2 the device in vertical construction below,

3 a sectional view and

4 Foam arrangements.

In the 1 and 2 is a device for air filtration with a partially open housing 1 shown. It is a vertical construction, so that the housing 1 supported on one foot. Below is the inlet for the airflow 2 , the first through the coarse filter 3 to be led. In the upper area is a flap 13 for the storage container 9 for the disinfecting solution, preferably a bottle with a gas diffusion cap and a cap with septum. It can also be seen that control switches for manual operation on top of the housing 1 are located.

3 shows a device for air filtering consisting of the air flow 2 the air to be cleaned flowed through the housing 1 in a sectional view.

With the entry of air into the housing 1 due to the suction effect of the housing 1 located blower 4 becomes the airflow 2 through the coarse filter 3 directed for particles. The coarse filter 3 filters particles up to 10 μm out of the air stream 2 and is preferably removable for cleaning purposes in the housing 1 arranged.

After the coarse filter 3 is located in the housing 1 a nebulizer or sprayer 5 for a disinfecting solution containing hydrogen peroxide (H ₂ O ₂ ) as an ingredient. A disinfectant solution with a concentration of up to 5% H ₂ O ₂ has proved suitable.

As nebulizer 5 For example, an ultrasonic nebuliser with a piezoelectric generator in the gigahertz range is preferably used. The nebulizer 5 or its piezoelectric agent should be controllable, for normal use cases the levels ON and OFF are sufficient, thus an interval-like operation takes place.

It is also envisaged that the nebulizer 5 controlled disinfectant solution from the on or in the housing 1 arranged storage container 9 can be supplied. Normally, a consumption of disinfectant solution of 50-100 ml / day is assumed. That's enough for air filtration. For humidification purposes, a higher water input would be necessary.

Since the liquid level in the nebulizer may vary as a result of supplied separated water, it is expedient that the liquid level in the nebulizer of the nebulizer 5 measurable, preferably with a level gauge, and the liquid level is adjustable. Preferably, the supply line 7 for nebulizer a means for closing the supply line 7 on.

Next, the nebulizer on a leakage protection, which prevents the fall of the disinfectant solution outlet. This can be a circumferential annular groove, which collects the liquid when falling over the device and returns it when erecting.

The waste heat from the electronics of the ultrasonic nebulizer can advantageously be used for process control if it is used to slightly heat the disinfectant solution, advantageously by 1-5 ° C.

The disinfectant solution is atomized or sprayed mixed with the air to be filtered for the purpose of their cleaning. This takes place in the air stream 2 the air to be cleaned the nebulizer or sprayer 5 downstream air-mist mixer 6 , As shown, a funnel-shaped mixer is preferred 6 used, the small funnel opening above the nebulizer 5 or the nebulizer basin and its lateral surface openings 10 to the entry of flowing air into the funnel interior. The openings 10 in the lateral surface of the funnel-shaped mixer 6 are formed in particular as a longitudinal slots in a columnar housing arrangement. Air can thus enter the funnel and run down water in the presence of an inner wall down and drip into the nebulizer.

By sealing the funnel in the flow direction to the openings 10 with its outer periphery opposite the housing 1 will ensure that all air through the air-mist mixer 6 is passed and above accumulating dripping water enters the funnel.

The foam layer 8th contains as catalyst platinum or platinum metal or copper and the residence time and contact time of the air flowing through the air mist stream in the foam and with the catalyst surface of the foam layer 8th is sized so that H ₂ O ₂ until it exits the housing 1 completely disintegrated. The foam layer 8th is preferably made of plastic, which is coated with platinum, a platinum metal or copper, preferably by evaporation or dipping. Proven has a porosity of the foam layer 8th in the range of 5-50 PPI, preferably 30 PPI.

Of course, the foam layer 8th be composed of several layers. In such a case, between the foam layers 8th a nonwoven fabric having a fine-pored structure for capturing microbiological contaminants. With only one foam layer 8th the fleece is simply rearranged to collect microbiological contaminants.

Since the residence time and contact time of the air flowing through the foam air mist flow in the foam and with the catalyst surface of the foam layer 8th should be such that H ₂ O ₂ until it leaves the housing 1 completely disintegrated, are also special forms for the foam layers 8th or the foam layer 8th intended. Some examples are in the 4 shown. In this case, such a variant provides that these are cup-shaped, wherein the air-mist stream enters the pot through the pot opening. It is further provided in special embodiments that the pot is formed cone or truncated pyramidal or hemispherical. Preferably, the pot is supported on the housing inner circumference.

Next it is shown that the foam layer 8th at least one humidity sensor 11 contains its measurement result for the control of the supply of disinfectant solution to nebulizer 5 is usable and / or for controlling the nebulizer, in particular the piezoelectric pathogen. This has already been referred to earlier.

LIST OF REFERENCE NUMBERS

1

casing

2

airflow

3

coarse filter

4

fan

5

nebulizers

6

Air mist mixer

7

supply line

8th

foam layer

9

storage container

10

Opening in the jacket of the mixer

11

humidity sensor

12

control switch

13

Flap for storage container

Claims (33)

Method for filtering and humidifying air, comprising the method steps - coarse filtration of solid particles to 10 microns - atomizing and / or spraying a hydrogen peroxide (H ₂ O ₂ ) -containing disinfecting solution in the air stream to be cleaned and humidified, wherein the hydrogen peroxide-containing disinfecting solution prior to and / or heated by atomization / spraying by waste heat of the electronics of the device used, - mixing of air flow and spray of the hydrogen peroxide solution - decomposition of hydrogen peroxide under free radical formation in the air-mist stream - catalytic conversion of unreacted hydrogen peroxide contained in the air flow to complete Decomposition of the hydrogen peroxide. A method according to claim 1, characterized in that the method steps mentioned in claim 1 in the order 1. coarse filtration of solid particles to 10 microns 2. atomizing and / or spraying a hydrogen peroxide (H ₂ O ₂ ) -containing disinfecting solution in the to be cleaned and humidifying air flow, wherein the hydrogen peroxide-containing disinfectant solution is heated before and / or during atomization / spraying by waste heat of the electronics of the device used 3. mixing of air flow and spray of the hydrogen peroxide-containing disinfecting solution 4. decomposition of the hydrogen peroxide with formation of free radicals in the air-mist stream. 5 catalytic conversion of the unreacted hydrogen peroxide contained in the air stream can be realized until complete decomposition of the hydrogen peroxide. A method according to claim 1 or 2, characterized in that the nebulization of the hydrogen peroxide-containing disinfectant solution is carried out with a Ultraschallvernebeler with a piezoelectric. Method according to one of claims 1 to 3, characterized in that the hydrogen peroxide-containing disinfecting solution is an aqueous hydrogen peroxide solution with up to 2-4 vol .-% hydrogen peroxide, preferably 3 vol .-% hydrogen peroxide, and this preferably contains a fruit acid, wherein the fruit acid is added as a stabilizer of the aqueous hydrogen peroxide solution. Method according to one of claims 1 to 4, characterized in that the hydrogen peroxide-containing disinfectant solution is heated by 1-5 ° C. A method according to claim 3, characterized in that the waste heat of the power transistor of the piezoelectric pathogen is used for heating the hydrogen peroxide-containing disinfecting solution. Method according to one of claims 1 to 6, characterized in that the air flow with the hydrogen peroxide-containing disinfectant solution is brought together and mixed in a funnel-shaped or prismatic mixer. A method according to claim 1 to 7, characterized in that the humidity of the air-mist stream in the region of the catalyst is measured and / or adjustable and regulated. Method according to one of claims 1 to 8, characterized in that the humidity of the air-mist stream is adjusted by switching on and off of a fan and / or by interval-like switching on and off of the nebulizer. Method according to one of claims 1 to 9, characterized in that the components which are deposited on a housing inner wall and / or on inner surfaces of the components through which the air-mist mixture flows are collected and conducted to the nebulizer. Device for filtering and humidifying air in a housing through which the air to be purified flows ( 1 ) at least one coarse filter ( 3 ) for particles, a blower ( 4 ) and a nebulizer or sprayer ( 5 ) for a disinfecting solution which comprises hydrogen peroxide (H ₂ O ₂ ) as constituent and is admixed with the air to be filtered or atomized or sprayed, characterized in that in the air stream ( 2 ) of the air to be cleaned the nebulizer or Versprüher ( 5 ) an air-mist mixer ( 6 ) and before exiting the housing ( 1 ) at least one foam layer through which the mixture flows ( 8th ), wherein the foam layer ( 8th ) Contains platinum or platinum metal or copper as catalyst and the residence time and contact time of the air flowing through the foam air mist flow in the foam and with the catalyst surface of the foam layer ( 8th ) is sized to hydrogen peroxide until it exits the housing ( 1 ) has completely disintegrated. Apparatus according to claim 11, characterized in that the coarse filter ( 3 ) Filters particles up to 10 μm and removes them in the housing ( 1 ) is arranged. Apparatus according to claim 11 or 12, characterized in that as nebulizer ( 5 ) an ultrasonic nebulizer with a piezoelectric generator in the gigahertz range is used working. Apparatus according to claim 13, characterized in that the piezoelectric actuator is controllable, preferably in the stages ON and OFF. Device according to one of claims 13 or 14, characterized in that the electronics of the piezoelectric pathogen is thermally coupled with a nebulizer basin. Device according to one of claims 11 to 15, characterized in that the nebulizer ( 5 ) controlled disinfectant solution from a on or in the housing ( 1 ) arranged storage container ( 9 ) is zuluhrbar. Apparatus according to claim 16, characterized in that the storage container ( 9 ) in the housing ( 1 ) and has an opening at the top and bottom, wherein the above opening is closed with a gas diffusion cap and the bottom is used for removal of disinfectant solution and is closed by a cap with septum. Apparatus according to claim 17, characterized in that for removing the disinfecting solution, a trocar with an inflow line ( 7 ) is connected to the nebulizer, which pierces a septum controlled by the closed position of a flap 13. Apparatus according to claim 18, characterized in that the inflow line ( 7 ) has a pressure gauge to Vernebelerbecken whose measurement result as an output signal for a level indicator of the storage container ( 9 ) is usable. Device according to one of claims 15 to 19, characterized in that a means for measuring and regulating the liquid level in the nebulization basin of the nebulizer ( 5 ) and preferably a means for closing the inflow line ( 7 ) is set up for misting basin. Device according to one of claims 15 to 20, characterized in that the nebulizing basin has a leakage protection, which prevents the exit of the disinfecting solution, preferably formed as an annular groove. Device according to one of claims 11 to 21, characterized in that for mixing the air flow ( 2 ) and the atomized disinfectant solution a funnel-shaped and / or prismatic trained mixer ( 6 ) whose small funnel opening is located above the nebulizer ( 5 ) or the nebulizer basin and the lateral surface of which is openings ( 10 ) for the entry of flowing air into the funnel interior. Apparatus according to claim 22, characterized in that the openings ( 10 ) in the lateral surface of the funnel-shaped or prismatic mixer ( 6 ) are formed as longitudinal slots. Apparatus according to claim 22 or 23, characterized in that the funnel or the prism open at the top in the flow direction of the Openings ( 10 ) with its outer periphery opposite the housing ( 1 ) is sealed. Device according to one of claims 11 to 24, characterized in that the foam layer ( 8th ) made of plastic, which is coated with platinum, a platinum metal or copper, preferably by evaporation or dipping. Device according to one of claims 11 to 25, characterized in that the foam layer ( 8th ) consists of several foam layers with at least one intermediate fleece with a fine-pored structure for collecting microbiological contaminants. Device according to one of claims 11 to 26, characterized in that the or the foam layers ( 8th ) is a non-woven with a fine-pored structure for collecting microbiological contaminants downstream. Device according to one of claims 26 or 27, characterized in that the nonwoven fabric is a deep-filtering non-woven, preferably a sterile-filter depth filter. Device according to one of claims 11 to 28, characterized in that the foam layer ( 8th ) or the foam layers are cup-shaped, wherein the air-mist stream enters the pot through the pot opening. Apparatus according to claim 29, characterized in that the pot is formed cone or truncated pyramidal or hemispherical. Apparatus according to claim 30, characterized in that the pot is supported on the housing inner circumference. Device according to one of claims 11 to 31, characterized in that the foam layer ( 8th ) at least one humidity sensor ( 11 ) whose measurement result for the control of the supply of disinfectant solution to the nebulizer ( 5 ) is usable and / or for controlling the nebulizer ( 5 ), in particular the piezoelectric pathogen. Device according to one of claims 11 to 32, characterized in that the porosity of the foam layer ( 8th ) is in the range of 5-50 PPI, preferably 30 PPI.

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