AT522492A1 - Method for cleaning or washing air using a spray chamber - Google Patents

Abstract

In a method for cleaning or washing air using a spray chamber through which the air to be cleaned is passed and in which a spray mist is generated by spraying scrubber water which is suitable for taking up impurities in the air to be cleaned, the scrubber water collected after spraying, subjected to a regeneration step in a regeneration circuit and fed back to the spray chamber for spraying, the regeneration step comprises adding ozone to a vortex chamber reactor.

Description

Contraption.

In the context of the present invention, the term “air” denotes a gaseous medium, in general air, which is used. withdrawn from closed rooms and returned again or supplied to these rooms from the environment, or air that is withdrawn and expelled into the environment as exhaust air. In connection with the present invention, the term “air” is not necessarily to be understood as breathing air, but can also be understood as chemically and biologically highly polluted process air that is purified with the method and the device according to the present invention in order to become breathing air qualify or at least have so little chemical and biological contamination that

it can be released into the atmosphere as exhaust air.

Methods and devices for air washing are already known in the prior art, with air washing being understood as the procedure that contaminated air, for example from air conditioning systems and exhaust air, is passed through a spray chamber in which water is sprayed and / or atomized, whereby it becomes a Humidification of the air and the precipitation of dust particles, soot particles and possibly bacteria and others

Pathogens. While the air wash to

Removal of dust particles and especially fine dust is highly suitable and delivers excellent results, it is rarely used for cleaning supply air. This is due to the fact that concerns about the hygiene of air washers arose from around the 1980s. In fact, the scrubber water is collected from the spray chamber and regenerated in order to be able to be fed back to the air washer, which without paying attention to the sanitation and disinfection of the regenerated water actually involves a considerable hygienic risk. The air washer, if it works perfectly hygienically, not only replaces the second filter stage, which is usually required, but also humidifies and cools at the same time and can thus be used with low energy consumption throughout the year. Today, complex water treatment with RO water technology and high-pressure nozzles is usually used, which is not only expensive, but also cannot ensure permanent hygienic conditions during operation. RO water is beyond that

very susceptible to contamination.

Various other approaches have therefore been pursued for cleaning and disinfecting the circular scrubbing water for air scrubbers, but these mostly involve a high expenditure of energy and / or a high chemical expenditure and thus associated with high maintenance costs

Plants are connected.

EP 25 157 B1 discloses a method for air washing in air conditioning systems in which the scrubber water is treated with ozone in the circulation circuit. Ozone is known to be a highly effective disinfectant and has been used according to the

EP 25 157 B1 from an ozone generator into a mixer chamber with

Harassment issued, whereby the scrubber water was mixed with a halogen in order to avoid inadmissibly high ozone pollution due to outgassing ozone in the air released from this system. While the method according to EP 25 157 B1 works quite satisfactorily for normally contaminated air flows, for highly contaminated air flows and in particular for air flows with germ contamination in sensitive areas, e.g. Hospitals, increased hygiene requirements placed on air conditioning systems, which cannot be met with the previously known methods for hygienizing air washers, without complex additional hygiene measures such as irradiation with UV-C light, microfiltration, chemical and / or high-frequency treatment

to use.

It is therefore the object of the present invention to improve an ozone treatment method for air washers according to the type mentioned in such a way that even the highest hygiene requirements are met without, however, the additional sanitation methods mentioned and which are expensive in terms of energy and associated with high maintenance costs

- apply measures.

To achieve this object, the method of the type mentioned at the outset is therefore characterized according to the invention in that the regeneration step comprises the addition of ozone to a vortex chamber reactor. The addition of ozone into a vortex chamber reactor ensures particularly good mixing of the ozone with the water through the central core vortex or the core column in such a reactor and thereby increases the disinfecting effect of the ozone. The strong friction of the molecules in the core column leads to the effects of

changed surface tension and viscosity and by the

If CO2 is added from the open air, the pH value rises to above pH 9 and the dissolved lime (carbonate hardness) changes into colloidal form. Because the ozone dissolves better, the formation of hydroxyl radicals is promoted before it outgasses from the water, so that on the one hand bacteria and other germs in the scrubber water are exposed to a higher ozone dose over a longer period and on the other hand, especially in the air scrubber higher doses of ozone can be achieved. This in turn has a positive effect on the disinfection performance in the scrubber water. Furthermore, other installations of an air conditioning system that work with the method according to the invention for air washing come into contact with the outgassing or outgassed ozone, so that parts of the air conditioning system that do not directly concern the air washer, i.e. pipelines for room air, blowers, humidifiers, heaters , Coolers and the like, disinfected and bacterial growth and other bacterial load effectively eliminated and prevented. Ozone also enters the room to be ventilated in the desired manner, where it can also develop its disinfecting effect. In the case of the cleaning of exhaust air, for example from industrial companies or agricultural operations, cheese factories, dairies and the like, as well as to remove odors from kitchen exhaust air, which can be highly polluted with organic toxins and / or odorous substances, and to replace biofilter systems if the ozone concentration is correspondingly high a highly efficient cleaning and odor removal can be achieved. At the same time, problematic substances such as odors and toxins as well as fats in the washing water are eliminated by the effect of the ozone. The ozone used in the process according to the invention is

preferably from oxygen using molecular sieves

5

generated, thereby providing an oxidizing environment which

is free of NOx.

The disinfecting and cleaning effect in the scrubber water is improved with the use of a vortex chamber reactor according to the invention, since this leads to a particularly favorable mixing of the water with the gas and thus to a change in the surface tension and the viscosity and, consequently, to an improved effect of the ozone in the water comes. This is presumably based on the shear forces occurring in the vortex chamber reactor, which have the effect that large parts of the introduced ozone are converted more quickly into OH radicals, thus preventing too rapid outgassing. In addition, the cavitations that may occur in the vortex chamber reactor achieve an additional cleaning and disinfecting effect with regard to microorganisms. The microbubble formation that occurs in the vortex chamber reactor and the resulting targeted mixing of the ozone with the fluid leads to a reduction in the surface tension and the viscosity of the fluid. The high pH value (e.g. pH> 9) creates additional washing quality. The physical change in the water leads to improved atomization of the water and, as a result, improved washing behavior compared to conventional water, this being achieved within the scope of the present invention without further chemical treatment of the water. By adding ozone according to the invention to a vortex chamber reactor, long-chain molecules such as hydrocarbons are broken down and subsequently broken down and bacteria such as legionella in particular are destroyed. This means a greatly improved cleaning and disinfecting effect compared to the prior art

Washer water, which is also applied to the connected

Plant parts extends. In particular, the addition of ozone according to the invention leads to degradation and

Prevention of the formation of new biofilms in the system.

In the context of the present invention, a swirl chamber reactor is generally understood to mean a device which is designed to generate turbulence in the supplied scrubber water in a controlled manner, the swirl chamber reactor preferably being set up to reduce the pressure in the scrubber water flowing through the swirl chamber reactor of about 6 bar overpressure to about 1 bar overpressure. In connection with the present invention, a vortex chamber reactor is also understood to mean a reactor which has at least one inlet opening and at least one outlet opening for the liquid or the scrubber water, the reactor being designed such that the entering liquid forms a column of liquid on the way to the outlet opening forms, in which the liquid rotates about the axis formed by the direction of movement of the liquid. The liquid moves forward in a helical or spiral shape. In contrast to a Venturi nozzle, which is usually used for introducing ozone, a swirl chamber reactor also has a rotating one

Movement provided.

The vortex chamber reactor can, for example, be formed by a chamber in which the liquid is introduced in the upper area and guided along a chamber wall, so that a wandering vortex is created with the tip pointing downwards. At the lower apex, where a local negative pressure in the range of 0.7-0.95 bar is created, this vortex is mixed with the ozone and then on the inside of one in the

opposite direction leading outlet pipe under

Water causes.

The swirl chamber reactor preferably comprises a Laval nozzle. This is preferably arranged in an outlet pipe of the vortex chamber reactor, in particular close to the inlet opening of the outlet pipe, and further improves the mixing of the water with the ozone. It is particularly preferred here if the ozone introduction is provided in the area of the narrowing of the Laval nozzle. In this area there is a negative pressure which improves the mixing. The flow rate through the nozzle is preferred

more than 10 m / s.

In a particularly preferred embodiment it is provided that the vortex chamber reactor has at least two fluid inlets and is preferably designed in a spiral or egg shape. The fluid inlets are arranged in particular in such a way that the inflowing fluid is guided tangentially on the reactor wall, so that a helical or spiral movement of the fluid is achieved on the reactor wall. This causes frictional forces within the reactor, through which connections within the fluid break open and

this results in better mixing with the ozone.

To set the pressure conditions in the swirl chamber reactor required for efficient swirling, provision is preferably made for a first controllable pump and preferably (but not necessarily) further one in the scrubbing water circuit upstream of the swirl chamber reactor

second controllable pump downstream of the

precisely adjust the amount of water supplied.

Various embodiments of vortex chamber reactors are known. According to a preferred embodiment of the present invention, however, a vortex chamber reactor of the type comprising a housing with a rotationally symmetrical, in longitudinal section, preferably essentially heart-shaped vortex chamber, further comprising at least one inflow that opens tangentially into the vortex chamber and an outlet pipe that plunges axially into the vortex chamber with a receiving end for the medium to be treated is used. This type of vortex chamber reactor is already used for wastewater treatment and can be modified to add the ozone to the scrubber water without much effort. With this design, the necessary negative pressure occurs at the entry point of a Laval nozzle of the vortex chamber reactor and leads to an optimal mixing of the ozone with the water. Vortex chamber reactors of this type can be regarded as operationally reliable with very little operating expenditure and are characterized by a compact design, which means that they can be integrated relatively easily into the water treatment when the method according to the invention is carried out

can.

According to a preferred embodiment of the present invention, ozone is added by means of an adding device at the receiving end of the drain pipe, i. on in

Direction of the eddy current considered the lower end of the

The method according to the invention can preferably be developed in such a way that the pH value, the conductance and / or the redox potential is measured upstream of the addition of ozone in the regeneration step and the addition of ozone is controlled as a function of this, which modern devices for measuring and controlling and regulating the Process according to the invention requires. The redox potential is preferably kept at values> 600 mV in order to meet the requirements of water sanitation

according to the drinking water ordinance.

The mentioned devices for measuring, controlling and regulating the method according to the invention can also be used to regulate the addition of ozone taking into account a concentration of ozone in the room air to be expected due to ozone degassing from the scrubber water after the regeneration step, as is the case preferred embodiment of the present invention. The expected concentration of ozone in the room air is dependent on the amount of ozone introduced, the vapor pressure of the ozone at a certain temperature in the system and other chemical and physical factors and can be estimated with the help of computer-aided control algorithms. The addition of ozone can subsequently be adjusted depending on this estimate

will.

According to a preferred embodiment, the procedure is alternatively or additionally such that the addition of ozone takes into account an ozone that is degassed from the scrubber water after the regeneration step

measured concentration of ozone in the room air

10

becomes. The method according to the present invention is thus also provided with measured values of the ozone content in the room air, so that the control and regulation of the addition of ozone can be adjusted accordingly. The regulation based on measured concentrations of ozone in the room air can be carried out on its own or can also be used to set and correct the aforementioned regulation of the addition of ozone on the basis of the expected concentrations of ozone in the room air. Here, a computational feedback of the two control and regulation approaches takes place, which leads to a sensitive control and regulation of the addition of ozone. Maximum levels of ozone in the room air required by law and in particular maximum levels of 50 ppb or lower, for example 30 ppb, can be reliably complied with in this way to avoid any risk to people

and exclude animal.

As mentioned at the beginning, the treatment of the supply air to be cleaned with air washers is also to be regarded as advantageous in that it results in a humidification of the room air. This naturally leads to a certain loss of scrubber water from the spray chamber or from the circuit for regeneration of the scrubber water. This shrinkage of the scrubber water can be regularly compensated for permanent operation, whereby, according to a preferred embodiment of the present invention, the procedure is that ozone is added to the make-up water supplied to the spray chamber or into the regeneration circuit to replenish the scrubber water. The scrubber water is therefore mixed with ozone from the start and thus meets the hygienic requirements of the

Overall process. Ozone is preferably added to the

Make-up water in that the make-up water is introduced directly into the vortex chamber reactor or upstream of the vortex chamber reactor into the regeneration circuit. Alternatively or additionally, microbiological entry protection can be implemented in that the make-up water is passed through a filtration device before entering the regeneration circuit, preferably through a membrane with an exclusion limit of at least 0.2 μm, preferably 0.1-0.2 μm, whereby due to their insensitivity to ozone in particular membranes

Ceramic or metal can be used.

In principle, any form of supplying the method according to the invention with sufficient amounts of ozone is conceivable when carrying out the method according to the invention. However, it is preferred that ozone to be added is obtained from the ambient air by using molecular sieves. The ozone is obtained in an ozone generator, which is connected to a filter system having an inlet opening for ambient air, so that ambient air purified by the filter system or essentially pure oxygen can be fed to the ozone generator to generate ozone. The filter system preferably comprises at least one CO2 filter and / or at least one N, filter. A molecular sieve is preferably used as the CO, filter. As a result, oxygen freed from other components can be fed to the ozone generator and essentially pure ozone can be generated by the ozone generator,

which is then introduced into the scrubber water. Taking essentially pure oxygen is under the

Invention a mixture with at least 90 vol .-% oxygen,

preferably understood at least 93 vol .-% oxygen.

0.05% by volume.

In the context of the invention, essentially pure ozone is a mixture with at least 90% by volume of ozone, preferably at least

93 vol% ozone understood.

The method according to the invention can preferably also be developed in such a way that ozone is additionally released directly into a room. This enables efficient disinfection of room air and surfaces in the room. It is necessary here that the air washer preferably maintains more than 60% relative humidity and that the room temperature is preferably kept above 25 ° C. The ozone then flows directly into the air conditioning system via an ozone line and the system is operated in recirculation mode. An algorithm uses the known quantities of ozone output and treated room volume to ensure the appropriate duration of disinfection. The ozone concentration in the room should and must be> 20ppm

stop for at least 90 minutes.

The device according to the invention for cleaning or washing air with at least one spray chamber for generating a spray mist from scrubber water for cleaning or washing the air to be cleaned, with means for sucking in air to be cleaned and means for discharging purified air into a room, the Spray chamber is connected to means for circulating and regenerating the washing water, is characterized according to the invention in that the means for regenerating the washing water comprise a swirl chamber reactor with an addition device for ozone. As

Adding device for ozone can within the scope of the present

13

Invention can be viewed as a connection for an ozone generator. The advantages of mixing in ozone, which have been explained in connection with the method according to the invention, are achieved with the device according to the invention. The device according to the invention is part of an air conditioning system, which is usually installed in a stationary manner in a building structure and is particularly suitable for cleaning and disinfecting the scrubber water of the air washer and the room air when the air conditioning system is used,

for example in hospitals.

The vortex chamber reactor is preferably of the type comprising a housing with a rotationally symmetrical, preferably in longitudinal section essentially heart-shaped vortex chamber, furthermore including at least one inflow that opens tangentially into the vortex chamber and a discharge pipe for the medium to be treated with a receiving end axially immersing into the vortex chamber. This type of vortex chamber reactor is already used for wastewater treatment and can be modified to add the ozone to the scrubber water without much effort. Vortex chamber reactors of this type can be regarded as operationally safe with very little operational expenditure and are characterized by a compact design,

making them relatively easy to integrate into air conditioning systems.

The adding device is preferably arranged at the receiving end of the drain pipe, i. at the lower end of the vortex chamber reactor viewed in the direction of the eddy current, which is structurally

easy to implement. According to a preferred embodiment of the present

Invention is the spray chamber a filling device for

Refilling of scrubber water assigned to the spray chamber

14th

wherein the filling device is preferably assigned a metering device for ozone. As mentioned at the outset, the treatment of room air to be cleaned with air washers is also to be regarded as advantageous in that the room air is humidified. This naturally leads to a certain loss of scrubber water from the spray chamber or from the circuit for regeneration of the scrubber water. This shrinkage of the scrubber water can be regularly compensated for permanent operation, whereby according to this preferred embodiment of the present invention the scrubber water is mixed with ozone from the beginning and thus the hygienic one

Meets the requirements of the overall process.

While it is desirable in the context of the present invention to have an appreciable ozone concentration in the supply air after the air washer, i. in the air that is subsequently pumped into the room, the handling of ozone must be closely monitored in order to reliably comply with the statutory maximum values. In order to ensure this, the invention is preferably developed in such a way that at least one sensor is provided for measuring the ozone concentration in the cleaned air, the measured values of which are fed to a control device which interacts with the ozone adding device in such a way that the amount of ozone added is selected to keep the ozone concentration in the purified air below a predetermined maximum value of

preferably to keep 50 ppb, especially 30 ppb.

According to a preferred embodiment of the present invention, the device is developed in such a way that at least one sensor is selected from the group consisting of a TVOC sensor, an ozone sensor and a particle sensor

is arranged in an exhaust duct. With the help of this

15th

Sensors can assess and control or monitor the quality of the air washing or cleaning and then control the device according to the invention, particularly with regard to the ozone concentration used

will.

The invention is explained in more detail below with reference to an exemplary embodiment shown schematically in the drawing. 1 shows a process circuit diagram of a ventilation installation in process air technology with an air washer, and FIG. 2 shows a process circuit diagram of an air conditioning installation in room air technology with an air washer, in which the method according to the invention is used for

Used.

In Fig. 1, a room is denoted by the reference numeral 1, from which air is drawn off and cleaned and, if necessary, returned to the room 1. For this purpose, air is sucked in through the motor flap 8 with motor M and the supply air line 2 'and passed through various units in a circuit 2 or treated with them. In particular, a pre-filter 3 and a heater 4 are provided in the supply air line 2 'and a fan 5 is provided in circuit 2. On the one hand, the air is guided in circuit 2 and, on the other hand, with the corresponding position of the motor flap 7 with the motor M and with the help of the fans 9 and possibly 5 from the circuit 2

blown out.

The cleaning or washing of the air that is guided in the circuit 2 takes place in the air washer 10, which is essentially formed by a spray chamber 11 with spray nozzles 12, from which

Scrubber water is sprayed to remove contaminants from the air

knock down. The scrubber water is at the bottom of the

is designated with 32 '.

A control device 23 is signal-connected to the various sensors and units (dashed lines) and to control the pump 14 of the regeneration circuit 13, the ozone generator 16 and its compressor 16 ', the motor flaps 7 and 8, the fans 5 and 9 and other devices such as the named valves and set up for reading out the sensors. In addition to an ozone sensor 17 and a TVOC sensor 19 (T-Ion / Volatile Organic CompoundSensor), a pH sensor 20, a conductivity sensor 21 and a redox sensor 22 are used as sensors. Several of the sensors mentioned can be arranged at different points in the circuit 2 and also in the area of the exhaust air line 30. With

FÜ are called frequency converters.

17th

The TVOC sensor 19 and the ozone sensor 17 are integrated into the control system in order to maintain the corresponding limit values in the exhaust air and to control the motorized flap 7 if the exhaust air quality is good. The ozone values for exhaust air are usually 10

ppm limited.

The measured values of the ozone sensor 17 are fed to the control device 23 and compared with a predetermined limit value. A regulating circuit of the control device 23 ensures that the amount of ozone supplied via the ozone generator 16 is set in such a way that the limit value is not exceeded if the ozone adsorber 31 is insufficient

Can adsorb ozone.

In Fig. 2, the same parts are provided with the same reference numerals and it can be seen that the air washer 10 is arranged in the area of the supply air line 2 'as an essential difference to the application of the present invention in process air technology in room air technology. Furthermore, ion emitters 6 are arranged in circuit 2 and in space 1. The ion emitters 6 do not form any nitrogen oxides since they are operated at voltages below 7.5 kV and can generate ion concentrations of more than 10,000 ions / cm *. In addition to the heater 4, a cooler 4 ’is also provided, the heater 4 and cooler 4’ together with a temperature sensor 33 and a humidity sensor 34 serving to control the system for a pleasant room climate. Reference numeral 17 denotes an ozone sensor and 19 a TVOC sensor (T-Ion / Volatile Organic Compound Sensor), the TVOC sensor 19 being intended to measure the odor nuisance in the air based on the determination of a reference substance. The air quality is further determined by means of a

Particle sensor 35 rated. According to the measured values of the

is delivered.

Claims (15)

Patent claims: 1. A method for cleaning or washing air using a spray chamber through which the air to be cleaned is passed and in which a spray mist is generated by spraying scrubber water which is suitable for taking up impurities in the air to be cleaned, the scrubber water collected after spraying, subjected to a regeneration step in a regeneration cycle and fed back to the spray chamber for spraying, characterized in that the regeneration step is the addition of ozone in one Swirl chamber reactor includes. 2. The method according to claim 1, characterized in that a vortex chamber reactor of the type comprising a housing with a rotationally symmetrical, in longitudinal section, preferably essentially heart-shaped vortex chamber, further comprising at least one inflow that opens tangentially into the vortex chamber and one with a receiving end axially immersing into the vortex chamber Drain pipe for that to be treated Medium is used. 3. The method according to claim 2, characterized in that the addition of ozone by means of an adding device on Receiving end of the drain pipe takes place. 4. The method according to claim 1, 2 or 3, characterized in that upstream of the addition of ozone in the regeneration step, the pH value, the conductance and / or the redox potential is measured and, depending on this, the addition of Ozone is controlled. 5. The method according to any one of claims 1 to 4, characterized in that the addition of ozone is to be expected taking into account an ozone which is to be expected due to the ozone being degassed from the scrubber water after the regeneration step Concentration of ozone in the room air is regulated. 6. The method according to any one of claims 1 to 5, characterized in that the addition of ozone is measured taking into account an ozone which is degassed from the scrubber water after the regeneration step Concentration of ozone in the room air is regulated. 7. The method according to any one of claims 1 to 6, characterized in that in the spray chamber or in the regeneration circuit to replenish the scrubber water supplied make-up water is added ozone. 8. The method according to any one of claims 1 to 7, characterized in that the ozone to be added from the ambient air is obtained by using molecular sieves. 9. The method according to any one of claims 1 to 8, characterized in that ozone additionally directly into a room is delivered. 10. Apparatus for cleaning or washing air with at least one spray chamber for generating a spray mist from scrubber water for cleaning or washing the air to be cleaned, with means for sucking in air to be cleaned and means for discharging purified air into a room, the Spray chamber is connected with means for circulating and regenerating the scrubber water, characterized in that the Means for regenerating the laundry water a Vortex chamber reactor with a device for adding ozone include. 11. The device according to claim 10, characterized in that the vortex chamber reactor is of the type comprising a housing with a rotationally symmetrical, preferably in longitudinal section essentially heart-shaped vortex chamber, further comprising at least one inflow that opens tangentially into the vortex chamber and one with a receiving end axially into the Vortex chamber immersing drain pipe for that too treating medium. 12. The device according to claim 10 or 11, characterized in that the adding device at the receiving end of the From £ flow pipe is arranged. 13. The device according to claim 10, 11 or 12, characterized in that the spray chamber is assigned a filling device for refilling scrubber water into the spray chamber, the filling device preferably being one Dosing device for ozone is assigned. 14. Device according to one of claims 10 to 13, characterized in that at least one sensor for measuring the ozone concentration in the purified air is provided, the measured values of which are fed to a control device which cooperates with the adding device for ozone that the amount of added Ozone is chosen to keep the ozone concentration in the purified air below a predetermined maximum value of preferably 50 ppb, in particular 30 to keep ppb. .. u. 0000 00 ... ° 22nd 15. Device according to one of claims 10 to 13, characterized in that at least one sensor is selected from the group consisting of a TVOC sensor, an ozone sensor and a particle sensor is arranged in an exhaust air line. Vienna, April 30, 2019 Applicants by: Haffne nd Keschmann PatentAnwäl GmbH lo