WO2009109354A1

WO2009109354A1 - Method, mixing system, and device for generating a disinfectant foam

Info

Publication number: WO2009109354A1
Application number: PCT/EP2009/001486
Authority: WO
Inventors: Wolfgang Holzwarth; Walter Klein
Original assignee: Alfred Kärcher Gmbh & Co. Kg
Priority date: 2008-03-06
Filing date: 2009-03-03
Publication date: 2009-09-11
Also published as: DE102008014281A1; DE102008014281B4

Abstract

The invention relates to a method for generating a disinfectant foam, wherein a foaming additive and a disinfectant additive are each suctioned via a suction line (31, 34) out of a supply container (32, 35) using an injector (21), which is disposed in a pressure line, and supplied in a specific mixing ratio of said additives to a cleaning liquid, which flows in said pressure line, wherein said mixing ratio of said additives is predetermined by metering elements (130), which are disposed in the flow path between said particular supply container and said injector, and wherein said cleaning liquid, which is mixed with said additives, is sprayed via a foaming nozzle, which is attached to said pressure line, on the surface to be disinfected. In order to refine the method such that it can be performed in a simple way, wherein it is ensured that an effective disinfectant foam is implemented, it is proposed according to the invention that the two additives are suctioned at identical flow rates from the supply containers. In addition, a mixing system and a device for performing the method are proposed.

Description

Method, mixing system and apparatus for producing a disinfecting foam

The invention relates to a method for producing a disinfectant foam, wherein sucking means of a arranged in a pressure line injector foam-forming additive and a disinfecting additive in each case via a suction line from a reservoir and supplying a flowing in the pressure line cleaning liquid in a certain mixing ratio of the additives, wherein the mixing ratio of the additives is predetermined by dosing members connected in the flow path between the respective storage container and the injector, and wherein the cleaning liquid mixed with the additives is sprayed onto a surface to be disinfected via a foam nozzle connected to the pressure line.

Moreover, the invention relates to a mixing system and an apparatus for carrying out the method.

It is known that one can disinfect an area by spraying on the surface a mixture of a cleaning liquid and a disinfecting additive. As a cleaning liquid, for example, pressurized water can be used. In particular, peroxyacetic acid (PES) can be mixed with the cleaning fluid as the disinfecting additive. In order to extend the contact time of the disinfecting additive, it is additionally possible to use a foam-forming additive in which the mixture of the two additives and the cleaning liquid is applied via a Apply the foam nozzle to the surface to be disinfected. It then forms on the surface of a foam, which has an extension of the contact time of the disinfecting additive result and dissolves after some time.

When preparing the mixture of cleaning fluid and the two additives, care must be taken to ensure the mixing ratio of the additives. If the mixing ratio is wrong, it may happen that a sufficient amount of foam is formed, but this has an insufficient disinfecting effect. On the other hand, it may happen that although a strong disinfecting effect is present, but only little foam is formed, so that the exposure time of the disinfecting additive is relatively low.

Object of the present invention is to develop a method of the type mentioned in such a way that it can be carried out in a simple manner, it being ensured that forms an effective disinfectant foam. In addition, a mixing system and an apparatus for carrying out the method are to be provided.

This object is achieved in a method of the generic type according to the invention by sucking the two additives with identical flow rates from the storage containers. This has the advantage that the user does not have to make any elaborate adjustments to achieve an optimal mixing ratio for the two additives. The additives are mixed in a mixing ratio of 1: 1, ie with identical flow rates of the cleaning liquid. Another advantage of the method according to the invention is that the provision of the additives is simplified, because in carrying out the process identical amounts of additives are consumed per unit time, so that identical reservoir, in particular identical volumes for the two reservoirs of the additives can be used , This results in a considerable simplification of logistics. In particular, it is ensured by the inventive method that the two additives are consumed in the same amount and therefore the two reservoirs are emptied at the same time and can be replaced by new reservoir. Therefore, the process is very easy for the user. There is no danger that the user uses too much amount of disinfecting additive or foaming additive, which may result in not only insufficient disinfecting effect but also environmental impact. Namely, the method according to the invention makes it possible to select the additives in such a way that the disinfecting additive is neutralized by the foam-forming additive after some time on the surface to be disinfected. If the mixture of the cleaning fluid and the two additives is applied to the surface to be disinfected, the disinfecting action of the one additive initially predominates, so that the surface is reliably disinfected. Thereafter, the neutralizing effect of the foam-forming additive predominates, so that the disinfecting additive, for example peroxyacetic acid (PES) is decomposed and therefore does not represent an environmental impact.

An additional advantage of the method according to the invention is that the two storage containers have the same level levels when the method is correctly carried out, since the consumption for both additives is the same. This gives the user the opportunity to control the timely disinfecting effect of the foam on the basis of the water levels: if the water levels are different, this means that a sufficient disinfecting effect is not present but there is a fault.

It is advantageous if one dictates the flow rates of the two additives by means of identical dosing. The metering members are connected in the flow path between the reservoirs and the injector. If identical dosing members are used, identical flow rates and consequently a mixing ratio of 1: 1 between the two additives can be ensured in a simple manner without the user having to undertake elaborate adjustment measures.

Conveniently, one uses dosing, which are not individually adjustable by the user. The metering members are specified by the manufacturer and can not be changed by the user relative to each other, so that the manufacturer's predetermined mixing ratio of 1: 1 between the two additives can not be mistakenly changed by the user.

Identical flow rates can be achieved in a simple manner by predefining the flow rates of the two additives by means of one or more diaphragms. For example, it may be provided that in the flow path of the additives between the respective reservoir and the injector in each case a single diaphragm switches whose diameter determines the flow rate. Conveniently, diaphragms with a maximum diameter of 5 mm are used, in particular diaphragms with a maximum diameter of 1 mm, for example 0.7 mm.

It is advantageous if one respectively arranges in the flow path of the additives between the respective reservoir and the injector downstream of the metering a check valve, wherein the check valves are designed identically. By means of the check valves can be avoided that one of the additives can get into the reservoir of the other additive and form there an additive mixture. The check valves are designed identically, so that the flow rates are not affected unevenly by differently configured check valves in the flow paths of the additives. Despite the use of the check valves, a mixing ratio of 1: 1 between the additives can be ensured. The check valves are arranged downstream of the dosing. It has been found that this allows an improved flow of additives while ensuring identical flow rates can be achieved.

There are known injectors, for example from DE 197 05 861 A1, which have two suction openings, so that two additives can be mixed with each other directly in the injector and also with the pressurized cleaning liquid. However, it has been shown that it is favorable to achieve optimal mixing of the two additives when the additives are first mixed together in a mixing chamber and then fed to a single injector only via a mixing line. Even before the additives are added to the cleaning liquid, they are first mixed directly with each other, and then the mixture of the two additives is mixed via the suction port of the injector to the cleaning liquid flowing through the pressure line. The mixture of the two Additives and the cleaning liquid is then applied by means of a foam nozzle on the surface to be disinfected.

The process according to the invention can be used in particular in agriculture and in the food industry.

As mentioned above, the invention also relates to a mixing system for carrying out the method explained above. The mixing system for admixing two additives to a cleaning liquid flowing in a main line has an injector through which the cleaning liquid can flow, and a first and a second suction connection, which can each be connected to a suction line for sucking an additive from a storage container, wherein the mixing ratio of the two additives can be predetermined in each case by means of a dosing. According to the invention, it is provided that the dosing members are designed identically and are not individually adjustable by the user.

The identical dosing elements ensure in a structurally simple manner that identical flow rates and thus a mixing ratio of 1: 1 for the two additives are formed during operation of the mixing system. To avoid that the user mistakenly changed the dosing, they are designed so that they can not be adjusted individually by the user.

Conveniently, the metering members are each designed as diaphragms. In particular, it can be provided that each dosing member is designed in the form of a single diaphragm whose diameter is a maximum of 5 mm, in particular Furthermore, the aperture diameter can amount to a maximum of 1 mm, for example 0.7 mm.

The diaphragms are preferably made of a mineral material, for example of sapphire material.

Downstream of the dosing a respective springless check valve is arranged in a preferred embodiment of the mixing system according to the invention, wherein the two check valves are identical. As already explained, the provision of identical non-return valves for the two additives reduces the risk of different flow rates for the two additives during operation of the mixing system. The check valves ensure that mixing of the additives in their reservoir can be avoided, but mixing of the additives takes place only downstream of the check valves. The additives contained in the storage containers are therefore not affected. In particular, it is avoided that the one additive in the reservoir is neutralized by the other additive.

The two check valves are each designed without a spring, that is, there are no spring elements are used, which act on the respective closing element of the check valves with a restoring force. It has been shown that such spring elements can stick together during operation of the mixing system. In addition, when using spring elements, there is the risk that one of the spring elements exerts a greater restoring force on the associated closing element than the other spring element. This could also result in different flow rates for the two additives. so that no optimal mixing ratio can be achieved. It has been found that by using springless check valves which are of identical design, identical flow rates can be achieved for the two additives while ensuring that the additives in the reservoirs can not mix.

In an advantageous embodiment, the non-return valves each have a sealing element that can be placed sealingly against a valve seat and that is freely movable in the non-pressurized state of the non-return valve in a flow channel adjoining the valve seat. The position of the shooting element is given in such a configuration solely by the forming pressure in the check valve, without the closing element occupies a predetermined position in the non-pressurized state of the check valve.

The closing element is conveniently designed as a freely movable valve ball in the flow channel.

It is advantageous if the valve ball is made of a mineral material, in particular of a sapphire material. The sapphire material has a very high chemical resistance to the additives used and can be manufactured with very high dimensional accuracy.

The valve seat associated with the respective closing element is preferably made of a ceramic material, preferably using zirconium dioxide. It has proved to be particularly favorable if, for the production of the valve seat, a material is used with a mixture made of zirconium dioxide and yttrium. In particular, when using a sapphire ball as a closing element, ceramic materials for producing the associated valve seat have proven to be very advantageous.

As already explained, it can be provided that the two additives are mixed together within an injector. In a particularly advantageous embodiment of the mixing system according to the invention, however, the mixing system has a mixing chamber to which the two additives can be supplied via the first suction connection and the second suction connection and from which the mixture of the additives can be fed to the injector via a mixing outlet, downstream the suction ports each have a metering member and a springless check valve are arranged, wherein the two metering members and the two check valves are each configured identically. Such a construction of the mixing system has the advantage that the two additives can initially be mixed directly with each other and that then the prepared additive mixture of the cleaning liquid can be mixed. Identical flow rates for the two additives are ensured by the use of identical dosing members and identical non-return valves, in which case the check valves are made without the use of a spring, so that different spring constants can not adversely affect the flow rates of the additives.

Conveniently, a dosing member and a check valve each form a dosing unit in the form of a prefabricated unit, which is inserted into a housing surrounding the mixing chamber. The mixing chamber is preferably made of stainless steel. The two metering units are preferably diametrically opposite each other, so that the additives in the mixing chamber meet directly one another and thereby optimally mixed with each other.

In an advantageous embodiment, the mixing chamber comprises a safety outlet which can be closed by means of a pressure relief valve. This ensures that no unacceptably high pressure can form within the mixing chamber. The safety outlet is preferably arranged diametrically opposite the mixture outlet.

As mentioned above, the invention also relates to a device for carrying out the aforementioned method. The device comprises a high-pressure cleaning device with a pump which can be driven by a motor, to the pressure outlet of which a mixing system of the type described above is connected, connected to a foam nozzle. The mixing system can be connected directly to the pressure outlet of the high-pressure cleaning device. However, it can also be provided that the mixing system is connected via a pressure line, in particular via a pressure hose, to the pressure outlet of the high-pressure cleaning device. At the exit of the mixing system a foam nozzle is connected. To connect the mixing system with the foam nozzle can also be a pressure line, in particular a pressure hose used.

The foam nozzle may be located at an outlet of a spray gun that can be operated by the user. Preferably, the spray gun is equipped with switchable jet pipe comprising a first outlet and a second outlet. The foam nozzle can be attached to the first outlet. be closed and at the second outlet, a conventional high-pressure nozzle may be connected. The foam nozzle is characterized in that it allows an air intake to the discharged mixture of cleaning fluid and the two additives. The air intake allows the generation of a foam and can be done, for example, according to the jet pump principle. Such foam nozzles are known in the art as well as switchable jet pipes with a first and a second outlet.

The following description of a preferred embodiment of the invention serves in conjunction with the drawings for further explanation. Show it:

FIG. 1 shows a schematic representation of a device according to the invention for producing a disinfecting foam with a high-pressure cleaning device, a mixing system and a foam nozzle connected to an outlet of a spray gun;

Figure 2 is a schematic representation of the mixing system of Figure 1 with two identically designed metering units and

FIG. 3 shows a schematic representation of one of the two metering units from FIG. 2.

FIG. 1 schematically shows a device according to the invention for producing a disinfecting foam. The apparatus is generally designated by the reference numeral 10 and comprises a high-pressure cleaning device 12 with an electric motor 13 and a Koi- driven by the electric motor 13 To the pressure outlet 15 of the piston pump 14, a mixing system 20 is connected via a pressure line 17 with a connected to the pressure line 17 injector 21, at the suction port 22 via a mixing line 24, a mixing device 26 is connected. The mixing device 26 has a mixing outlet 27, to which the mixing line 24 is connected, and a first suction port 28 and a second suction port 29. To the first suction port 28, a first suction line 31 is connected, which establishes a flow connection between the mixing device 26 and a first storage tank 32 for an additive, for example a disinfecting additive, which can be mixed with the cleaning liquid conveyed by the high-pressure cleaning device 12, preferably water. To the second suction port 29, a second suction line 34 is connected, which establishes a flow connection between the mixing device 26 and a second reservoir 35, which receives a further additive, such as a foam-forming additive, which is also to be mixed with the conveyed cleaning liquid.

The two additives are first mixed together directly in the mixing device 26. For this purpose, the mixing device 26 has a mixing chamber 38, which is connected to the first suction port 28 via a first metering unit 41 and to the second suction port 29 via a second metering unit 42. Via a safety outlet 44, which can be closed by a pressure relief valve 45, the mixing chamber 38 is in communication with the outside atmosphere. If an inadmissibly high pressure develops within the mixing chamber 38, the overpressure valve 45 opens and releases the safety outlet 44. In the mixing line 24, which connects the connection opening 22 of the injector 21 with the mixing device 26, a spring-loaded check valve 47 is connected, and the injector 21 is bridged by a bypass line 49, in which a bypass valve 50 is connected.

The pressure outlet of the injector 21 is in flow connection via the pressure line 17 with a spray gun 52 which can be actuated by the user and to which a switchable jet pipe 54 is connected with a first jet pipe outlet 56 and a second jet pipe outlet 57 and a switching device 58 Jet outlet 56 is connected to a high-pressure nozzle 60 and to the second jet tube outlet 57, a foam nozzle 61 is connected. By means of the switching device 58, the user can set the cleaning fluid pressurized by the high-pressure cleaning device 12 to which a disinfecting additive and a foam-forming additive are mixed by means of the mixing system 20, optionally via the high-pressure nozzle 60 or the foam nozzle 61. The foam nozzle has two air inlets 63, 64, can enter through the air, which can be admixed to the mixture of the cleaning liquid and the two additives according to the jet pump principle, so that a disinfectant foam is formed, which can be directed to a surface to be disinfected ,

The high-pressure cleaning device 12 is connected via a supply line 66 to a supply of cleaning fluid, for example a water reservoir 67. Alternatively it can be provided that the high-pressure cleaning device 12 is connected to a water supply network, for example to a drinking water pipe.

The mixing device 26 is shown enlarged in FIG. It comprises a housing 70 made of stainless steel, which surrounds the mixing chamber 38 and a total of four pairs of diametrically opposed receptacles 72, 73, 74, 75 has. In a first receptacle 72, the first metering unit 41 is used, which is designed as a prefabricated unit. The second receptacle 73, which accommodates the second metering unit 42, which is identical to the first metering unit 41, is arranged diametrically opposite the first receptacle 72. A third receptacle 74 accommodates a connection nipple 77 of the mixing line 24 and diametrically opposite the third receptacle 74 is the fourth receptacle 75, in which the pressure relief valve 45 is inserted.

As already explained, the two metering units 41 and 42 are identical. The dosing unit 41 is shown schematically in FIG. It comprises a cylindrical metering housing 81, which has on the outside a circumferential annular groove 82 which receives a sealing ring 83. The dosing housing 81 has a through-bore 85, which extends from a first end face 86 to a second end face 87 and comprises a plurality of steps. Starting from the first end face 86, the through-bore 85 defines a first section 89, which receives a support plate 90 and to which a second, radially inwardly directed step 91 connects a second section 92, which receives a sealing ring 93, which comprises a ceramic valve body 94 surrounds in the circumferential direction. The valve body 94 is inserted into a third portion 96, which connects via a radially inwardly directed second stage 97 to the second portion 92. Facing away from the support plate 90, the valve body 94 forms a spherical valve seat 99, which at the level of a third, radially inwardly directed step 100 of FIG Through hole 85 is arranged. Via the third stage 100, a central flow channel 102 connects to the third section 96. Starting from the third stage 100, the central flow channel 102 extends to a fourth, radially outwardly directed step 103, to which a first extension section 104 of the through-hole 85 connects. A second extension section 107 of the through-bore 85 adjoins the first extension section 104 via a fifth, radially outwardly directed step 106. The second extension portion 107 opens into the second end face 87 and, together with the first extension portion 104 has a cross-sectionally T-shaped plug 109, which has at the level of the first extension portion 104 a circumferential annular groove 110 in which a sealing ring 111 is arranged, and which has a coaxial with the longitudinal axis 113 of the through hole 85 arranged through hole 114. At its end face 116 facing the valve body 94, the plug 109 carries two transverse grooves 118, 119 perpendicular to the longitudinal axis 113 of the metering housing 81 and perpendicular to one another.

The end face 116 of the plug 109 forms a stop for a freely movable in the central flow passage 102 closing body in the form of a valve made of sapphire valve ball 121 which is sealingly engageable with the spherical valve seat 99 and in combination with the valve seat 99 forming valve body 94 a springless Check valve 123 is formed.

The support plate 90 inserted into the first section 89 is penetrated by a stepped passage 125 having an input section 126 and an output section 127. The output section 127 assumes a diaphragm stop. ter 129, which holds an aperture 130. The diaphragm holder 129 is glued to the support plate 90 with the diaphragm 130 interposed.

The diaphragm 130 is made of a ceramic material, preferably made of sapphire and has an inner diameter of 0.7 mm in the illustrated embodiment. The valve body 94 is in the form of a cylindrical sleeve and preferably has an inner diameter of less than 5 mm, in particular about 2 mm.

On the outside, the closing connection nipple 132, which is shown only in FIG. 2, adjoins the first end face 86. The connection nipple 132 protrudes out of the housing 70 of the mixing device 26, whereas the dosing housing 81 is received by the first receptacle 72 of the housing 70.

As already explained, the second metering unit 42 is configured identically as the first metering unit 42. It also has an aperture 130 and a springless check valve 123, of a freely movable in a central flow channel 102 valve ball 121 of sapphire and a valve body 94 with a spherical valve seat 99 is formed, wherein the valve body 94 is made of a ceramic material, preferably using a mixture of zirconia and yttrium.

The use of the mixing system 20 with a single injector 21 and a mixing device 26 having identical dosing units 41 and 42 ensures that additives are drawn in from the two storage tanks 32 and 35 at an identical flow rate, mixed together and then admixed with the cleaning liquid. The flow rates can from the Users are not changed, they are given by the dosing in the form of aperture 130. The identically designed check valves 123 ensure that the two additives can mix only in the mixing chamber 38 with each other, without the risk that the one additive enters the reservoir of other additive. The check valves 123 go alone due to the pressure conditions developing in their closed or in their open state, they have no spring elements for returning the respective valve ball 121 from. This avoids the risk that, due to different spring constants of the spring elements, different flow rates for the two additives could form.

The inventive method for producing a disinfectant foam can be performed by the user in a simple manner, it being ensured due to the identical flow rates of the two additives that sets an optimal disinfecting effect, the two additives are consumed in the same amount per unit time, so that the two reservoirs 32 and 35 have identical water levels. Different levels indicate the user is disturbed with possibly insufficient disinfecting effect of the foam.

Claims

P AT EN TA NSP TROUBLESHOOTING

1. A method for producing a disinfectant foam, wherein sucking means of a arranged in a pressure line injector, a foam-forming additive and a disinfecting additive in each case via a suction line from a reservoir and in a certain mixing ratio of the additives of a flowing in the pressure line cleaning liquid, wherein specifies the mixing ratio of the additives by in the flow path between the respective reservoir and the injector switched dosing, and wherein the mixed with the additives cleaning liquid is sprayed via a connected to the pressure line foam nozzle on a surface to be disinfected, characterized in that the two additives with identical flow rates sucks from their storage containers.

2. The method according to claim 1, characterized in that one predetermines the flow rates of the two additives by means of identical dosing.

3. The method according to claim 1 or 2, characterized in that one does not use individually adjustable dosing members by the user.

4. The method according to any one of the preceding claims, characterized in that one predetermines the flow rates of the two additives by means of one or more diaphragms.

5. The method according to any one of the preceding claims, characterized in that in the flow path of the additives between the respective reservoir and the injector downstream of the dosing member each arranges a check valve, wherein the check valves are configured identically.

6. The method according to any one of the preceding claims, characterized in that the two additives are first mixed together in a mixing chamber and then fed via a mixing line to a single injector.

7. mixing system for admixing two additives to a cleaning liquid flowing in a pressure line, in particular for carrying out the method according to one of the preceding claims, with an injector (21) through which the cleaning liquid can flow and with a first and a second suction connection (28, 29), each of which can be connected to a suction line (31, 34) for sucking an additive from a reservoir (32, 35), wherein the mixing ratio of the additives in each case by means of a metering member (130) can be predetermined, characterized in that the metering members (130) identical trained and not individually adjustable by the user.

8. mixing system according to claim 7, characterized in that the metering members are each formed as a diaphragm (130).

9. mixing system according to claim 8, characterized in that the diaphragms (130) are made of a mineral material.

10. mixing system according to claim 7 or 8, characterized in that downstream of the metering members (130) identically designed, springless check valves (123) are arranged.

11. A mixing system according to claim 10, characterized in that the check valves (123) has a sealing engagement with a valve seat (99) closing element (121) which in the non-pressurized state of the check valve (123) in a valve seat (99 ) subsequent flow channel (102) is freely movable.

12. mixing system according to claim 11, characterized in that the closing element as in the flow channel (102) freely movable valve ball (121) is configured.

13. Mixing system according to claim 11 or 12, characterized in that the closing element (121) is made of a mineral material.

14. Mixing system according to one of claims 7 to 13, characterized in that the mixing system has a mixing chamber (38) via the first suction port (28) and the second suction port (29), the additives are supplied and from which a mixture of both additives via a mixture outlet (27) to the injector (21) can be fed, wherein downstream of the suction ports (28, 29) are each a metering member (130) and a springless check valve (123) are arranged, wherein the two metering members (130) are configured identically, and wherein the two check valves (123) are designed identically.

15. A mixing system according to claim 14, characterized in that in each case a metering member (130) and a check valve (123) form a metering unit (41, 42) in the form of a prefabricated structural unit, which in a mixing chamber (38) surrounding the housing (70). is used.

16. A mixing system according to claim 14 or 15, characterized in that the mixing chamber (38) comprises a means of a pressure relief valve (45) closable safety outlet (44).

17. An apparatus for carrying out the method according to one of claims 1 to 6, with a high-pressure cleaning device (12) having a motor (13) driven by a pump (14) at the pressure outlet (15) with a foam nozzle (61) connected mixing system (20) is connected according to one of claims 7 to 16.