Microbiological safety cabinet

Abstract

A microbiological safety cabinet (1) comprising a work compartment (10), an openable door (20) for accessing the work compartment (10), an electronic cabinet control unit (30), a decontamination apparatus (100) for decontaminating said work compartment (10), said decontamination apparatus (100) comprising: at least one nebulization nozzle (101) communicating with said work compartment (10) and arranged so as to dispense and diffuse a mist of a sterilizing agent solution into said work compartment (10); a mist generation device (102) comprising piezoelectric elements, associated with said at least one nozzle (101), a tank (103) containing said decontamination agent solution; a delivery duct (104) connected to said tank (103) and to said mist generation device (102), and a return duct (105) connected to said mist generation device (102) and to said tank (103), said delivery duct (104) and said return duct (105) globally forming a closed fluid circuit passing in said tank (103) and in said mist generation device (102), said mist generation device (102) taking a part of fluid circulating in said closed fluid circuit, electrically operated pumping means (106) located along said delivery duct (104); an electronic apparatus control unit (107) connected to said pumping means (106) and to said mist generation device (102), configured to control said pumping means (106) and said mist generation device (102); wherein said apparatus control unit (107) is connected to and in communication with said cabinet control unit (30).

Description

MICROBIOLOGICAL SAFETY CABINETDESCRIPTIONField of the invention

[0001] The present invention relates to a microbiological safety cabinet having a microbiological decontamination ( sterili zation) apparatus .Background art

[0002] A microbiological safety cabinet is an apparatus comprising a work compartment within which some operators handle some microbiological substances which are potentially dangerous to humans .

[0003] In particular, reference is made to a microbiological safety cabinet according to the regulatory reference framework .

[0004] Such a regulatory framework requires that such microbiological safety cabinets be sterili zed at the end of each work day so as to eliminate any possible microbiological contamination from the working chamber, to make them available for the next work day .

[0005] To sterili ze the work compartment at the end of a procedure , the prior art involves using, at the end of the work and in the absence of operators , a UV-C lamp capable of decontaminating the irradiated surfaces ; alternatively, it is possible to place a special portable sterili zation apparatus within the work compartment andremove it at the end of the sterilization cycle.

[0006] The known portable sterilization apparatuses used for the sterilization of microbiological safety cabinets include, for example, the vaporization of formaldehyde, or the vaporization of high concentration hydrogen peroxide, or the vaporization of peracetic acid-based solutions (PAA) , or nebulization the same substances by atomization with high-speed discs, compressed air, or piezoelectric elements.

[0007] All the aforesaid sterilization technologies, as mentioned above, relate to portable apparatuses to be connected or placed in the cabinet and removed at the end of the sterilization cycle.

[0008] The use of such portable sterilization apparatuses for sterilizing the work compartment of the microbiological safety cabinet is not without disadvantages .

[0009] In fact, such apparatuses are not capable of communicating with the safety cabinet and therefore it is not possible to automatically check the safety of the installation before dispensing the biocide, leaving the operator the obligation of manual verification.

[0010] Another disadvantage of using such known apparatuses is that removing the apparatus from the work compartment after the sterilization cycle requires opening the workcompartment and accessing therein to remove the apparatus , exposing the work compartment to ambient air and nulli fying the ef fect of the sterili zation carried out .

[0011] A further disadvantage of the use of the aforesaid portable apparatuses is that such apparatuses must include dedicated coupling systems , which are not always interchangeable , and which limit the development of universal devices .

[0012] In addition, the portable apparatuses which use a toxic sterili zing solution, such as formaldehyde and peracetic acid, generate risks of damage to people and materials in the cabinet .

[0013] The known apparatuses based on peroxide vapori zation (HPV or VHP ) are particularly expensive , both for the purchase cost of the apparatus , and for the need to precondition the work compartment of the cabinet to be sterili zed, such as dehumidi fication and heating, which leads to extending the time necessary for the sterili zation procedure .

[0014] The known peroxide nebuli zation / atomi zation (NHP ) sterili zation apparatuses are fundamentally based on three categories and have speci fic critical issues which will be described hereinbelow .

[0015] Nebuli zation by means of a high-speed rotating discrequires an installation at well-defined angles with respect to the vertical direction, i.e., 0°, 45°, 90°, limiting the possibilities of positioning and integration. Furthermore, the presence of a high-speed rotating element can become a source of generation of undesired particles.

[0016] Nebulization by means of compressed air exploits a flow of compressed air to generate a spray of the hydrogen peroxide solution. This implies both the need for a source of compressed air, such as a cylinder or a compressor, and the introduction of a volume of air into the area to be decontaminated, resulting in an increase in internal pressure and risk of leakage of hydrogen peroxide into the surrounding environment if the cabinet is not properly and effectively sealed.

[0017] The known portable apparatuses which nebulize by means of nozzles and based on piezoelectric elements overcome some of the critical issues cited above, but also have all the disadvantages described above related to the fact of not being stably integrated in the safety cabinet .

[0018] Therefore, the need is felt to provide a microbiological safety cabinet capable of carrying out the necessary sterilization operations of the work compartment in an effective, repeatable (thus not subjectto the human variable and to the placement of the decontamination apparatus within the cabinet ) and automatically programmable manner at the end of a work cycle , capable of ensuring the maintenance of an adequate state of microbiological decontamination until the next work cycle .Summary of the invention

[0019] It is the obj ect of the present invention to make and provide a microbiological safety cabinet which allows meeting the aforesaid needs and at least partially obviating the drawbacks complained of above with reference to the prior art .

[0020] In particular, the task of the present invention is to provide a microbiological safety cabinet capable o f carrying out the necessary sterili zation operations of the work compartment in an ef fective , repeatable , validatable and programmed manner at the end of a work cycle and capable of ensuring the maintenance of an adequate state of microbiological decontamination until the next work cycle .

[0021] It is another obj ect of the present invention to provide a microbiological safety cabinet capable of checking that the status of the cabinet is correct , for example that the front glass is closed and the ventilation is stopped, before starting the dispensing ofthe sterili zing agent , and interrupting the same dispensing i f such conditions cease , preferably activating a warning alarm .

[0022] These and further obj ects and advantages are achieved by a microbiological safety cabinet according to the independent claim .

[0023] Further obj ects , solutions , and advantages are present in the embodiments described below and claimed in the dependent claims .Brief description of the drawings

[0024] The invention will be shown below through the description of certain embodiments thereof , given by way of a non-limiting example , with reference to the accompanying drawings , in which :

[0025] - Figure 1 shows a section view through a vertical section plane of a safety cabinet according to the invention;

[0026] - Figure 2 shows an isometric view of the safety cabinet in Figure 1 ;

[0027] - Figure 3 shows an angled view of a decontamination apparatus belonging to the safety cabinet in Figure 1 , in which an upper wall of the casing has been removed to facilitate showing the internal components ;

[0028] - Figure 4 shows a flow chart of an operating method of the safety cabinet in Figure 1 .Description of preferred embodiments

[0029] With reference to the figures , a microbiological safety cabinet according to the invention is indicated by reference numeral 1 as a whole .

[0030] The microbiological safety cabinet comprises a work compartment 10 , an openable door 20 for accessing the work compartment 10 , an electronic cabinet control unit 30 , and a decontamination apparatus 100 for decontaminating said work compartment 10 .

[0031] The decontamination apparatus 100 comprises at least one nebuli zation noz zle 101 communicating with said work compartment 10 and arranged so as to dispense and di f fuse a mist of a sterili zing agent solution into said work compartment 10 ; a mist generation device 102 comprising piezoelectric elements , associated with said at least one noz zle 101 .

[0032] The decontamination apparatus comprises a tank 103 containing said decontamination agent solution; a delivery duct 104 connected to said tank 103 and to said mist generation device 102 , and a return duct 105 connected to said mist generation device 102 and to said tank 103 , in which said delivery duct 104 and said return duct 105 globally form a closed fluid circuit passing in said tank 103 and in said mist generation device 102 , said mist generation device 102 taking a part of fluidcirculating in said closed fluid circuit .

[0033] The decontamination apparatus further comprises electrically operated pumping means 106 located along said delivery duct 104 .

[0034] The decontamination apparatus comprises an electronic apparatus control unit 107 connected to said pumping means 106 and to said mist generation device 102 , configured to control said pumping means 106 and said mist generation device 102 , in which the apparatus control unit 107 is connected to and in communication with said cabinet control unit 30 .

[0035] In accordance with an embodiment , the work compartment 10 has a hermetically closed box-like shape and is delimited by a floor wall 11 , an opposite ceiling wall 12 , a front wall 13 and an opposite rear wall 14 connecting together said floor wall 11 and said ceiling wall 12 , and two opposite side walls 15 , 16 which close said work compartment 10 between said front wall 13 and said rear wall 14 , in which said front wall 13 comprises said openable door 20 .

[0036] In accordance with an embodiment , at least one noz zle 101 is arranged, or integrally fixed, along said rear wall 14 and oriented into said work compartment 10 .

[0037] In accordance with an embodiment , at least one noz zle 101 is arranged, or integrally fixed, along atleast one of said side walls 15, 16.

[0038] In accordance with an embodiment, at least one nozzle 101 is oriented according to a preset angular orientation with respect to a horizontal direction, preferably upwards.

[0039] In accordance with an embodiment, the preset angular orientation with respect to a horizontal direction is an angle between 1° and 45°, preferably an angle of about 5° .

[0040] Thereby, undesired dripping from such at least one nozzle is avoided.

[0041] In accordance with an embodiment, the apparatus control unit 107 is integrated with said microbiological safety cabinet control unit 30.

[0042] In other words, according to an embodiment, the decontamination apparatus control unit 107 is placed within said microbiological safety cabinet 1, preferably adjacent to the said microbiological safety cabinet control unit 30, or physically made together with said microbiological safety cabinet control unit 30 in a single unit.

[0043] According to a different embodiment, the decontamination apparatus control unit 107 is placed within a container casing 109, described below.

[0044] In accordance with an embodiment, themicrobiological safety cabinet 1 comprises at least one electronic closing sensor 21 of said openable door 20 , configured to provide said electronic cabinet control unit 30 with a closing / opening signal .

[0045] In accordance with an embodiment , said tank 103 comprises at least one electronic level sensor 10 configured to provide said electronic apparatus control unit 107 with a level signal of said decontamination agent inside said tank 103 .

[0046] In accordance with an embodiment , said pumping means 106 comprise at least one electrically operated peristaltic pump .

[0047] In accordance with an embodiment , said decontamination apparatus 10 comprises a container casing 109 having a box-like shape , containing said tank 103 therein, and said pumping means 106 .

[0048] In accordance with an embodiment , said container casing 109 comprises at least one electrical connection connector 110 for the connection with said cabinet control unit 30 .

[0049] In accordance with an embodiment , said container casing 109 comprises a first fluid connector 111 for the connection of said delivery duct 104 and a second fluid connector 112 for the connection with said return duct

[0050] In accordance with an embodiment , said first connector 111 and said second connector 112 comprise a respective non-return valve .

[0051] In accordance with an embodiment , said microbiological safety cabinet 1 , comprises a forced ventilation circuit configured to ensure an adequate ventilation of the work compartment 10 , said forced ventilation circuit comprising an ambient air suction opening 51 , an air outlet opening 52 , an internal fluidic ventilation circuit between said suction opening 51 and said outlet opening 52 and passing through said work compartment 10 , an electrically operated ventilation pump 53 along said fluidic ventilation circuit , in which said container casing is placed inside said fluidic ventilation circuit .

[0052] In accordance with an embodiment , said container casing 109 is placed in a section of said forced ventilation circuit interposed between said work compartment 10 and said outlet opening 52 .

[0053] According to another embodiment , said container casing 109 is placed in a section of said forced ventilation circuit interposed between said inlet opening 51 and said work compartment 10 .

[0054] In accordance with an embodiment , said container casing 109 has an aerodynamic shape according to a flowdirection of said fluidic ventilation circuit .

[0055] In accordance with an embodiment , said container casing 109 has a lower wall 113 opposite to an upper wall 114 , and a closed side wall 115 connecting together said lower wall 113 and said upper wall 114 , said closed side wall 115 having a substantially drop-shaped or wingshaped cross-section .

[0056] In accordance with an embodiment , said decontamination agent solution comprises hydrogen peroxide (H2O2 ) and water (H20) , in which the hydrogen peroxide is at a concentration less than or equal to 12 % by volume .

[0057] In accordance with an embodiment , the dispensing flow rate of the decontamination agent solution comprising hydrogen peroxide and water is preferably between 1 and 12 ml / minute .

[0058] In accordance with an embodiment , the decontamination agent mist comprising hydrogen peroxide and water is formed by a plurality of droplets having an average diameter preferably between 2 and 20 microns , even more preferably having a diameter of about 5 microns .

[0059] In accordance with an embodiment , said decontamination apparatus 100 is associated with a preexisting microbiological safety cabinet 1 , as a retrofit .

[0060] According to another aspect of the present invention, the aforesaid objects and advantages are fulfilled by an operation method 200 of a microbiological safety cabinet as described above, controlled by said electronic apparatus control unit 107 and by said electronic cabinet control unit 30.

[0061] Such a method comprises the steps of checking (201) that the access door to the work compartment 20 is closed, and after said checking step (201) , starting (202) said pumping means 106.

[0062] The method further comprises a step of waiting for a preset preparation time (203) starting from said step of starting (202) said pumping means 106, and a step of starting (204) said mist generation device 102 at the end of said step of waiting (203) for a preset preparation time .

[0063] By way of example, the preparation time is preferably between 10 and 15 minutes.

[0064] The method further comprises a step of waiting for a preset generation time (205) starting from said step of starting (204) said generation device 102.

[0065] By way of example, the preset generation time is preferably between 15 and 30 minutes.

[0066] At the end of said generation time, the method includes a step of deactivating (206) said pumping means106 and said generation device 102, and a step of waiting (207) for a preset abatement time starting from the end of said step of waiting (205) a preset generation time.

[0067] By way of example, the abatement time is preferably between 6 and 9 hours .

[0068] In accordance with an embodiment, the method comprises a step of locking (208) the opening of the door 20 at the end of said checking step 201 and a step of unlocking (209) the opening of the door 20 at the end of the step of waiting (207) said abatement time.

[0069] In accordance with an embodiment, the method comprises a step of turning on (210) auxiliary warning lights for decontamination activity of the work compartment 10 following said checking step (201) , and a step of turning off (211) said auxiliary warning lights for decontamination activity of the work compartment 10 at the end of said step of waiting (207) for an abatement time .

[0070] For example, such auxiliary decontamination activity warning lights are blue in color.

[0071] In accordance with an embodiment, the method comprises a step of turning off (212) main lights of the work compartment 10 before, or simultaneously with said step of turning on (210) said auxiliary warning lights for decontamination activity.

[0072] In accordance with an embodiment, the step of checking (201) that the access door to the work compartment 20 is closed, is carried out by means of at least one door closing sensor 21, connected to said electronic cabinet control unit 30.

[0073] In accordance with an embodiment, following said checking step, the cabinet control unit 30 could provide (213) a user with a manual door closing instruction.

[0074] In accordance with an embodiment, after said step of checking (201) that the access door to the work compartment is closed, the electronic cabinet control unit 30 can provide (214) a user with cabinet ready information to start the decontamination cycle.

[0075] In accordance with an embodiment, the method includes a request step (215) for a user to start the contamination cycle, by means of a user start command.

[0076] In accordance with an embodiment, at the end of said step of unlocking (209) the opening of the door 20 at the end of the step of waiting (207) said abatement time, the method includes a starting step (216) of the ventilation pump 53 to ventilate the work compartment 10, and carry out the end of the decontamination cycle (217) .

[0077] In accordance with an embodiment, before the step of checking (201) that the access door to the work compartment 20 is closed, the method includes a step ofchecking ( 218 ) the presence of an adequate amount of decontamination solution inside the tank ( 103 ) by means of an electronic level sensor, and allowing the execution of the step of checking ( 201 ) that the access door to the work compartment 20 is closed, i f the amount of decontamination solution is adequate , or of asking ( 219 ) the user to fill the tank i f the amount of decontamination solution is not suf ficient .

[0078] In accordance with an embodiment , the method, after a start-up step ( 222 ) of the decontamination cabinet 1 , includes an initial step of requesting a user login ( 220 ) , to allow controlled access to the controls of the decontamination cabinet 1 .

[0079] After the login request step, in the case of correct login, the method allows the user to start ( 221 ) the steps related to the decontamination of the work compartment 10 .

[0080] Those skilled in the art may make changes and adaptations to the embodiments of the device described above or may replace elements with others which are functionally equivalent in order to meet contingent needs without departing from the scope of the following claims . Each of the features described as belonging to a possible embodiment can be implemented independently .

Claims

CLAIMS1. A microbiological safety cabinet (1) comprising a work compartment (10) , an openable door (20) for accessing the work compartment (10) , an electronic cabinet control unit (30) , a decontamination apparatus (100) for decontaminating said work compartment (10) , said decontamination apparatus (100) comprising:- at least one nebulization nozzle (101) communicating with said work compartment (10) and arranged so as to dispense and diffuse a mist of a sterilizing agent solution into said work compartment (10) ;- a mist generation device (102) comprising piezoelectric elements, associated with said at least one nozzle (101) , a tank (103) containing said decontamination agent solution;- a delivery duct (104) connected to said tank (103) and to said mist generation device (102) , and a return duct (105) connected to said mist generation device (102) and to said tank (103) , said delivery duct (104) and said return duct (105) globally forming a closed fluid circuit passing in said tank (103) and in said mist generation device (102) , said mist generation device (102) taking a part of fluid circulating in said closed fluid circuit;- electrically operated pumping means (106) located along said delivery duct (104) ;- an electronic apparatus control unit (107) connected to said pumping means (106) and to said mist generation device (102) , configured to control said pumping means (106) and said mist generation device (102) ; wherein- said apparatus control unit (107) is connected and in communication with said cabinet control unit (30) .

2. A microbiological safety cabinet (1) according to claim 1, wherein said work compartment (10) has a hermetically closed box-like shape and is delimited by a floor wall (11) , an opposite ceiling wall (12) , a front wall (13) , and an opposite rear wall (14) connecting together said floor wall (11) and said ceiling wall (12) , and two opposite side walls (15, 16) which close said work compartment (10) between said front wall (13) and said rear wall (14) , wherein said front wall (13) comprises said openable door (20) .

3. A microbiological safety cabinet (1) according to claim 2, wherein said at least one nozzle (101) is arranged, or integrally fixed, along said rear wall (14) and oriented into said work compartment (10) .

4. A microbiological safety cabinet (1) according to claim 2, wherein said at least one nozzle (101) is arranged, or integrally fixed, along at least one of said side walls (15, 16) .

5. A microbiological safety cabinet (1) according to claim 4, wherein said at least one nozzle (101) is oriented according to a preset angular orientation with respect to a horizontal direction.

6. A microbiological safety cabinet (1) according to claim 5, wherein said preset angular orientation with respect to a horizontal direction is an angle between 1° and 45°, preferably an angle of about 5°.

7. A microbiological safety cabinet (1) according to claim 1, wherein said apparatus control unit (107) is integrated with said microbiological safety cabinet control unit (30) .

8. A microbiological safety cabinet (1) according to claim 1, comprising at least one electronic closing sensor (21) of said openable door (20) , configured to provide said electronic cabinet control unit (30) with a closing / opening signal.

9. A microbiological safety cabinet (1) according to claim 1, wherein said tank (103) comprises at least one electronic level sensor (108) configured to provide said electronic apparatus control unit (107) with a level signal of said decontamination agent inside said tank (103)10. A microbiological safety cabinet (1) according to claim 1, wherein said pumping means (106) comprise atleast one electrically operated peristaltic pump.

11. A microbiological safety cabinet (1) according to claim 1, wherein said decontamination apparatus (100) comprises a container casing (109) having a box-like shape, containing said tank (103) therein, and said pumping means (106) .

12. A microbiological safety cabinet (1) according to claim 11, wherein said container casing (109) comprises at least one electrical connection connector (110) for the connection with said cabinet control unit (30) .

13. A microbiological safety cabinet (1) according to claim 11, comprising a first fluid connector (111) for the connection of said delivery duct (104) and a second fluid connector (112) for the connection with said return duct (105) .

14. A microbiological safety cabinet (1) according to claim 13, wherein said first connector (111) and said second connector (112) comprise a respective non-return valve .

15. A microbiological safety cabinet (1) according to claim 1, comprising a forced ventilation circuit configured to ensure an adequate ventilation of the work compartment (10) , said forced ventilation circuit comprising an ambient air suction opening (51) , an air outlet opening (52) , an internal fluidic ventilationcircuit between said suction opening (51) and said outlet opening (52) and passing through said work compartment (10) , an electrically operated ventilation pump (53) along said fluidic ventilation circuit, wherein said container casing is placed inside said fluidic ventilation circuit.

16. A microbiological safety cabinet (1) according to claim 15, wherein said container casing (109) has an aerodynamic shape according to a flow direction of said fluidic ventilation circuit.

17. A microbiological safety cabinet (1) according to claim 16, wherein said container casing (109) has a lower wall (113) opposite to an upper wall (114) , and a closed side wall (115) connecting together said lower wall (113) and said upper wall (114) , said closed side wall (115) having a substantially drop-shaped or wing-shaped crosssection .

18. A microbiological safety cabinet (1) according to claim 1, wherein said decontamination agent solution comprises hydrogen peroxide (H2O2) and water (H2O) , wherein the hydrogen peroxide is at a concentration less than or equal to 12% by volume.

19. An operation method (200) of a microbiological safety cabinet (1) according to at least one preceding claim, controlled by said electronic apparatus control unit(107) and by said electronic cabinet control unit (30) , comprising the steps of: checking (201) that the access door to the work compartment (20) is closed;- after said checking step (201) , starting (202) said pumping means;- waiting for a preset preparation time (203) starting from said step (202) of starting said pumping means;- starting (204) said mist generation device at the end of said preset preparation time (203) ;- waiting for a preset generation time (205) from said step (204) of starting said generation device;- at the end of said generation time, deactivating (206) said pumping means and said generation device;- waiting (207) for a preset abatement time starting from the end of said generation time.

20. A method according to claim 19, comprising a step of locking (208) the door (20) at the end of said checking step (201) and an unlocking step (209) for opening the door (20) at the end of said abatement time.

21. A method according to claim 19, comprising a step of turning on (210) auxiliary warning lights for decontamination activity of the work compartment (10) following said checking step (201) , and a step of turning off (211) said auxiliary warning lights fordecontamination activity of the work compartment (10) at the end of said step (207) of waiting for an abatement time .

22. A method according to claim 21, comprising a step of turning off (212) main lights of the work compartment (10) before or simultaneously with said step of turning on (210) said auxiliary warning lights for decontamination activity.

23. A method according to claim 19, wherein before the step of checking (201) that the access door to the work compartment (20) is closed, there is included a step of checking (218) the presence of an adequate amount of decontamination solution inside the tank (103) by means of an electronic level sensor, and allowing the execution of the step of checking (201) that the access door to the work compartment (20) is closed, if the amount of decontamination solution is adequate, or asking (219) the user to fill the tank if the amount of decontamination solution is not sufficient.

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