HUT55900A - Apparatus for producing fresh air zone - Google Patents

Abstract

Apparatus for providing a clean air zone, for example in a hospital operating theatre or microbiological clean room comprises a housing (30) preferably mounted above the zone and having a plenum chamber (P) and a fan and filter means (89, 52) operative to supply air, e.g. from inlets (39), to the plenum chamber, as well as diffuser means (40) in the form of one or more perforated plates (60, 64) arranged below the chamber so that air flows out therethrough. In order to reliably ensure a downward and outward air flow pattern, without the need for temperature controls or differential air velocities, so that influx of airborne contaminants to the sterile zone is precluded, the central diffuser area (60) is planar and successive peripheral diffuser areas (72, 73) are arranged at increasing greater angles relative to the central area so that each increasingly deflects the air outwards, e.g. at 5 DEG , 15 DEG or more, from the central downflow. Advantageously the peripheral diffuser areas (perforate) and intervening imperforate areas serving as deflector vanes are formed integrally as adjacent regions of specially corrugated elongate panels (63).

Description

APPARATUS FOR THE PRODUCTION OF A CLEAN AIR ZONE

HOWORTH Frederick Hugh, Nr Chorley, Lancashire, GB

HOWORTH Nigel Hugh, Nr Chorley, Lancashire, GB

- Inventions -; - Identical to a-b-e ·

Date of filing: 30.11.1989.

Priority: 02.12.1988 (88 28127.4) GB

The present invention relates to apparatus for producing a clean air zone, for example in a surgical operating room, or in clean rooms for the manufacture and packaging of medicaments,

6Θ428-4818 KH • · ·

- 2 in electronics manufacturing.

The natural behavior of the air discharged from an orifice or unidirectional flow diffuser is such that a peripheral suction of contaminants is created around the diffuser, which not only mixes with the discharged clean air but is dispersed inward at an angle of 1012 °. To avoid this, without the need for a trim trim or side panels around the airflow zone, a device was proposed to streamline the air flow from the diffuser by moving from the center of the diffuser at a higher velocity and toward the center of the diffuser. air is emitted at lower and lower speeds. Such an apparatus, first described in GB 1488513 and 1488514, is incorporated herein by reference. describes a downward and outward distribution of airflow from a ceiling mounted diffuser and minimizes contamination in the area below the diffuser.

However, the efficiency of the above-mentioned gradual flow system depends on three conditions. First, the difference between the temperature of the exhaust and the ambient air must not exceed + 2 ° C. Secondly, and as described in later GB 1555563 and 1555564. U.S. Pat. Finally, the amount of air-conditioned control air supplied to the incremental air flow unit for mixing with its recirculated air must not exceed the total volume

- 3 to 25%, otherwise the negative velocity pressure generated by the evenly distributed air recirculation inlets is not sufficient to drive the peripheral air outward.

Difficulties in reconciling these three conditions for the efficient operation of such a gradual flow system are considerable, both in summer and in winter, when alternating cooling and heating are required. Where these conditions were not assured throughout the year, it was found that the outward flow of air changes direction and results in peripheral suction of pollutants. In some cases, the air from the middle section will not reach the floor, so the clean zone will decrease. Of course, this error does not immediately appear in the eye and can only be detected by examining the air flow and monitoring the pollutants.

In order to overcome the sensitivity of gradual flow systems to the effects mentioned above, the speed of the feed air, and thus its total volume, was increased. This causes increased noise and inadmissible drying of wounds in operating rooms and, due to increased evaporation, causes the wounds to cool down, which in turn leads to hypothermia in patients. Further, in pharmaceutical applications where the powders must not be agitated or flames distorted, such high air velocity is unacceptable.

It is an object of the present invention to provide a system for producing clean air which is insensitive to the aforementioned problems.

The apparatus for producing the clean air zone of the present invention is provided with a supply means for supplying clean air to a pressure equalization chamber and a distribution means in the form of one or more perforated plates disposed adjacent to the chamber so that air is supplied to the chamber. characterized in that the center portion of the distributor means has substantially flat and successive circumferential portions which are arranged at an increasing angle to the center portion such that each deflects the flowing air outwardly relative to the direction of the flowing air from the middle portion.

During use, the aforementioned device generates an air flow distribution outward from the distribution device. Air inlets distributed around the air outlet distributor for air recirculation are no longer relevant, since the distribution of air flow is determined by the angles of the peripheral portions of the distributor device rather than the differentially lower velocity of air from these portions. In addition, the amount of air-conditioned control air introduced into the air supply system does not affect the air distribution and the difference between the temperature supplied by the unit and the ambient air temperature has less impact on operation than with previous units.

Preferably, baffles are disposed between successive circumferential portions of the distribution means.

In another embodiment of the device according to the invention, successive circumferential portions of the distribution device may comprise separate perforated plates which are joined to the corresponding non-perforated baffles. In this way, the angle of each disc can be set independently, either during installation or afterwards.

In another embodiment of the device, the successive circumferential portions of the distributor means and the intermediate non-perforated baffles form a unit with the corresponding profiled panels disposed along the circumference of the center portion of the distributor means. In practice, this design is easier to install because the relative angles of the perforated areas are given and you do not need to adjust it during installation. The relative angles can be pre-selected from a small number of different profile layouts in a manner that best suits the location.

The invention will be described in more detail with reference to the drawings, which are exemplary of the apparatus according to the invention. their embodiment.

Figure 1 is a diagrammatic sectional view of the first embodiment of the unit installed in the ceiling of the room.

Figure 2 is a perspective view of the second embodiment of the unit installed on the ceiling of the room.

Figure 3 is a side view of the second embodiment, on a larger scale.

Figure 4 is a larger sectional view taken along the center line of the second embodiment.

Figure 5 is a top view of the second embodiment showing its module structure.

FIG. Figures 3 to 5 are a plan view of a module of the apparatus shown in Figs.

Fig. 7 is an enlarged view of the module of Fig. 6, viewed in the direction of arrow VII of Fig. 6.

Figure 8 is a bottom view of the module of Figure 6.

8a. Figure 8 is an enlarged view of the end piece of the module shown in Figure 8, marked VIII.

Figure 9 is a diagonal sectional view of the module of Figure 6 taken along line IX-IX of Figure 6, leaving the extreme panel for clarity.

Figure 10 is a cross-sectional view taken along the line X-X of Figure 6, leaving the line lamp out.

FIG. 8a. Figure XI-XI is a larger cross-sectional view of the fragment.

The device of the present invention can be installed in operating room ceilings to create a clean air zone around the patient to be operated, or in pharmaceutical or electronic clean room ceilings to create a clean air zone around a machine or a manufacturing process, or any other location where minimal microbiological contamination. In addition, instead of being installed in the ceiling, the device according to the invention can be mounted in a movable frame, e.g. wheelchair to move from one place to another.

The general principles of the invention will be described in particular with reference to Figure 1, which strongly illustrates an embodiment of the invention.

Air supply devices, such as electrically driven fans (not shown), are arranged to supply air through a pressure equalization chamber 10 located above the level of the suspended ceiling 12, just above the area to be kept substantially free of germs and contaminants. , for example, above the operating room surgical operating table. In addition to the fans, air purifying, heating, cooling and humidifying devices may be arranged to supply properly conditioned and sufficiently clean air to the pressure equalizing chamber 10. In the example shown, a final air filter 14 is also provided in the open bottom of the chamber 10 »· ♦ ·· · ·····»

A · * ·· «···· • ♦ · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·

I

- positioned along its side, substantially at the height of the ceiling 12.

Immediately below the air filter 14, the distribution device 20, indicated by reference numeral 20, is mounted on the suspended ceiling 12, the distribution device 20 comprising a plurality of perforated plates. These plates effectively cover the open bottom side of the chamber 10 and form an outlet for the air supplied by the fans to the chamber 10. The perforated panels consist of a large rectangular substantially flat central panel 21 arranged horizontally parallel to or parallel to the ceiling 12, and a first group of narrow angular panels 22 disposed about and at an angle to the central panel 21. with the center panel 21 upwards from the plane. They fall at 20 °. A second group of rectangular panels 24, in turn, surrounds the first group of panels 22. This second panel 24 slopes upwardly at a greater angle from the plane of the central panel 21 than the first panel 22, for example at 40 °. A third group of rectangular panels 26, on the other hand, is located around the second group of panels 24 and extends approx. It slopes upwards at an angle of 60 °. Panels 22, 24 and 26 are successively narrower and perforated.

Each panel 22, 24 and 26 is connected along its inner edge to its associated flaps 23, 25, 27, which form an air deflector. The panels 22, 24, 26 or their respective wings 23, 25, 27 are mounted pivotally about an axis, thereby adjusting the inclination of the panels 22, 24, 26 and the proportion of air passing through them. At the outer edge of each of the outermost panels 26, an additional deflector 29 is attached.

During operation, the fans supply clean air to the

I • · 4 · · · · · 4 · · · 4 · «

4 4 ·

- Pressure equalizer 8 through chamber 10 as shown by arrows A. The appropriate airflow rate is 0.55 m / sec. Clean air enters the room through the perforated panels 21, 22, 24, 26, in each case exiting perpendicular to the plane of the perforated panel. Thus, the air flows directly down through the large central panel 21 as shown by arrows B, but where it flows through inclined panels 22, 24, 26 located in the circumference of the distributor 20, it deflects outwards in increasing angles as shown by the arrows C show.

There is a gap between the outermost baffle 29 and the ceiling 12 of the ceiling lowering the underside of the pressure equalization chamber 10, through which the baffle 29 deflects air so that the air flows substantially horizontally, just below the ceiling 12 as shown by arrow D.

Generally, an air distribution from the distributor 20 in all directions is obtained. Provided that the flow rate is adequate, e.g. At 0.55 m / s, the flow reaches down to the floor and sprays outward, and finally exits through the outlets, door or doors at the edge of the room. Such a flow distribution is advantageous in that it minimizes aeromicrobiological contamination in the area below the distributor, as it purifies the sterile air out of the zone and cleans the ambient air and contaminants brought on by workers, including our naturally released bacterial cells. An advantage of the device according to the invention is that it produces the air distribution more reliably than previous devices which are based on differential air velocities.

The second practical embodiment, which is described in more detail in Figures 2-11. are also mounted on the ceiling. This device is substantially rectangular, substantially square in the plane (Fig. 5), and its housing 30 has four contiguous side walls 31, 32, 33, 34. Within these are perforated manifolds in the path of air exiting the apparatus, which are collectively designated by reference numeral 40.

The housing 30 consists of four modules A, B, C, D as shown in FIGS. . A separate module is described in more detail in Sections 6-10. .

Each module has an outer metal frame 35 consisting of an upper wall 36 adjacent to the side wall portions a, b and inner walls 37, 38 which are not as high as the side wall portions a, b and which lie on the respective inner wall of the two adjacent modules. all four modules are assembled. Each side wall portion a, b has an air intake grid 39 so that there are two on each side of the assembled device. Although such an air intake is not necessarily required for the concept of the invention, it is practically useful because the apparatus is self-contained, so that there is no need to design it at installation sites that do not have suitable pre-positioned air vents. Pre-filters 89 are provided on the inside of the grids 39 to filter out major impurities.

The sidewall portions a, b are connected to narrow, low, inwardly sloping walls 41, 42 which engage in upwardly sloping auxiliary walls 43, 44. The latter define the external chamber of the apparatus. Where the individual modules a, b are connected to the side wall portions, that is, in each corner of the unit, a fan 45 is integrated into this outer chamber. The outlet pressure 46 of the fans 45 is · · · · · · · · · ·

Its chambers 10 lead to an internal chamber of the apparatus which forms a pressure equalization chamber P. Thus, during operation, the fans 45 draw in ambient air through the grilles 39 (or possibly a further air intake as shown in Figure 3) into the outer chamber and feed it into the pressure equalization chamber P.

Inside each corner are internal walls 47, substantially parallel to the upper wall 36, to direct air from the fans 45 to the center of the pressure equalization chamber P.

The walls of each module frame are internally covered with sound-absorbing material, preferably with foam plastic which is fire retardant. Further sound absorbing panels 48 are located in the outer compartment of each module. The purpose of all these sound absorbing materials is, of course, to suppress the operating noise of the fans 45.

In the corner of each module, between the inner walls 37, 38 (i.e., against the fan), the frame is partially provided with a cylindrical rounding 49. When modules A through D are combined, the roundings 49 define a central aperture through which the axis 50 for holding the torch lamps 51 extends (Figures 2-4).

Through the pressure equalization chamber, parallel to the upper wall 36, a high-performance HEPA filter 52 is mounted in each module between the auxiliary walls 43, 44 and the inner walls 37, 38 by means of fastening elements 53. Below the pin 52 is the distribution device 40.

The distribution device 40 comprises a flat central portion consisting of four substantially square perforated panels 60 fixed to each module, and successive perforated peripheral portions comprising four elongated, angled panels 61, 62, 63, 64 consist of appropriate parts. These panels are located along the four sides of the central section (i.e., the internal compartment between adjacent modules). from one corner to the other). Therefore, the respective ends of the panels 61, 62, 63 are bevelled to form an oblique corner joint and secured such that only a narrow gap 83 remains between them in the corners (Fig. 8).

Each large, flat panel 60 has a flanged flange 65 extending along the edges facing the side wall portions a, b of said module, and upwardly and inwardly sloping edges 66 along the other two edges flush with the inner wall 37, 38 of the module ( Figure 10). Each panel 60 is suspended along only one edge, with pins 68 secured to the folded lower edge of one of the inner walls 37 by a strap 67 secured to the flange 66. The outer edge of panel 60 is suspended by means of separate brackets 69 which are detachable so that panel 60 can be folded down, e.g. filter 52 must be accessed.

The longitudinal, extreme panels 61, 62, 63, 64 are bent and their specific bending profile is best shown in Figures 7, 10 and 11. They have distributed longitudinal, perforated portions 71.72 and 73, the last two being in a plane inclined at 10 ° and 15 ° to the plane of the 71 portions. Non-perforated portions 74, 75 and 76 extend longitudinally between portions 71, 72 and adjacent portions 73, each forming an acute angle with adjacent perforated portions.

Referring in particular to FIG. 11, it is shown that a hook portion 77 is formed on the inner edge of the panels 61, 62, 63, 64 which, during operation, extends over the flange 65 of the central panel 60 of the connector. Preferably, a rubber seal fits over the flange 65 for a more secure play-free contact. Each of 61, 62, 63, 64 ··· · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · „« everything everything - different · · ·· ···

There is a substantially flat strip 78 along the outer edge of the panel 12, which is screwed to the bottom of the lower walls 41, 42 of the connection modules so as to remain a narrow gap 79. These slots 79 and their width are determined by washers on the fixing screws.

When the central panels 60 and the peripheral panels 61, 62, 63, 64 are mounted, as shown, the central panels 60 are substantially horizontal and the perforated peripheral portion 71 is substantially horizontal while the other two perforated portions 72, 73 with approx. 10 ° and 15 ° to the horizontal. Also in this embodiment, as best illustrated in FIG. 11 and 11, the three perforated portions 71, 72, 73 are respectively provided with three, five, five rows of perforations.

Between the outermost non-perforated portion 76 and the flat outermost strip 78 there is an additional longitudinal portion 81 which is 30 ° to the horizontal and is located on each of the panels 61, 62, 63, 64 and has a line lamp 80 equipped. The shape of the line lamp 80 is preferably thinned, as can be seen to cause minimal disturbance to the distribution of airflow during operation of the apparatus. At the end of each panel, the portion 81 extending beyond lamp 80 is perforated (see Figures 8 and 8a). An additional narrow portion 82 is provided with a single row of perforations at an angle of 60 ° between the portion 81 for mounting the lamp 80 and the outermost strip 78.

In operation, the fans 45 draw in ambient air through the grilles 39 and pre-filters 89 (and possibly one or more distant air intakes as shown in Figure 3) and are fed centrally to the pressure equalizer P • 4

* «· · Chamber. From there, air passes through the HEPA filter 52, which removes any remaining impurities and exits as sterile air through the perforations of the dispenser panels 60, 61, 62, 63, 64 and the predetermined slots 83 and 79, as shown by the various arrows in Figure 11. show. The air flows vertically inwardly from the central panel 60 and the first perforated portion 71. Where air passes through portions 72 of the second perforated circumference, it is deflected outward by approx. 5 °, and where the third perforated circumference passes through 73 portions, where there is approx. 15 °. In this case, the intermediate and adjacent, non-perforated portions 74, 75, 76 act as baffles, contributing to the above air distribution. At the corners of the apparatus, air flows downwardly through small gaps 83 remaining between adjacent oblique angled edges of the peripheral panels 61, 62, 63, 64, and outwardly flows for approx. At an angle of 30 ° through additional perforations beyond the ends of the line lamps 80. In this way, contaminated ambient air does not tend to flow into the corners of the area underneath the unit, and sterility of the zone is maintained. In addition, approx. An outward air flow of 60 ° occurs through a further single-line perforation of portion 82, outwardly from line lamp 80, and apparently horizontally through slot 79 below housing 30. The air flow from portions 73 and 82 separates along the tapered surface of the liner 80 and then recombines so that no adverse effect is produced which could result in the inflow of external contaminants into the sterile zone.

The foregoing is, of course, for illustrative purposes only, and is not intended to limit the scope of the invention, and many variations are possible. The line lamps 80 are not relevant and the operating lamps 51 are only appropriate when the equipment is used in an operating room. The modular design is not essential, although useful in practice to facilitate production and installation. The exact manner and arrangement of the mounting of the extreme panels can also vary in many ways, as the designers of this technical field will contemplate, depending on the air distribution that best fits the installation location. Finally, the unit does not have to be mounted on a ceiling, but can be mounted on a wheelchair or other wall structure.

Intermediate structures are also possible, some of which are illustrated in FIG. 1 to 4 have some characteristics of the embodiment of the figures, i.e. some peripheral panels, more than one perforated portion, some completely perforated or just one such portion, or possibly adjustable panels.

Claims (10)

Claims Apparatus for producing a clean air zone having a housing or a tent roof having a pressure equalization chamber and a supply means, including a fan and a filter for supplying clean air to the pressure equalization chamber, and a distribution means in the form of one or more perforated plates adjacent to the chamber so that the air supplied to the chamber flows through it, characterized in that the distributor means has a substantially planar central portion, and successive increments of air flow from the central portion are arranged at an increasing angle to the central portion. outwardly diverging districts. Apparatus according to claim 1, characterized in that non-perforated baffles are disposed between successive circumferential portions of the distribution device. Apparatus according to claim 2, characterized in that the successive circumferential portions of the distribution device have separate perforated plates which are separately connected to the respective non-perforated baffles. Apparatus according to claim 3, characterized in that the successive circumferential portions of the distribution means and the intermediate non-perforated baffles form a unit with the corresponding profile panels which are arranged around the central part of the distribution means. Apparatus according to claim 4, characterized in that elongated lamps are mounted on profiled boards around the periphery of the distribution device. Apparatus according to claim 5, characterized in that the cross-section of the lamps is tapered in such a way that the distribution of the airflow exiting the distribution means is minimized. 7. Apparatus according to any one of claims 1 to 4, characterized in that there is a slot for air flow out at right angles to the flow direction of the air flowing out of the central part of the distribution device along the peripheral edge of the distribution device. 8. Apparatus according to any one of claims 1 to 3, characterized in that the housing is mounted on or in the ceiling and the central part of the distribution device is in a substantially horizontal position and the air flow therefrom is directed downwards. 9. Apparatus according to any one of claims 1 to 3, characterized in that the housing is mounted on a wheelchair for moving over any desired area or machine. 10. Apparatus according to any preceding claim, characterized in that the housing consists of four substantially identical modules _z. The agent shall: z> * danubia Imi and Trademark Office Ltd. 26.