"Electrostatic device with high hourly capacity for indoor air sanitization"

The first historical evidence, written in cuneiform script, of empirical and magical remedies for improving the sanitary conditions of the environment and combatting contagious diseases dates back to the second millennium BC in Mesopotamia. Since then, attention and interest in this subject have been periodically rekindled during the recurrent epidemics that have arisen over the centuries. A treatise written in 1416, entitled "Rules for Government during the Plague", indicates the procedure for burning incense and other aromatic resins to combat "air corruption".

Following the research published by Lazzaro Spallanzani in 1765 and the advent of the scientific approach, we leave the supernatural behind. In the modern era, with the involvement of NASA, in the 1960s and 1970s, environmental sanitisation became an important branch of technology, which has since expanded from the cockpits of the Project Gemini spacecraft to all environments, whether public, private or industrial. In the last decade, different types of devices have been manufactured that operate through photocatalysis systems with electromagnetic radiation at various frequencies I? and also with coherent light, giving satisfactory results in terms of the degree of contaminant reduction. These have, however, presented some critical issues regarding the ratio between the volume of air treated and installed power and the ratio between sanitation efficiency and operating costs.

The particular technologies adopted in the electrostatic device, which are the subject of this patent application, are aimed at absorbing and concentrating microscopic and sub-microscopic contaminants, such as bacteria and viruses, into much larger structures.

The greater interactivity of these liquid particles in gaseous suspension with the use of high-voltage electrostatic fields on the atomised mist leads to the total aggregation of all viral and bacterial particles on the gaseous suspension nuclei.

This mist in gaseous suspension, generated in the injection zone of the particular atomised solution, is particularly effective for the subsequent decomposition phase of the protein capsids of viruses and of the cell wall of bacteria. Decomposition is carried out in the special multi-reflective duct, consisting of a mirror chamber that creates planes of coherent light from numerous high-efficiency UV emitting diodes. The coherent radiation is diffused and strongly absorbed around the mist particles, where the contaminants are most concentrated. The strong interaction between the UV laser radiation and the embedded particles makes the protein alteration process of the DNA and RNA associated with viruses and bacteria extraordinarily fast and efficient. This technology makes it possible to treat considerable airflow rates of 500 - 1000 m ³ /hour with limited power consumption.

Fig. 1 shows the external shape of the electrostatic device, which is mounted on four pivoting wheels (3) for movement and is lockable in the operating position.

The air intake port Ea (5) is positioned on an external wall at the base. On the upper end of the external wall is the sanitised air outlet duct Oa (60) and the control knob (2) for starting the electrostatic device and for adjusting the flow rate of the air being treated within the operating range, between minimum and maximum flow. The perimeter panels (1), which can be easily removed and opened, enclose the electrostatic device itself and not only perform visual and structural functions, but also constitute sound-absorbing elements, significantly contributing to the overall quietness of the electrostatic device during operation.

Fig. 2 shows both front and rear views of the set of all the components that make up the electrostatic device, positioned on the platform (4) equipped with special elastic shock absorbers (61) that act as high damping anti-vibration mounts, contributing to the noticeable quietness of the electrostatic device.

The set of components consists of: variable flow turbofan (6), refrigeration compressor (15), heat exchanger (7), box containing the electronic boards that are part of the command and control system of the electrostatic device (62) , collection tank of the specific liquid treatment solution (30), peristaltic pump (46), rectangular cross-section duct (12), exchange cooler (38).

The variable flow turbofan (6) draws air from the environment through the air intake Ea (5) and directs it into the rectangular cross-section duct (12), passing through the heat exchanger (7). The refrigeration compressor (15), through the pipes (16 - 18), sends the heating fluid to the heat exchanger (7), thus allowing the temperature of the air sucked in from the environment to rise. The specific liquid treatment and agglomeration solution (41) is collected at the bottom of the tank (30), the forr ulation of which is the subject of a separate patent application. The device (25) for managing the specific liquid treatment solution .T* is fixed on the upper part of the tank (30). The peristaltic pump (46), which carries the specific treatment and agglomeration solution (41), is assembled between the tank (30) and the rectangular cross-section duct (12). The tank (26) used for refilling the specific liquid treatment solution is positioned on the upper part of the rectangular cross-section duct (12). The interchangeable cartridge line filter (20) is mounted on the side of the tank (26). The rectangular cross-section duct (12) is semi-circular in shape and contains numerous rectangular silica mirrors (14) with high ultraviolet reflectance, thus forming a highly efficient multi-reflecting chamber. In the lower part of the rectangular cross-section duct (12), a container is fixed inside in which there is a particular electrical circuit with high-voltage coils, 15 - 30 KV (11), which feed the injection system of the specific treatment solution.

The specific liquid treatment and agglomeration solution (41), which is located in the lower part of the tank (30), is sucked by the peristaltic pump (46) through the highly insulated flexible tube (42), which connects the outlet hole (29) of the tank (30) with the interchangeable cartridge line filter (20). At the outlet of the interchangeable cartridge line filter (20) there is another flexible tube with high electrical insulation (42) which connects the filter itself with the rectangular cross-section duct (12) and which in the terminal part has a special group of injector nozzles (10) made of electro-conductive material subjected to high voltage through the particular electric circuit with high-voltage coils, 15 - 30 KV (11).

In the upper part of the rectangular cross-section duct (12) there are numerous diodes (12 30) of UV frequency laser light (13) that emit laser lines. The latter, as a result of the very numerous reflections on the rectangular silica mirrors (14), form a series of coherent light planes.

The peristaltic pump (46), owing to its special design, can generate considerable pressure which causes the specific liquid treatment and agglomeration solution (41) to take the form of a dense atomised mist with positive electrical charge at the outlet from the injector nozzles (10) by virtue of the action of the particular electrical circuit with high-voltage coils, 15 - 30 KV (11). In the rectangular cross-section duct (12), this positively-charged atomised mist encounters the flow of contaminated air coming from outside through the variable-flow turbofan (6) and engulfs all the viral particles, known to be negatively charged, attracting these and the bacteria present in the contaminated air stream. The resulting fluid current crosses the coherent light planes, enabling the decomposition of the viral capsids, thus completing the sanitisation process of the aspirated air.

The exchange cooler (38), fed into the cold sector of the fluid carrier of the refrigerating compressor (15) by means of the pipes (17 - 19), is connected to the outlet of the rectangular cross-section duct (12). The air that passes through the exchange cooler (38) is sanitized and is released into the environment through the sanitised air outlet duct Oa (60).

The optimal efficiency of the sanitisation process derives from the high electrical voltage value used and therefore requires a high degree of electrical insulation, avoiding the occurrence of electric discharge on the sanitising liquid.

At the same time, in the exchange cooler (38) the dense atomised mist is condensed and descends, in a liquid state, into the containment tank (25). By means of the synchronised solenoid valve (28), the specific liquid treatment and agglomeration solution (41) flows out of the nozzle (37) with cyclic intermittent operation, filling the hemispherical loops of the rotor (32) operated by the toothed pulley (58) through the toothed belt (35), which ensures the rotary valve (32) operation. The revolving motion of the rotary valve (32) is ensured by a particular intermittent motion mechanism consisting of a conical toothed crown (53) placed inside the oil bath box (50), driven by the electric motor (55) and fed through the connector (59). The particular intermittent motion mechanism (53) has a shaft (56) positioned on the fixed support (57).

To achieve the condition of electrical insulation, the rotary valve (32) is made of Teflon loaded with silicon carbide micro-particles. The collection tank of the specific liquid treatment solution (30) is also made of a similar material. The synchronism between the solenoid valve (28) and the rotary valve (32) is achieved by means of a particular intermittent motion mechanism (53).

The rotary valve (32) is coaxial with the driven toothed pulley (34), keyed onto the shaft (33), supported by the sides (31) and constrained by the cover (36).

The shape of the intermittent exhaust mechanism allows a stop pause for the filling of the specific liquid treatment and agglomeration solution (41), which comes out of the nozzle (37), whose opening is controlled by the solenoid valve (28).

The driving toothed pulley (58) is concentric and integral with the disc (48) in whose three radial and equidistant grooves runs the roller (51) integral with the crank (49) rotating from the shaft (54), on which the bevel crown (53) is fitted, uniformly rotated by the coupled bevel pinion (52) fitted on the shaft of the electric motor (55). The whole mechanism is contained in the oil bath box (50). For a given ratio between the radius "r" of the crank,(49) and the radius "R" of, the disc (48), it is calculated that, for each 120° arc of rotation, the disc and therefore also the pulley (58) remain stopped allowing the sequential filling of the hemispherical containment loops, while the electric motor (55) continues to rotate at uniform revolutions. When the crank (49) meets the next channel of the disc (48), the rotation of the same disc (48) resumes for another 120° and therefore the rotor (32) is able to fill the next containment loop, simultaneously discharging the former into the collection tank (30) for the specific liquid treatment and agglomeration solution (41).

With the adoption of this construction scheme, an electrical interruption of the specific liquid treatment and agglomeration solution (41) is established, preventing the formation of electric discharges between the liquid accumulated in the collection tank (30) and that contained in the tank (25) which is connected to ground. Under these operating conditions, excellent and reliable operational functionality is achieved, with maximum operating safety of the sanitising equipment.

The peristaltic pump (46) is also built in insulating materials, with the idle rollers in ceramic (43) and the flexible tube (42) in reinforced silicone rubber.

The particular internal profile of the track (47) of the pump body is suitably combined with the flexible hose (42) deformed during rotation by the action of the rollers (43) moved by the shaft (45) and integral with the triangular drive plate (44).