Patent Description:
To make the atmosphere into living or working spaces healthy, the market has developed various types of air purification devices. In general, air purifiers are devices that eliminate contaminants, toxic agents, powders, VOCs (Volatile Organic Compounds), etc. from the air through filters of different types. A natural air purifier is a device that uses the roots of plants or also the matrix in which they grow as filters.

In the roots there are microorganisms that actively biofiltrate toxic agents and decompose them. Currently available natural air purifiers promote the transport of air to the roots and/or culture matrix with ventilation systems integrated in the pots, as described, e.g., in US documents <CIT>, <CIT> and <CIT>. In these systems the air flow is not optimized within the pot which contains the plant and the matrix, as well as the purification itself which is not fully satisfying yet. Other flower pots for air purifying are described in <CIT>, <CIT>, <CIT>, <CIT>, <CIT> e <CIT>. Air purifiers with fan and photocatalytic filter are disclosed in <CIT> and <CIT>.

The object of the invention is to propose an improved air purifier for purifying the air in internal spaces, in particular an air purifier with an optimized air flow to the roots and through the matrix in which the roots are rooted. Another object of the invention is to further improve the degree of air purification with respect to the state of the art. These objects and others which will become evident from the following description of the invention are obtained by an air purifier as defined in the first claim.

The insertion of the second pot with the ribs in the first pot creates said gap between the walls of the pots and admit a defined air flow which is channeled through the slots also linearly towards the bottom of the system. Then, the slots allow the roots to exit from the second pot and their "diffusion" in the gap, where air enters easily to reach the roots.

The axial direction of the pot is to be understood as the vertical direction to the support surface, where the pot is placed.

In an advantageous variant of the invention, the fan is placed horizontally under the bottom of the second pot. Such a position creates a vertical air flow inside the purifier.

In a preferred variant of the invention, the ribs are forming at least a part of the bottom. To form a part of the bottom, the ribs branch off at the height of the bottom to continue downwards in a linear shape and in a curved shape inside the bottom.

The presence of the photocatalyst adds a further contribution to the purification, being the filter capable of degrading other compounds with respect to the natural components of the system. According to the invention, the filter is arranged in the space created under the bottom inside the lateral walls of the second pot.

Advantageously, the purifier according to the invention contains sensors to measure the air quality and a control and communication unit to manage the sensors, indicate the air quality and manage the fan speed based on the values detected by the sensors. These components are suitable for making the system autonomous and automatic.

Preferably, the first pot comprises a bottom which is provided with.

The water tank can be used for automatic irrigation of the system (if provided with relative ropes or capillaries that connect inside the second pot and/or the gap to supply water to the roots) and/or for the collection of water in excess. The presence of channels helps to channel the water flows.

The case is advantageously a recess in the external pot of the air purifier which is closed by an interface which communicates information on the system status to the user; i.e. preferably the case and the wall of the first pot each have an opening placed in correspondence between them to position LEDs and an interface for communicating with the user and possibly a light diffuser. Advantageously, the lid is provided with a series of oblique cuts that allow outside air to enter the sensor chamber for analysing the air quality. The cuts have been designed advantageously with a grating system to protect the electronic part from any water coming from the outside but guarantee a correct air flow.

In a very preferred variant of the invention, in the gap there is a granular matrix, in particular expanded clay, preferably with a grain size equal to or greater than <NUM>, more preferably with a grain size in the range from <NUM> to <NUM> determined according to the UNI EN <NUM>-<NUM> standard, paragraph <NUM>. This granular matrix has deflector capacities, like the ribs of the second pot, and can be penetrated by roots through the interstices. These characteristics allow a good passage of air and a good accessibility to the roots that are also found in the channels (interstices) created between the granules that act as deflectors.

The purification system illustrated is characterized by two stages, the first entirely natural consists of the plant and its root apparatus, the second consists of a photocatalytic filter, in particular a ceramic honeycomb filter (SiO<NUM>) treated with titanium dioxide (TiO<NUM>) and activated with UVA type ultraviolet LED light.

One of the active hearts of the purification system is the plant. In nature, plants have the ability to remove harmful agents present in the air not only through their volatile part (the leaves) but also through the root apparatus and its interaction with the cultivation substrate. In this lower region of the plant, bio-chemical processes take place which permit to block and degrade/convert harmful substances present in the external air, purifying the air.

The system according to the invention has been designed to amplify and make this natural property of common houseplants more effective.

To ensure a greater and constant air flow through the root apparatus, the upper part of the air purifier has been designed by carefully calibrating the full and empty areas.

The key element is the central crown, that is the second ribbed pot, where the plant is housed. The crown is characterized by a series of ribs arranged at regular intervals, which keep the plant in an optimal position, leaving the space necessary for the passage of the air flow and the growth of the roots.

Between the central crown and the internal wall of the pot, a gap is created, which is advantageously filled with inert material (for example expanded clay) and has the function of regulating the supply of air between the first filtering stage (the plant) and the second (the photocatalytic filter), balancing it and significantly increasing the air flow.

With this system, the growing roots of the plant will invade the gap, thus ensuring better growth for the plant and an increase in purification capacity.

In the studies conducted by the inventors, it has been noted that this first filtering stage is particularly effective in the abatement of VOCs (volatile organic compounds).

In the second stage, the air purifier houses a photocatalytic filter, consisting for example of a ceramic honeycomb filter, <NUM> in diameter, dip-coated with titanium dioxide (TiO<NUM>) nanoparticles, and activated by four UVA LEDs. Other filters that the person skilled in the art can easily identify with his general knowledge are conceivable.

Photocatalysis is a natural process by which light hits a mineral (such as titanium dioxide - TiO<NUM> - a common mineral) and activates a chemical process that safely and instantaneously oxidises and decomposes organic matter to form water steam and carbon dioxide.

All the air conveyed by the ventilation system ultimately passes through this second filtering stage, which guarantees the elimination of viruses, bacteria and odours.

Such a filter is not subject to wear, it does not need to be replaced, but it's necessary to simply wash it with running water to clean it.

The combination of photocatalysis with the plant guarantees a significant improvement in purification performance.

The air purifier according to the invention, thanks to a forced air ventilation system (preferably characterized by a fan placed horizontally), advantageously completely automated, conveys the external air inside the filtering system, first towards the root apparatus of the plant, then towards the photocatalytic filter, to then come out of the system, for example from an opening located along the lower edge of the pot.

The slots in the crown have the following functions:.

A further aspect of the invention relates to a method for purifying the air of a space using the air purifier according to the invention, containing a plant in the second pot, comprising the following steps.

The features described for one aspect of the invention may be transferred mutatis mutandis to the other aspect of the invention.

Embodiment variants of the present invention and further objects and advantages are described hereinafter with reference to the drawings. Embodiment variants of the invention are the object of the dependent claims. The description of preferred executive examples of the air purifier and his use according to the invention is only given in an exemplary and non-limiting manner.

<FIG> is an exploded view of an embodiment variant of an air purifier according to the invention. Starting from the bottom, there is a base <NUM> which can be made of various materials, such as metal, plastic or wood, such as beech wood. On the base <NUM> the entire remaining system is constrained by means of screws to be inserted in the four holes 2a, for example, applied in the base <NUM>. In the lower part, the base <NUM> has a milling around the perimeter of the same which allows the housing of a power cable (not shown).

On the base <NUM> there is a fan <NUM> which is arranged in a horizontal position but causes an air vortex in the axial direction of the air purifier. A 12V fan with a diameter of <NUM> and a height of <NUM>, designed to minimize noise, can be chosen as a fan <NUM>. Its maximum rotation is <NUM> rpm (+/- <NUM>%). Its maximum flow rate in ideal conditions is <NUM><NUM>/h; its maximum noise emission is <NUM> dB (A). Thanks to the fan <NUM>, the external air is conveyed into the system, passing through the central crown <NUM> and the gap <NUM>, as will be illustrated with reference to <FIG> and <FIG>.

Above the fan <NUM> there is a LED UVA board <NUM> (light emitting diode of the ultraviolet type A), i.e. an electronic board that houses four UVA LEDs that allow the activation of a photocatalytic filter <NUM> thanks to their light beam.

An electronic closing box <NUM> made of ABS (acrylonitrile butadiene styrene) is then provided, which represents the closing system of the entire electronic part by means of two screws.

The electronic board <NUM> represents the brain of the product, in addition to a LED system, a power connector and a reset button, it houses temperature, humidity, VOC (volatile organic compounds), CO (carbon monoxide), CO <NUM> (carbon dioxide), PM2. <NUM> (particulate material having an average aerodynamic diameter of less than <NUM>) and proximity sensors. It also has a connectivity system consisting of: a Wi-Fi module; a Bluetooth module; a microcontroller to remotely manage the system.

A light diffuser <NUM>, made of semitransparent material, is capable of diffusing and amplifying the LED light beam. In addition to its main feature, on both sides it is provided with a series of oblique cuts that allow outside air to enter the sensor chamber for air quality analysis. The cuts have been designed with a grating system to protect the electronic part from any water coming from the outside but guarantee a correct air flow.

A carcass bottom <NUM>, here made of ABS, is the support on which all product technology is mounted. It houses the honeycomb photocatalytic filter <NUM>, the lid <NUM> for the components <NUM> and <NUM> previously illustrated, the UVA LED board <NUM>, the fan <NUM>, and, within a space 14c, the light diffuser <NUM>, the electronic board <NUM> and the electronic closing box <NUM>.

The lid <NUM> is made of bioplastic, and represents the product interface. Thanks to a series of LEDs placed on the back, it communicates the air quality to the user through a light code.

On the carcass <NUM>, another annular-shaped carcass is placed which acts as a tank <NUM> which is made of bioplastic and houses about <NUM> litres of water. The tank <NUM> surrounds a cylindrical or tubular part 14a of the carcass <NUM> which comprises a grid 14b which protects from the wings of the fan <NUM> and serves as a support for the photocatalytic filter <NUM> admitting at the same time an air flow.

The honeycomb filter <NUM> is made of ceramic sponge (SiO<NUM>), has a diameter of <NUM> and is dip-coated (coating by immersion) with titanium dioxide (TiO<NUM>) nanoparticles and is used for photocatalysis.

Everything described so far is housed on the base <NUM> inside a pot (composed of lateral walls <NUM> and a bottom <NUM>) which has an opening 22a which can be closed by the lid <NUM>.

The pot also receives a part of the heart of the invention, and precisely a crown <NUM> which serves as a container for the matrix for the roots of the plant to be grown in the natural air purifier. The crown is also made of bioplastic, it houses the plant and allows a greater air flow into the system. It is characterized by a series of ribs 24a placed at regular intervals creating slots between the ribs 24a. In the shown example, the ribs, i.e. rod-shaped elements, 24a are arranged in a vertical position around a ring 24b spaced from each other to form a slot each time between two adjacent ribs creating a succession of a series of essentially parallel slots which extend around the entire perimeter of the crown <NUM> and across the entire height thereof. At a certain height inside the crown <NUM> there is a bottom <NUM> provided with four drain channels 24c which lead directly to the tank <NUM>, thus allowing excess water present in the lower part of the crown to drain onto the bottom <NUM> and into the tank <NUM> without invading the electronic part of the system. The air can pass along the entire length of the slot passing from the part of the crown <NUM> upper to the bottom <NUM> to the part of the crown <NUM> lower to the bottom <NUM>, the ribs 24a being placed perimetrically around the bottom <NUM> whose perimeter essentially coincides with the ring 24b. The diameter of the crown <NUM> is greater than that of the cylindrical part 14a of the carcass <NUM>; so that between the two components an opening of about <NUM> is created which allows the water to flow also directly into the tank (this opening is provided for a possible not recommended watering of the plant from above).

A self-watering cap <NUM> made of semitransparent plastic material and a float <NUM> housed by the latter complete the system. The float <NUM> is made of plastic and expanded material and marks the water level in the tank.

<FIG> shows a side view of the air purifier of <FIG> in the assembled state. The pot is applied on the base <NUM> so as to leave an empty space between both for the passage of the air coming out of the pot. The lid <NUM> closes the opening 22a (not visible) which contains the electronic boards. Note also the float <NUM>.

<FIG> illustrates the assembled air purifier of <FIG> in a section view. The crown <NUM> and the photocatalytic filter <NUM> are permeable to air thanks to respective holes in the filter and the passages created by the slots between the ribs 24a in the crown <NUM>. A gap <NUM> is observed between the inner wall of the pot <NUM> and the crown <NUM> which allows to direct an air flow entering the pot from above through this gap <NUM> and the slots in the crown <NUM>. The air flows created inside the system are evident from <FIG>.

<FIG> shows the air purifier in the view of <FIG> provided with cultivation matrices and a plant <NUM> indicating the air flows <NUM> inside the purifier. The gap <NUM> is filled with an inert expanded material which, thanks to the pores created therein, allows an air passage. The crown <NUM> is filled in the lower part <NUM> by the same expanded material as the gap <NUM> and in the upper part <NUM> by a soil particularly suitable for the purposes, as described, for example, in the patent application of the same applicant <CIT> not yet published. The soil comprises a mixture of an organic matter containing soil and a granular material of a grain size between <NUM> and <NUM>. Above is a layer of expanded material again. The plant <NUM> develops roots that also cross the slots in the crown <NUM> and reach the gap <NUM>. The air passing through the latter easily reaches the roots which provide an efficient natural air purification. Activating the fan <NUM>, the air, following the direction of the arrows <NUM>, enters the gap <NUM> and the crown <NUM> passing the relative matrices contained therein and reaches the roots to be conveyed then towards the bottom <NUM> of the crown <NUM> and along the slots which it passes through in the part of the crown <NUM> below the bottom <NUM> to pass the photocatalytic filter <NUM> which is activated by the UVA LED board <NUM>, all drawn by the action of the fan <NUM> below. The air path <NUM> follows the axial direction of the purifier.

The air purifier presented is a smart pot that combines an innovative natural air purification system, based on the phytodepuration principle, with a sophisticated air monitoring system with sensors, all managed through an application.

The purifier is also provided with a passive self-watering system, consisting of a tank with <NUM> litres capacity, and two cords, which by capillarity allow the plant to absorb the necessary amount of water. In the upper part of the pot there is a cap in semitransparent material, from which you can see the water level by means of a float.

Claim 1:
An air purifier comprising:
(a) a first pot (<NUM>, <NUM>);
(b) a second pot (<NUM>) which is provided with a bottom (<NUM>) and is housed inside the first pot (<NUM>, <NUM>) in which the lateral walls of the second pot are formed by a plurality of ribs (24a) which extend in the axial direction of the pot (<NUM>) and in which adjacent ribs are arranged essentially parallel to each other, creating slots between them essentially of the length of the ribs (24a), wherein a gap (<NUM>) is formed between the first pot (<NUM>, <NUM>) and the second pot (<NUM>) which preferably extends at least along the entire length of said slots;
and
(c) a fan (<NUM>) suitable for carrying out an air flow between the inside and the outside of said air purifier,
characterized in that said air purifier further comprises
(d) an air permeable photocatalytic filter (<NUM>) arranged between the bottom (<NUM>) of the second pot (<NUM>) and the fan (<NUM>) and (e) a light source (<NUM>) for activating the catalyst of the photocatalytic filter (<NUM>); and in that
said bottom (<NUM>) of said second pot (<NUM>) is located at a certain height inside said lateral walls of said second pot (<NUM>) and that said ribs (24a) are arranged around said bottom (<NUM>) extending beyond the bottom (<NUM>) downwards and also forming at least a part of the bottom (<NUM>) admitting an air flow along said slots from the part of said second pot (<NUM>) which is located above the bottom (<NUM>) towards the part of said second pot (<NUM>) which is located under the bottom (<NUM>) and creating a space under the bottom (<NUM>) inside said lateral walls; and in that
the photocatalytic filter is arranged in the space created under the bottom inside the lateral walls of the second pot.