Patent Description:
Biologic reactors are known and used in the purification of industrial and/or civil liquid waste (in particular containing water) and in applications where the culture of microorganisms is used to carry out microbiological processes adapted to prepare chemical and pharmaceutical substances; as is known, there are aerobic microbiological processes and anaerobic microbiological processes.

Biologic reactors with fixed biomass (also known as "adhering") are known; the biomass is fixed to a "contactor". An important factor in this type of reactor is the area of the contact surface between biomass and liquid to be treated, in particular the area of the contact surface per unit of volume of the contactor (expressed for example in m2/m3).

Fixed-biomass biologic reactors with rotating contactors are known, for example from European patents no. <CIT> and no.

In general, the contactors of known biological reactors have drawbacks linked to mechanical stresses; in particular, the torque moment on the masses involved can cause mechanical breakages.

In general, a further drawback is linked to the proliferation of "undesired" microorganisms which can hinder the growth of and/or the activity of and/or access to the "desired" microorganisms which should determine the operation of the reactor.

From document <CIT> a bioreactor is known for the treatment of municipal or industrial contaminated water in which there is a conical "helicoid" (called in this document "filling body" and shown in <FIG>) covered with a microbiotic mix, home to biological reactions. According to this solution, the microbiotic mix consists of two different types of microorganisms: the microorganisms of a first type are adapted to emit light and the microorganisms of a second type are adapted to receive the light emitted by the others and use it to make photosynthetic reactions. Again according to this solution (see paragraph <NUM>), in the upper part of the "helicoid" there are microorganisms and there is biofilm formation and in the lower part there is a catalyst, in particular a photocatalyst (for example titanium oxide as indicated in paragraph <NUM>), which avoids the formation of biofilm and serves to start the process of degradation of polluting substances which is then completed by microorganisms; moreover, the catalyst or photocatalyst can also be positioned on the walls of a basket which surrounds the "helicoid". This document also discloses a solution with cylindrical "helicoid" (Fig. <NUM>) which is similar to the solution with conical "helicoid" (<FIG>) as regards the positions of microorganisms and catalyst. It is therefore understood that the microorganisms must be fixed to the helicoid in a suitable position, i.e. in such a way that they are separated from the catalyst or photocatalyst.

The document <CIT> discloses a fixed-biomass biologic reactor with rotating cylindrical contactor with a horizontal axis; the contactor comprises walls which extend radially from the centre of the contactor and which define angular sectors in which a plurality of filling bodies covered with biomass are arranged. In cross section (the section is uniform moving along the direction of the rotation axis of the contactor - see <FIG>), it is seen that the walls form a sort of turbine which is rotated by gas bubbles which are generated on the bottom of the reactor at a given distance from the contactor. It is understood that the bubbles remain in contact with the filling bodies for a relatively short time (corresponding to the time taken by the contactor to make half a turn) and substantially always with the same filling bodies, i.e. those that are close to the walls.

The general object of the present invention is to improve the known art.

This general purpose and other specific purposes are substantially achieved thanks to what is expressed in the appended claims which form an integral part of the present description.

The idea behind the present invention is to use a rotating helicoid in the contactor, in particular shaped like an "Archimedes screw", and a plurality of filling bodies on which biomass is fixed; in particular, the helicoid is located inside a tube (closed laterally, but not at the ends) of the contactor; in particular, the filling bodies are placed in one or more compartments of the helicoid and/or in one or more compartments of the tube in the inner space of the tube not occupied by the helicoid.

A "helicoid" is a surface generated by the rotation and at the same time by the translation of a curve along a line, where said line constitutes the axis of the helicoid. In other words, a helicoid is a surface formed by screwings having a given diameter around an axis, spaced by a pitch defined by the translation motion in the direction defined by the axis. In particular, the surfaces of two consecutive screwings define at least one free space, that is a space not occupied by the helicoid. For the purposes of the present invention, the helicoid can have a variable pitch and/or a not constant diameter.

The present invention shall become more readily apparent from the detailed description that follows to be considered together with the accompanying drawings in which:.

As can be easily understood, there are various ways of practically implementing the present invention which is defined in its main advantageous aspects in the appended claims.

The biologic reactor according to the present invention can have various applications according to the specific embodiment. It can find application for example in the purification of industrial and/or civil liquid waste and in the preparation of chemical and pharmaceutical substances. It can be used both to carry out aerobic microbiological processes and to carry out anaerobic microbiological processes.

In general and as shown in <FIG> and <FIG>, a reactor <NUM> comprises a tub <NUM> adapted to contain a liquid to be processed, and a contactor <NUM> placed in the tub <NUM>. The tub <NUM> can be opened or closed according to the desired process. The contactor <NUM> contains biomass and, during the operation of the reactor <NUM>, it is traversed by the flow of the liquid contained in the tub <NUM>; in this way, the flowing liquid comes into contact with the biomass and is subject to microbiological processes by the biomass. The contactor <NUM> comprises a helicoid adapted to rotate during the operation of the reactor <NUM>, and a tube in which the helicoid is located. As shown in the attached figures, this helicoid is shaped like an "Archimedes screw". As will be understood hereinafter, the contactor of a reactor according to the present invention could comprise multiple tubes. Typically, the helicoid of the contactor <NUM> is completely immersed in the liquid of the tub <NUM>.

Typically, a reactor according to the present invention is equipped with multiple contactors or with a multiple-helix contactor; however, simple examples with a single helicoid contactor are described here.

In the embodiments of <FIG> and <FIG>, the axis of the helicoid (i.e. the rotation axis of the helicoid) is positioned in such a way as to form an angle with respect to a horizontal plane, i.e. it is fixed, during the operation of the reactor. Preferably but not necessarily, the angle is a right angle, i.e. <NUM>°.

In the embodiments of <FIG> and <FIG>, the axis of the helicoid and the axis of the tube coincide; in practical embodiments, the axes may not even exactly coincide.

In the embodiments of <FIG> and <FIG>, the length of the helicoid and the length of the tube coincide; alternatively, the tube could be a little longer than the helicoid at one or at each end, and/or a little shorter than the helicoid at one or at each end.

In <FIG>, the side wall of the tube <NUM> is entirely full, i.e. there can be no flow of liquid through this wall. Alternatively, the tube <NUM> could have a side wall partially or entirely with openings, for example pierced.

In <FIG>, the side wall of the tube <NUM> is entirely with openings, i.e. there is flow of liquid through this wall; the tube <NUM> can be, for example, an entirely full wall tube with side holes or an entirely mesh tube. Alternatively, the tube <NUM> could have a partially or entirely full side wall.

In <FIG>, the helicoid <NUM> and the tube <NUM> are separated from each other. Typically, the helicoid <NUM> is adapted to rotate and the tube <NUM> is adapted to remain fixed.

In <FIG>, the helicoid <NUM> and the tube <NUM> are joined together. Typically, the helicoid <NUM> and the tube <NUM> are adapted to rotate integrally. In <FIG>, the angle of the axis of the helicoid <NUM> is about <NUM>°.

In <FIG>, the angle of the axis of the helicoid <NUM> is about <NUM>°.

The reactor <NUM> of <FIG> and <FIG> can comprise a motor <NUM> adapted to rotate at least the helicoid; the motor <NUM> is drawn with a dotted line because its presence is advantageous, but not essential and depends on the specific embodiment of the present invention. By way of non-limiting example, in <FIG> and <FIG> the motor <NUM> is completely external to the tub <NUM>, in <FIG> and <FIG> the motor <NUM> is partially internal and partially external to the liquid of the tub <NUM>, in <FIG> and <FIG> the motor <NUM> is completely external to the liquid of the tub <NUM>. It should be noted that a mechanical transmission <NUM> can be placed between the motor shaft <NUM> and the helicoid shaft.

The reactor <NUM> of <FIG> and <FIG> can comprise a generator <NUM> of gas bubbles (for example air) adapted to emit gas bubbles in the liquid of the tub <NUM>; the generator <NUM> is designed with a continuous line because its presence is advantageous and very typical, although not essential, and depends on the specific embodiment of the present invention. The generator <NUM> can be adapted to emit gas bubbles in the tub <NUM> and/or in the tube of the contactor <NUM>.

The generator <NUM> can be adapted to rotate at least the helicoid due to the gas bubbles emitted. In this case, for example, the generator <NUM> can be adapted to emit gas bubbles in the vicinity of a first end of the helicoid and/or of the tube.

The simultaneous presence of both a motor and a gas bubble generator may be envisaged.

As previously mentioned, the contactor <NUM> contains biomass. According to the present invention the contactor <NUM> contains a plurality of filling bodies and the biomass is fixed only on the filling bodies; the filling bodies are in one or more compartments of the helicoid and/or in one or more compartments of the tube in the inner space of the tube not occupied by the helicoid. According to a non claimed second possibility, the biomass can also be fixed on the helicoid (and/or the accessories thereof). According to a non claimed third possibility, the biomass can also be fixed on the tube (and/or the accessories thereof). These three possibilities can be combined between them.

According to some advantageous embodiments of the present invention, the degradation of polluting substances is taken over only by the biomass fixed on the filling bodies, in particular to the microorganisms contained. In this way, for example, the "regeneration" of the reactor can be achieved very simply by replacing the filling bodies.

Typically, the filling bodies can be granules or pellets that act as a support for biomass. "Granules" refers to small bodies having irregular shape and, in general, shape and size that are different from each other; their size can range from for example a few millimetres to for example ten millimetres. Their surface can be porous.

"Pellet" refers to a body having a shape typically larger than a granule, for example with size that can range from about ten millimetres to for example a hundred millimetres. In general, they can have various forms, typically hollow (for example with a filling index greater than <NUM>% or <NUM>%), so as to allow them to be traversed by a fluid and increase the surface available to the interaction between biomass and fluid. Their surface can be porous. Pellets of this kind are produced for example by the company Ecoplast Srl - see the link "https://www. it/site/prodotti".

The reactor <NUM> of <FIG> and <FIG> is similar to the reactor of <FIG>.

The reactor <NUM> comprises a tub <NUM> adapted to contain a liquid to be processed, and a contactor <NUM> placed in the tub <NUM>.

The contactor <NUM> comprises a helicoid <NUM> adapted to rotate during the operation of the reactor <NUM>, an inner tube <NUM> joined to the helicoid <NUM>, and an outer tube <NUM> (in particular coaxial and with a slightly larger diameter) separated from the helicoid <NUM> and adapted to remain fixed during operation of the reactor <NUM>. The contactor <NUM>, in particular the helicoid <NUM>, is completely immersed in the liquid of the tub <NUM>.

The axis of the helicoid <NUM> (i.e. the rotation axis of the helicoid) is placed in such a way as to form an angle of about <NUM>° with respect to a horizontal plane, i.e. it is fixed. The axes of helicoid <NUM>, of the tube <NUM> and of the tube <NUM> coincide.

The length of the helicoid <NUM>, of the tube <NUM> and of the tube <NUM> coincide.

The side wall of the outer tube <NUM> is entirely full.

The side wall of the inner tube <NUM> is entirely with openings.

The angle of the axis of the helicoid <NUM> is about <NUM>°.

The reactor <NUM> can comprise a motor <NUM> adapted to rotate the helicoid <NUM> and the inner tube <NUM>.

The reactor <NUM> comprises a generator <NUM> of gas bubbles (for example air) adapted to emit gas bubbles in the tub <NUM> in the vicinity of the lower end of the helicoid <NUM>, of the tube <NUM> and of the tube <NUM>. Said gas bubbles can contribute to rotating the helicoid <NUM> and the inner tube <NUM>.

In <FIG>, filling bodies <NUM> on which biomass is fixed are schematized; the bodies <NUM> are placed in compartments of the helicoid <NUM>.

As can be seen particularly well in <FIG>, the helicoid <NUM> can have a circumferential edge <NUM> (which can be full or pierced) which extends (at least in part) axially; the edge <NUM> is preferably full to contain both the filling bodies and the gas bubbles, but it can also be with openings (for example pierced).

As can be seen particularly well in <FIG>, the helicoid <NUM> can have a plurality of septa <NUM> which extend (at least in part) axially and radially; the septa <NUM> are preferably full to contain both the filling bodies and the gas bubbles, but they can also be with openings (for example pierced).

It is advantageous that the circumferential edge and the septa are present in combination. Each of these elements serves to constrain the filling bodies to the "helicoid", however avoiding a fixed connection; in other words, the filling bodies may have small movements with respect to the "helicoid" during the operation of the reactor which are very useful in exploiting the active biomass at best.

In general, the active biomass can be also fixed (in addition to the filling bodies <NUM>) to one or more of the following components:.

In the example of <FIG> and <FIG>, during the operation of the reactor <NUM>, there is flow of liquid and gas bubbles from a lower end of the outer tube <NUM> to an upper end of the outer tube <NUM>.

The flowing liquid is subject to microbiological processes by the biomass present in the contactor <NUM>.

Claim 1:
Reactor (<NUM>) comprising a tub (<NUM>) adapted to contain a liquid and a contactor (<NUM>) placed in said tub (<NUM>) and adapted to be traversed by a flow of said liquid, wherein said contactor (<NUM>) contains a plurality of filling bodies on which biomass is fixed, said biomass being adapted to carry out a microbiological process on the flowing liquid, wherein said contactor (<NUM>) comprises:
- a helicoid (<NUM>, <NUM>) adapted to rotate, and
- a tube (<NUM>, <NUM>) in which the helicoid is located (<NUM>, <NUM>);
characterised in that the biomass is fixed only on the filling bodies, the filling bodies being placed in one or more compartments of the helicoid and/or in one or more compartments of the tube in the inner space of the tube not occupied by the helicoid.