"INTERNAL VENTILATION SYSTEM"

The internal ventilation is a set of elements which have the aim of substituting the secondary ventilation system for drains with what is being proposed here.

STATE OF THE ART:

It is known that the sewer drainage system for the civilian homes is equipped with ventilation ducts which have the function of eliminating the presence of pressures in the discharge pipes caused by the fast drainage of the waters in the pipes. This is to avoid eddies that drain the siphons with consequent leakage of foul smells which go from the sewer to the sanitary ware.

The ventilation systems are generally constituted by a primary system and a secondary system. The primary system connects the sewer drainage to the top of the buildings through pipes; the secondary system connects the drainage pipes of the WCs to the primary ventilation system or it is simply brought out of the building and left free.

The open extremities of the columns vents of the ventilation system are placed on the outside of the building and placed in a way that the vapours and the bad smells coming from the system, will not come into contact with the inside of the building.

In the buildings, in addition to the primary ventilation, it is desirable to achieve a secondary ventilation by connecting the WCs to the column vent or anyway connected to the outside of the building through appropriate ducts. This solution is particularly expensive because the pipes have to be located within the walls and almost always have to cross structural reinforced concrete elements.

The patents: US 2014/0090160 A, WO 2008/055911 A, DE 195 35 600 A offer some similarities which are only apparent because do not involve the secondary ventilation of the sewer drainage system but involve picking up the bad odours present in the bathroom and pushing them in the sewer drainage via fans. The differences are both in the form and in the concepts.

The patent which is most similar to the proposed is "VENTILATION SYSTEM WITH SIPHON-VENT" which I submitted on 29 ^th April 2014 with Number SA2014A000005 which foresaw the use of a duct connecting the drain pipe from a point placed in proximity of the WC to another point placed inside the cistern and which forms a siphon with the water present in the cistern.

A substantial difference with the proposed patent is that the connection between the ventilation system and the drainage happens directly with the WC and not in a point of the duct next to the WC; the proposed solution requires a WC specifically constructed for this function and the other components of the mechanism designed so as to interface with this WC.

The main advantage of the proposed sotution is that it allows the equipment of secondary ventilation (substituted by the internal ventilation) on all existing systems without any work on the drainage pipes because it is possible to simply substitute the WC with its cistern utilizing the pre-existing attachment of the WC to the sewer drainage system.

In other words, the internal ventilation is constituted by a duct (Cv) which allows communication between the sewer drainage, immediately after the siphon of the WC and in a point belonging to the same WC, with the cistern and which forms a siphon with the water present in the cistern. On this duct there is a unidirectional valve which allows a possible flow of air from the cistern (therefore from the inside of the bathroom) towards the duct of the sewer drainage system.

The proposed solution can be seen as a set of elements, a specific WC, a specific cistern, a duct and a unidirectional valve: the WC including a section of the duct (A-B), the duct B-C which goes from the WC to the cistern, cistern which incorporates a section of the duct or equipped with a specific hole for the passage of the duct, last section C-D which forms a siphon with the water present in the cistern (to form a siphon it is sufficient that the extremity of the duct is immersed in the water); a unidirectional valve is placed on the duct B-D. The unidirectional valve can be one piece with the siphon, hence it becomes a siphon-valve.

In summary, the system is composed by a duct A-D and by elements predisposed to its passage, thus dividing the overall system in the following subsystems: a) Tract A-B incorporated in the WC. The WC has to be specifically designed and produced for this function (Figs 6, 10).

b) Tract B-C (Figs 3, 4, 7, 8, 9, 13) which can also be composed of flexible elements. This element (tract B-C) could, in some sections incorporate or could be itself be incorporated by the duct of discharge of the cistern (duct in duct).

c) Specific cistern intrinsically containing part of the duct Vu (Figs 7, 8, 9), or predisposed to the placement and passage of the system (Figs 11, 12).

d) Tract C-D:

1) constituted by a simple duct which immerses itself in the water when the cistern is full

2) constituted by a siphon and an unidirectional valve (Figs 4, 5, 8, 14, 15, 16, 17). The subdivision of the internal ventilation in subsets highlights the intention of this patent to also cover the single parts or the predispositions of elements aimed at the realization of the system; also in view of the fact that some parts can be produced by different firms or sold in kits.

Figures 14, 15, 16, 17 represent two types of unidirectional valves, a sphere (S) or a blade (L) but they can be of various types, also handled electronically, for example:

- Unidirectional valve constituted by an electro-valve which intervenes when the pressure in the discharge duct becomes too low.

- Addition of an electro-fan to rapidly re-equilibrate the pressures in the discharge duct. t is clear that to manage and electrically operated valves or fans in an automatic manner it is necessary to have sensors and electronic control units. The sensor or sensors, are positioned in any place in the duct and have the function to indicate to the electronic control unit whenever a depression (reduction of pressure inside the duct, as compared to the atmospheric pressure) happens in the sewer drainage system; the electronic control will therefore control the given elements (electro-valve and potentially a fan) in response to the information received by the sensors.

Up to now we have seen that it is possible to substitute the secondary ventilation system for sewers with an internal ventilation system which is more cost effective and which can be used in any type of building. This is achieved by having a duct connecting the sewer discharge system, immediately after the first siphon of the WC, to the water which is present in the cistern, thus forming a siphon with it. The internal ventilation system can be implemented also if the cistern is excluded. This reduce the system to a duct which connects the sewer drainage system, taken in any point, with a unidirectional valve placed on the internal or external walls of the building. An example is shown on Fig. 18, where there is a unidirectional valve (Vu) with two spheres (S), but it could be any type of valve or electro-valve.

An advantage of this latter solution is that it can be applied in any point of the sewer drainage system, even on the drainage system of the white waters. In this latter case, as there is no cistern water to produce the siphon, it is necessary that the system is perfectly and tightly closed if it is positioned in the inside of the building, to ensure that no malodorous fumes are discharged.

In conclusion, I have described two types of internal ventilation systems which can be applied in any building, even in condominium buildings and historical buildings, and that do not require complex planning, hence without any difficulty to achieve.

I wish to highlight that all the single elements which constitute the internal ventilation described above, are covered by this patent because, even if not complete, they are specifically produced for the specific purpose described in this patent. I also wish to highlight that many of those elements are not shown on the pictures or they have been only partially represented because they are of common knowledge.