WO2015166517A2

WO2015166517A2 - Ventilation system with siphon-vent

Info

Publication number: WO2015166517A2
Application number: PCT/IT2015/000116
Authority: WO
Inventors: Cosimo Sarno
Original assignee: Cosimo Sarno
Priority date: 2014-04-29
Filing date: 2015-04-29
Publication date: 2015-11-05
Also published as: WO2015166517A3

Abstract

The siphon-vent is a ventilation system which, applied to the sewers of the buildings, eliminates the problem of the escape of sewer gases (due to the drying of the siphons) into the buildings, in a simple and efficient way. The proposed system substitutes the secondary ventilation system which connects the sewage system through pipes from nearby the WC to the outside of the buildings, in order to eliminate the depressions (i.e. negative pressures which are below the atmospheric pressure) which can build up within the sewer drain following the flushing of the WC. The new proposed system of secondary ventilation is composed of a duct, including a unidirectional valve, which originates close to the top of the WC and which will form a siphon with the water present in the cistern.

Description

DESCRIPTION:

"VENTILATION SYSTEM WITH SIPHON-VENT"

It is known that the discharge systems of buildings, including civilian homes have ventilation ducts which have the function of eliminating the presence of pressures in the discharge pipes and generated by the fast flow of water in the pipes, in order to avoid suctions that empty the siphons with consequent escape of bad odours (sewer gases) from the sewers to the sanitary ware.

NOTE: In the following descriptions, negative or positive pressures refer to pressure which are below or above the atmospheric pressure, respectively.

STATE of THE ART:

The State of the Art offers two solutions:

1) The ventilation systems are generally constituted by a primary and a secondary system. The primary system connects the sewer drain to the top of the buildings through pipes (See Figure 1, vertical dashed line); the secondary system connects the sewer drain pipes of the sanitary ware to the system of the primary ventilation (See Figure 1, sloped lines) or it is directed straight to the outside of the building and left free.

In common practice, the primary ventilation is achieved by extending the vertical section of the sewer drain column (see Figure 1) beyond the roof of the building, leaving the extremity open to the outdoor environment. The secondary ventilation is usually neglected because too expensive and often difficult to achieve due to pillars and beams that create a physical obstacle to the system to reach the outside of the building. Therefore, the position of the drain of the WC is preferred to be placed as close as possible to the sewer drain column (see Figure 1, continuous vertical line). With Sfo Figures 1,2,3,4,6,7 it is meant the section of the horizontal sewer drain (slightly inclined and positioned under the flooring of the buildings) which connects the sanitary ware to the column of the vertical drainage.

2) The patent WO 89/00219 Al (MOLYNEUX PRODUCTS LTD [GB]) 12 JANUARY 1989 provides solutions which refer to both the primary and secondary ventilation:

-The primary ventilation is addressed by making the ventilation duct pass from the cistern to the outside of the building. -The secondary ventilation is addressed by connecting a duct which goes from a waste appliance to the cistern of the WC, excluding the WC, hence only treating the grey waters (i.e. the waste waters which do not include excreta matter). Often the grey waters are discharged via a separate circuit from the dark waters (waste water from WC) because of different decontamination treatment.

Detailed description of the proposed patent:

The most important depressions (i.e. pressures below the atmospheric pressure) occurring within the sewer drainage are due to the discharge action (flushing) of the WC because significant amount of water and other masses (faeces, paper etc) with fast flowing, may generate negative pressures causing emptying of the siphons of all sanitary appliances in the bathrooms, including the siphon of the WC.

Therefore, with the proposed patent, it is intended to safeguard the discharge system from the negative pressures generated by the drain of the WC by means of a system which is confined to the WC and its cistern (CS Figure 3). This will avoid the need of ventilation pipes going through the walls of the buildings, where there may also be obstacles to overcome (pillars and beams).

The drain siphon (Figure 2,3,5,6 and 7) is constituted by a duct which starts from the closet bend of the WC (or from a point very close to it) and forms a siphon with the water present in the cistern of the WC. On this duct, preferably at the extremity which is in the cistern and forms the siphon, there is a unidirectional valve which only allows the flowing of the air from the inside of the building to the sewage system but not viceversa.

In other words, the system is constituted by a duct (AD Figures 2,3) which starts from the closet bend (point A Figures 2,3) and ends in the cistern, thus forming a siphon with the water which is inside the cistern (point D Figures 2,3). In addition, a unidirectional valve is positioned within the above mentioned duct (Vu Figures 2,3).

A portion of the above duct can be incorporated in the cistern (section BC Figure 2).

The proposed ventilation system works as follows:

When the system is at rest, through the ventilation duct AD, no sewer gases can escape from the drainage pipes to the inside of the building (Sfo Figures 2,3,4,6 and 7) because point D is immersed in the water of the cistern (siphon). When the flush is actuated the following two hypotheses can happen:

1) No negative pressure builds up in the drainage duct, the point D of the ventilation duct is free and, until the water level in the cistern is reinstated, the unidirectional valve guarantees that there is no escape of sewer gases.

2) Negative pressures build up in the drain duct, the point D of the ventilation duct is freed and the unidirectional valve (the ball whirls and will not close anymore the duct) allows a flow of air which goes from the indoor environment towards the sewage system until the pressures equilibrate again. At this moment the unidirectional valve closes itself, blocking the flowing of gases from the sewer drain to the indoor environment, until the level of the water in the cistern is restored, hence back to the initial condition of siphon.

In other words, in this novel system, the siphon is freed at each flushing of the WC and becomes a ventilation terminal able to equilibrate the negative pressures which build up at the back of the discharged waste matter. This allows the restoring of the initial water level and hence to the initial condition of siphon.

Therefore, the unidirectional va!ve guarantees that the air flows are only directed to the sewer drain.

Unidirectional valve: The unidirectional valve can be constructed in various ways, for example: by using reed valves or through a very light element which closes the duct by sitting on a given seat within the duct, hence stopping the escape of sewer gases (from the sewage system to the inside of the building). However, when a depression occurs, the valve allows the flow of air towards the sewer drain (due to being a very light item) (Vu fig. 2,3,5,6 and 7).

The unidirectional valve can also be made using an electro valve controlled via a control panel which senses, responds to the readings of pressure sensors located along the ducts.

Below it is described how the ventilation system behaves when depressions occur, even in the case that the WC has not been flushed:

Bearing in mind that a siphon is an hydraulic cap and is capable of withstanding (before emptying itself) differences in pressures which build up before and after it, this difference of pressure (depth seal) in our case is determined by the value of H (Figure 4 where for a more clear graphic representation of the above concept, the unidirectional valve has been omitted).

If it is desired that the ventilation system works also for depressions which may happen in the sewer drain pipes, independently from the actuation of the flushing of the WC, it is necessary that the value of H is inferior to the other siphons which are present in the bathroom. In fact, in case of depression, our siphon (Sif in Figure 4) sucks some water from the cistern, lowering the level of the water down to point C and then sucks some air. in summary, our siphon can become a terminal of ventilation also when accidental depressions occur; these can happen in the sewer drain pipes if the depth seal of the siphon-vent is lower than the depth seal of the other siphons which are present in the bathroom.

It is therefore preferred that the depth seal of our siphon is as low as possible. In order to achieve this, it is necessary that the level of the water remains constant. The precision of the level of the water in the cisterns is ensured by mechanical elements which however do not guarantee the desired level of the water over a long period of time. It is therefore preferred that the level of the water in the cistern is not controlled in a mechanical but rather in an electronic fashion i.e. using electro valves (Ev Figure 6 and 7- electric taps), sensors (S Figure 6 and 7) and potentially electronic control units. A sensor, which can be placed in the ventilation duct, signals the presence of water to the electronic control unit, thus triggering the closure of the electro valve.

On the drawings (Figures 2,3), the duct AD is divided in sections AB+BC+CD because the system is constituted by several elements which may also be produced by different industries. It is intended to save the patent from selling of kits which can be applied to existing cisterns or predisposed to this purpose. Specifically, section AB can be made using a flexible tube, section BC can be made using a tube or it can be incorporated in the cistern and, section CD can be made of a tube which has the extreme D immersed in the water of the cistern, when this latter is full. The unidirectional valve Vu is placed inside one of the above sections; on the drawings it substitutes the section CD - see Figures 2,3,5,6 and 7.

Finally, in drawings 3,4,5,6 and 7, a recessed cistern toilet is represented. However, the present proposal can be applied to any type of flushing units. In fig. 8, a classic wall cistern is represented at the stage of end of flushing with arrows indicating the direction of the ventilation flow coming in and the fluctuation of the closure sphere. Again, the above proposal, despite the drawings only show a WC with a wall cistern (as one example of type of WC with its cistern), it is applicable to any closet bend, even those of WCs which have a discharge to the floor.

It is emphasized that many parts of the system are not represented or have been partially represented in the drawings and/or mentioned in the text, because they are well known items.

Claims

CLAIMS:

'VENTILATION SYSTEM WITH SIPHON-VENT"

1) Secondary ventilation system with siphon-vent for sewers (Fig. 2 and 3) constituted by a duct (Cv) which connects point A placed on the sewer drain duct (Sfo) near the water at the point D and forms a siphon with the water present in the cistern of the WC. The system is completed by a non-return valve (i.e. unidirectional valve) which is placed on the duct (Cv).

2) Secondary ventilation system with siphon-vent for the sewers (Fig. 2,6 and 7), as per claim number 1, where part of the duct (B-C) is incorporated within the cistern.

3) Ventilation system with siphon-vent for sewers, as per claims numbers 1 and 2 where it is intended to extend the patent also to the single parts of the system and at predispositions if aimed at the objective of claim 1.

4) Secondary ventilation system with siphon-vent (Fig. 2,3,5,6 and 7), as per claims numbers 1 and 2 in which the unidirectional valve is constituted by a container where a very light sphere is inserted in and having two openings, one which connects to the ventilation system and the other where the sphere sits and which connects the valve to the water present in the cistern.

5) Secondary ventilation system with siphon-vent , as per claim number 1, where there is a unidirectional valve which is electronically controlled by an electronic control unit and sensors.

6) Secondary ventilation system with siphon-vent (Fig. 6 and 7), where the level of the water which is present in the cistern is determined by a hydraulic electro valve (Ev) controlled by an electronic control unit and by sensors (S).

7) Secondary ventilation system with siphon-vent for sewers, as per claim number 1, where also the ventilation terminals of the other sanitary ware are connected to the duct (Cv).