Patent Description:
The self-cleaning filter device adaptable to the volume of rainwater object of the invention is designed for use in continuous flow filtration of rainwater collected in various building locations or residential, commercial or industrial facilities.

Usually, after the beginning of a rainfall, the first collected rainwater contains a high concentration of debris, such as dust, insects and small animals, etc., which have accumulated over time in various water catchment locations and carried by the flow of rainwater to the rainwater collection and filtering system.

This debris tends to accumulate in the filter elements of the rainwater filtration devices known in the art, thus reducing their filtering capacity due to said accumulation of debris.

In particular, the accumulation of plastic bags, paper and smaller debris on the walls of the filter elements, greatly impairs the filtering ability of the filtering devices, and may even make them practically inoperative. In these situations, it is necessary to interrupt the flow of filtered rainwater in order to clean or replace the filter element. Due to this loss of filtration capacity of the filter elements of the filtration devices, preventive and / or corrective measures become necessary to solve this problem.

One such measure is to perform periodic cleaning of the filter elements of the filtering devices, or their replacement, if necessary, especially in periods when it is not raining. This measure solves the problem only in part because debris that was deposited in the filter elements during the initial period of rainfall will remain there, compromising the filtering capability of the filtering devices.

In these situations, if accumulation of debris which is deposited on the filter elements is very large, there will be a serious impairment of the filtering capacity of the rainwater filtering devices.

A solution to this problem would be to divert the flow of rainwater to the sewage system in order to clean or replace the filter elements. The disadvantage of this solution is that it would not be possible to take advantage of the water flow that was diverted to the sewer, which cannot be filtered.

One possibility of avoiding this loss would be the provision of reservoirs for the temporary storage of rainwater flow, while the filter elements of the filtration devices are being cleaned or replaced.

However, in addition to increasing the funding costs of system installation, the provision of such reservoirs could also cause problems. The storage of rainwater in these reservoirs facilitates settling of debris at the bottom, which, with time, tends to decrease storage capabilities. The possibility of organic contaminants should also be mentioned, such as the debris of dead animals and insects, which also accumulates at the bottom, which would be undesirable. As a result, it would then be necessary to perform periodic cleaning of these reservoirs, thereby increasing the cost of system maintenance.

Another solution to solve the problem would be to use multiple filtering devices, designed in such a way that the momentary stop of one of them for cleaning or replacement of filter elements would not adversely affect the filtering ability of the rainwater filtering system.

The disadvantage of this solution is the increased cost for the installation of multiple filtering devices, not to mention the need to provide periodic cleaning or replacement of filter elements, which would also increase the maintenance cost of the filtration system.

A solution to this problem is proposed in the patent <CIT> belonging to the applicant of this present application.

<CIT> describes a self-cleaning filter separator and adapter to rainwater volume having a filtering device comprising first, second and third filter elements (<NUM>, <NUM>, <NUM>), the first and the third filter element being expandable and flexible and the second and central element being not expandable and not flexible. All the three filter elements are provided with walls made of a screen mesh which retain debris, sand and the like but allow rainwater to pass through its mesh interstices.

The non flexible second filter element <NUM> has its ends connected to the flexible first and third filter elements (<NUM>, <NUM>). A calibrator <NUM> is attached to the central filter element <NUM> and is also attached to the lower end of a rod <NUM> around which it can perform an oscillating motion. The location where the calibrator <NUM> is attached to the central filter element <NUM> can be changed as needed, in order to regulate the inclination of the central filter element <NUM>. The upper end of the rod <NUM> is pivotally attached to the upper cover of the filtering device, in a manner that can also perform an oscillating motion.

The self-cleaning filter separator and adapter to rainwater volume of <CIT> is able to adapt to changes in the volume of rainwater, wherein the central second filter element <NUM> may tilt in consequence of the passing flow of rainwater thereby making the flexible first and third filter elements (<NUM>, <NUM>) to expand or to retract depending on said passing flow of rainwater, whereby promoting the removal of debris from the interior of the filtering device, which accumulated there during the filtering process.

Consequently, the first, second and third filter elements <NUM>, <NUM>, <NUM> can perform oscillating movements between them as a consequence of the flow rate of the flow of rainwater passing through their interior, adjusting their position according to the intensity of the rain. On occasions when the flow of rainwater is low, the central semi-rigid filter element <NUM> is in its initial position, substantially sloped, and thus the filter elements <NUM>, <NUM>, <NUM> are in a very inclined position, forming an obtuse angle to the upper wall of the self-cleaning filter device.

In this way, the exit of debris is facilitated, even with a low flow of rainwater. When the flow of rainwater is somewhat more intense, the central rigid filter element <NUM> assumes a near horizontal position, due to the action of the impact of the flow of rainwater against it. When the flow of rainwater is high, the filter element bends in a direction opposite to its initial position. The articulated filter elements <NUM>, <NUM> expand or retract, conforming to the movement of the central semi-rigid filter element <NUM>.

These movements of the filter elements <NUM>, <NUM>, <NUM> serve to facilitate the filtration of water and also the expulsion of debris that accumulates inside them, providing a filtering capacity of the filtering device which remains substantially constant since there is virtually no accumulation of debris inside the filter elements <NUM>, <NUM>, <NUM>.

The invention will now be described in greater detail together with the accompanying drawings which, for illustrative purposes only, depict some embodiments of the invention.

The self-cleaning filter device adaptable to the volume of rainwater <NUM> can be observed in <FIG>, <FIG> and <FIG>, object of the present invention, which comprises a body <NUM> provided with a rainwater inlet <NUM>, a debris outlet <NUM> and at least one filtered rainwater outlet <NUM>. Two filtered rainwater outlets <NUM> and <NUM>' are shown in the drawings, but there is no limitation to the number of outlets that may be employed.

A rainwater collection system <NUM> collects rainwater <NUM> and connects to a supply duct <NUM>, which connects to the rainwater inlet <NUM> of the self-cleaning filter device adaptable to the volume of rainwater <NUM>.

The self-cleaning filter device adaptable to the volume of rainwater <NUM> is provided with a filter element <NUM> comprising an upper portion <NUM>, a central portion <NUM>, and a lower portion <NUM>. The upper portion <NUM> of the continuous filter element <NUM> is connected to the rainwater inlet <NUM>, and the lower portion <NUM> of the continuous filter element <NUM> is connected to the debris outlet <NUM> of the self-cleaning filter device adaptable to the volume of rainwater <NUM>.

The filter element <NUM> is depicted in <FIG>. In a preferred embodiment it comprises a continuous flexible element <NUM>, able to contract or expand. A filtering means <NUM> covers and is secured to the flexible element <NUM>.

In this embodiment the flexible element <NUM> comprises a continuous spiral element and the filtering means <NUM> is a multifilament fabric, allowing little penetration of particulate material in the interstices of the web, whose porosity is lower than the size of the smaller dimension of particulate material to be retained. As such, the filter element <NUM> takes the form of a fully flexible an continuous bellows <NUM>, providing the filter element <NUM> with flexibility and ability to be compressed or to expand.

A regulating device <NUM> is also provided within the self-cleaning filter device adaptable to the volume of rainwater <NUM>, which comprises a support member <NUM> attached to the inner upper part of the body <NUM> of the self-cleaning filter device adaptable to the volume of rainwater <NUM> by means of a fixing structure <NUM>.

A flexible fixation element <NUM>, in this case a cable, rests on the support member <NUM> and has a first segment 106a attached to the upper portion of the filter element <NUM> of the filter element <NUM>, and a second segment of the flexible fixation element 106b connected to the lower portion <NUM> of the filter element <NUM>.

First and second adjustable limiting devices 124a and 124b may also be provided on the flexible fixation element <NUM>, installed respectively on the first segment 106a and the second segment 106b, which serve to limit the travel of the flexible fixation element <NUM> on the rotary support member <NUM>. The positioning of the first and second adjustable limiting devices 124a and 124b may be adjusted in order to enable the filter element <NUM> to better operate in accordance to the intensity of the rainwater.

The support member <NUM> must be able to allow the flexible fixation element <NUM> to easily travel along it. In a preferred embodiment the support member <NUM> is a pulley, which facilitates the travel of the flexible fixation element <NUM> along it.

The process of operation of the self-cleaning filter device adaptable to the volume of rainwater <NUM> is quite simple. When it starts raining, rain water <NUM> is collected by the rainwater collection system <NUM> and conducted by means of the supply duct <NUM> to the rainwater inlet <NUM> of the self-cleaning filter device adaptable to the volume of rainwater <NUM>.

The amount of debris carried into the filter element <NUM> during this initial period of rain is usually more intense, and it is desirable that this debris be removed as quickly as possible so as not to impair the usefulness of the filter element <NUM>.

During periods of no rain, or when the volume of rainwater passing through the interior of the filter element <NUM> is not yet intense, the filter element <NUM> assumes a shape as shown in <FIG>, wherein the upper region of the upper portion <NUM> of the filter element <NUM> is substantially upright, for being connected to the rainwater inlet <NUM>, but the remaining part of the upper portion <NUM> and the central <NUM> and lower <NUM> portions of the filter element <NUM> are in a substantially inclined position, wherein an imaginary tangent line "t" located at the middle region of the upper portion <NUM> of the filter element <NUM> forms an obtuse angle "α" with respect to an imaginary horizontal line "p", as can be seen in <FIG>.

In this initial operating situation, where the filter element <NUM> is substantially inclined and the flexible element <NUM> are substantially retracted, which facilitates the removal of waste because the water flow, even if still at low volume, can lead debris toward the debris outlet <NUM> due to the substantial inclination of the filter element <NUM>.

A filtering process of rainwater flow will occur at the same time that debris is removed from the interior of the filter element <NUM>. As can be seen in <FIG>, filtered rain water <NUM> exits the filter element <NUM> and will be deposited in the lower body region <NUM> of the body <NUM> of the self-cleaning filter device adaptable to the volume of rainwater <NUM>, which is drained by means of at least one filtered rainwater outlet <NUM>.

In a situation where rain intensity begins to increase, and becomes moderate, the force exerted by the impact of the flow of rainwater and debris on the filter element <NUM> will increase, especially on its upper portion <NUM>. This impact force will cause the flexible element <NUM> to expand. In the present embodiment, as the flexible element <NUM> is a spiral element, its spires begin to move away from each other in certain regions, especially in border regions between the central portion <NUM> and the upper and lower portions <NUM>, <NUM> of the filter element <NUM>.

Since the first and second segments 106a, 106b of the flexible fixation element <NUM> regulating device <NUM> are respectively connected to the upper portion <NUM> and the lower portion <NUM> of the filter element <NUM>, they cause a limitation in this movement of expansion of the flexible element <NUM>. In the present embodiment, as the flexible element <NUM> is a spiral element, the movement of its spires away from each other is limited. Despite this limitation, the fact that the flexible fixation element <NUM> of the regulating device <NUM> can move on the surface of the rotary support member <NUM> permits some adjustments to occur in the positioning of the filter element <NUM>, but only in a limited manner.

With this limitation of movement, the upper portion <NUM> and the central portion <NUM> of the filter element <NUM> will initially tend to expand more. In this situation the impact of the rainwater flow containing debris against the upper portion <NUM> and the central portion <NUM> of the filter element <NUM> will cause the flexible element <NUM> to expand in the regions of these two upper <NUM> and central <NUM> portions of the filter element <NUM>. The lower portion <NUM> will also move away from each other, as the regulating device <NUM> limits the movement of the filter element <NUM>. In the present embodiment, as the flexible element <NUM> is a spiral element, the spires will move away from each other.

Therefore, the upper portion <NUM> and the central <NUM> and lower <NUM> portions of the filter element <NUM> will begin to change their substantially inclined shape. In this situation the central portion <NUM> of the filter element <NUM> tends to assume a substantially horizontal position, which favors filtering of the passing flow of rainwater in the region of the central portion <NUM> of the filter element <NUM>, in special in the region of the central portion <NUM> of the filter element <NUM>, thereby reducing waste of water.

In the event of a significant increase in the flow of rainwater in a heavier rain situation, and an ensuing increase in the impact of this flow on the filter element <NUM>, and also by the debris carried by the rainwater flow, the flexible element <NUM> will have a stronger tendency to expand, and in special the lower portion <NUM>. In the present embodiment, as the flexible element <NUM> is a spiral element, its spires will have a tendency to move away from each other. Consequently the spires of the upper portion <NUM> and the central portion <NUM> of the filter element <NUM> will tend to expand even more, the same occurring with the spires of the flexible element <NUM> in the lower portion <NUM>, which will also move away from each other even more.

Consequently the filter element <NUM> assumes a very similar configuration to a letter "S", as depicted in <FIG>, due to the limitation of its movement caused by the regulating device <NUM>.

In this process of variations of the shape of the filter element <NUM>, as a result of variations in the flow of rainwater, the flexible element <NUM> will tend to suffer alternate expansion and retraction movements, thereby causing a huge oscillating motion in the whole filter element <NUM>, and the combination of the variations of the shape of the filter element <NUM> and this oscillating motion, in special in the region of the central portion <NUM> of the filter element <NUM>, will increase the expulsion of debris from the interior of the filter element <NUM> towards the debris outlet <NUM>.

Thus, the form to be taken by the filter element <NUM> will always be adjusted as a consequence of the flowrate of the rainwater flow and the volume of debris carried by this flow.

It should be mentioned that the first and second limiting devices 124a and 124b serve to limit the travel of the flexible fixation element <NUM> on the surface of the rotary support member <NUM> in order to guarantee that the filter element <NUM> will suffer the variations in shape shown above, within limits that ensure that the filtering process always occurs effectively.

It is also important to mention that the shapes depicted in <FIG>, <FIG> and <FIG> which the filter element <NUM> assumes in view of the flow rate of rainwater are exemplary only, and cannot be considered as limitation of the invention. In use, the filter element <NUM> will be able to assume a number of shapes responsive to the flowrate of rainwater an debris.

The use of the filter element <NUM> provided with a flexible element <NUM> allows the debris carried by rainwater flow to be rapidly discarded by the debris outlet <NUM>, which favors the filtering process and reduces waste of water. In <FIG>, <FIG> and <FIG> it can be observed filtered rainwater flow <NUM> exiting the filtered rainwater outlet <NUM>.

Tests made by the Applicant, in which the rainwater flow contained considerable amount of debris, showed the volume of unfiltered rainwater flow <NUM> that could not be filtered, which exits the debris outlet <NUM>, to be very small.

The self-cleaning filter device adaptable to the volume of rainwater <NUM> is provided with inspection windows, not shown in the Figures, which facilitate the cleaning of the filter, the cleaning or replacing of the filter element <NUM>, regulation of the regulating device <NUM>, periodic inspections, etc..

For example, in situations in which the interstices of the filter means <NUM> are impregnated with small particulate material, thereby reducing its capacity to filter rainwater, these inspection windows may be used to allow access for maintenance workers to use highpressure water jets to facilitate the removal of these small particulate particles from inside the interstices of the filter means <NUM>.

If it is necessary to change the positions where the first and second segments 106a, 106b of the flexible fixation element <NUM> of the regulating device <NUM> in order to meet a specific need, multiple connection points may be provided in the filter element <NUM> to connect the ends of the first and second segments 106a, 106b of the flexible fixation element <NUM>, thereby allowing to adjust the regulation of the regulating device <NUM> according to momentary convenience.

As a reference, the table below gives some values used by experts to define rain intensity:.

The provision of a self-cleaning filter device adaptable to the volume of rainwater <NUM> having a fully flexible and continuous filter element <NUM> able to contract or to expand enables a prompt reaction of said continuous filter element <NUM> to the variations of the flow of rainwater, thereby making the self-cleaning filter device adaptable to the volume of rainwater <NUM> object of the invention very efficient to filter a rainwater flow, minimizing the losses of rainwater.

Modifications and adjustments can be made in the self-cleaning filter device adaptable to the volume of rainwater <NUM> without departing from its basic concept, as described above.

For example, is possible to connect separate parts of flexible filter elements each other in order to provide a filter element having basically the same features as the continuous filter element <NUM> described herein.

Claim 1:
A self-cleaning filter device adaptable to a volume of rainwater comprising:
- a body (<NUM>) including:
- a rainwater inlet (<NUM>);
- a debris outlet (<NUM>);
- at least one filtered rainwater outlet (<NUM>);
- a flexible filter element (<NUM>) provided inside the body and comprising an expandable and contractible fully flexible element (<NUM>) and a filter means (<NUM>) covering and secured to the expandable and contractible fully flexible element, the flexible filter element having an upper end directly attached to said rainwater inlet and a lower end directly attached to said debris outlet, said flexible filter element being provided with an upper portion (<NUM>), a central portion (<NUM>) and a lower portion (<NUM>);
- a regulating device (<NUM>) provided inside the body and connected to the flexible filter element,
wherein the regulating device comprises: J Z
- a fixing structure (<NUM>) attached to an inner upper part of the body;
- a support member (<NUM>) supported by the fixing structure;
- a flexible fixation element (<NUM>) supported by the support member, said flexible fixation element comprising first and second segments (106a, 106b) having ends respectively connected to said upper and lower portions of the flexible filter element.