DEVICE FOR INCREASING DRAUGHT IN CHIMNEYS DESCRIPTION
The present invention refers to a device for increasing draught in household chimneys and flues in general, as a result of the action of outside wind. It is common knowledge that the operation of household chimneys is greatly influenced by the presence of wind. In particular, wind incidence may increase draught, in case of upward winds, or decrease it, in case of downward winds.
Oft-times, even state-of-the-art chimneys cannot be used on particularly windy days, as the fumes (or smoke), prevented from being outletted due to the outside wind, fail to reach the outlet of the chimney cap, thereby invading the fireplace room.
Even an upward wind, usually improving the outletting of fumes from the flue, in case of excessively strong gusts does not help the outletting of the fumes from the chimney cap.
To mitigate the negative effects of the outside wind, there are used a score of windbreak fittings and chimney caps inserted above the flue, shielding the outlet of the latter from the gusts, preventing, at least partially, the inletting of downward winds, and somehow limiting the action of strong gusts of upward winds.
Hence, these products, having being designed in order to hinder or baffle the wind flow from the inlet of the flue, exhibit a scarce or even insignificant sucking power. Due to this limitation, under particularly windy atmospheric conditions said products do not solve the problem of a draught decreasing due to strong and turbulent winds.
Hence, the technical problem underlying the present invention is to provide a device for increasing draught in chimneys allowing to overcome the drawbacks hereto- mentioned with reference to the known art. Such a problem is solved by a device for increasing draught in chimneys according to claim 1.
The present invention provides several relevant advantages. The main advantage lies in that any kind of wind not only fails to prevent the correct outletting of the fumes from the flue, but also increases the draught in the chimney, thereby allowing the use of fireplaces also on particularly windy days, moreover providing chimneys of lesser height or badly-exposed with the option of an increased draught, by virtue of an improved draught/flue height ratio.
In fact, outside wind is collected via a specifically designed inlet chamber and sent down to the bottom portion of the chimney, where it assumes an upward direction, facilitating the outletting of the fumes.
Other advantages, features and the operation modes of the present invention will be made apparent in the following detailed description of some embodiments thereof, given by way of a non-limiting example. Reference will be made to the figures of the annexed drawings, wherein: figure 1 is a partially exploded perspective view, illustrating an embodiment of the device for increasing draught in household chimneys according to the present invention; figure 2 is a perspective view of an exemplary set-up of the device for increasing draught of figure 1; figure 3 is a sectional side view showing the operation of the device for increasing draught of figure 1 ; figure 4 is a plan section of a inlet chamber for wind, detail of figure 3 ; figure 5 is a front section of a bush for adjusting the airflow, detail of figure 3; figures 6A and 6B are two perspective views illustrating the use of the device for increasing draught in household chimneys combined to a decorative fitting for covering the former; figure 7 is a perspective view showing a third embodiment of the device for increasing draught according to the present invention, comprising a fume outlet portion; figure 8 is a perspective view showing the device for increasing draught in household chimneys according to a fourth embodiment, comprising a fan for increasing the air flow.
With initial reference to figure 1, a device for increasing draught in chimneys comprises an inlet chamber 1 for wind flows, a tubular duct 2, an end elbow outlet section 3 and, according to a preferred embodiment, the device also comprises one or more intermediate elbow outlet sections 4 for collecting any condensation. The inlet chamber 1 is located above an existent chimney cap, and it is formed by a hollow parallelepiped, having, at each of its four side surfaces or sidewalls 11, an inlet port 12, of a circular shape, protected by a door 13.
Moreover, the inlet chamber 1 has a removable or openable top cap 16, to allow access therein during the set-up or for any maintenance thereof .
The inlet chamber 1 does not obstruct the outlet of the chimney cap, which, with reference to figure 1, in a first embodiment is of the kind with side louvers for outletting the fumes. Hence, the inlet chamber 1, located in the top portion of the chimney cap, does not hinder the outletting of fumes.
The use of the device for increasing draught in chimneys, combined to different chimney typologies, will be described in the subsequent embodiments.
At the bottom base of the inlet chamber 1, it is obtained a hole 14 opening the inlet chamber on the tubular duct 2 extending inside of the flue, as illustrated in figure 3, for a standard length of about 100 - 150 cm, also with regard to the number of elbow sections 4 that are to be inserted.
The measures are not binding and may vary depending on wind conditions and quality of chimney draught. In particular, for chimneys in which the draught proves remarkably insufficient the tubular duct will extend more inside of the flue, whereas for chimneys not exhibiting serious draught problems a shorter length of the tubular duct 2 will suffice.
The inlet of the tubular duct 2, at the hole 14 inside of the inlet chamber 1, is elevated with respect to the base of said inlet chamber 1, in order to prevent any rainwater seepage from entering into the tubular duct 2.
Moreover, according to a preferred embodiment there is a small hole, not shown in the figure, obtained at the base of one of the four side surfaces 11, in order to discharge any water possibly entering the inlet chamber 1. In order to facilitate the discharging of the water, the inlet chamber 1 has a base portion tilted toward the hole.
The diameter of the tubular duct 2 is selected on the basis of the operation of the chimney, and anyhow sufficiently reduced with respect to the chimney flue, so as not to excessively reduce the useful section of the flue: in general, to overcome greater inadequacies in the draught, a greater diameter is used for the tubular duct 2. The tubular duct 2 is joined, at the hole 14, to the inlet chamber 1 by welding, threaded connection or other kind of connection suitable for the purpose.
Moreover, the tubular duct 2 may be made of a single element, or partitioned into plural parts, at the end of each of the latter there being inserted an intermediate elbow
outlet section 4.
With further reference to figure 3, the doors 13 are disc-shaped, of a diameter slightly greater than that of the inlet ports 12, and are hinged to the side surface 11, tiltable toward the inside of the inlet chamber 1. The action of a wind gust coming along a direction substantially perpendicular to the door 13 pushes the latter toward the inside of the inlet chamber 1, freeing the respective inlet port 12 and thereby allowing the air to enter the inlet chamber 1.
The wind, once entered inside of the inlet chamber 1 via one or more of the doors 13, pushes the remaining doors 13 against the respective sidewalls 11, closing the corresponding outlet holes and, substantially, preventing the outletting thereof from the inlet chamber 1. The wind may exclusively go toward the tubular duct 2, via the hole 14.
To prevent the doors 13, which close back at the end of the action of a wind gust, from generating excessive noise by knocking the sidewall 11, a gasket 15 is arranged along the perimeter of the doors 13.
Said gasket 15 is, e.g., made of a plastic material or the like, in order to cushion knocks and dampen the entailed noise.
Alternatively, the gaskets 15 may be replaced by other means for dampening noise.
The wind, once inside of the tubular duct 2, proceeds bottomward therein until reaching the elbow outlet sections 3 and 4, respectively, arranged at the bottommost end of the tubular duct 2, in the intermediate portion of the tubular duct 2.
The elbow shape of the elbow outlet sections 3 and 4 backflows the wind-generated air flow, so as to generate an upward motion, thereby pushing upward the fumes produced by the combustion in the chimney, substantially improving the draught of the latter.
According to a preferred embodiment, the tubular duct 2 is partitioned into plural parts joined by intermediate elbow outlet sections 4, at each of which a fraction of the air flow backflows in order to ensure a more homogeneous draught in chimneys of elevated lengths. In particular, the use of a greater number of intermediate elbow sections is desirable in case of very long chimneys on particularly windy zones, in which the use of a single end elbow outlet section 3 would entail a markedly inhomogeneous draught along the flue.
On sites where the wind is particularly strong in certain periods of the year only, it is
possible to reduce the action of increasing the draught of the device according to the present invention, in said periods, by inserting or screwing down a bush 17 having a lesser diameter, illustrated in figure 5, on the inlet of the tubular duct 2, at the inlet chamber 1. The steps of inserting and/or replacing said bush 17 are facilitated by the option of removing or opening the top cap 16, allowing an easy access to the inside of the inlet chamber 1.
The device for increasing draught in chimneys, according to the present invention, may be used on newly built chimneys, or inserted in extant chimneys. In particular, according to a second embodiment, with reference to figures 6A and 6B, the inlet chamber 1 may be inserted inside of the end wall of the chimney, so as to improve the aesthetic impact of the chimney and obtain a better protection from external agents.
Upon setting up the device for increasing draught according to the hereto-described modes, a masonry wall 5 is applied thereabout. The wall 5 has louvers 51, arranged along a vertical direction in the present embodiment, allowing the inletting of air inside of the inlet chamber 1.
A third embodiment is illustrated in figure 7. In this case the chimney on which the device for increasing draught is used has the outlet at the top portion thereof, and therefore it is not possible to apply the inlet chamber 1 thereabove without obstructing the normal outlet flow of the fumes.
For this purpose the device according to the present invention comprises a portion 6 for the outletting of the fumes from the flue. With reference to figure 7, said portion 6 is interposed between the top end portion of the flue and the inlet chamber 1. The portion 6 has a section of shape and dimensions analogous to those of the flue, and it comprises sidewalls 61 having a plurality of louvers 62 allowing the flowing of the fumes.
The portion 6 is fixed at the top end portion of the flue and, once set up, enables the use of the device for increasing draught according to the present invention, also in such chimneys, according to the modes described hereto.
A further embodiment, shown in figure 8, comprises a fan 7 that is set up on the inlet chamber 1 in order to generate an airflow to be sent to the tubular duct 2, in case of absence of wind.
The fan 7 is driven by a solar cell, not in figure, optionally connected to a rechargeable buffer battery, power-supplied therefrom.
Alternatively, the fan 7 may be driven by any one other equivalent power source, e.g. an electric connection to the household system. In case of absence of wind the fan 7 activates, automatically or following the actuation of a switch controlled by the chimney user, and inlets an airflow, incoming from the outside environment, inside of the inlet chamber 1. Therefrom, all doors 13 being closed, said airflow is conveyed toward the tubular duct 2, to be then outletted via the elbow outlet sections 3 and 4, analogously to what takes place for the outside wind. The present invention has been described hereto with reference to preferred embodiments thereof. It is understood that other embodiments might exist, all afferent to the same inventive kernel and all falling within the protective scope of the claims hereinafter.