CHIMNEY HAVING DISCHARGE MEANS FOR CONDENSATED FLUID

Abstract: Chimney, comprising a transport shaft (3) for waste gases which can be mounted protruding through a roof and which can be connected to an end shaft (1), mountable on top of the roof, being in communication with the open air at its top end, in which furthermore the dia­ meter of the end shaft is larger than the diameter of the trans­ port shaft, and comprising means with which the end shaft can be secured in such a way that the end shaft with its bottom end ex­ tends to a lower level than the top end of the transport shaft, so that the transport shaft protrudes into the end shaft.

Description: The invention relates to a chimney according to the preamble of the main claim. Such a chimney is described in US-A-3,650,198, wherein a terminal device or vent top is attached to a flue or vent pipe above the roof level of a house or building. The vent top is a double-discharge vent top, as the vent top is provided with a flow divider band having upper and lower discharge openings. The flow divider band is a tubular member having a greater diameter than the vent pipe, while the width of the band for terminal devices on a conventional vent pipe should be around 0.25 to 0.31 times piping diameter. The object of said double-discharge vent top is to produce highly favourable air flow characteristics including a tendency to induce aspiration within the vent pipe while offering a minimum resistance to flow. When waste gases, such as e.g. combustion gases, vapours or contaminated air, are discharged through a chimney, liquid, e.g. water, may condense from said waste gases against the end shaft protruding above the roof of a building, since that end shaft, due to the surrounding outside air, is cooler than the waste gases. Apart from that some rain water may end up in the end shaft if the connection of the end shaft to the outside air is insufficiently shielded. The problem is that the condensate and possibly the rain water flows down from the end shaft along the transport shafts to places in the building where this liquid is undesired, e.g. in the equipment that produces the waste gases. According to the invention this problem is solved by the features of the characterising portion of claim 1. Due to this construction, condensate formed on the inner wall of the end shaft and possible rain water cannot flow into the transport shaft. Preferred embodiments of the invention have been indicated in the pertaining sub-claims. These and other advantages of the invention will be further described in the following description of an embodiment of the invented chimney, in which reference is made to the pertaining drawing. In the drawing: figure 1 shows a schematic section of the left-hand halve of an embodiment of the invented chimney that is mounted on a sloping roof, figure 2 shows a section as in figure 1, but then of the right-hand halve of the chimney, mounted on a flat roof, figure 3 shows a section through the centre line of an embodiment of the invented discharge member according to figures 1 and 2, figure 4 shows a top view of the discharge member according to figure 3. According to figures 1 and 2 the invented chimney comprises an end shaft 1 that is known per se and a shield 2 mounted near the top end of the end shaft. The end shaft 1 comprises near its top end openings (not drawn) under the shield 2 and via said openings the end shaft is in open communication with the outside air. This arrangement is known in many types so that further description and drawing are superfluous. Furthermore the invention comprises a transport shaft 3 that can be connected to discharge shafts (not drawn) for waste gases. These waste gases can originate from a heater, oven or other combustion appliance, so that then the waste gases will be combustion gases. Otherwise these discharge shafts may originate from a kitchen or laboratory or other (work) space, so that then the waste gases are vapours or contaminated air. Since this is known art further description and drawing are superfluous. With a sloping roof the transport shaft 3 according to figure 1 protrudes through the roof and a collar shaped sealing member 4 with a spherically curved lower portion 5 is arranged around the transport shaft. On the roof a second sealing member 6, having an upwardly extending spherically curved inner portion 7, is mounted on the roof covering, such as roof tiles (not shown). The spherically curved lower portion 5 is borne by the complementarily curved inner portion 7, so that a rain water proof connection is created between the lower portion 5 and the inner portion 7. Since this is known art further description and drawing are superfluous. If the roof does not slope but is horizontally positioned, then a connecting sealing member 8 as shown in figure 2 is arranged about the transport shaft that protrudes through the roof. The bottom flange 9 of the connecting sealing member can be sealed against rain water by closely fitting it to the remainder of the roof covering (not drawn), such as roof plates for a flat roof. The connecting sealing member 8 extends upwards with an upper flange 10 near and around the transport shaft 3. This is also known art, so that further description and drawing are superfluous. Finally it is also known to connect the above-described and itself known chimney 1 to the transport shaft 3 known per se. A disadvantage of this kind of structure, however, is that the waste gases transported through the transport shaft and described above are warmer than the end shaft whose temperature is defined by the surrounding air, so that liquid, e.g. water, can condensate from the waste gases onto the inner wall of the end shaft. Also, if the connection of the end shaft to the outside air is not sufficiently shielded, some rain water may end up in the end shaft. This condensate and possible rain water will flow downwards from the end shaft through the transport shafts to places in the building where this liquid is undesired, e.g. in the equipment that produces those waste gases, or in other producers of gases. It is also remarked that the end shaft 1 can be far higher than casually glancing at figures 1 and 2 would lead one to suspect, for the connection of the end shaft to the outside air should be at a sufficiently high level with respect to the surrounding roofs to safeguard a proper discharge of waste gases. A higher end shaft, however, produces more condensate than one would suspect upon casually glancing at figures 1 and 2. The invention aims to remove this disadvantage by the features of the characterising portion of claim 1. Thus liquid condensated within on the end shaft and possible rain water cannot flow into the transport shaft, so that the purpose of the invention is attained. In order to be able to secure the end shaft 1 onto the transport shaft 3, the invention provides a discharge member 11 that at its inner circumference can be connected to the transport shaft 3 and at its outer circumference to the end shaft 1. The discharge member may have the shape of a carrier member or carrier members, so that the transport shaft 3, by this carrier member, supports the end shaft 1, in which arrangement these carrier members allow sufficient space for condensate and possible rain water on the inner wall of the end shaft 1 to flow to the collar shaped sealing member 4 in figure 1 or the connecting sealing member 8 on the roof covering, and therefore cannot flow into the transport shaft 3. The discharge member 11 preferably has the shape as shown in figures 1, 2, 3 and 4, i.e. a ring with stepped axial section. The ring according to figure 3 comprises an upwardly extending inner flange 13 that abuts the cylindrical transport shaft 3 and can, if desired, be secured onto the transport shaft, e.g. by welding. According to figure 3 the ring shaped discharge member 11 furthermore comprises a lowermost step 14, the bottom end of the cylindrical shaft 1 being connected to this lowermost step by means of e.g. a weld 12 according to figures 1 and 2. Preferably the ring shaped discharge member according to figure 3 comprises between the inner flange 13 and the lowermost step 14, a higher step 15, the collar shaped sealing member 4 according to figure 1 or the connecting sealing member 8 according to figure 2 extending upwards below this intermediate step 15 and outside the transport shaft 3. Here it is possible that the collar shaped sealing member 4 or the connecting sealing member 8 abuts the lower side of the higher step 15. Thus rain water cannot end up in the transport shaft 13. According to figures 1, 2, 3 and 4 the discharge member 11 comprises at least one lowered step 16 in the bottom step 14. According to figures 1 and 2 this lowered step 16 forms a discharge port passing the bottom edge of the end shaft 1. Preferably the discharge member 11 is joined with the transport shaft 3 through its flange 13 in a waterproof manner and to the end shaft 1 through the weld 12 in a waterproof manner, so that the discharge member 11 and particularly the space between the bottom step 14 and the opposite portion of the end shaft 1 form a drain for collecting liquid that flows down along the end shaft 1 (condensate plus possible rain water). The liquid collected in this drain can flow out of the drain along the lowered step 16 and past the collar shaped sealing member 4 according to figure 1 or the connecting sealing member 8 according to figure 2 it flows onto the roof covering, so that no liquid can end up in the transport shaft 3. Instead of the lowered step 16, it is also possible to have discharge ports (not shown) through the horizontal portion of the lowermost step 14. Since this lowered step 16 or the (not shown) ports form an exit of only slight diameter with respect to the total diameter of the space between the end shaft 1 and the transport shaft 3, the undesired inflow of outside air past the bottom end of the end shaft is quite limited, for the annulus between the end shaft 1 and the transport shaft 3 is closed, with the exception of the lowered step 16 or the (not shown) ports, by means of the invented discharge member 11, as the the discharge member, by its flange 13, joins the transport shaft entirely and, by the weld 12, joins the entire bottom edge of the end shaft 1 almost entirely, with the exception of the lowered step 16. The above-described embodiments, also shown in the pertaining drawings, are devised for a cylindrical transport shaft 3, a cylindrical end shaft 1 and a discharge member 11 adapted to these cylindrical shapes, but it will be clear that the invention can just as well be applied with a transport shaft 3 and/or a transport shaft 1 of different cross-section, the invented discharge member 11 having a shape that is adapted to those cross-section.

Claims: A chimney, comprising: a transport shaft (3) for waste gases which can be mounted protruding through a roof and which at its top can be connected to a tubular member (1) being in communication with the open air at its top end, the diameter of the tubular member (1) being larger than the diameter of the transport shaft (3); a discharge member (11) with which the tubular member (1) can be secured in such a way that the tubular member (1) with its bottom end extends to a lower level than the top end of the transport shaft (3), so that the transport shaft (3) protrudes into the tubular member (1); said discharge member (11) being connectable to the inner wall of the tubular member (1) and also being connectable to the outer wall of the transport shaft (3) and moreover being stepped in cross-section having a lowermost step and a next, higher step, its outer step (14) being the lowermost one and joining the tubular member (1) near its bottom end, characterized in that the tubular member is an end shaft (1) mountable on top of the roof and being in communication with the open air via a shield (2) at its top end, while the higher step (15) of the discharge member (11) serves to receive at its bottom side the top end of a sealing member (4, 6 or 8, 9) which seals the roof covering onto the transport shaft (3), the discharge member (11) being formed to discharge liquid condensed on the inner wall of the end shaft (1) and, if any, rain water, to the roof. A chimney according to claim 1, characterized in that the discharge member (11) forms a drain together with the inner wall of the end shaft (1), said drain comprising at least one discharge opening (16) debouching outside the periphery of the transport shaft (3) for discharging condensed liquid and possible rain water. A chimney according to claim 2, characterized in that the discharge member (11) is annular with an upwardly extending inner flange (13) that fits around the cylindrical transport shaft (3) and has locally at least one step (16) that is lowered with respect to the lowermost step (14), the cylindrical end shaft (1) being joinable with the top of said lowermost step (14), so that the space between the transport shaft (3) and the end shaft (1) is only in open communication with the open air by means of the lowered step (16). A chimney according to claim 3, characterized in that instead of having a lowered step (16), ports are present in the horizontal part of the lowermost step (14). A chimney according to claim 3, characterized in that instead of having a lowered step (16), ports are present near the bottom end of the end shaft (1) in the wall of the end shaft (1).

Inventors: VAN SCHELLEBEEK, DIRK JOHANNES
Applicants: UBBINK NEDERLAND B.V.
Application year: 1988
Main classification: F23L17
IPC codes: F23L17