DE2924963A1 - FIREPLACE HEAD FOR AIR EXHAUST FIREPLACES - Google Patents

Abstract

1. A flue terminal for room-sealed flue systems for taking clean combustion air to and venting products of combustion from all room-sealed appliances connected to any such room-sealed flue systems, characterized in that the cross section of the flue (2) at the top widens into a diffuser (3) and ends with a sharp upper edge (5), and further characterized in that the upper edge (6) of the air duct (1) is rounded from the outer edge towards said air duct and the cross section of said air duct is smaller in the rounded inlet edge area (6) than the cross section of the air duct proper and widens in a divergent section (7) to reach said cross section of the air duct proper.

Description

Ruhrgas Aktiengesellschaft, 3

Chimney head for air-exhaust chimneys The invention relates to a chimney head for air-exhaust chimneys.

It is known that combustion air is required for the operation of fireplaces, which air is taken from the space surrounding the fireplace will. Since joint-tight windows are required in new buildings to save energy, the air exchange is reduced of the room surrounding the fireplace. In extreme cases, this can lead to a reduction in the quality of the combustion or to incomplete combustion Incineration with the associated known disadvantages or dangers, in order to avoid these, are Measures have already been proposed that are intended to provide the fireplaces with the necessary combustion air to others Way than to feed from the surrounding space. These measures include B. the so-called air-exhaust chimneys, which are used in particular to connect several gas fires should. These chimneys supply combustion air to the fireplaces from outside the house and at the same time conduct the exhaust gases over the roof to the outside.

Various designs of air-exhaust chimneys are known:

a) In the case of the one-legged construction, which is partly in the literature as "Se-duct" is called, the combustion air is at the lowest point of the chimney over a horizontal Duct supplied and the exhaust gas-air mixture discharged via a chimney, which is connected to the duct. The connected fireplaces take their combustion air from the chimney and conduct their exhaust gases back in the same chimney. In this way, only the lowest fireplace receives pure combustion air and the air above it, which is more or less diluted with exhaust gas.

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b) In the case of the double-legged construction, which is used in literature Often referred to as "ü-duct", the combustion air is drawn through a vertical duct from the roof of the Building goes out, and also an exhaust-air mixture via a chimney, which is below with the air shaft is connected, discharged. As with the "Se-duct", the fireplaces take their combustion air from the chimney, which is more or less diluted with exhaust gas, and return their exhaust gases to the same chimney.

c) From GM 77 06 857 an air-exhaust chimney is known in which the exhaust shaft is concentric in the air shaft is arranged. In this air-exhaust chimney, too, the air and exhaust ducts are connected to one another at the bottom. However, this is a system in which the fireplaces only send their combustion air to the air shaft and feed their exhaust gases into the exhaust shaft. It is also possible to have an exhaust duct and an air duct to be arranged side by side. Here, too, the air duct and the exhaust duct are connected to one another at the bottom. All fireplaces are supplied with pure combustion air, but are due to the different pressures in the air and in the flue gas duct exposed.

Measurements on air-exhaust chimneys of this type have shown that both with and without known chimney attachments or covers, even without the influence of wind, significantly different pressure differences between the air inlet and exhaust gas outlet on the individual devices, which decrease with increasing shaft height and away from it depend on which or how many devices are already in operation. The uppermost devices may have kicked in even negative pressure differences, which made it impossible to operate the devices. When the wind comes a further influence on the operation of the gas fireplaces. Depending on the wind speed, more or

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less large pressure fluctuations between the air and exhaust duct, which at the top of the duct air. are strongest. Also shift depending on the wind direction and speed, the mean pressure differences at the individual fireplaces at different heights, The influences have a direct effect on the operation of the fireplace, so that the air ratios during combustion and the exhaust temperatures change undesirably. This can lead to unstable operation or lead to a deterioration in the efficiency of the connected fireplaces; in extreme cases the operation of the fireplace even becomes impossible.

The object of the invention consists in air-exhaust chimneys Influences of the weather conditions prevailing outdoors, in particular wind, on the To diminish fireplaces. The pressure difference between Combustion air inlet and exhaust gas outlet of the individual fireplaces should be as small as possible. Also should this pressure difference at all fireplaces regardless of the floor on which they are installed, if possible be equal.

The object is achieved by the measures mentioned in claims 1 to.

The training and the Operation of the chimney head according to the invention explained.

Fig. 1 shows a longitudinal section through the chimney head a double-sided air-exhaust chimney, in which the connected fireplaces use their combustion air remove them from the air duct 1 and discharge their exhaust gases into the exhaust duct 2.

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S- 2324963

Fig. 2 shows a longitudinal section through the chimney head an air-exhaust chimney, in which the /-.bgasschacht is arranged concentrically in the air shaft 1 and in which the fireplaces also use their combustion air to enter the air shaft Remove Ξ and discharge your exhaust gases into exhaust duct 2.

In the application examples of the chimney head according to the invention shown in FIGS. 1 and 2, the head is of the exhaust duct 1 designed such that the Inner cross-section expanded like a diffuser in the flow direction of the exhaust gases. It has been shown to be beneficial the diffuser-like extension 3 preferably has an angle of inclination with respect to the vertical of up to 10 give up to 5.

In the embodiment shown in Figure 2 is located As a further advantageous embodiment below the diffuser-like enlargement 3, a rounded cross-sectional constriction 4, from which the cross-section is derived, as above described, expanded like a diffuser.

Through the diffuser-like extension 3, the exhaust gases So guided that the flow speed and thus the kinetic energy of the exhaust gases is reduced and almost without loss is converted into pressure energy. This makes it possible to control the pressure level in the upper part of the exhaust duct lower and to match that in the air shaft at the same height. One directed against the exhaust gas outflow Wind flow is hindered by the diffuser-like extension 3. The end edge 5 of the exhaust duct 2 is sharp-edged. Tests have shown that it is directed towards the chimney head In this case, wind has less of an adverse effect on the pressure conditions in the chimney than it does in the execution with blunt or rounded edge. The wind current

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ORIGINAL INSPECTED

is divided at the sharp edge of the exhaust shaft head and does not get, as with a blunt one. Edge, arms with adjacent air currents in the chimney

Z A further reduction of wind effects is achieved through the embodiment illustrated in Figure 2 rounded Querschnitrsverengung 4 in the exhaust stack, followed by a diffuser-like enlargement. 3 This device does not hinder the outflow of the exhaust gases, while the inflow of wind - as a result of a flow separation due to the abrupt cross-sectional expansion - is considerably hindered. In this embodiment, too, the end edge 5 is sharp-edged for the reasons mentioned above.

The upper end edge 6 of the air shaft 1 is of rounded on the outside inwards. This brings a higher and more favorable pressure level in the upper part of the Air supply shaft as a blunt end edge. The air passage cross-section is in the area of the rounding smaller than the shaft cross-section and from there gradually expands to the full shaft cross-section. It has proven to be advantageous to give this diffuser-like extension 7 an angle of inclination compared to the vertical up to 10, preferably up to

to give 5 ⁰ C. The above-mentioned measures lead to an almost lossless guidance of the air flow - without impact and acceleration losses at the entry into the air shaft. A backflow of air generated by wind suction at the air duct inlet or a gust of wind that propagates backwards from the chimney to the air duct inlet is largely prevented by the reduced cross-section of the air duct inlet and the rounded cross-sectional constriction with subsequent diffuser-like expansion 3 of the exhaust duct or chimney head.

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The technical rules for air-exhaust chimneys (DVGK-Arbeirsbiatt G 627) .The air supply opening is corresponding at least 10 cm below the exhaust outlet arranged.

The chimney head according to the invention can depending on the design of the Chimney manufactured as an attachment and possibly subsequently placed on the chimney or when building the chimney can be manufactured as a part thereof.

The inventive design of the chimney head has to As a result, the pressure differences between the air inlet and the exhaust gas outlet at the individual fireplaces are very high are low and fluctuate little even in strong winds. It is also achieved that the pressure differences at the individual fireplaces regardless of location, d. H. the floor height at which the fireplace and the chimney shafts are connected, are almost the same, so that even the fireplaces on the upper floors of a house without Work impairment.

For a further reduction in the pressure differences the individual fireplaces were found to have pressure equalization openings between the air duct and the flue gas duct in the Close to the exhaust nozzle or concentric to the exhaust nozzle the fireplaces as appropriate.

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L e "r s e i t

Claims (4)

Check * he -... ___ Kair. ^ Nkopf for air-exhaust chimneys, which supply clean air to all connected fireplaces and remove the exhaust gases,
characterized, that the inner cross-section of the exhaust duct (2) at the top End widening like a diffuser in the direction of flow of the exhaust gases is formed (3) and has a sharp-edged cbere end edge (5), and that the upper end edge (6) of the air duct (T) is rounded from the outside to the inside and that the air passage cross section in the area of the rounding (6) is smaller than the shaft cross-section and extends from there like a diffuser the shaft cross-section is designed to widen (7). 2. Chimney head according to claim 1
characterized, that the exhaust duct (2) at the upper end below the diffuser-like Expansion (3) has a rounded cross-sectional constriction (4) and that this cross-sectional constriction (4) is followed by the diffuser-like expansion (3). 3. Chimney head according to claim 1 or 2, characterized in that that the diffuser-like extensions (3, 7) of the air shaft (1) and the exhaust duct (2) have an angle of inclination relative to the vertical of up to 10 °, preferably have up to 5. 4. Chimney head according to one of claims 1 to 3, characterized in that that the upper parts of the exhaust duct and the air duct, which form the chimney head, are designed as chimney attachments. 030064/01 1 1 ORIGINAL INSPECTED