AT402760B - CATALYTIC BURNER ARRANGEMENT - Google Patents

Description

AT 402 760 B

The invention relates to a catalytic burner arrangement according to the preamble of claim 1.

With such burner arrangements, there is always the problem that the catalytic burner requires a certain operating temperature for its proper functioning. Arrangements are known in which the catalytic burner is preheated either electrically or according to DE 4 222 711 A1 by means of a flame burner which can be controlled separately via a fuel gas switchover valve. However, there is the disadvantage of a considerable control effort, a gradual start-up of the catalytic combustion and thus an optimal utilization of the low-pollutant catalytic converter operation being impossible.

The aim of the invention is to avoid this disadvantage and to propose a burner arrangement of the type mentioned at the outset which, with a simple construction, requires only little control effort and in which the pollutant emission is further reduced.

According to the invention, this is achieved in a catalytic burner arrangement of the type mentioned at the outset by the characterizing features of the independent patent claim.

The proposed measures have the advantage that in the starting phase of the catalytic burner through this unreacted gas via the line connected to the catalytic burner, the flame burner designed as a blue burner can be fed and burned by the latter, whereby the catalytic burner is heated up very quickly . As the temperature of the catalytic burner rises, it converts more and more gas mixture, which means that less and less combustible gas mixture is fed to the blue burner until it no longer receives and extinguishes a combustible mixture when the supplied fuel gas mixture is completely converted. The operating status of the blue burner controls the flap for the outflow of gases directly from the catalytic burner. This prevents gases from flowing directly out of the catalytic burner during the start-up phase, as a result of which the fuel gas mixture flowing into the catalytic burner can only flow out via the line connected to it and leading to the blue burner, thereby reaching the blue burner and being burned there.

The features of claim 2 give the advantage of very simple control of the flap.

The invention will now be explained in more detail with reference to the drawing. Show:

1 schematically shows a catalytic burner arrangement according to the invention,

2 shows a section along the line II-II in FIG. 1 and FIG. 3 shows a section along the line III-III in FIG. 1.

The same reference numerals mean the same details in all figures.

1 shows a burner arrangement according to the invention. In this, a catalytic burner 2 is arranged in a combustion chamber 1, which is connected at its lower end to a mixture supply pipe 3, the mixture supply pipe 3 being arranged coaxially with an air pipe 4, into which a gas pipe 5 opens, in which a gas valve 6 is arranged is. The air tube 4 is connected to a blower 7.

In the lower region of the catalytic burner 2, distributor plates 8 are arranged, the inside of the catalytic burner having a catalytic coating which, at a corresponding operating temperature, enables a mixture flowing in via the mixture feed pipe 3 to be converted.

In the uppermost region of the catalytic burner 2, a line 9 branches off from the latter, which leads down to a blue burner 10 which, as can be seen from FIG. 3, is arranged essentially concentrically to the catalytic burner 2 and below it.

At the top of the catalytic burner 2 there is a flap 11 which is connected in a rotationally fixed manner to a shaft 12 which is connected to a drive 13. The drive 13 can expediently be formed by a moving-coil measuring mechanism, the drive 13 being operated by a flame detector, not shown, e.g. an ionization electrode is controlled.

With this flap 11, an escape of exhaust gases into the combustion chamber 1 can be controlled.

A heat exchanger 14 is arranged above the catalytic burner 2, wherein, as can be seen from FIG. 3, the space between the heat exchanger 14 and the inner wall of the cylindrical combustion chamber 1 is filled with insulating bodies 15. The heat exchanger 14 is connected to a return line 16 and a flow line 17 at diagonally opposite points.

A baffle plate 18 is arranged above the heat exchanger 14. The combustion chamber 1 is connected to an exhaust hood 19 to which an exhaust pipe 20 is connected.

At the start of the catalytic burner 2, a gas-air mixture is fed to the catalytic burner 2, where, however, there is no conversion due to the temperature being too low and the gas mixture is fed to the blue burner 10 via line 9. There the mixture burns after a second

Claims (2)

AT 402 760 B corresponding ignition of the mixture by means of an ignition electrode, not shown. The flap 11 remains closed. With increasing temperature, more and more gas mixture is converted in the catalytic burner 2. As a result, less gas mixture reaches the blue burner 10, so that it goes out as soon as the gas mixture in the catalytic burner 2 is essentially completely converted. After the blue burner 10, which is detected by the flame monitor, has gone out, the flap 11 is opened, so that the heat exchanger 14 is acted upon by the hot exhaust gases. Claims 1. Catalytic burner arrangement with a catalytic burner (2) connected to a mixture supply line (3) and flowing through it from bottom to top, and a flame burner arranged below the same for heating the catalytic burner (2) to its operating temperature, the flame burner after the operating temperature has been reached goes out, characterized in that a line (9) is connected to the upper area of the catalytic burner (2), which leads to the flame burner designed as a blue burner (10) and that on the upper side of the catalytic burner (2) facing an exhaust gas space Adjustable flap (11) is arranged, which is closed before the blue burner (10) goes out and is opened after the blue burner (10) goes out. 2. Burner arrangement according to claim 1, characterized in that in the region of the blue burner (10) a flame detector, for example an ionization electrode, is arranged which controls a drive (13) of the flap (11). Including 2 sheets of drawings 3