DE20308866U1 - Non-return flap, for the gas/air flow channel from the fan blower to the gas burning surfaces in a multi-stage gas burner, is a thin blade mounted at one end with a seal around its circumference and tensed against the channel wall - Google Patents

Abstract

The non-return flap, for the gas/air flow channel to burner surfaces, has a thin-walled metal blade flap (1) which can be shaped. Its shape structure and sealing (2) around it gives a pretension against the gas/air flow direction from the fan blower. The flap is fitted at a single mounting point (3), with a curvature from the mounting to the free end of the flap, to give the pretension.

Description

BUDERUS HEATING TECHNOLOGY GMBH

G 1593 TE-P Z

Description Check valve

The innovation concerns a check valve for installation in a flow channel for the gas/air mixture in a gas burner according to the generic term of claim 1. Gas burners work with atmospheric combustion or with a fan for the combustion air or the gas/air mixture. They have a device for regulating the gas/air ratio, consisting of a gas control system with a first and a second solenoid valve, a gas pressure regulator and at least one downstream gas nozzle. In known fan burners, the injection of gas takes place upstream of the fan, so that the gas/air mixture reaches the assigned burner surfaces via a flow channel.

Gas burners are generally designed with multiple stages in order to better adapt the combustion or heat output of a boiler to the actual heat requirement. Fuel rods, burner surfaces or burner stages are then assigned to individual heating gas flues in the boiler. If only one burner stage is in operation, it must be prevented that the gas flows through neighboring heating gas flues. On the one hand, cooling would then be relatively high and on the other hand, exhaust gas could flow back. For this reason, exhaust-side blocking systems, such as flaps, are well known.

In contrast to room air-dependent combustion, these measures are not sufficient for room air-independent operation because exhaust gases or, in the case of technical defects, the gas/air mixture, may escape from the combustion chamber via the non-operating fuel rods, burner surfaces or burner stages and a stationary fan.

The innovation is therefore based on the task of preventing the flow against the conveying direction of the fan when the gas burner is not in operation in multi-stage burner arrangements using simple measures.

04.06.2003/G 1393. ;·

According to the innovation, this was solved with the features of claim 1. Advantageous further developments can be found in the subclaims.

A check valve was created for installation in a flow channel for the gas/air mixture in a gas burner that leads to assigned burner surfaces. This is characterized by a thin-walled, lamellar, deformable, metallic flap element. Due to its shape, this has a pre-stress directed against the fan conveying direction and an assigned circumferential sealing surface.

The flap element is preferably fixed to a fastening point arranged on one side. The flap element itself and the associated sealing seat have a curvature between the fastening point and the free end that opens with the blower pressure in order to generate a pre-tension. Furthermore, the flap element is preferably installed at an angle in the flow channel. The fastening point is located slightly further upstream and the free, opening end is then downstream.
In a first embodiment, the flap element can form a structural unit with the associated sealing seat of the check valve, which is to be inserted into the flow channel. Alternatively, the flap element can also be attached directly to the flow channel with a fastening element. In this case, the associated sealing seat is molded directly onto the flow channel.

With the new arrangement, simple measures are taken to prevent the flow against the direction of flow of the blower when the gas burner is not in operation in multi-stage burner arrangements. The check valve is inexpensive to manufacture and can be integrated as a simple component in the flow channel downstream of the blower.

The drawing shows an example of the innovation. It shows a check valve:

Fig. 1: as a structural unit to be inserted into a flow channel in a perspective view,

Fig. 2: as a structural unit to be inserted into a flow channel in side view and

04.06.2003/G 1393. "

Fig. 3: as part of a flow channel, with molded sealing seat, in a perspective view.

The check valve for installation in a flow channel 5 leading to associated burner surfaces for the gas/air mixture in a gas burner essentially consists of a thin-walled, lamellar, deformable, metallic flap element 1. Due to its curved shape, which generates pre-tension, it is pressed against the blower conveying direction against an associated circumferential sealing surface on a sealing seat 2. Due to the existing blower pressure, the flap opens automatically as soon as the blower is started.

The flap element 1 is fixed at one point with a fastening element 3. If the check valve with the flap element 1 and the associated sealing seat 2 is to be inserted separately into the flow channel 5 as a structural unit, it is fixed in the flow channel 5 via an opening 4. In addition, the flap element 1 can be attached directly to the flow channel 5 with the fastening element 3. In this case, the associated sealing seat 2 is molded directly onto the flow channel 5.

04.06.2003 / G 15&*· V"

Claims (6)

1. Non-return valve for installation in a flow channel leading to associated burner surfaces for the gas/air mixture in a gas burner with a fan which is arranged upstream together with the associated gas nozzle, characterized by a thin-walled, lamellar, deformable, metallic flap element ( 1 ) which, due to its shape, has a prestress directed against the fan conveying direction and an associated circumferential sealing surface. 2. Check valve according to claim 1, characterized in that the flap element ( 1 ) is preferably fixed to a fastening point arranged on one side. 3. Check valve according to claims 1 or 2, characterized in that the flap element ( 1 ) and the associated sealing seat ( 2 ) have a curvature between the fastening point and the free, opening end for generating a prestress. 4. Check valve according to one of claims 1 to 3, characterized in that the flap element ( 1 ) is preferably installed obliquely in the flow channel ( 5 ), wherein the fastening point is located somewhat further upstream and the free, opening end is located downstream. 5. Check valve according to one of claims 1 to 4, characterized in that the flap element ( 1 ) and the associated sealing seat ( 2 ) form a structural unit which is to be inserted into the flow channel ( 5 ). 6. Check valve according to one of claims 1 to 4, characterized in that the flap element ( 1 ) is fastened directly to the flow channel ( 5 ) by means of a fastening element ( 3 ) and that the associated sealing seat ( 2 ) is formed onto the flow channel ( 5 ).