Premixing apparatus
AssigneeRinnai Corporation
InventorsTakahiro OINE, Kotaro KUZUYA
Life of this patent
Estimating the term…
Abstract
In a premixing apparatus in which a butterfly valve is provided on an upstream side of a downstream end of a gas suction part to which the gas supply passage is connected, a failure to secure the necessary amount of air over a long period of time when the butterfly valve is brought into a closed position can be prevented. A ventilation hole, through which air flows from the upstream side to the downstream side of the butterfly valve when the butterfly valve is in the closed position, is formed in the butterfly valve. In addition, a protrusion extending in a thickness direction of the butterfly valve is provided, on each side surface of the butterfly valve, at a downstream part of a periphery of the ventilation hole when the butterfly valve is in an open position.
Claims4
A premixing apparatus in which fuel gas is mixed with air and an air-fuel mixture is supplied to a burner through a fan, comprising:
- a gas supply passage, having a downstream end connected to a gas suction part that is disposed in an air supply passage positioned on an upstream side of the fan;
- a butterfly valve, provided in a portion of the air supply passage positioned on the upstream side of the gas suction part, the butterfly valve being pivotable, about a pivot-shaft line extending along a predetermined diametrical direction of the butterfly valve, between at least two positions:
- an open position in which the butterfly valve is oriented parallel to a longitudinal direction of the air supply passage;
- and a closed position in which the butterfly valve is oriented orthogonal to the longitudinal direction of the air supply passage;
- and
- a ventilation hole, formed in the butterfly valve, through which air flows from the upstream side to the downstream side of the butterfly valve when the butterfly valve is in the closed position,
- wherein a protrusion extending outward in a thickness direction of the butterfly valve is provided, on each side surface of the butterfly valve that faces the upstream side or the downstream side when the butterfly valve is in the closed position, at a location corresponding to a portion of a periphery of the ventilation hole that becomes the upstream side when the butterfly valve is in the open position.
Dependencies are inferred from the claim text.