A fuel injection assembly for a combustor of a gas turbine includes a fuel injector configured to couple to an outer sleeve of the combustor. A boss is configured to couple to a combustion liner of the combustor at a position axially and circumferentially aligned with the fuel injector. An insert is removably coupled to the boss. The insert includes a flange portion and an annular wall portion extending from the flange portion and defining a mixing channel. The insert defines a plurality of partial direct injectors spaced apart from one another and disposed about the mixing channel. A combustor including such a fuel injection assembly is also provided.

Provided is a dual venturi. The dual venturi includes a housing including a housing body opened in a reference direction so that a gas or air flows, an inner partition wall through which an inner space of the housing body is divided into a first conduit and a second conduit, and a gas providing part provided with a first gas conduit passing through the first conduit to allow the first conduit to communicate with the outside therein and a second gas conduit configured to allow the second conduit to communicate with the outside, an opening/closing unit disposed in the inner space to open and close the first gas conduit and the second conduit, and a driver connected to the opening/closing unit to provide driving force to the opening/closing unit.

This application is directed to a device and method for providing a variable orifice restrictor to an air induction system to achieve an improved turndown ratio of an airflow rate. The devices of the invention improve turndown ratio by relying on a pressure differential.

Disclosed are an anti-backflow premixing device and a fuel gas water heater, where the anti- backflow premixing device includes a casing body, a premixing cavity is provided in the casing body, and the premixing cavity includes a gas outlet pathway; a baffle, the baffle is connected in the casing body, the baffle has a first position and a second position, the baffle can continuously move between the first position and the second position, the baffle obstructs the gas outlet pathway of the premixing cavity when at the first position, and the gas outlet pathway gradually opens when the baffle is moved from the first position to the second position; and a fuel gas passage, the fuel gas passage and the premixing cavity being in communication.

A restrictor for an air induction system is described herein. The restrictor includes a ducting box, a housing, and a flap assembly that is hingedly coupled to the housing. The flap assembly is designed to rotate in response to a pressure differential between the ducting box and the housing. A holding force may be based upon one or more of a weight of the flap assembly or an angle of a closed position of the flap assembly.