Air/gas mixers are designed for low-pressure drop operation. Combustion air delivered through a control valve is metered through a precision machined orifice. Controlled air pressure is impulsed to the top of the gas balanced zero regulator. The zero regulator outlet pressure is always the same as the controlled air pressure. An adjustable gas orifice sets the gas fuel flow rate. The pressure interlocked system maintains equal air and gas pressure drops at all flow rates. Air-gas ratio is constant over the entire turndown range of the system. These mixers selections are based on blower air pressure available, mixture pressure required at the burners, BTU/hr. input, percentage primary aeration and turndown ratio required.
Airboat is a flat-bottomed punts powered by a propeller attached to an automobile or aircraft engine. It is also called as fan boats. The propeller has the typical shape and size of an airplane propeller and so requires a large metal cage to protect passengers and other users. The flat bottom allows air boats to navigate easily through shallow swamps and marshes as well as in canals, rivers and lakes, it can also be used on frozen lakes. The driver sits high on a platform to improve visibility and to permit spotting floating obstacles and animals in the path of the boat. Steering is accomplished by swiveling vertical rudders positioned in the propeller wash in the very rear of the airboat, so control is a function of current, wind, water depth and propeller thrust.