Only by changing the air pressure (air capacity), it is possible to adjust the thermal power while maintaining a constant mixing ratio.
The venturi mixer is a device which mixing air and various kind of gas. Venturi mixer sucks and mixes gas with negative pressure generated around the nozzle when low pressure air (1 to 10 kPa) passes through the nozzle of the mixer.
Gas of 1 to 3 kPa is always adjusted to atmospheric pressure with zero governor, and even if the air pressure changes (air volume changes), the gas amount follows a constant mixing ratio and the heating power can be adjusted. Since the mixing ratio can be varied by the gas volume control knob, when you change the gas fuel later, you can adjus according to the gas type.
It is connected to each type of burner from the mixed gas outlet and burning is done.
The air-gas ratio will be maintained at safety combustion range and always improve the combustion effect greatly. Turndown ratio is about 1.3 (At an air pressure of 10 kPa it is about 1.4).
It is not necessary to boost the gas and you can change the thermal power freely by just adjusting the air butterfly valve. It is safe and easy to handle with one hand control.
By controlling the combination of "control butterfly valve" and "control motor", various automatic control such as P, PI, PID, etc. is possible as well as 2 position control." control but also P, PI, PID, control.