Selas Midget Mixer Forced Air

Selas Midget Mixers (MM) are suction type proportional air-gas mixers. Air passing through the jet produces a suction in the throat section to entrain a fuel gas.

The quantity of gas entrained is easily set by the adjuster plug in the gas throttle cock. Once set, the fuel to air ratio remains constant over a wide range of air flows (assuming a constant gas pressure).

A Zero Regulator can be used to maintain a constant gas pressure, precisely at atmospheric pressure, for all gas flows.

Total heat input of the mixture delivered to the burner system is controlled by a single valve in the combustion air line. This valve may be motor operated for automatic process control.

The MMSR, MMCR, and MMTR assemblies include a correctly sized midget Zero Regulator. The accuracy of these units permits turndown ranges up to 3:1 on a capacity basis. Where wide turndown ranges are required, or where a number of mixers are connected to a single regulator, the ‘BZR’ Series Regulators (see Bulletin 5101) are recommended.