Non-foaming surfactant to add to water
Conceptual thoughts about mixing two immiscible liquids (not on surface tension):

A reflux condenser used in the ochem lab equally has a circulation of about 2 L/min water (reference from an advertisement, which doesn't look too much off-range)

After the two liquids are mixed, what application will follow?  Do you target cleaning an engine, or deployment for food processing?  What are intended storage conditions once the two are mixed (e.g., time of storage / transport, temperature of storage / use)?  Altogether with the other liquid you want to mix with water, this may narrow your choice of the surfactant.

Mixing the two continuously may be achieved with a tube reactor with two inlets, one outlet, and a screw-shaped inner geometry

(reference, section «Liquid-Liquid &amp; Liquid-Gas Mixers»)
Depending on parameters of your liquids (e.g., density, viscosity, flow rate, key word Reynolds number) you may enter the regime of turbulent flow until you divide the liquid into tiny droplets which increases the surface accessible for mixing.  The addition of surfactant may help to achieve the intended mixing, too.

(loc. cit.)

The formation of foam however is the result of an entrapment of a gas.  Whipping cream with a whisk for example intentionally aerates the cream.  Liquids like water may boil (i.e., generation of gas) because of sudden pressure changes while passing a propeller blade at a flow rate too high (cavitation), too.
Thus, mixing water and your other liquid in a tube reactor like the one mentioned above, in absence of air and at the right hydrodynamic state may prevent the formation of foam.  (You mau fight foam by ultrasound (example), though.)