| 摘要 |
<p>A foam proportioner suitable for a fire tender, the proportioner including a pump (2, 9, 10), venturi (A), dual differential regulator controller (4), metering valve (17), regulator (11), the arrangement being such that water from the tank is drawn by the pump and directed to the venturi from which mixed foam and water is delivered, the foam being proportioned after being drawn from a foam tank (5) through the regulator to the metering valve from which the concentrate passes to a venturi which surrounds the pump, the volume of foam being controlled by the dual differential regulator controller, controlled from the venturi to the regulator.</p> |
