摘要 |
A valving arrangement for use in the production of an aerated product such as chocolate, in which the product is pressurized with a gas, preferably a soluble gas such as carbon dioxide, wherein the valving arrangement includes a first valve plate (22) having a tapered orifice (22A) therein, a second valve plate (25) which is adjustable relative to the first plate in a plane transverse to the axis of the tapered orifice, and having a corresponding tapered orifice (25A) therein, the axis of which is parallel to the first axis, whereby the flow passage through these orifices can be preadjusted. Means are provided to close off the flow passage through the orifices abruptly without altering the preadjustment of the flow passage. This can be achieved by inserting a rod (16, 30) into the upstream orifice or by moving the valve plate a greater distance than the diameters of the orifices. |