Producing or dispensing liquid products

摘要

A liquid product is dispensed via a membrane contactor. The contactor employs a plurality of gas-permeable hollow fibers. The contactor has a gas port communicating with the interior of the fibers and input and output ports for liquid communicating with space within the contactor surrounding the fibers. A gas comprising carbon dioxide or nitrous oxide is dissolved in the liquid in the contactor. The gas at a controlled pressure is supplied to the gas port. The liquid is supplied at a higher pressure than the gas to the input port for liquid from a supply of such liquid via a first valve having a first valve inlet port communicating with the supply of liquid and a first valve outlet port communicating with the inlet port for liquid. Liquid with the gas dissolved therein is dispensed from the outlet port for liquid via a dispense tap to ambient. The dispensing liquid step includes a start dispense step in which dispensing commences and a stop dispense step in which dispensing is stopped. The first valve is opened with the dispensing tap in the start dispense step, and is closed in the stop dispense step. Pressure build-up is relieved in liquid in communication with the space within the contactor surrounding the fibers after closure of the first valve and while maintaining the first valve closed. The balance between gas pressure and liquid pressure during the systems' standby periods protects the membranes from flooding.

主权项

1. Apparatus for adding a gas comprising carbon dioxide or nitrous oxide to a liquid during dispense thereof from a supply of said liquid; the apparatus comprising:
a membrane contactor having a contactor housing with a plurality of gas-permeable hollow fibres mounted therein, the contactor housing having a gas port communicating with the interior of the fibres and adapted to receive said gas at a controlled pressure thereat, and input and output ports for liquid communicating with space within the contactor housing surrounding the fibres; a first valve having a first valve inlet port arranged for communication with the supply of liquid and a first valve outlet port communicating with the inlet port for liquid and arranged for supply of said liquid to the inlet port for liquid at a higher pressure than said controlled gas pressure; a dispense tap coupled to the output port for liquid and adapted to dispense liquid to ambient: and a control system coupled to monitor opening and closing of the first valve and the dispense tap, whereby to the control a start dispense step in which dispensing commences and a stop dispense step in which dispensing is stopped, the control system being arranged to open the first valve with said dispensing tap in said start dispense step, and being arranged to close said first valve in said stop dispense step, and to relieve pressure build-up in liquid in communication with the said space after closure of the first valve and while maintaining the first valve closed.