FLOW CONTROL SYSTEM, METHOD, AND APPARATUS
A gas flow control system for delivering a plurality of gas flows. The gas flow control system has a gas flow path extending from a gas inlet to first and second gas outlets. First and second flow restrictors are operably coupled to the gas flow path. First and second valves are operably coupled to the gas flow path such that when both first and second valves are in a fully open state, flows of gas from the first and second gas outlets are split according to the impedances of the first and second flow restrictors.
1 .- 136 . (canceled)
137 . A gas flow control system for delivering a plurality of gas flows, the gas flow control system comprising:
a gas flow path extending from a gas inlet to a first gas outlet and a second gas outlet;
a first valve operably coupled to the gas flow path and located between the gas inlet and the first gas outlet;
a second valve operably coupled to the gas flow path and located between the gas inlet and the second gas outlet;
a first flow restrictor having a first flow impedance operably coupled to the gas flow path and located between the gas inlet and the first gas outlet;
a second flow restrictor having a second flow impedance operably coupled to the gas flow path and located between the gas inlet and the second gas outlet;
wherein, when both the first and second valves are in a fully open state, a ratio between a first gas flow from the first gas outlet and a second gas flow from the second gas outlet is determined by a ratio of the first flow impedance and the second flow impedance.
138 . The system of claim 137 further comprising a controller having a memory, the memory storing a value representing the first flow impedance or the second flow impedance.
139 . The system of claim 137 further comprising a pressure transducer operably coupled to the gas flow path between the gas inlet and the first and second flow restrictors.
140 . The system of claim 137 further comprising a base, the first valve, the second valve, the first flow restrictor, and the second flow restrictor all mounted to the base.
141 . The system of claim 137 wherein the gas flow path comprises a third gas outlet and the gas flow control system further comprises a third valve operably coupled to the gas flow path and located between the gas inlet and the third gas outlet.
142 . The system of claim 141 wherein the third valve is a proportional valve.
143 . The system of claim 141 wherein a third flow restrictor having a third flow impedance is operably coupled to the gas flow path and located between the gas inlet and the third gas outlet.
144 . The system of claim 141 wherein the first and second valves are proportional valves.
145 . The system of claim 141 wherein the ratio of the between the first gas flow and the second gas flow deviates from the ratio of the first and second flow impedances.
146 . A gas flow control system for delivering a plurality of gas flows, the gas flow control system comprising:
a gas flow path extending from a gas inlet to a first gas outlet and a second gas outlet;
a first valve operably coupled to the gas flow path and located between the gas inlet and the first gas outlet;
a second valve operably coupled to the gas flow path and located between the gas inlet and the second gas outlet;
a first flow restrictor having a first flow impedance operably coupled to the gas flow path and located between the gas inlet and the first gas outlet;
a second flow restrictor having a second flow impedance operably coupled to the gas flow path and located between the gas inlet and the second gas outlet;
wherein the first and second valves are proportional valves, the first and second valves selectively permitting gas flow from the first and second gas outlets.
147 . The gas flow control system of claim 146 wherein, when the first and second valves are in a fully open state, a ratio between a first gas flow from the first gas outlet and a second gas flow from the second gas outlet is determined by a ratio of the second flow impedance and the first flow impedance.
148 . The gas flow control system of claim 146 further comprising a base, the first valve, the second valve, the first flow restrictor, and the second flow restrictor all mounted to the base.
149 . The gas flow control system of claim 146 further comprising a pressure transducer operably coupled to the gas flow path upstream of the first and second valves and the first and second flow restrictors.
150 . The gas flow control system of claim 146 wherein a ratio of the between a first gas flow from the first gas outlet and a second gas flow from the second gas outlet deviates from a ratio of the second flow impedance to the first flow impedance.
151 . A method of delivering a process gas, the method comprising:
(a) flowing the process gas through a first gas outlet of a gas flow apparatus, the gas flow apparatus having a gas flow path extending from a gas inlet to the first gas outlet, a first valve operably coupled to the gas flow path and located between the gas inlet and the first gas outlet, a first flow restrictor having a first flow impedance operably coupled to the gas flow path and located between the gas inlet and the first gas outlet, the first valve in a fully open state and delivering a first controlled flow of process gas to the first gas outlet;
(b) subsequent to step (a), transitioning a second valve to a fully open state and the first valve to a fully closed state and delivering a second controlled flow of process gas to a second gas outlet, the second valve operably coupled to the gas flow path and located between the gas inlet and the second gas outlet, a second flow restrictor having a second flow impedance operably coupled to the gas flow path and located between the gas inlet and the second gas outlet; and
(c) subsequent to step (b), transitioning the first valve to a fully open state and delivering the first controlled flow of process gas to the first gas outlet simultaneously with delivering the second controlled flow of process gas to the second gas outlet.
152 . The method of claim 151 wherein, in step c), the first and second controlled flows of process gas are delivered at a ratio determined by the ratio of the first flow impedance to the second flow impedance.
153 . The method of claim 151 wherein the first and second valves are proportional valves.
154 . The method of claim 152 further comprising step d) subsequent to step (c) comprising delivering a first controlled flow of process gas at a first flow rate from the first gas outlet and a second controlled flow of process gas at a second flow rate, a ratio of the first flow rate to the second flow rate differing from a ratio of the second flow impedance to the first flow impedance.