| 摘要 |
In a system for delivering vapor from a container partially filled with liquid to be vaporized by bubbling a carrier gas therethrough, the flow of the vapor is precisely regulated by a controller so as to provide a uniform mass flow rate of vapor. The controller is programmed to receive signals representing the sensing of the total gaseous pressure, temperature and liquid level in the container and to use the signals in a computation according to the following formula: m*=AFc (1+B DELTA T-C DELTA P-DFc+E DELTA L) wherein m*=Approximate vapor mass flow Fc=Carrier gas mass flow DELTA T=Temperature variation from nominal (T-To) DELTA P=Pressure variation from nominal=(P-Po) DELTA L=Charge in liquid level=- INTEGRAL m*dt A,B and C=Positive constants computed for each chemical and nominal operating conditions; and D and E=Positive or negative constants computed for each chemical and nominal operating conditions. A, B and C=Positive constants computed for each chemical and nominal operating conditions; D and E=Positive or negative constants computed for each chemical and nominal operating conditions.
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