Vapor feed regulator

Claim 1

A system for controlling the mass ratio of species in a flowing binary mixture of a vapor and a carrier gas, said system comprising: first carrier gas means operative to provide a first flow of carrier gas; vaporizer means coupled to said first carrier gas means for introducing a vapor into said first flow of carrier gas to provide fluid mixtures which are characterized by different mass ratios of vapor to carrier gas; second carrier gas means bypassing said vaporizer means and operative to provide a controlled second flow of carrier gas; conduit means for combining said second flow of carrier gas with said first flow of carrier gas and said vapor introduced into said first flow of carrier gas to provide a combined flow; detector means responsive to incipiency of vapor phase change, said detection means being coupled to said conduit means and adapted to sample said combined flow to provide a detector signal varying in accordance with deviation of the condition of said combined flow from said point of incipiency; controller means coupled to said second carrier gas means and responsive to said detector signal to generate a control signal to control the flow rate of said second flow of carrier gas thereby to adjust the mass ratio of vapor to carrier gas in said combined flow whereby said detector signal is maintained at a commanded value; and means for controlling the temperature within said detector means whereby said point of incipiency is made to correlate with the mass ratio of vapor to carrier gas in correspondence with said commanded value.

Claim 2

A system for controlling the mass ratio of species in a flowing binary mixture of a vapor and a carrier gas, said system comprising: first carrier gas means operative to provide a first flow of carrier gas; vaporizer means coupled to said first carrier gas means for introducing a vapor into said first flow of carrier gas to provide fluid mixtures which are characterized by different mass ratios of vapor to carrier gas; second carrier gas means bypassing said vaporizer means and operative to provide a controlled second flow of carrier gas; conduit means for combining said second flow of carrier gas with said first flow of carrier gas and said vapor introduced into said first flow of carrier gas to provide a combined flow; detector means responsive to incipiency of vapor phase change, said detection means being coupled to said conduit means and adapted to sample said combined flow to provide a detector signal varying in accordance with deviation of the condition of said combined flow from said point of incipiency; controller means coupled to said second carrier gas means and responsive to said detector signal to generate a control signal to control the flow rate of said second flow of carrier gas thereby to adjust the mass ratio of vapor to carrier gas in said combined flow whereby said detector signal is maintained at a commanded value; and means for controlling the temperature within said detector means whereby said point of incipiency is made to correlate with the mass ratio of vapor to carrier gas in correspondence with said commanded value.

Claim 4

A system according to claims 1 or 2 wherein said detector means is a dew point cell having a condensing plate in the path of said combined flow, and wherein said means for controlling the temperature is coupled to said plate for adjusting the magnitude of said temperature.

Claim 6

A system according to claims 1 through 4 wherein said conduit means includes mixer means operative to mix said first and second flows upstream of said detector means.

Claim 7

A system for controlling the mass ratio of species in a flowing binary mixture of a vapor and a carrier gas, said system comprising: flow control means operative to provide first and second flows of carrier gas; vaporizer means coupled to said flow control means to accept said first flow for introducing a vapor into said first flow to provide fluid mixtures which are each characterized by a dew point corresponding to a particular mass ratio of vapor to carrier gas. vapor phase-change detection means coupled to said vaporizer means and adapted to sample said fluid mixtures to provide a detector signal which varies according to variations in the phase change point; controller means responsive to said detector signal to generate a control signal which varies in accordance with variations in said detector signal; and modulating means coupled to said flow control means to accept and introduce said second flow into said first flow downstream of said vaporizer means, and responsive to variations in said control signal to control the rate of flow of said second flow thereby to regulate the phase change point of the combined said first and second flows entering said vapor phase change point detection means.

Claim 8

A system for controlling the mass ratio of species in a flowing binary mixture of a vapor and a carrier gas, said system comprising: flow control means operative to provide first and second flows of carrier gas; vaporizer means coupled to said flow control means to accept said first flow for introducing a vapor into said first flow to provide fluid mixtures which are each characterized by a dew point corresponding to a particular mass ratio of vapor to carrier gas. vapor phase-change detection means coupled to said vaporizer means and adapted to sample said fluid mixtures to provide a detector signal which varies according to variations in the phase change point; controller means responsive to said detector signal to generate a control signal which varies in accordance with variations in said detector signal; and modulating means coupled to said flow control means to accept and introduce said second flow into said first flow downstream of said vaporizer means, and responsive to variations in said control signal to control the rate of flow of said second flow thereby to regulate the phase change point of the combined said first and second flows entering said vapor phase change point detection means.