Apparatus for automatic crystal point detection

Claim 1

An apparatus for detecting the crystal point of a normally liquid composition having constituents which crystallize upon being cooled, comprising: a container adapted to contain a sample of said liquid composition up to a predetermined level, said container comprising a cup and an insulated jacket surrounding and spaced from said cup to form an annular space between the well of said cup and said jacket; a point source temperature measuring device disposed below said sample level of said container; sample cooling means operatively engaging said container for cooling said sample, said cooling means comprising a vortex tube disposed to discharge cooled air into said annular space; sample inlet means coupled to said cup for introducing said sample therein; sample drain means coupled to said cup for draining any sample within said cup; first valve means disposed to control flow through said sample inlet means and second valve means disposed to control flow through said sample drain means whereby said cup may be drained and refilled with a new sample. recording means for registering the change in temperature of said sample on a cooling curve, said recording means being coupled to said temperature measuring device; differentiating means coupled to said temperature measuring means for detecting any changes in the slope of the cooling curve of said sample, zero point recording means coupled to said differentiating means for recording the point on said cooling curve when the slope thereof approaches zero and recycling means coupled to said zero point recording means for actuating said first and second valve means in timed sequence to refill said container with a new sample.

Claim 2

An apparatus for detecting the crystal point of a normally liquid composition having constituents which crystallize upon being cooled, comprising: a container adapted to contain a sample of said liquid composition up to a predetermined level, said container comprising a cup and an insulated jacket surrounding and spaced from said cup to form an annular space between the well of said cup and said jacket; a point source temperature measuring device disposed below said sample level of said container; sample cooling means operatively engaging said container for cooling said sample, said cooling means comprising a vortex tube disposed to discharge cooled air into said annular space; sample inlet means coupled to said cup for introducing said sample therein; sample drain means coupled to said cup for draining any sample within said cup; first valve means disposed to control flow through said sample inlet means and second valve means disposed to control flow through said sample drain means whereby said cup may be drained and refilled with a new sample. recording means for registering the change in temperature of said sample on a cooling curve, said recording means being coupled to said temperature measuring device; differentiating means coupled to said temperature measuring means for detecting any changes in the slope of the cooling curve of said sample, zero point recording means coupled to said differentiating means for recording the point on said cooling curve when the slope thereof approaches zero and recycling means coupled to said zero point recording means for actuating said first and second valve means in timed sequence to refill said container with a new sample.