초록 ▼

To supply a programmed gradient to a high pressure pump for introduction into a column, a mixer, degasser and accumulator communicates with the high pressure pump to supply fluid thereto, having a volume no more than 150 times the chamber volume of the high pressure pump. The mixer, degasser and acc

To supply a programmed gradient to a high pressure pump for introduction into a column, a mixer, degasser and accumulator communicates with the high pressure pump to supply fluid thereto, having a volume no more than 150 times the chamber volume of the high pressure pump. The mixer, degasser and accumulator includes temperature sensors which sense when the mixer, degasser and accumulator has been emptied to a level where it cannot respond to a demand for fluid from said high pressure pump and provides a signal to a low pressure pump which responds by cycling to again fill the mixer, degasser and accumulator. Upon receiving a demand signal, the low pressure pump fills by drawing fluid from a plurality of fluid sources to compose the gradient being used at that time, with the pump slowing during valve opening and closing so as to avoid cavitation.

대표청구항 ▼

A liquid chromatographic system comprising: first pump means for pumping a liquid at a first pressure; second pump means for pumping liquid at a second pressure; at least one source of fluid; a chromatography column; means for controlling the flow rate of liquid from said first pump means; reservoir

A liquid chromatographic system comprising: first pump means for pumping a liquid at a first pressure; second pump means for pumping liquid at a second pressure; at least one source of fluid; a chromatography column; means for controlling the flow rate of liquid from said first pump means; reservoir means for liquid; said first pump means communicating with said reservoir means for liquid to draw liquid therefrom as needed; said second pump means further including means for supplying liquid to said reservoir means; said means for supplying liquid to said reservoir means including means for keeping the reservoir means with sufficient liquid in it for one cycle of said first pump means; at least one valve; said second pump means including speed control means; said means for supplying liquid to said reservoir means including means for causing at least one of said sources of liquids to communicate with said second pump means through said at least one valve; said speed control means including means for slowing the speed of said second pump means while said at least one valve is opening; and means for increasing the speed of said second pump means when said at least one valve is fully opened, whereby fluid is introduced into said second pump means efficiently without cavitation; said reservoir means including an inlet and a hollow frit column communicating with said inlet whereby influent to said reservoir means must flow through the frit column which serves as a tortuous path and flow spreader before reaching an outlet.