초록 ▼

An improved system for sensing and controlling the level of fluent material in two reservoirs when material is transferred from one reservoir to the other. In electrically conducting materials, levels are sensed by direct current conduction between electrode pairs placed in each reservoir at desired

An improved system for sensing and controlling the level of fluent material in two reservoirs when material is transferred from one reservoir to the other. In electrically conducting materials, levels are sensed by direct current conduction between electrode pairs placed in each reservoir at desired “high”and “low”control levels which send D.C. digital logic sensing signals from these four sensors over connecting wires to four high resistance input circuits of a digital signal processing circuit; in electrically nonconducting materials, levels are sensed by suitable transducers which upon immersion send D.C. digital logic sensing signals to the digital signal processing circuit. The digital signal processing circuit receives the multiple sensor signals and provides a digital output signal or absence thereof, depending on the relative state and sequence of the sensing signals and transmits this digital output signal to the input circuit of a solid state relay, the output circuit of which controls the power of flow control means in a manner to maintain desired levels of fluent material in both reservoirs.

대표청구항 ▼

The method of controlling the level of fluent material during transfer of said material between two reservoirs and maintaining said level between desired high and low levels in each of said reservoirs, said method comprising: detecting increasing or decreasing levels of said material by using upper

The method of controlling the level of fluent material during transfer of said material between two reservoirs and maintaining said level between desired high and low levels in each of said reservoirs, said method comprising: detecting increasing or decreasing levels of said material by using upper and lower level sensors placed at said desired levels in each of said reservoirs, said sensors individually transmitting a digital voltage output signal upon immersion in said material and terminating said digital output signal upon emergence from said material; transmitting said digital voltage signals from said sensors to input circuits of a digital signal processing circuit being supplied with operational power from a connected power supply and having an output circuit; processing said digital signals in said processing circuit in a manner producing a digital output signal from said processing circuit when the increasing level of said material in said first reservoir immerses said upper sensor and when the decreasing level of said material in said second reservoir falls below said lower sensor, and terminating said digital output signal from said processing circuit when the increasing level of said material in said second reservoir immerses said upper sensor and when the decreasing level of said material in said first reservoir falls below said lower sensor; transmitting said digital output signal from said processing circuit to the input circuit of a solid state relay having an input circuit and an output circuit, said relay output circuit being serially connected between a source of electrical power and power driven flow control means for regulating flow of said material being transferred between said reservoirs, said relay input circuit responding to said output signal from said digital processing unit and changing the normal operating state of said relay output circuit; operating said flow control means by said change of state of said relay output circuit; and controlling flow of said material in a manner to maintain level of said material within said desired levels in each of said reservoirs.