Abstract: A characterization factor monitor samples oil and provides a signal K corresponding to the characterization factor of the oil. Signal K may be used as a control signal or may be displayed by conventional display means to an operator. The monitor includes a refractometer and a flash point analyzer sampling the oil and providing signals RIt and F corresponding to the refractive index of the oil and to the flash point in degrees F of the oil, respectively. A temperature sensor senses the temperature of the oil and provides a signal T representative thereof. An output circuit connected to the refractometer, to the flash point analyzer and to the temperature sensor provides signal K in accordance with signals F, RIt and T.

Abstract: A monitor which provides a signal corresponding to the Universal Oil Product (UOP) characterization factor of a hydrocarbon stream includes apparatus for sampling a portion of the hydrocarbon stream. Other apparatus changes the temperature of the sample to a predetermined temperature. A viscosity analyzer receives the sample and provides a signal corresponding to the viscosity of the hydrocarbon stream at the predetermined temperature. A refractometer receives the sample and provides a signal corresponding to the refractive index of the hydrocarbon stream at the predetermined temperature. An output network connected to the viscosity analyzer and to the refractometer provides the signal corresponding to the UOP characterization factor in accordance with the signals from the viscosity analyzer and the refractometer.

Abstract: A dual solvent refining process for solvent refining petroleum based lubricating oil stocks with N-methyl-2-pyrrolidone as selective solvent for aromatic oils wherein a highly paraffinic oil having a narrow boiling range approximating the boiling point of N-methyl-2-pyrrolidone is employed as a backwash solvent. The process of the invention results in an increased yield of refined lubricating oil stock of a predetermined quality and simplifies separation of the solvents from the extract and raffinate oil fractions.

Abstract: A special blending vessel lends itself to shifting from one continuously blended product to the next in a continuous flow with a sharp change so that there is substantially no mixing of the two products at the change over. There are two sets of ingredient inputs and product outputs for the blending vessel. And, there is a follower type divider that separates one set of ingredient inputs and product output from the other set. When a shift is to be made from the one product to the next, the ingredients of the second product are introduced and blended in the vessel while displacing the remainder of the one product without mixing therewith. Then the outputs are switched so that the second product follows with an abrupt change from the first product to the second.

Abstract: A solvent refining process utilizing N-methyl-2-pyrrolidone as solvent in which primary extract from the extraction zone is cooled to form a secondary raffinate and secondary extract and the secondary and primary raffinates are blended to produce an increased yield of product of desired quality. In a preferred embodiment of the process, the lubricating oil feedstock to the process is first contacted with a stripping medium previously used in the process for the recovery of solvent from at least one of the product streams whereby solvent contained in said stripping medium is recovered therefrom.

Abstract: A method for determining the Watson-Nelson characterization factor of hydrocarbons wherein the absolute viscosity and specific gravity are sensed providing first and second signals, respectively, corresponding to the absolute viscosity and specific gravity. The signals are then combined in accordance with the following equation:K = A + B/S.sub.2 + C 1n 1n (V/S.sub.1)where:K = the Watson-Nelson characterization factor of the hydrocarbon mixture;V = the absolute viscosity of the hydrocarbon mixture;S.sub.1 = the specific gravity of the hydrocarbon mixture;S.sub.2 = the specific gravity of the hydrocarbon mixture adjusted to 60.degree. F; andA, b and C are predetermined constants.

Abstract: Apparatus provides a signal corresponding to a miscibility temperature for a solvent-oil mixture in a solvent refining unit. The apparatus includes a circuit receiving signals related to flow rates of solvent and charge oil for the solvent refining unit. The circuit provides a signal corresponding to the solvent dosage. A network provides the miscibility temperature signal in accordance with the solvent dosage signal from the circuit.

Abstract: A solvent refining unit is controlled so that it has a maximum allowable solvent flow rate or a maximum allowable extract oil flow rate. The temperature of the extract-mix in the refining tower, the flow rate of the charge oil, the flow rate of the solvent and the flow rate of the extract oil are sensed by sensors which provide corresponding signals. A circuit provides signals corresponding to desired flow rates for the charge oil and the solvent and for a desired temperature for the extract-mix in the refining tower. The refining unit is operated in accordance with the desired signals so as to achieve either a maximum allowable flow rate for the solvent or a maximum allowable flow rate for the extract oil, or a maximum allowable flow rate for the refined oil, or a reduced charge oil flow rate for a fixed refined oil flow rate.

Abstract: A gas-filled thermometer which employs hydrogen and an adsorbent compound in a temperature sensitive bulb, with a pressure transducer connected to the bulb to indicate the temperature. The adsorbent compound has a composition conforming to the formula LT.sub.5 where L is a lanthanide rare earth element and T is a 3d-transition element.