Abrégé

A method and apparatus for calculating the derived cetane number of a liquid hydrocarbon sample is disclosed. The method comprises combusting (19) the sample in a constant volume combustion chamber (45). The method comprises obtaining (23) a pressure versus time combustion profile (69) of the sample wherein the profile comprises a first region (81) and a second region (83), the first region (81) including the start of combustion, and the second region (83) relating to a later time than the first region. The method comprises selecting a single data point from the second region (83) of the combustion profile (69), said data point representing a combustion delay (CD) of the combustion profile; and calculating a derived cetane number for the sample using the time value associated with said single data point.

Classes IPC  ?

• G01N 33/28 - Huiles

Abrégé

An apparatus for measuring the vapour pressure of a liquid hydrocarbon sample is disclosed. The apparatus comprises a sealed chamber (25) for receiving the sample. The chamber (25) is at least partially defined by a moveable element (26) such that moving the moveable element (26) alters the volume of the chamber (25). The apparatus comprises a displacement sensor (29) configured to measure a displacement of the movable element (26).

Classes IPC  ?

• G01N 7/14 - Analyse des matériaux en mesurant la pression ou le volume d'un gaz ou d'une vapeur en permettant au matériau d'émettre un gaz ou une vapeur, p.ex. la vapeur d'eau, et en mesurant une différence de pression ou de volume
• G01N 25/02 - Recherche ou analyse des matériaux par l'utilisation de moyens thermiques en recherchant le frittage
• G01N 33/28 - Huiles

Abrégé

Embodiments of the present invention relate to a method and apparatus for mixing additives into a fluid fuel at a predictable concentration. The method comprises: taking a sample of the fuel; mixing the additive into the sample in metered proportions; testing the sample to determine that the correct amount of additive is present; storing the remaining fuel until it is time for the fuel to be used; and mixing the additive into the remainder of the fuel in the same metered proportions.

Classes IPC  ?

• G05D 11/13 - Commande du rapport des débits de plusieurs matériaux fluides ou fluents caractérisée par l'usage de moyens électriques