Abstract: Methods are provided for conducting chemical analyses by combusting a sample in a combustion tube. A primary combustion chamber receives and combusts a sample to form first combustion products. A secondary combustion chamber receives and combusts the first combustion products to form second combustion products. The secondary chamber is disposed around the primary chamber and comprises a plurality of—preferably, three—combustion compartments. Each successive compartment is disposed around the preceding compartment and defines a respective gas flow channel having an inlet opening and an outlet opening at opposite ends. Each successive gas flow channel shares its inlet opening with the outlet opening of the preceding channel. The plurality of combustion compartments define a substantially continuous gas flow conduit from the inlet opening of the innermost compartment to the outlet opening of the outermost compartment. Static gas mixers may be employed to enhance mixing of the combustion products.

Abstract: Combustion tube (100,130,150) and method for combusting a sample to form combustion products for analysis. A primary combustion chamber (102) receives and combusts a sample to form first combustion products. A secondary combustion chamber (110) receives and combusts the first combustion products to form second combustion products. The secondary chamber is disposed around the primary chamber and comprises a plurality of—preferably, three—combustion compartments (112-116). Each successive compartment is disposed around the preceding compartment and defines a respective gas flow channel having an inlet opening (108,118,120) and an outlet opening (118,120,122) at opposite ends. Each successive gas flow channel shares its inlet opening with the outlet opening of the preceding channel. The plurality of combustion compartments define a substantially continuous gas flow conduit from the inlet opening of the innermost compartment to the outlet opening of the outermost compartment.

Abstract: Combustion tube (100,130,150) and method for combusting a sample to form combustion products for analysis. A primary combustion chamber (102) receives and combusts a sample to form first combustion products. A secondary combustion chamber (110) receives and combusts the first combustion products to form second combustion products. The secondary chamber is disposed around the primary chamber and comprises a plurality of—preferably, three—combustion compartments (112-116). Each successive compartment is disposed around the preceding compartment and defines a respective gas flow channel having an inlet opening (108,118,120) and an outlet opening (118,120,122) at opposite ends. Each successive gas flow channel shares its inlet opening with the outlet opening of the preceding channel. The plurality of combustion compartments define a substantially continuous gas flow conduit from the inlet opening of the innermost compartment to the outlet opening of the outermost compartment.

Abstract: Apparatus and method for determining incomplete combustion in a combustion analyzer comprising a combustion chamber (60). A sample is supplied to the combustion chamber and combusted to produce combustion products. A target gas characteristic of incomplete combustion of the sample is detected in the combustion products by a target gas sensor (72). The target gas may be carbon monoxide, methane, methanal and/or methanol, among others. Preferably, the gas sensor is an electronic or catalytic combustible gas sensor. Whether incomplete combustion of the sample has occurred may be determined. A signal indicative of incomplete combustion is output from the target gas sensor to a controller (78). The combustion products can be directed to waste and/or further supply of the sample/oxygen may be stopped/adjusted. Faulty analysis measurements and/or contamination of downstream components, which would otherwise result from incomplete combustion—in particular, from soot formation—can thereby be avoided.

Abstract: A combustion analyzer apparatus and method for combustion analysing a sample, the analyzer comprising a combustion chamber (82) for receiving a sample for combustion therein to form combustion products, and a fluid supply apparatus for supplying fluid(s) into the chamber. The fluid supply apparatus (130-140) comprises a nitrogen oxides (NOx) generating apparatus (140,190,210,240) and is arranged to supply NOx into the combustion chamber. A yield of sulphur dioxide in the combustion products may thereby be improved. The NOx generating apparatus may be operated at a raised working temperature. The NOx generating apparatus may be provided by an ozonator with a supply of nitrogen and oxygen. A Venturi tube arrangement (246) may draw the generated NOx into a (carrier or oxygen) gas line to the combustion chamber. Ozone may be supplied to the combustion products to convert nitrogen monoxide therein to nitrogen dioxide. The NOx and ozone may be supplied by a single device (210,240).

Abstract: A combustion analyzer sample introduction apparatus and method for supplying a liquid sample into a combustion chamber (130,150) of a combustion analyzer. A supply member (108, preferably, cooled) extends through a combustion chamber opening (132,152) and comprises a downstream member end within the combustion chamber. A supply spray head (92) is received in the member end and comprises a discharge opening (94) to deliver liquid sample and carrier gas into the combustion chamber. A carrier gas supply conduit (106,114,122) supplies carrier gas (preferably, oxygen) to the discharge opening, along a carrier gas flow path. A sample supply conduit (100,102) having a downstream first end passes through the supply member towards the spray head and supplies liquid sample into the carrier gas flow path at a sample supply location within the combustion chamber at/adjacent the discharge opening. Liquid sample is thereby transported by carrier gas out of the discharge opening into the combustion chamber as a spray.