GB1332065A - Burner construction for a flame spectrophotometer - Google Patents

Abstract

1332065 Burner for a flame spectrophotometer TECHNICON INSTRUMENTS CORP 29 Oct 1971 [30 Oct 1970] 50364/71 Heading F4T The Burner.-A burner for a flame spectrophotometer comprises a burner tube 32 communicating with a mixing chamber 12, into which chamber the liquid sample under test is introduced together with a combustion supporting gas or nitrogen through one fitting 28 and fuel gas is introduced through a second fitting; a gas manifold 62 having an inlet 80 for the supply of a combustion supporting gas or nitrogen; and a burner cap 194 attached to the top of the tube 32 and formed with a plurality of vertical bores. As shown in Fig. 1 the cap 194 has a dual form with the gaseous mixture from the burner tube being discharged through central bores 206 and a further gaseous mixture supplied through inlets as 180 into an annular chamber 204 being discharged through outer bores 208 to form a sheath about the central flames. In an alternative embodiment the chamber 204 and inlets as 180 are omitted. The liquid sample is supplied to the mixing chamber through a capillary tube located within an outer tube, and having its outlet adjustable axially in a bore of stepped diameter. The axial adjustment of the inner tube is accomplished by a lead screw having two screw-threaded portions of slightly different pitch engaging a fixed member and a part movable with the capillary tube respectively (Fig. 3, not shown). Control system for the burner.-Fig. 8 shows a control system for supplying the burner with alternative fuels (acetylene or hydrogen) and alternative combustion supporting gases nitrous oxide or air through solenoid-operated three-way valves 264, 262, 260 and 258. These valves may rapidly switch between the two gases being supplied and they are controlled by a cable 250 from a console. In addition valves 254 and 256 are closed by a pressure sensitive switch 252 when the air pressure in a supply line falls below a certain value. Further a photosensitive device 257 closes the valves 254 and 256 in the event of flame-failure. When either of the last two conditions develop the valve 262 is closed against N 2 O flow by an OR gate 263.