Patent GB-709200-A (GB)
Title: Improvements in or relating to combustion systems of internal combustion engines
Inventor: OULIANOFF GEORGE
IPC: F23R3/22
Filed: 1950-09-27
Abstract: 709,200. Jet propulsion plant. ROLLS-ROYCE,  Ltd. Sept. 25, 1951 [Sept. 27, 1950], No. 23718/50. Class 110(3) [Also in Group XII] In a combustion system for internal combustion engines having a duct through which combustionsupporting gas flows and in which baffle means are disposed to provide a sheltered region in the duct where stable combustion can take place, the baffle means may be moved to a non-baffling position in which they merge with an associated flow-defining wall and do not disturb the gas-, flow through the duct when it is not desired to employ the combustion system. The invention may be applied to an exhaust reheater in a gas turbine jet propulsion engine, to a reheater between two gas turbine stages or to a ram-jet engine. In Fig. 5, baffle arms 23 are pivotally mounted on pins 25 in the conical bullet 17 and may be swung into or out of the path of exhaust gases flowing through the annular duct 15. A fixed piston 21 is disposed within the cylinder 22 and pilot fuel is led through the bullet-supporting strut 30 to the downstream side of the piston and causes the cylinder to move in a downstream direction to the position shown. The cylinder is connected by pivoted links 24 to the baffle arms 23 which are thereby moved to the operative position shown. Pilot fuel passes radially through the burner nozzzle 32 across the fixed igniter 45 and burns in the zone behind the pilot baffle means 33 to which combustion-supporting gases are supplied through the ports 36 and passages 35 in the baffle arms 23 to the slots 34. The pilot combustion is sensed by the thermocouple 50 which causes the main fuel supply to be switched on. The main fuel flows through the strut 19 to the manifold 40 and through, pipes 41 to channels on the upstream faces of the baffle arms, from which it is distributed through the slots into the exhaust gas stream and ignited by the pilot flame. As the baffle arms swing outwardly. they engage arms 37 on the baffle elements 28 which therefore swing inwardly and with the fixed baffle elements 27 form baffle elements 26. In the embodiment shown, there are eight radially-disposed baffle arms 23 and eight baffle elements 26 which form an octagonal ring pivotally mounted at the corners. The baffle arms 23 are held in the inoperative position by means of pressure air led through the pipe 51 to the upstream face of the piston 21. The baffle arms may also be formed of V-section with the open face upstream and openings along the sides, or as closed channels with openings along the sides thereof and deflectors within. In a further embodiment shown in Fig. 15, the fuel passes a restriction 68 whereby the pressure is reduced and the fuel at reduced pressure passes through the pilot burner 60, and at the same time moves the cylinder 62 in a downstream direction and raises the baffle arms 64 to an intermediate position. When pilot combustion occurs, it is sensed by the thermocouple 67 which operates the solenoid 69 and causes the restrictions 68 to be removed. The higher pressure of the fuel causes the cylinder to be moved to its end position and raises the baffle arms 64 to their fully-operative position, and during the movement the ports 66 in the cylinder wall are uncovered and the fuel passes to the main fuel feed pipes 65 to the up-  stream faces of the baffle arms. In another embodiment, Fig. 18, the baffle arms 98 operate in conjunction with the sectors 88 of a variable area jet propulsion nozzle so that when the baffle arms are in the operative position, i.e. when the reheat system is in operation, the jet nozzle is fully open. The output of the servofluid pump 90 is controlled by the valve 91. When pressure fluid passes to the duct 92, the sectors 88 are in the fully-open position and the baffle arms are held in the operative position by the pressure. of fuel led to the downstream face of the piston 21 as before. In this embodiment, the main reheat fuel is led to the headers 197 which are spaced upstream of the baffle arms 98. When the reheater is not in operation, pressure fluid passes through the duct 94 and causes the sectors 88 to move to the retracted position, and servofluid at the same time passes through the duct 101 to the upstream face of the piston 21 causing the cylinder 22 to move in an upstream direction and the baffle arms 98 move to their inoperative positions. In another embodiment, the baffle arms are mounted obliquely so that in the operative position they give a swirl to the exhaust gases flowing past them. Specifications 648,497 and 667,394 are referred to.