1.12.7. Screed Burner System

TM 5-3895-373-20 1.12.7. Screed Burner System. A screed burner system is located in each of the main and extension screeds. The burner systems are used to heat screed plates to approximately the same temperature as the paving material. Heating the screed plates prevents hot aggregate mixtures from cooling and sticking to the bottom of the screed. The left burner systems are controlled from the left screed control panel. The right burner systems are controlled from the right screed control panel. The main screed burner system components are as follows: a. Screed Burner Chambers. Separate burner chambers are located on the left and right sides of the main screed and on the left and right extension screeds. A fuel spray nozzle and forced air duct are located on the input side of the burner chamber. When burner fuel flow is turned on, the spray nozzle atomizes the incoming fuel and the fuel is ignited by a 12 VDC glow plug. In normal use, fuel combustion continues until the fuel flow is shut off. b. Screed Burner Blowers. The burner blowers consist of a fan rotor mounted on the shaft of a 12 VDC motor. The blowers force combustion air into the burner chambers for increased combustion efficiency. The blower motors are controlled from both left and right screed control panels. c. Manual Fuel Shutoff Valves. Manual fuel shutoff valves are used to turn fuel flow on and off to the burner chambers. The paving machine is equipped with four solenoid controlled valves controlling fuel flow to each screed burner. The +12 VDC solenoid valves are activated by switches on the screed control panels. The manual fuel shutoff valve provides a backup shutoff capability in case of solenoid valve failure. 1-12