The items to be studied are as follows:
1. Layout
-As the furnace handles direct fire, a safety distance should be maintained between this furnace and equipment handling flammable liquid.
-The interrelated layout between the furnace and equipment (equipment to which the furnace outlet piping is connected) should be decided after studying measures against the thermal expansion and vibration of the piping.
-A space should be secured for the maintenance work of heater coils.
-Care should be taken to arrange the furnace upwind of the average wind direction. Then, the furnace should not be arranged to avoid the suction of light hydrocarbon.
-If a duct is connected to the centralized stack, the layout of the furnace and the duct should be studied after discussions with a furnace engineer in charge.
2. Piping arrangement
Piping around the furnace is as follows:
a. Process piping
-Furnace inlet piping
-Furnace outlet piping
b. Utility piping: Piping associated with fuel
-Fuel oil feed piping
-Fuel oil return piping
-Fuel oil gas piping
-Pilot gas
-Atomizing steam piping
c. Snuffing steam piping
d. Soot blower piping
e. Decoking piping
3. Piping detailed arrangement
1. Furnace inlet and outlet piping
-It is necessary to make piping symmetrical to allow the flow rate of each outlet and inlet piping to be uniform.
-The symmetrical piping is arranged to allow the configurations of lines to be quite the same, symmetrical and also to permit the same and symmetrical shapes to be mixed, to make the flow rate of each branch to be constant, if one line is branched into a number of lines.
-Piping arrangement considering thermal expansion and vibration
4. Utility piping
Fuel piping, snuffing steam piping and steam piping for the soot blower are installed as the utility piping around the furnace.
-Fuel piping
Basically, it is necessary plan the piping arrangement considering the operability of burners, valves, etc.
-Burner piping: Piping around the gas burner, oil burner. The burner line must not cross a sightglass, etc., and must not interfere with the open and close of the window glass.
-The piping should be arranged to allow the valve to be close to the sightglass, in order to operate this valve while monitoring the combustion condition of the burner.
-The valve for the pilot burner (the first valve from the burner nozzle) should be installed near the burner to facilitate the ignition operation of the pilot burner.
-Piping detailed arrangement around Snuffing steam piping, Soot blower piping and Decoking piping
5. Support plan
-The supports should have enough rigidity to withstand vibration, and should be structures independent from the furnace considering the frame strength of the furnace proper.
-The construction of the supports should be planned considering the installation points and orientation of the oil damper, friction-proofing device and spring-type vibrationproofing, as vibration-proofing supports.
