Abstract: In a heat exchange vessel which conducts a hot, pressurized synthetic gaseous stream carrying particulate matter through a central heat exchange chamber, a safety system for monitoring pressures within the vessel. Said heat exchange vessel includes a shell surrounding a water wall, defining an annulus therebetween. Pressure sensing means communicated with the respective heat exchange chamber and said annulus, connects to means for determining the pressure differential between said points. A purge gas source communicated with the monitor system maintains the latter free of internal passage blockage caused by accumulations of particulate matter.

Abstract: In a heat exchange vessel which conducts a hot, pressurized synthetic gaseous stream carrying particulate matter through a central heat exchange chamber, a safety system for monitoring pressures within the vessel. Said heat exchange vessel includes a shell surrounding a water wall, defining an annulus therebetween. Pressure sensing means communicated with the respective heat exchange chamber and said annulus connects to means for determining the pressure differential between said points. A purge gas source communicated with the monitor system maintains the latter free of internal passage blockage caused by accumulations of particulate matter.