Coal fired steam boiler for bath will be the double-cylinder, water-tube assembly, chain grate boiler. Two cylinders are laid from the lower and upper a greater level boiler longitudinally for the center. Front part of top of the cylinder and water-cooled tubes at side walls make up the radiation-heating area from the hearth. Since the rear section and tube bank within the lower cylinder function as convection-heating area, the coal economizer is mounted powering boiler. Some heat of hot combustion fume is absorbed from the hearth, then hot combustion heat flows for that convection heating area through cooling chamber and exhausts outside over the chimney via coal economizer, dust collector and draught fan.

The types of boiler’s overpressure :

1.The pressure rises rapidly and surpass the designed allowing pressure. Currently, the pointer from the pressure indicator runover the red line.
2. The boiler’s overpressure interlock device send alarming signal.
3. The steam temperature reduced even though the the steam flow increased.
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