Insulated heater module

摘要

A heater module having a cylindrical heat exchanger surrounding a central cavity and burner wherein an end manifold is covered with a layer of insulation to reduce the temperature differential between the outer annular trough of the manifold and the inner central flat disk which covers the end of the cavity. The annular trough and the disk are stamped from a unitary piece of plate steel. Without the insulation, the disk would heat to a temperature much higher than the annular trough because the trough communicates with tubes of the heat exchanger and contains recirculating liquid. By reducing the temperature differential, less strain is put on the end manifold as a result of nonuniform expansion.