Circulation Heaters
Circulation heaters are packaged units designed to heat a flowing medium using inline or side-are pipng configurations. Complete units consist of built-in heating elements, a heating chamber, thermostat and/or sensors (stock units), insulation, insulation jacket, mounting brackets and inlet and outlet connections.
Circulation heaters offer high efficiency since all heat is generated within the solution. Fluids are directed past the heating elements giving fast response and even heat distribution.
A wide selection of kilowatt ratings, materials, vessel sizes, terminal enclosures, control features and mounting methods are available for all types of heating requirements. SCR and Contactor Control Panels available for integral or remote mounting. Consult Controls section for details.
Application Engineering
The Proheat sales and service organization has the technical capabilities and equipment to satisfy virtually any circulation heating application and to assist you in calculating requirements for the more common heating processes.
Typical Applications
Special Features
Kilowatt Ratings — Large kilowatt circulation heaters (500 kW and above) are available as single chambers or with multiple chambers in series. Skid mounting and integral control panels are also available.
Vessel Construction — Chamber size available in 10, 12, 14, 16, 18″ and above for larger kilowatt capacities.
Pressure Ratings — 150, 300, 400, 600, 900, 1,500 and 2,500 Lb. Class.
Materials — 304, 316, 321, 347 Stainless Steel, INCONEL® and more.
Thermocouples can be provided on element sheath for over-temperature protection and/or mounted in the outlet nozzle for process control.
Inlet and Outlet Nozzles — Available with flanged or threaded connections, smaller or larger pipe sizes and different orientations.
Baffles mounted on element bundle inside chamber to increase fluid or gas velocity.
Terminal Standoffs in 4, 6 and 8″ allow the terminal enclosure housing and the field wiring connection to operate at lower temperatures in high temperature heaters. Standoffs are frequently used in heat transfer and gas heating applications. Mounting Saddles for horizontally mounted circulation heaters. Weatherproof Insulation Jacket for outdoor unprotected installations.
Basic Construction
Terminal Enclosures — E1 General Purpose, sheet metal, painted with red enamel, E2 Moisture Resistant/Explosion Resistant, E3 Explosion Resistant, E4 Moisture Resistant.
Controls — Stock and assembly stock NWH, NWHO and GCH circulation heaters, models -A, -MT, -3 and -6, are provided with a thermostat mounted on the heater.
Mounting — Small units supported by inlet and outlet piping; larger units provided with mounting lugs for support.
Outer Jacket — Constructed of heavy gauge painted steel sleeving which contains high temperature thermal insulation to reduce heat losses from heating chamber.
Heating Chamber — Pipe chambers (150 Lb welded construction, standard) have a flanged or threaded end to receive heater assembly and are closed at the opposite end. Larger units have drain connections to allow sludge removal. Inlet and outlet nozzles are provided for circulation of fluid or gas through heater chamber. Chamber material available in Steel, Galvanized Steel or Stainless Steel depending on the application.
Heating Elements — Flange or screw plug mounted tubular type heating elements offered in Stainless Steel, Copper, Steel or
INCOLOY® sheath to suit corrosive resistance requirements.
Wiring Connections — All Chromalox circulation heaters are provided with internal wiring and power connections that are sized in accordance with wiring tables in the National Electrical Code. For safe operation of the heaters, all external wiring should also be in accordance with NEC, state and local codes.
