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Types of Heaters Steam Quaker Oats St. Joseph, MO. Steam Heaters. Why use steam heaters How they work Types of steam unit heaters Advantages/disadvantages Start-up process for steam heating Process during heat treatment Post heat treatment follow-up procedures. Steam Heaters.
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Types of Heaters Steam Quaker Oats St. Joseph, MO
Steam Heaters • Why use steam heaters • How they work • Types of steam unit heaters • Advantages/disadvantages • Start-up process for steam heating • Process during heat treatment • Post heat treatment follow-up procedures
Steam Heaters • Why use steam heaters • How they work • Types of steam unit heaters • Advantages/disadvantages • Start-up process for steam heating • Process during heat treatment • Post heat treatment follow-up procedures
Why Heat Treat with Steam???? • Boiler in place • Boiler capacity • Heaters already in place
How Steam Heaters Work... • Coils, fans, housing, dampers, traps, strainer, check valve, thermostats, etc. • Coils are heated by steam passing through them • Air is heated as fan pulls air up through heated coils • Fans aid in dispersion of heated air throughout area • To decrease heat: open damper • To increase heat: close damper
Types of Steam Heaters • Portable units • Fixed units • Ceiling mounted • Floor mounted
Portable Steam Heaters • Advantages • Can be used in areas where heat is slow to rise • Can be moved around where needed • Easy to clean and maintain • Disadvantages • Additional storage area • May get lost
Fixed Steam Heaters • Ceiling mounted heaters • Maintain floor space • Smaller, considered space savers • Do not get damaged as easy • Harder to access for cleaning and maintenance • Ability to direct heat in all directions
Fixed Steam Heaters • Floor mounted heaters • More heat at floor level initially • Easier to clean and maintain • Get damaged more easily • Generally larger than ceiling mounted units • Ability to shoot heated air in all directions
Advantages of Steam Heaters • Hotter heat • Better control of steam heat if heaters are working properly • Open dampers if area gets overheated • Close dampers if area needs more heat • Cheaper than gas/electric • Steam provides much of the humidity (30-50%) necessary for wooden equipment (sifter boxes) • Safer than gas fired/electric heaters
Disadvantages of Steam Heaters... • Boiler capacity-necessary steam pressure • Coils must be clean so they will heat efficiently • Maintenance of traps, steam pipes, valves, couplers, fans, motors, etc. • Employee safety concerns: burns • System may become water logged resulting in slow or ineffective heat-up
Quaker Oats - St. Joseph, MO • Goal: Core temperature 130°F / 30 hrs • 6 heat-ups/year • Mar, May, July, Aug, Oct, Nov • Heat 3.5 million cubic feet • 145-150 steam heaters • various sizes • ceiling/floor mounted units • 3 gas fired heaters • Departmental prep checklists • Post heat follow-up procedures
Pre-Heat Treatment ChecklistFor Steam Heating… • 2 week inspection prior to heat • inspect fan motors on heaters • check couplers • inspect coils • check traps • repair steam leaks • inspect unit heater coils • inspect condensate return lines • ensure system is ready for heat treatment
Pre-Heat Treatment ChecklistFor Steam Heating... • Day of heat treatment • Increase boiler pressure to maximum capacity (25,000-30,000 pounds) • Set all heaters to manual mode • Set thermostats on unit heaters at 140°F • Ensure steam valves and return lines are open at heaters
Pre-Heat Treatment ChecklistFor Steam Heating cont... • Turn on main header valves to get steam to unit heaters • Heat unit heater coils • Turn fans on to unit heaters • Set out thermometers
Steam Heaters During Heat-Up... • Auto vs. manual mode • Heaters started in manual mode • Once temperatures heat up, positioned in auto mode if thermostats are working • 3 pipefitters per shift to monitor heat progress • Temperature readings every two hours • Maintain 130°F for 30 hours • Making repairs as necessary
Steam Heaters During Heat-Up... • Slow Heat-Up • system may be waterlogged • check condensate return line • ensure steam valves are open • waterlogging will cause slow heat in all areas • ensure fan on heater is running if area(s) are cool • check unit heater coils for buildup if area(s) are cool • ensure openings to outside are closed
Steam Heaters During Heat-Up... • Fast Heat-Up • use auto mode to shut heat off at desired temperatures • open up dampers with fan running • throttle steam back at heaters • shut heater fan off • reduce steam pressure if fast heat-up is noted in all areas
Other Factors Affecting Heat Treatment Success... • Wind • Outside temperature • Rain • Openings to outside not properly sealed • Knowledge and/or preferences of pipefitters/maintenance personnel running the heat treatment
Post Heat Follow-Up Includes... • Determine shutdown time • Shut boiler down two hours prior • Coast 2 hours • pickup thermometers • shut off header valves / unit heater valves • leave fans running for circulation • Departments open up for cool down **********