Energy Conservation Preventive Maintenance
Industrial Boilers 600 BHP 2,400 BHP 200 BHP 50 BHP
Capital Cost vs Operating Cost Source: Steve Connor, 2010
Boiler Energy Balance http://www.energysolutionscenter.org 3/9/08
Energy Efficiency Source: Steve Connor, 2010
Types of Boilers Firetube - Dry-back Firetube Wet-back Watertube Electric Boiler http://www.spiraxsarco.com/resources/, 3/1/08
Energy Savings Boiler Type The cost to operate a boiler is 4 times the initial installation cost. Boiler Efficiency Oil $2.75/gal Natural Gas $1/therm Base Operating $1,400K/yr $717K/yr 70% 75% -92K -48K 80% -173K -89K 85% -245K -126K Assuming 500 BHP @ 3000 hrs/yr
Energy Savings - Scaling Boiler Water Scale Tube Metal Hot Gases metal = good conductor of heat scale = poor conductor of heat Modified Dale Williams, 2006 Chem Treat
Energy Savings Scaling Scale Thickness (Inches) Additional Fuel Usage (Percentage) 1/32 8.5% 1/25 9.3% 1/20 11.1% 1/16 12.4% 1/8 25.0% 1/4 40.0% 3/8 55.0% 1/2 70.0% Example - $750K fuel bill with 1/16 scale cost $93K. http://www.energysolutionscenter.org 3/9/08
Energy Savings - Economizer Example 500 hp Boiler 20,000,000 BTU 5% recovered with economizer 1,000,000 BTU s Water returned to boiler http://www.energysolutionscenter.org 3-5-08
Boiler Blowdown - Why do we blowdown? To remove the dissolved solids that have concentrated in the boiler due to evaporation Too Much Blowdown Increased fuel costs Increased water costs Increased chemical costs Too Little Blowdown High TDS will occur, resulting in: Foaming Priming Corrosion Scale PURE WATER SOLIDS
Energy Savings Blowdown Heat Recovery TDS Monitor Blow down is 5-10% of boiler capacity Recovery systems can capture steam that would go to the drain Pre-heat make up water Reduces water usage to cool the blow down prior to the drain http://www.energysolutionscenter.org 3-5-08
Energy Savings Steam Traps Example: 52.8 lbs/hour x 8,760 hours per year x $9 per 1,000 pounds = $4,162 per year. http://www.energysolutionscenter.org 3/9/08
Energy Savings - Insulation http://www.energysolutionscenter.org 3/9/08
Energy Savings - Steam Leaks http://www.energysolutionscenter.org 3/9/08
Boiler Efficiency Analysis www.natcomonline.com http://www.energysolutionscenter.org 3/9/08 Source: Steve Connor, 2010
Resource Source: Steve Connor, 2010
Compressed Air an Expensive Utility Compressed air is the most expensive energy source in the feed plant. Do you know your compressed air costs? Do you know how much compressed air is really required for your plant? Do you select compressed air equipment with energy costs in mind? Do you monitor the use of compressed air like your other utilities? http://www.maintenanceresources.com/referencelibrary/aircompressors/kaeserpage7.htm
Air Compressor Energy Savings Equipment selection Intake air temperature Operating pressure A 2% psi reduction can save 1.5% cost Air leaks Maintenance Oil Filters Belts Demands vibrators, air gates
Lighting Lighting audits can determine if you have the correct type of lights and lumen in different areas of the feed mill. Federal & State Grants may be available to replace lights in commercial plants Energy Savings Tips Use Compact Fluorescent Lights (34watt) Turn off lights when not used. Use timers and occupancy sensors
Electrical Motors Evaluate the motor load associated with each process and determine if the motors are operating in the recommended range.
Electrical Motors Energy Savings Rewinding vs. Replacement Select a new energy-efficient motor under any of the following conditions: The motor is less than 40 hp. An energy-efficient motor is recommended according to Table 3. The cost of the rewind exceeds 65% of the price of a new motor. The motor was rewound before 1980.
Electrical Motors Energy Savings Turn off motors when not in use. Note: Motors have a cool downtime therefore take the time into consideration as part of the decision. Determine the clean out time of each conveyor in the shutdown sequence, the conveyor only needs to run long enough to clean out the material.
PREVENTIVE MAINTENANCE
Feed Mill Maintenance A safe, clean and well maintained feed mill does not just happen it takes the efforts of management, operators and maintenance. Management has to set the example and standards Operators need to alert management about potential problems before breakdowns occur Maintenance needs to work with operators to keep equipment maintained and sealed to prevent dust leaks
Housekeeping & Preventive Maintenance A preventive maintenance program combined with dust control measures are key elements in maintaining a safe, clean and orderly work environment for employees and customers A clean mill will leave a good First Impression on management, customers and future employees
Preventive Maintenance Program Effective Preventive Maintenance Program: Goals Measurable Time Specific Structure Personnel Equipment Records and History Schedules Spare parts and ordering Documentation Management of the program Reports and Tracking
Maintenance Goals & Objectives Limit Unscheduled Downtime No Customer Waiting Time Low Cost Well Maintained Facility Compliance with Safety Regulations No Dramatic Events
Structure - Personnel Hire or Contract Qualified/Trained Personnel for Skilled Tasks Licensed Electricians Certified Welders Boiler Operators Hire experienced millwrights for repairs and preventive maintenance task Pellet mill rebuilds, replacing gearboxes Hire employees with mechanical aptitude for general maintenance Greasing bearings, cleaning magnets
Training Safety Training Lock-out/Tag-out Hot Works Confined Space Electrical Safety PPE Eye protection Fall protection Cotton Clothes Steel Toe Boots Gloves Hearing protection Hard Hats
Maintenance Personnel Responsibilities Schedule routine maintenance Develop and implement a preventive maintenance program Record maintenance completed on each piece of equipment Labor hours Parts cost Root cause of repairs Select the correct lubricants for each application
Maintenance Personnel Responsibilities Seal all equipment upon completion of a task or work order Clean up the area and remove old parts Check that material is not left in the equipment (tools, parts, etc) that could damage equipment or adulterate the feed.
Structure - Equipment Information Supplier National, Local Model Size, Capacity Mill Location Receiving, Grinding Owner Manual Operations, Spare Parts Maintenance Frequency Spare Parts Motor, Bearing, Belts
Structure - Schedules Time - Maintenance Schedules Daily Weekly Monthly Quarterly Annually Production Maintenance Schedules Ingredients received Feed manufactured
Maintenance Schedule - Daily Boiler Water Treatment Clean Magnets Grease Pellet Rolls Several times a shift to keep rolls purged Fat Traps
Maintenance Schedule - Weekly Damaged Screen Hammermill Screens Hammermill Hammers Housekeeping Area New Worn Corner
Maintenance Schedule - Monthly In-House Scale Check Pellet Cyclones
Maintenance Schedule - Quarterly Certified Scale Check Air Compressors Conditioner Chamber Distributors
Maintenance Schedule - Annually Boiler Inspection MCC Infrared
Spare Parts Inventory Critical - Stock Required to operate the feed mill Has a long lead time for manufacturing or shipping Overseas part Limited Manufacturing Schedule Examples Pellet Mill Motor Gearboxes Dies & Rollers Computer Parts
Spare Parts Critical Non-Stock Parts that can be purchased locally or shipped overnight Parts that are expensive and not used frequently Parts shared between other plants Examples MCC part Small gearboxes PLC cards, Modules, etc
Spare Parts Basic - Stock Parts used on a regular basis in the feed mill Nuts & Bolts V-belts Bearings Seals Hammermill Screen Hammermill Hammers
Work Order
PM History
Monthly Inspection Feed Mill Inspection Date Inspected by: Area: Receiving OK Corrective Action Required Date Completed Lights Electrical Sanitation Fire Extinguisher Evacuation Plan Emergency Lights Safety Signs Add SPCC, Environmental Assessments, etc.
Cost of not doing PM s - Example Problem: Not removing tramp metal from die. Lose 10% production on a 20 ton/hr pellet mill Lose 240 ton/wk on (24/5 operation) Result: Cost $100/hr in normal labor to operate the mill Requires 13 extra hrs of overtime/wk($150/hr OT) $150/hr X 13 hrs = $1950 or $.81/ton on every ton manufacture during the week.