Component Scales Storage pits Cranes TABLE 4-3-17E Principal Components in the Design of Incinerators Charging hoppers Furnace grates Combustion chamber Heat-recovery system Auxiliary heat Air pollution control facilities Auxiliary facilities and equipment Purpose/Description Required to maintain accurate records of the amount of wastes processed. Design of pits depends on furnace capacity, storage requirements (approximately 1-day capacity), collection schedules, and truck-discharge methods. Used to transfer wastes from storage pit to charging hoppers to mix and redistribute wastes in storage pit. Constructed of metal or concrete, used to introduce wastes to furnace grates. Used to move wastes through furnace. Traveling, reciprocating, rocker arm, and barrel grates have been used successfully. Burning rate of 60 to 65 lb/ft2/h has been adopted as a "generally allowable" standard for mass firing. Depends on capacity of unit and fuel characteristics. Types of systems vary. Typically, two boiler sections are used: convection and economizer. Need depends on moisture content of wastes as Used to control particulate and gaseous emissions. Normally includes residue handling facilities, air supply and exhaust fans, incinerator stacks, control building, etc. 4-3-17F. 4.3.17.19 Recommended facility safety features are shown in Table 4.3.17.20 Table 4-3-17G shows a range of incinerator sizes that might be considered by military installations. Many installations benefit from small capacity incinerators which might operate only 8 h/day. Rarely would a military installation consider a 1000-ton/day plant unless it was operating as a partner with municipalities. An example of such a cooperative effort is an RDF plant built by the Southeastern Public Service Authority (SPSA) (Masley 1987). Here the Norfolk Naval Shipyard participates both by supplying garbage and purchasing steam energy. Eight other communities are involved in this combined facility which consists of nine transfer stations, an ash landfill, and a refuse-only landfill in addition to the incinerator to serve a fast growing area. This incinerator capacity is roughly 2000 tons/day. 4.3.17.21 Operation Procedures 4.3.17.22 Maximum incinerator efficiency is obtained with continuous operation. However, military installations usually do not generate enough waste to justify this schedule. Except at the largest installations, one person, working an *8-h shift, can operate an incinerator that has sufficient capacity to burn all installation refuse during the working day. Cleanup is mandatory before and after firing. If the workload is too heavy, additional operators can be assigned. A staggered schedule will provide an adequate crew during peak delivery hours. The following typical staggered schedule allows 2 h for morning and evening cleaning and 9-1/2 h for incineration at full burning capacity. 1. 0700 - 1530: The first operator cleans the furnace and builds a fire from 0700 to 0800, then supervises the unloading and charging of refuse. 2. 0900 - 1730: The second operator stokes the fire and controls the rate of charging. From 1630 to 1730 the same operator accomplishes incinerator shutdown and ensures that the facility is left in a safe configuration. 4.3.17.23 Any furnace manufacturer will supply detailed technical operating instructions for the equipment. General plant procedures shall ensure that Personnel are provided with face shields or safety goggles, heavy gloves, respirators, safety shoes, and hard hats. OSHA Standard 1910.133 is the requirement for eye and face protection. Safety belts are worn when personnel are working on ladders. Fly ash is removed from the flues only when the ash temperature is below 38°C (100°F). Procedures for operation during emergency situations, such as power failure, air or water supply failure, equipment breakdowns, and fires, are developed and posted. These procedures shall be practiced so that personnel become familiar with them and able to apply them when necessary. 1. 2. 3. TABLE 4-3-17F Shredder to reduce size of lumber and other combustible refuse being charged to the furnace. Oversized wood or lumber causes bridging in the charging hopper, which may cause flame propagation and combustion of solid waste outside the furnace. Automatic or manual sprinkler systems for storage pits and charging floors. Fire-hose stations and fire extinguishers at strategic locations for fire protection. Sprinklers in the charging hoppers are needed to put out fire backlash. 7. 8. 9. 10. 11. 12. Building ventilation using outdoor suction intakes to prevent the Stacks equipped with aircraft warning, lightning rods, and safety Stack sampling ports as required by air pollution control regulations. Provide TV monitors in the control room for the charging hoppers, Access ladders to storage pits. 13. Forced-air ventilation in storage pits. 14. 15. 16. 17. 18. Drains to allow hosing of the storage pits. A method of quickly removing an injured person from the storage pit. Guardrails to prevent personnel from falling into the incinerator Permanent, fixed backing bumpers to prevent vehicles from backing into the storage pit. TABLE 4-3-17F 19. Overhead cranes equipped with an alarm to indicate that the crane is in motion. 20. Safety valves in any facility designed to generate steam or hot water. 21. Provide a quench tank for ash to put out embers and prevent re-ignition of unburned solid waste. Building ventilation shall be designed so that foul air from the refuse pit, segregation areas, etc. is conveyed to the furnace as part of the primary combustion air for sanitation and odor control. Solid Waste Type 100% combustible to 65% dry rubbish + 35% wet garbage 35% dry combustible rubbish + 65% wet garbage Special handling of unique disposal problems, usually waste with <15% moisture Waste with heating value ~6500 Btu/1b; usually have auxiliary burners fired with oil, gas, or both. Designed to fit waste stream of waste within narrow composition limits. (1) TM 5-814-4 (Incineration) |