1、3535787 0223745 511 c/-53 - ?o TM 5-848-3 a TECHNICAL MANUAL GROUND STORAGE OF COAL a HEADQUARTERS, DEPARTMENT OF THE ARMY MARCH 1984 0394 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-3535789 0223746 458 REPRODUCTION AUTHORIZATION/RESTRICTIONS Thi
2、s manual has been prepared by or for the Government and is public prop- erty and not subject to copyright. Reprints or republications of this manual should include a credit substantial- ly as follows: “Department of the Army Technical Manual TM 5-848-3, Ground Storage of Coal.” 0355 Provided by IHSN
3、ot for ResaleNo reproduction or networking permitted without license from IHS-,-,-W 3535789 0223747 394 W *TM 5-848-3 TECHNICAL MANUAL NO. 5-848-3 GROUND STORAGE OF COAL HEADQUARTERS DEPARTMENT OF THE ARMY WASHINGTON, DC, 1 March 1984 APPENDIX Purpose and Scope Definitions . Potential Hazards of Coa
4、l Storage Site Considerations Determining Quantity of Storage . Short-Term Storage . Long-Term Storage . Dry Storage Equipment . A. Bibliography Paragraph 1 2 3 4 5 6 7 8 9 LIST OF FIGURES 1 Retention Pond Section 2 4 Medium Plant Layout with Reclamation by Front-End Loader . 8 5 Medium Plant Layout
5、 with Underground Reclamation . , . 8 7 Large Plant Layout with Double Windrow 10 8 Thaw Shed . 11 Typical Steps in Coal Handling Operations 3 Small Plant Layout I 6 Large Plant Layout with Single Windrow . 9 Page 1 1 1 3 5 5 9 9 9 A-1 4 6 “ 1. Purpose and scope. This manual provides information on
6、the design and operation of facilities for ground storage of coal. Guidelines for receiving, distribution, and reclamation are presented. Special attention is giv- en to the prevention and treatment of potential safety and environmental problems which may be associated with coal storage and handling
7、. 2. Definitions. a. Short-term storage. The short-term storage pile provides coal for the day-to-day operation of the heating plant. b. Short-term live storage. Live storage is the portion of the short-term coal pile which is uncom- pacted, easily reclaimable, and first to be sent to the heating pl
8、ant. c. Short-term dead storage. Short-term dead storage is the portion of the short-term pile which is compacted. As needed, coal from dead storage is taken to the live portion of the pile. d. Long-term storage. The long-term storage pile is separate from the short-term storage pile. It is always c
9、ompacted, sealed, and used only in emergencies when the short-term supply is depleted. e. Degree-days. For any one day, the number of degree-days equals 65 degrees Fahrenheit minus the mean temperature. 3. Potential hazards of coal storage. a. General. Coal storage and handling opera- tions carry th
10、e potential for three safety and envi- ronmental problems-spontaneous combustion, air pollution, and water pollution. However, if a clear understanding of the reasons for these problems is reflected in the design and operation of the proc- ess, no significant difficulties will be encountered. b. Spo
11、ntaneous combustion. (i) General. Spontaneous combustion is the result of oxidation, which is related to the mois- ture, oxygen, and sulphur content of coal. All types of coal oxidize if exposed to air, but younger, lower-ranked coals such as lignite and bituminous are much more susceptible to combu
12、stion than older types such as anthracite. Coal begins to oxi- dize when it reaches a range of 60 to 85 degrees Fahrenheit and may ignite spontaneously within 72 hours after reaching a temperature of 170 degrees Fahrenheit. Oxidation is most rapid during the first 120 days after the coal is mined. (
13、2) Prevention. (a) Higher-ranked coals and coals washed at *This manual supersedes TM 5-848-3/AFM 88-12, Chapter 3, May 1968. 1 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-= 3515789 TM 5-848-3 the mine are less prone to combustion than other coal
14、s. Therefore, these types of coal should be pur- chased where permitted by cost and availability. To cut down on the likelihood of combustion in any coal, exposure to heat, air, and moisture must be controlled. High temperatures increase the rate of oxidation, air speeds up oxidation and is necessar
15、y for ignition, and water in the pile creates channels for air and leads to chemical changes which in- crease the possibility of fire. (b) Sources of heat to be avoided include, among others, steam lines, hot water tanks, and smokestacks. The piles will not surround any verti- cal posts or structure
16、s and must include no foreign objects, especially those with low ignition tempera- tures. (c) To minimize exposure to air and water, coal in short-term dead storage will be compacted. Long-term piles will be compacted and sealed. The shape of the pile and the construction of the foun- dation will be
17、 designed to facilitiate drainage. Short-term live storage cannot be compacted, but the length of its exposure to air and water will be reduced by using a “first-in, first-out” method of reclamation. For example, if the left end of a windrow pile is placed before the right, the left end should be de
18、livered first to the heating plant. (d) To determine the presence of any “hot spots, visual inspection of both long- and short- term piles will be made daily. A hot spot is easily recognized in periods of wet weather because it dries faster and has a lighter color. In cold or hu- mid weather, vapors
19、 and the odor of gas may be detected. In addition, temperatures will be moni- tored on a weekly basis by temperature measuring devices on 10- to 20-foot centers. The devices may be thermometers or thermocouples fitted in in- stalled pipes. If no other means is available, an iron rod may be thrust in
20、to the pile, withdrawn, and checked to see if it can be held by hand. When tem- peratures in any area exceed 150 degrees Fahren- heit, the coal at that location will be dug out and used immediately. (3) Treatment. Should a fire occur in a storage pile, water must not be used except as a last re- sor
21、t. If possible, the air supply should be cut off by compaction of the area with a bulldozer. Dry ice may be buried 12 inches above the fire spot. For a fire deep within the coal pile, hollow pipes filled with broken dry ice may be used. Sheets of heavy plastic may be placed around the base of the pi
22、le to prevent air from entering. c. Air Pollution. (1) Fugitive dust will be controlled to help keep the work area clean, prevent a nuisance to 0223748 220 = nearby residents and workers, and minimize pollu- tion of runoff. (2) When possible, washed or dustproofed coal should be purchased, since it
23、reduces problems with air pollution. (3) Walls may be needed to cut down on dust in exceptionally windy areas; however, if properly constructed, storage piles generally do not experi- ence excessive dust problems. (4) Fugitive dust is more likely to result from transfer and crushing procedures than
24、from stor- age. Several measures can be taken to reduce dust from crushing and handling: (a) If possible, the coal should be purchased in sizes that are ready for the heating plant with- out crushing at the delivery site. (b) The number of transfer points should be minimized, and each transfer point
25、 should be made as airtight as possible. (c) All conveyors must be covered (but not enclosed) for their entire length. (d) The free-fall distance of coal from the conveying system to the pile must be kept as short as possible. (e) In the past, water was sprayed at each dust-producing point to suppre
26、ss fugitive emis- sions. Because it introduces moisture to the coal, this system is counterproductive and must no long- er be used. If it is necessary to spray transfer points to make particles conglomerate, a chemical designed for that purpose should be applied. d. Water pollutiox. (i) Wastewater a
27、t a coal storage and handling site results from rain falling around and seeping through the storage pile. Runoff outside the pile contains dust and similar particles from the air and ground surface. The leachate that results from water flowing through a pile is highly acidic and contains metallic su
28、lfates in solution. (2) To collect the on-site wastewater, a reten- tion pond will be provided. Off-site runoff will be diverted to hold down the size of this pond. Guidelines for pond design are listed below: (a) The retention pond will be sized to con- tain the runoff from a 10-year, 24-hour storm
29、 with 2 feet of freeboard. (b) A perforated standpipe surrounded by crushed stone will be provided to help filter the water draining from the pond. The top of the standpipe will be open and set at the 10-year, 24-hour storm elevation. (e) The sides of the pond should be designed at a slope that will
30、 facilitate cleaning and dredging operations. Slopes not steeper than approximately 20 degrees are recommended. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-3515789 0223749 167 TM 5-848-3 (d) To prevent the impounded water from infiltrating the si
31、des and bottom of the pond and possibly contaminating the groundwater, the pond will be lined with an impervious material. If avail- able, impervious soil will be used to line the pond. The minimum thickness will be 3 feet, with the ex- act thickness depending on permeability test re- sults. The imp
32、ervious soil will be covered with one foot of crushed stone for protection during con- struction and dredging. (e) If adequate impervious soil is not avail- able, an impermeable membrane liner will be used. Before the liner is installed, the pond area will be cleared of stones and trash, and if the
33、area is rocky, a 6-inch layer of sand will be placed. The lin- er will be covered with a 6-inch layer of clean earth below a 6-inch layer of crushed stone. Selected membrane liners should be durable and resist dete- rioration by acidic water. Figure 1 is a half-section illustrating linings of both i
34、mpervious soils and membrane liners. (B Retention ponds should be dredged peri- odically to prevent reduction in capacity. Care should be taken not to damage the impervious liner during dredging. (3)The water in the retention pond must be monitored regularly for suspended solids and pH. If the water
35、 meets local and federal guidelines, it can be released into surface waterways. If local re- quirements are not met, the water must be treated before being released. There are three basic ways of providing the necessary treatment: (a) The water may be drained to the local sewer system to be treated
36、along with the other wastewater. This is the simplest method of treat- ment and should be used if permission can be ob- tained from appropriate authorities. (b) The wastewater can be mixed with the fly ash from the heating plant. If the ash is suffi- ciently alkaline, it will raise the pH of the wat
37、er to an acceptable level. (c) If ash is unavailable or not sufficiently al- kaline, chemical treatment may be required. After the suspended solids settle out in the retention pond, the liquid is drained to another pond where sodium hydroxide or calcium hydroxide (lime) is added until the pH reaches
38、 an acceptable level. The metals then settle out in the second pond and the water is released to the nearest watercourse. 4. Site considerations. a. Site selection. (i) The size of the area required for storage and handling is related to several factors, such as the quality of coal needed for live a
39、nd dead storage (para. 51, the shape of the pile, and the facilities re- quired for handling, dry storage, and collection and treatment of wastewater. (2) The location of the site should be as close as practicable to the rail or roadway from which deliveries are made and to the plant which will burn
40、 the coal. (3) Storage areas will be located away from any heating sources or systems such as steam or condensate lines, smokestacks, furnaces, or hot water tanks. (4) Coal piles shall not be placed over utility pipes or conduits, not only to avoid hazards to the pile but to avoid inconvenience and
41、delay if access to the pipes and conduits is necessary. (5) Upright pillars, trestles, posts, supports, or other vertical structures will not be located in the pile, since these can create a chimney effect. (6) The location of the site should be selected to minimize exposure to heavy winds, floodwat
42、ers, and tides. (7) For both safety and aesthetic considera- tions, storage and handling facilities should be kept a sufficient distance from populated areas. At troop housing projects, coal storage will be located at least 500 feet from a laundry or bakery on the lee- ward side. If practicable, thi
43、s distance will also ap- ply to other buildings where construction can be accomplished without materially increasing the cost of the railroad spurs and access roads. (8) The site selection must be on level, solid ground. If the most convenient location for the storage site lacks these characteristic
44、s, prepara- tions must be made to provide them before the coal is delivered. b. Site preparation. (i) If no data on the site are available, subsurface evaluations should be conducted to de- termine whether remedial measures are necessary for the site to support the weight of the coal stor- age and h
45、andling facilities. To estimate the load imposed, a value of 50 pounds per cubic foot can be used for uncompacted piles and 70 pounds per cubic foot can be used for compacted piles. (2) Coal piles will rest on level ground to avoid any movement and to assist in handling. Prefera- bly, the actual sto
46、rage site should be slightly higher than the surrounding area so that water will drain away rapidly. Runoff from the pile and sur- rounding work area will be directed toward a re- tention pond. (3) Any vegetation or other organic matter will be cleared from the site, and the area will be free of for
47、eign material such as wood, paper, waste oil, or other item with a low ignition temperature. (4) To ensure an adequate base, the topsoil will be removed, and the ground will be well com- 3 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-M 3515789 022
48、3750 989 M TM 5-848-3 O I 0 z W Z a a m I I W L O C s o e G 3 c: Li Y al c *ri W ci m a Li o U m 3 4 035s Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-3515789 0223751 815 TM 5-848-3 pacted. Storage and handling areas will be provid- ed with flexib
49、le or rigid pavement adequate to sup- port a 9,000-pound wheel load. The wearing surface will be stable enough to prevent inter- mixing of pavement materials and coal due to weather or equipment operation. Flexible pave- ment will consist of an adequate base course with a bituminous wearing surface not less than 1.5 inches thick. 5. Determining quantity of storage. a. General. It is important that not more coal will be stored than is necessary for efficient plant
