Maintenance drums

Maintenance of guards on machinery, open vessels, handrails, screens at sampling/ drumming-up points etc. and on glass equipment Use of sparkproof tools where appropriate Record-keeping... 

The slow rotation of the drum and reciprocation of the agitator reduce maintenance requirements to a minimum but the following should be inspected periodically. The strip liner of the trunnion bearing at the valve end will normally wear at the lower half. However, in situations when the slurry has a high specific gravity, the drum has a tendency to become buoyant causing wear to the upper half. 

Such care includes washing of the filter material with the spray jets after every period of use, removal of grease and fats with warm soap solution if clogged, treatment with diluted hydrochloric acid for removal of lime encrustations, maintenance of scraper bade in careful adjustment to filter drum to prevent tearing of the filter material. 

Section 1.1.4 described how fumes got into a steam drum because it was not properly isolated. Even when service lines are not directly connected to process materials, they should always be tested before maintenance, particularly if hot work is permitted on them, as the following incidents show ... 

Steam drums (top drums) often are difficult to enter or move around in because of the fixed mechanical equipment contained within the confined space. It should not be assumed that this equipment has always been correctly reinstalled after any previous inspection or maintenance programs. Consequently, steam drums should first be inspected for proper location, orientation, and anchoring of steam separators, FW lines, baffles, continuous BD lines, and chemical injection lines. 

The maintenance of constant liquid level in the reflux drum can be expressed by the following proportional control equation... 

The operations and maintenance program consisted of routine maintenance of the SVE unit and vapor conveyance lines. Data recording units (disk recorders) required maintenance, as well as emptying the recovery drum of accumulated knock-... 

An additional estimated cost breakdown comes from Sandia National Laboratory. According to this source, the estimated cost breakdown is the detoxifier, 325,000 drum feeder, 50, 000 and the moving bed evaporator, 165,000. The cost of other peripherals is estimated to be 150,000. Daily operating and maintenance costs are estimated at 600,000. Life-cycle costs are 340,000 (5 years) and 270,000 (10 years). Steam reforming is approximately 75% less expensive that off-site thermal regeneration of granular activated carbon (D17028F, p. 3). 

Drum diameters are typically 762, 914, or 1219 mm, all of which have been used in the various basic applications. In some instances, standardization of diameter is specified because of maintenance considerations. Because these separators are constructed more ruggedly and require repulping stages, capital costs are higher than heavy-media separators. Costs in 1995 were approximately 10,000/m of width for single-drum modules and multiples of the single-drum module. 

Therefore, the liquid level in the overhead condenser would have to be somewhere in the condenser s shell. But then, the liquid in the condenser would be below the reflux drum. How, then, does the liquid get from the lower elevation of the condenser to the higher elevation in the reflux drum We will have to explain this hydraulic problem later. But for now, we can say that most reflux drums are elevated 20 or 30 ft above grade to provide net positive suction head (NPSH) for the reflux pump. Also, most shell-and-tube condensers are located at grade, for easier maintenance during unit turnarounds. 

A safe estimate of power requirement for double drum dryers is approx 0.67 HP/(rpm)(100 sqft of surface). Maintenance can be as high as 10%/yr of the installed cost. Knives last from 1 to 6 months depending on abrasiveness of the slurry. Competitors for drum dryers are solid belt conveyors that can can handle greater... 

Maintenance. Good plant maintenance (qv) obviates the crash shutdowns that could follow failure of critical components. Maintenance in the chemical industry differs from that in other industries because of the nature of the materials, processes, and types of equipment used. Because much chemical work involves the movement of fluids, gases, and powdered solids from one piece of equipment to another, many pipelines (qv), conveyors, forklift tmcks, and other material-handling devices are used. Containers are more likely to be tanks, drums, or some form of closed container than in other industries. Prior to maintenance inside equipment, all lines and equipment containing hazardous materials should be effectively separated, disconnected, blanked, or purged in order to minimize the possibility of release of harmful materials. Maintenance personnel must make sure that all equipment and piping is so prepared. 

Drill site construction and rigging-up This involves the use of heavy equipment, which should be well maintained to reduce the potential for fuel and lubricating oil leaks that may contaminate the site. Preventative maintenance during the construction phase can help prevent the generation of contaminated soil and water. For example, secondary containment beneath fuel storage drums can prevent releases to soil and water. 

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