Design considerations Maintenance

Design considerations and costs of the catalyst, hardware, and a fume control system are direcdy proportional to the oven exhaust volume. The size of the catalyst bed often ranges from 1.0 m at 0°C and 101 kPa per 1000 m /min of exhaust, to 2 m for 1000 m /min of exhaust. Catalyst performance at a number of can plant installations has been enhanced by proper maintenance. Annual analytical measurements show reduction of solvent hydrocarbons to be in excess of 90% for 3—6 years, the equivalent of 12,000 to 30,000 operating hours. When propane was the only available fuel, the catalyst cost was recovered by fuel savings (vs thermal incineration prior to the catalyst retrofit) in two to three months. In numerous cases the fuel savings paid for the catalyst in 6 to 12 months. 

This chapter highlights and summarizes considerations dealing with expander subsystems, materials, manufacture, installation, component design, equipment maintenance and repair that might assist users in developing or evaluating turboexpander specifications. 

Brown, Royce N., Design Considerations for Maintenance Clearance Change Affecting Machine Operation, Dow Chemical USA. Housloii, T. 1976. 

Reinjection wells are not without disadvantages. One disadvantage referred to above is the possibility of accelerating off-site migration or dispersion of the pool. Another disadvantage is the additional costs for operation and maintenance (i.e., redevelopment). Redevelopment costs can be kept to a minimum by initial design considerations, but, as the time frame between redevelopment decreases, redevelopment costs increase. Eventually the cost of constructing a new reinjection well becomes the only cost-effective alternative. 

Maintenance and costs of cooling towers circulating brackish water is naturally of considerable concern. Inadequate consideration of materials of construction and disregard of the simple rudiments of water control can be expensive. If the above suggestions for designing and operating such a unit are taken into consideration, maintenance should be little more than that of a standard tower employing fresh water makeup. 

The primary purpose of local exhaust ventilation is to control contaminant exposure by establishing a control surface or barrier between the emission source and the worker so that the contaminant is captured and does not reach the worker s breathing zone. Local exhaust ventilation is cumbersome, inconvenient, and requires considerable maintenance. It is an effective form of control that can be retrofitted to an existing plant and thus minimize a problem that was not anticipated in the original design. However, local exhaust ventilation is rarely completely effective since capture is not complete and not all release points are adequately covered. 

Service access to system utilities is an important design consideration. Routine calibration, maintenance, and repair are integral parts of maintaining a GMP facility. Areas to store critical spare parts and supplies should be included. 

Routine lining inspection and maintenance procedures must be followed to obtain suitable lining life. Maintenance procedures described for acid sulfite digesters apply here with one addition, replacement of brick "fall-outs." This problem can be caused by movements of the lining and the steel shell, low compression in the lining, and the low bond strength between the Portland cement mortar and the carbon brick. Proper design considerations will normally reduce or eliminate this problem. 

AY-103 The Application and Maintenance of Polyurethane Foam Systems for Outdoor Service Vessels Operating Between -30°F and 225°F. Reconunended design considerations and guide specifications (PFCD-G52-10/87. 

As with laboratory operations, basic safety considerations in low-temperature plants and test sites are similar to those in many chemicalprocessing plants. For example, many of the items considered by Kintz and Hill in their study of safety at gas-processing plants are also applicable to cryogenic facilities. Many of these are also discussed by Armistead, Liston, and Cost." They are considered here under six categories—design concepts, maintenance, normal and emergency operations, personnel protection, and plant and test site protection. 

Heat treatment furnaces are known to be continuous sources of well known non-air components. Emission levels are closely related to energy consumption, burner design and maintenance. Emission collection is trivial in annealing furnaces. The capture of the emissions in the different furnaces does not differ considerably, and emissions are expelled via the waste gas pipe. In general, no further waste gas treatment is applied. 

---