Soft shutdowns

Hardness breakthrough can be particularly troublesome at those small, hard-working facilities that employ just one automatic softener. The problem may develop gradually and go unnoticed for some time. This may be because the softened water is not tested daily or, more usually, because the soft water is tested soon after resin regeneration rather than immediately before the point of exhaustion (which may be many hours later, but perhaps still 2 or 3 hours before the end of a working shift or plant shutdown). 

Weekend shutdown maintenance at WP L has shown some unusual deposits on the ESP plates and wires, but the deposits are soft and easily removed.18... 

The main purpose of the first series of runs was to determine the effectiveness of the pulse system for scale reduction, and determination of the shutdown time. This run lasted for 1560 hours and the average reduction of salinity for 13 weeks was 1762 p.p.m. The production rate of the pilot plant was 5200 gallons per day. Almost no adherent scale deposited on the membrane. However, part of the soft sludge was held back by the expanded plastic spacer material and caused a slow increase of voltage. When the over-all voltage reached 125% of the mean operating value, reversed polarity was applied for 1 or 2 hours. This procedure was adopted in addition to the short cycle pulse system. 

Bai Chongen, et al. 2011. Regulation and Property Right Effect of China s Coalmine Shutdown Policy on Work Safety. China Soft Science (10) 12-26. 

For the social criteria, two methods are applied in this study. A more detailed safety-related discussion of the bioethanol process can be found in the open Hterature [45]. In the first method, safety during operation, operability of the plant, safe startup and shutdown, and location-specific demands are selected as four soft indicators for sustainability assessment. The evaluation and justification of each indicator are provided in Table 6.13, where standard definition and scaling system can be found in Othman et al. [1]. In this approach, the process with the higher score is more desirable. Again the dry grind process is found to be superior. 

The key features of the current-ramp soft-start unit are that it limits the motor inrush current to a specific amount, it can provide physical soft start, and it limits motor torque. These units are used mainly for electrical soft start (reducing inrush current). The shutdown of production is a... 

Process Design of Abnormal Situation is Completed (IPL3,4, 5) "Process Design of Recovery (Fallback) is Completed" "Process Design of Partial Shutdown is Completed" "Process Design of Total Shutdown is Completed" Functional Equipment Specifications Soft Sensors Information Flowsheets Information Time and Cost Estimation ... 

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