4.2 System Capacity
4.2.1 The design capacity per day of material handling system for petrochemical service should be 1.2 times the daily raw material(fuel)consumption or daily product output of the process plant.
4.2.2 The design capacity per hour of material handling system for petrochemical service shall be calculated by Equation(1)below:
where:
q——sytem capacity per hour,t/h;
Q——system capacity per day,t/d;
T——total actual work hours per day,h/d.
4.2.3 The total actual work hours per day shall be calculated by Equation(2)below:
where:
n——number of work shifts per day;
t——actual work hours per shift,h.
4.2.4 Work shifts and work hours:
a)The number of work shifts for raw material unloading system and product loading/unloading system shall be determined according to the agreement reached between the owner and transportation companies,and if there is no such agreement,a two-shift work system should be executed.
b)Raw material storage,transportation and processing systems should be of single-train design if the total demand of raw materials is less than 60t/h and a two-shift work system is executed;and should be of double-train design(one train for operation,one train for standby)if the total demand of raw materials is no less than 60t/h or a three-shift work system is executed.
c)Drying,cooling,crushing and milling systems should execute a three-shift work system,and should have their operation hours the same as those of the process plant.Operation hours of each shift should be 8h.
d)A two-shift work system for packing should be executed when the products are stored in silos.
e)A three-shift work system should be executed when the products are packed with continuous system and stored in bags.A two-shift work system may be executed when a buffer silo is used for non-continuous packing system.
f)For the packaging systems without buffer silos and being directly connected to the process plant,a three-shift work system,the same as the process plant,should be executed.Operation hours of each shift should be 8h.
g)The actual work hours per shift should be 6h except mentioned above.