Method for determining the end of devolatilizing in a coke oven and adjusting the coke cycle based thereon

In a process for manufacturing coke in a by-product coke oven battery, the battery having a plurality of ovens;

• each oven operated over a plurality of coking cycles;
• each coking cycle having an aim total coke cycle time defined by a charging time and an aim push time, which aim push time has a permitted plus or minus deviation;
• and between the charging time and aim push time, (1) a devolatilizing period of estimated length, which length is controlled by the heating rate of the oven, and (2) a coke soaking period of pre-selected length, immediately following the devolatilizing period, the method for (1) determining the length of the devolatilizing period and (2) adjusting the heating rate of the oven based upon such length of devolatilizing period, comprising:
• (A) in a first coking cycle:
• (1) during a devolatilizing period, obtaining a plurality of liquid catch specimens having condensed therein volatiles from gas samples withdrawn from within the coke oven;
• (a) for each such liquid catch specimen, determining a light-transmitting value;
• (b) from the light-transmitting values of (A)(1)(a), determining a reference light-transmitting value for the devolatilizing period;
• (2) during a coke soaking period, obtaining a plurality of liquid catch specimens having condensed therein volatiles from gas samples withdrawn from within the coke oven;
• (a) for each such liquid catch specimen, determining a light-transmitting value;
• (b) from the light-transmitting values of (A)(2)(a), determining the rate of change of light-transmitting values for the soaking period;
• (B) in a second coking cycle:
• (1) as the coking cycle approaches an estimated end of the devolatilizing period, obtaining a plurality of liquid catch specimens having condensed therein volatiles from gas samples withdrawn from within the coke oven;
• (a) for each liquid catch specimen, determining a light-transmitting value;
• (2) beginning the measurement of the soaking period when an individual light-transmitting value of value of (B)(1)(a) varies from the reference light-transmitting value of (A)(1)(b), by a pre-selected amount, which pre-selected amount is defined as the product of:
• (a) the rate of change of light-transmitting value (A)(2)(b) of the soaking period multiplied by
• (b) the permitted plus or minus deviation of the aim push time;
• (3) when a soaking period of pre-selected length elapses, comparing the actual total elapsed coke cycle time to the end of the soaking period versus the aim total coke cycle time required to reach the aim coke push time, plus or minus permitted deviation;
• and
• (4) adjusting the heating rate of the oven in a subsequent coking cycle to bring the actual total elapsed coke cycle time to within the aim coke push time, plus or minus permitted deviation.

In a process for manufacturing coke in a by-product coke oven battery, the battery having a plurality of ovens;

• each oven operated over a plurality of coking cycles;
• each coking cycle having an aim total coke cycle time defined by a charging time and an aim push time, which aim push time has a permitted plus or minus deviation;
• and between the charging time and aim push time, (1) a devolatilizing period of estimated length, and (2) a coke soaking period immediately following the devolatilizing period, the method of determining the end of the devolatilizing period comprising:
• (A) in a first coking cycle, during a devolatilizing period, obtaining a plurality of liquid catch specimens having condensed therein volatiles from gas samples withdrawn from within the coke oven;
• (1) determining a reference light-transmitting value of such catch specimens for the devolatilizing period;
• (B) in a second coking cycle, as the coking cycle approaches an estimated end of the devolatilizing period, obtaining a plurality of liquid catch specimens having condensed therein volatiles from gas samples withdrawn from within the coke oven;
• and
• (1) determining when an individual light-transmitting value of one of such specimens varies by a pre-selected amount from the reference light-transmitting value of (A)(1).