Hi;
For a loaf making plant where natural gas and LPG (alternatively) were used in burner to cook the loaf, the customer was facing loaf quality issue because of unstable NG (natural gas) pressure. To maintain the furnace temperature, I installed Honeywell (refurbished) motorized control valves M7284Q1009 (4-20mA, 30-60sec, 220V/24VAC) at NG and LPG, thermocouple installed in Furnace and Fatek PLC to control the operation including conveyor speed.
In short, after installation, programing and commissioning, i found that system controlled the furnace temperature well but a problem is hurting the system. For example, if temperature rises or lowers the set point temperature (675c), system gives command to NG/LPG valve to close/open, the valve requires time to close/open. During this period, some of loafs remain uncooked or overcooked.
I am wondering how to get control on this issue. Is there any idea? For me, system needs fast operation of control valves. Looks like i will have to change the valves with max 5sec time for fully open/close.
You have had lots of excellent suggestions from the forum I second them.
I assume as this is bread making and you are using LPG (food regs here in Oz) that you have some form of heat exchanger this will introduce its own transfer delay.
I would be interested in the final outcome.