Hi, I've got a project and was just wondering am i going about the right way of calculating it. I know this is basic engineering from secondary school but I'am still probably have it arse ways! Just not that fimiliar with this kind of thing.
I've got a conveyor with a load cell measuring the weight of the load on the conveyor and a Pulse Encoder measuring the speed. Pending on the flowrate of food on conveyor a proprtional amount of salt needs to is added from an overhanging hopper.
To calculate the flow rate on conveyor:
- Do I measure the weight at fixed intervals (say 1sec recording quantity in Kg) then calculate the Mass (x 9.8) and then multiply by the Density (of the food object) to get the end result equal the to volume,
- Is the volume then multiplied by the speed in m\sec from the encoder to get the flow rate in m3\s??
I plan to use a PID to apply salt as there is another load cell measuring the weight of salt in hopper and a control valve to dispense salt from hopper.
Is the folowing concept OK?
PID Setpoint = amount of salt to be dispensed (a %proportional value to food flow rate(previously calculated), again in m3/s)
Process Variable = LoadCell (Current Weight - Previous Weight calculated every sec x 9.8 x Density of Salt)= Process Variable (amount dispensed in m3\s)
Ouput= Control signal to control valve
I plan to do the above sequencially every 1 sec in the PLC code. Am I on the right lines or totally amiss? Appreciate any feedback on this. Thanks - Rpax
I've got a conveyor with a load cell measuring the weight of the load on the conveyor and a Pulse Encoder measuring the speed. Pending on the flowrate of food on conveyor a proprtional amount of salt needs to is added from an overhanging hopper.
To calculate the flow rate on conveyor:
- Do I measure the weight at fixed intervals (say 1sec recording quantity in Kg) then calculate the Mass (x 9.8) and then multiply by the Density (of the food object) to get the end result equal the to volume,
- Is the volume then multiplied by the speed in m\sec from the encoder to get the flow rate in m3\s??
I plan to use a PID to apply salt as there is another load cell measuring the weight of salt in hopper and a control valve to dispense salt from hopper.
Is the folowing concept OK?
PID Setpoint = amount of salt to be dispensed (a %proportional value to food flow rate(previously calculated), again in m3/s)
Process Variable = LoadCell (Current Weight - Previous Weight calculated every sec x 9.8 x Density of Salt)= Process Variable (amount dispensed in m3\s)
Ouput= Control signal to control valve
I plan to do the above sequencially every 1 sec in the PLC code. Am I on the right lines or totally amiss? Appreciate any feedback on this. Thanks - Rpax