We have open circuit ball mill grinding OPC 43 grade, feed moisture 2% max, Inlet temp 35 Deg C and outlet temp we are getting around 90 to 95 deg C, what could be the reason of high temp at mill outlet, since we have not supplied hot gas at feed, can anybody suggest the possible reason please, which helps to take necessary action.
Regards,
Ramesh AItal
Hi there,
Well it’s known that more than 85% of the energy in the ball mill is converted into heat and not used to grind the material. The heat is generated when the ball impact each other and this is the source of your heat in the mill. Below are some guidelines for cement mill temperatures in first and second compartments:
Intermediate diaphragm - maintain temperature around 100 [°C]
Mill discharge (product or air) -Ideal 100 – 120 [°C] - Air normally 5 [°C] lower than material
Control the temperature with: 1. Separating air – cooling effect in separator 2. Cement cooler – cooling needs for final product or 3. Water injection: Water injection [l/h] 1st compartment- Only with clinker temp > 100 [°C] - up to 1/3 of total water injection• 2nd compartment- control of mill discharge temp.- up to 2/3 of total water injection
In your case with temperatures of 95 for cement I presume you don’t have any problems if any you should check your product setting time since the product exit temperature is low.
Let me know if you need more information.
Regards;
F.Jalali
Heat is generated during grinding due to ball impact. also feed material having temp.