The function of dip tube is to increase the efficiency of cyclone. more the length of dip tube more the separation efficiency and much the pressure drop, normally  last stage cyclones are 70-75 % efficient and we can run without diptubes in last stages.

 

Regards,

Shafi,

Process 

thanks shafi brother. sir can u will explain how dip tube helps in separation

Hey Nael;

Running the kiln without a dip tube may only decrease the settling efficiency of cyclone-5, this can result in a higher temperature at top of the preheater and in a higher heat consumption. The negative pressure at top is expected to rise a little.

Regards