Improving energy and operational efficiences with rotary phosphate drying, 17th Oct 2016

Energy efficiency, operational maintenance, and less downtime these three are most important attributes for an industrial drying process. The purpose of the project is to replace the existing ageing burner systems and fuel handling system to ensure the desired attributes.

This phosphate drying plant has two rotary dryers each heated by a burner firing waste oil. The outlet pressure of the oil handling unit is designed for 15 bar maximum. The combustion system burns the oil in a combustion chamber, mixes the combustion products with air and delivers hot air to the rotary drum at a temperature set in the 700 C to 850 C range.

The burners are capable of an output of 19.3GJ or 1600 l/h of the FOC50 fuel oil. This burner range operates with 30% of the combustion air supplied by the burner as Primary air. This air is supplied at 11kPa as it also atomises the oil.

The combustion air control valve is fitted with a conventional control motor, mounted shaft to shaft with no external linkage. The air valve opens and closes as the system calls for more or less heat, increasing and decreasing the downstream air pressure. A loading line transfers the controlled air pressure to the top of the oil control valve (OCV) ratio regulator.

A quarl is fitted into the same diameter steelwork as the burner ignition chamber in order to minimise modifications to the combustion chamber. The burner firing rate is controlled by the material discharge temperature and controlling the chamber outlet temperature by adjusting the flow from the secondary fan.

The waste oil fuel is being preheated before firing in the burner to ensure proper atomization of the oil. Hull Nu-Way supplied a packaged pumping and heating unit along with the burner systems to raise the temperature of the waste oil.

Please contact us directly for specialised process heating or combustion application.

Leave a Reply

Your email address will not be published. Required fields are marked *