Abstract: Apparatus is provided for controlling the burning of a volatile waste liquid together with a conventional fuel in a boiler in the form of a free-standing module which contains a flow-control valve for the waste liquid. This system includes a means for monitoring the position to the fuel-control valve for the conventional fuel and a separate means for monitoring the position of a controlled valve for feeding of the volatile liquid. The two monitoring means are coupled and comparisons are made of the relative valve positions indicated thereby. The process controller used for such comparison contols a valve which stops the flow of volatile liquid to the burner in the event that more than a predetermined discrepancy occurs between the indicated valve positions. Said controller may also be employed to correct the valve position. Other features include a reverse purge pumping system which is actuated upon shutdown of volatile fuel flow.

Abstract: A system for utilizing a fuel having a high ash content, water content in excess of 50% and large particles of combustibles is shown which includes a holding tank for the fuel. Fuel is circulated in the holding tank to maintain the consistency of the fuel and a metered portion is removed, strained and fed to a combustion device. The combustion device is a fire tube boiler for generating steam and includes a furnace tube insulated with refractory material extending for its entire length. The system mixes a preselected amount of atomized fuel with combustion air and natural gas. Special ash and particulate accumulation means are provided in the boiler. The boiler also has a water spraying system in its combustion chamber to reduce combustion temperature and increases water content of the combustion mixture based on the temperature of the combustion gases at the end of the furnace tube. Finally, when the boiler is shut off, the entire system, including a bypass system, may be purged by air or water.