I would like to ask the experts whether it’s possible to modify the boiler in this way?

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This post was last edited by Bai Se Yi Hao on 2016-10-26 at 11:23. Background: The poster is a novice when it comes to boilers. Recently, their supervisor assigned them a task to convert an existing coal-fired thermal oil boiler with a mechanical grate in the factory into an incinerator for burning waste liquids from various devices (which are classified as hazardous waste and cannot be disposed of externally). The specific modification plan is as follows: 1. The original thermal oil boiler is a 1200W coal-fired mechanical grate thermal oil boiler. The thermal oil inside the boiler was emptied through purging. To prevent the boiler tubes from overheating and getting damaged, steam at a rate of 2 t/h was introduced into the tubes to protect them; this steam was then vented on-site (at present, the issue of utilizing the heat generated by this boiler is not being considered)； 2. A steam atomization nozzle is installed at the hole in the furnace wall of the main combustion zone, allowing various types of waste liquids to be sprayed horizontally into this area. The main components of these waste liquids are propylene glycol and dimethyl carbonate, etc.; their calorific value ranges from 3500 to 5000, and the processing capacity is 0.5 t/h ； 3. Coal is added to the furnace; first, the coal is ignited to raise the temperature of the furnace to 200 degrees Celsius, after which the waste liquid is sprayed in. Tests have shown that the atomization effect achieved by the nozzles is satisfactory, and the furnace temperature can be maintained at around 500 degrees Celsius after spraying the waste liquid ； 4. Through testing, the boiler consumes 100 kW/h of electricity, 0.3 tons of coal per hour, 0.5 tons of waste liquid per hour, and 2 tons of steam per hour. After several days of testing, the following problems arose: Problem 1: The injection of waste liquid caused local temperatures on the grate to become too high, resulting in the bending of the steel beams supporting the grate. How can this be avoided? Question 2: The supervisor is concerned about high steam consumption and requires that the steam not be discharged; instead, it should flow through the furnace tubes before being incorporated into the steam network. The steam used has a pressure of 1.0 Mpa and a temperature of around 260°C. So, how much steam needs to be supplied in order to provide the heat required for combustion and prevent the furnace from being damaged? Question 3: Is it feasible to treat waste liquid in this way? Are there any better ways to handle this that anyone can think of?