🔍 Key Concepts

• Slagging in boiler furnaces – what it is and what mainly causes it • Effect of ash content and ash fusion temperature in fuel oil on furnace deposits • How firing rate and fuel type influence furnace temperature and slag formation

💭 Think About

• Which of these options would most increase the amount of inorganic material (non‑combustible residue) going into the furnace? • What happens to slag formation as furnace temperature rises close to or above the ash fusion temperature? Which choice most likely raises that risk? • Compare diesel fuel to heavier fuel oils: which generally has more ash‑forming components?

✅ Before You Answer

• Identify which option directly relates to ash quantity or ash behavior at high temperature. • Ask whether low firing rates tend to increase or decrease furnace temperature and slagging risk. • Consider which fuel type is normally used in boilers when slagging is a concern, and which fuel type is usually cleaner with lower ash.