Seeking help regarding abnormal noises from the economizer and condenser
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A 6-ton condensing flue-type boiler: 1. The boiler body features a double-pass wet-back design for the flues. 2 Fuel: alcohol-based fuel. 3 Hydration method: Intermittent. 4. Water supply process: The multi-stage pump draws water from the water softening tank and sends it to the condenser; there, the water exchanges heat with the flue gas before entering the economizer. After exchanging heat with the flue gas in the economizer, the water enters the boiler. Problem: After half a year of operation, the condenser started leaking; the condenser and economizer were replaced. After the new economizer and condenser were installed, a trial run was conducted. The burner burned normally for about five to six minutes, after which scraping noises arose inside the economizer and condenser; the furnace was immediately shut down. Scrapping noises continued to be heard for a few minutes after the furnace was turned off. After the modification, the short-circuit circulation sound between the economizer, condenser, and water softening tank (with a capacity of 13 cubic meters) disappeared; however, when the boiler pressure reached 1 kilogram, the temperature of the water in the tank became too high, and the water exiting the economizer had already vaporized. Please, experts, take some time to analyze the reasons. Note: The furnace was opened for inspection; the ash accumulation was not severe, and there was no scale inside the boiler. Is it related to incomplete exhaust of air from the economizer and condenser? Or is there a leak in the check valve of the water inlet pipe between the economizer and the boiler?
It’s impossible to explain this thing in just a few sentences; one needs to see it in person and consider various aspects
;P:L:dizzy:
Based on the issue you described, in my opinion, the amount of water pumped by the multi-stage pump from the water softening tank to the condenser is too small; as a result, too much heat is absorbed by the water in the condenser, which may push it to the critical point of vaporization. Upon entering the economizer to absorb heat, it vaporizes immediately; a two-phase flow of water vapor is formed in the condenser and the economizer, and the rattling sound produced is what is commonly known as water hammer. If the gas flow velocity is too high, it drives the water flow within the equipment, and the impact of the water flow against the pipe walls causes abnormal noises. It is recommended to double the flow rate of the multi-stage pump, so that more cold water can flow in to absorb heat; this may help reduce the gasification phenomenon.
Increase the feed water pressure and replace the check valve