Safety issues related to the combustion of flammable exhaust gases in boilers
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Our company’s vacuum pumps emit a strong odor from their exhaust gases. We tried many methods to solve this problem, but in the end we had to install a gas pipe that leads into the boiler furnace for combustion. Because, to address safety concerns, a nitrogen generator was specifically purchased to purge the pipelines before they enter the furnace. But it still doesn’t feel very safe, so I installed two more flame arrestors (in front of the boiler). In actual operation, backflow still occurs because the exhaust gas contains methanol; some of this methanol condenses into a liquid form before entering the furnace. We have a gas-liquid separation tank located outside the boiler room, but still a small amount of liquid reaches the flame arrester. This backflow causes the flame arresters to get damaged frequently. Thank you in advance for any good suggestions everyone has!
First, a dedicated burner must be used; it is not possible to directly feed gas into the furnace through a pipe. Second, the pressure and flow rate of the exhaust gases need to be stabilized. Be careful to prevent liquid from being carried in the exhaust gas.
A separation tank must be installed when handling liquids; it is also recommended to engage a design firm to carry out the design, and measures such as shutdown systems and backflow prevention will be taken into account
The suggestions for the first floor are excellent; they enable voltage stabilization, gas-liquid separation, and sequential nitrogen valve operation to maintain pipeline pressure
I’ve seen designs for water seals; just like yours, the water is discharged directly into the furnace for combustion after passing through the seal
Using a water seal to prevent backfire is a good approach!
Methanol also falls into Category A-B in terms of fire hazard; its explosive range is quite wide. Introducing this gas into open-flame equipment for combustion without proper evaluation poses a significant safety risk. Even if a combustion device is to be introduced, it is necessary to conduct studies on the flammability of the gas as well as on its calorific value, and to compare the oxygen content in the gas with its limiting oxygen content, in order to ensure that there is no risk of deflagration during transportation and combustion. Only when both the deflagration studies and the calorific value studies are successful can the matter of further incineration be discussed; otherwise, it is inappropriate to discuss combustion settings without meeting these prerequisites.
One problem with the water seal is that the liquid level in the seal tank rises too quickly, but it is still necessary for safety reasons. Since it is the exhaust gas from the vacuum pump outlet, as long as the system is functioning properly, there is very little oxygen in the exhaust gas. Unless there is a severe leak in the system, and if there really is a serious leak, it’s likely that the tower will experience an explosion. When starting distillation, the vacuum in the system is first reduced to the appropriate level before feeding material in, so the risk of detonation is very low.
Add a vacuum buffer tank, and then use water to spray the vacuum pump in order to draw the combustible gases from the buffer tank and send them to the furnace for combustion
Doing this is not in compliance with the regulations; it must be designed by a design institute. Although we do the same, our exhaust gas is isooctanol, which is relatively better.