Atmospheric pressure storage tank exhaust system

The exhaust gas system of atmospheric pressure storage tanks can be sealed using a vacuum extraction outlet, with the exhaust gas being directly sent to a heating furnace for combustion. This method is feasible in some applications. Whether a flame arrester or other safety devices are needed in the pipeline depends on the specific process conditions and safety requirements. In pipelines involving flammable gases, it is usually necessary to consider installing flame arrestors to enhance safety and prevent flames from spreading through the pipelines. In addition, it is also necessary to evaluate and select other safety equipment in accordance with local regulations and relevant standards. In summary, when designing and operating the exhaust gas system of atmospheric pressure storage tanks, it is necessary to take into account factors such as process conditions, safety requirements, and regulatory standards to ensure the safe and reliable operation of the system. It is best to consult a professional engineer or consulting firm for more accurate advice and guidance. .

The small factory is carrying out the modifications on its own, mainly for safety reasons. We would like to hear the opinions of colleagues in this field, as environmental regulations are now very strict – the use of breathing valves is prohibited. Moreover, allowing air to enter the system seems dangerous as well. Since there are no nitrogen-based systems available, we are considering avoiding the use of nitrogen sealing and instead using exhaust gas instead. Before this exhaust gas is used for combustion, there is a liquid separation tank and a flame arrester; we’re not sure if this will be sufficient

The original poster asked whether the exhaust gas from a vacuum pump could be used to seal a storage tank; you mentioned using negative pressure to seal the tank. . .

From the schematic you provided, it seems that the outlet of the vacuum pump is connected to the exhaust pipeline of the storage tank. Is this done in order to reintroduce exhaust gas into the tank when its liquid level drops, thereby preventing negative pressure from causing damage to the tank or allowing air to enter? Personally, I think this design is a bit problematic. I have a few questions here; you can consider them on your own: 1. How much exhaust gas is there? Does it meet the requirements? When the liquid level in the storage tank drops rapidly (for example, due to rapid feeding out), more gas needs to be supplied. If the flow rate of exhaust gas is insufficient, it is possible for the gas inside the heating furnace to be drawn back into the storage tank through the intake pipe of the heating furnace. If this intake pipe is where multiple streams of gas converge, it is also possible for other gases to be drawn into the tank as well; such a situation is extremely dangerous. 2. How stable is the operation of the vacuum pump? Once the vacuum pump stops operating or shuts down, the air supply to the vacuum pump is interrupted. In such a situation, it becomes necessary to determine how to handle the gas seal in the storage tank; otherwise, there is a risk that the high-temperature gases from the heating furnace could flow back into the storage tank through the intake pipes. 3. What is the pressure in the inlet pipeline of the heating furnace? How many streams of exhaust gas are there in this intake pipeline? What is the highest pressure? When the heating furnace is shut down, could there be an increase in pressure in the intake manifold, with that pressure entering the storage tank and causing overpressure? Or, what is the pressure inside the heating furnace? Could the heating furnace be in a negative pressure condition? Due to the suction effect of the heating furnace, the intake pipeline may also be under negative pressure, which in turn causes the pressure in the storage tank to become negative, ultimately leading to damage to the tank? Please analyze the above questions accordingly.

1. The amount of exhaust gas is sufficient, as the storage tank has a capacity of only about ten cubic meters; moreover, the pump used for transferring the gas outside is not very powerful, being a 15-cubic-meter pump. 2. The pump used for transferring the gas does not deliver it continuously, but rather in intermittent bursts at a low frequency. 3. For the heating furnace, the exhaust gas enters through a separate pipeline, separate from the pipeline for fuel gas. Currently, we are considering whether it’s sufficient to add a flame arrester or if a water seal tank is also needed. We originally planned to use nitrogen for sealing, but it’s not possible to handle the exhaust gas in that way. Additionally, purchasing a nitrogen generation unit would require a significant investment. We would like to ask whether this approach is feasible; if not, then we will have to opt for nitrogen sealing after all

1. The amount of exhaust gas is sufficient, as the storage tank has a capacity of only about ten cubic meters; moreover, the pump used for transferring the gas outside is not very powerful, being a 15-cubic-meter pump. 2. The pump used for transferring the gas does not deliver it continuously, but rather in intermittent bursts at a low frequency. 3. For the heating furnace, the exhaust gas enters through a separate pipeline, separate from the pipeline for fuel gas. Currently, we are considering whether it’s sufficient to add a flame arrester or if a water seal tank is also needed. We originally planned to use nitrogen for sealing, but it’s not possible to handle the exhaust gas in that way. Additionally, purchasing a nitrogen generation unit would require a significant investment. We would like to ask whether this approach is feasible; if not, then we will have to opt for nitrogen sealing after all

Are there any shut-off measures on the gas pipeline of the tank? It just seems that with it set up this way, with the stove on one end and the jar on the other, it’s not very safe. I have no experience in the petrochemical industry; there may be differences between industries.

This post was last edited by cust008 on 2023-7-7 21:04. Nitrogen is still necessary; otherwise, I’m not sure how to meet the safety requirements. The exhaust gas can be used to fill the gas phase space inside this tank. I believe the oxygen content in your exhaust won’t be excessive, right? If the oxygen content is too high, then there’s nothing to discuss. But just the line between the storage tank and the elbow at the vacuum pump outlet pipe, I’m afraid, won’t work. Consideration must be given to the pressure control of the storage tank, as well as the operating conditions during abnormal steady operation. Normally, you should share your ideas with the design institute so that they can review them for you. The truth is, you might not want to spend that money and prefer to do it secretly on your own ； A design institute is just for drawing diagrams; it doesn’t bother to consider aspects that such institutes fail to take into account. But, but, regardless of that matter you’re checking, if it doesn’t work, you’ll be fined. At this time, it’s better not to be clever; it’s easy to get caught. If you don’t consult a design firm, it essentially amounts to illegal construction, and all the responsibility falls on you. The quality of the design institute isn’t necessarily high either; what’s most important is its qualifications, as they can help take on most of the responsibilities, which in turn may result in a shorter sentence.

Hello, may I ask? When you say that environmental regulations prohibit the use of breathing valves, do you mean that such regulations prevent their use under the circumstances you mentioned, or is it prohibited in all situations? Is there any specific document regarding this? Thank you.

I’m not sure about the specific documents. We are an environmental protection-oriented enterprise; our management is overseen by the Environmental Protection Bureau, while the Emergency Management Bureau does not handle our affairs. As a result, safety measures here are relatively relaxed. Environmental protection regulations, on the other hand, are very strict – ordinary flame arrestor breathing valves are not allowed to be used; emissions must be conducted in a sealed manner, with no open outlets or direct release into the atmosphere