The issue of air release from ammonia ball tanks

The poster can directly connect the air release system to the low-pressure ammonia system, eliminating the need for additional investment in building an ammonia recovery system.

The venting of safety valves is primarily carried out in emergency situations for recovery purposes, and it is done with the aim of avoiding environmental pollution. It is necessary to carefully consider whether other protective measures for the liquid ammonia sphere tank are effective in the event of an accident. From this perspective, it is still necessary to install a recycling device. However, as described by the original poster, a recovery device can be installed to recover ammonia into the low-pressure ammonia recovery system; alternatively, a simple water scrubber can be used for purification in order to prevent environmental pollution and personal injury.

Regarding the issue of venting air from ammonia storage tanks, the new petrochemical fire protection standards require that the air released from the safety valves of such tanks be recovered. It seems that ammonia storage tanks already come equipped with numerous protective measures, such as insulation and interlocked water spray systems; therefore, the possibility of the safety valves needing to release pressure is quite low. Is it not an overinvestment to add an ammonia recovery system as well? The colleagues on the second and fourth floors came up with some practical solutions. In the storage of ammonia in liquid ammonia tanks and spherical tanks, there are various methods for implementing vent recovery (in normal circumstances, there is little need for venting, and ammonia is not meant to be wasted; the venting referred to here mainly occurs in case of safety valve activation or other abnormal situations). 1. Recovering the vented ammonia into a low-pressure ammonia recovery system helps to save energy, protect the environment, and ensure safe production ； 2. After the vent gas is recovered to the boundary valve of the ammonia storage container’s recovery pipe, the pressure here is lower than that in the storage container; this approach is safe, energy-efficient, environmentally friendly, and requires less investment (the issue is generally resolved within the boundary area) ； 3. A normal-pressure water seal tank is installed at the outlet of the safety valve, which facilitates the recovery of ammonia (ammonia is absorbed in water, while the inert gases that are not absorbed are vented to a higher altitude); however, this setup requires careful calculation regarding the tank’s volume, water depth, pressure settings, pipe diameter, and gas flow rate, as well as regular maintenance to ensure the safety of people in the vicinity and downwind areas and to minimize environmental pollution------ ； In short, recovery is required; whether it can be recovered is one aspect of the issue ； On the other hand, it is necessary to strengthen the core role of indicator operation and management in various positions, and integrate them organically with enterprise management (the three key disciplines for production operations: process operation discipline, labor management discipline, and safety production discipline) as well as corporate culture ； Adopting strict procedures to ensure the proper operation of the indicators, regularly calibrating and replacing measuring instruments to guarantee accurate readings, setting pressure-warning mechanisms to address and reduce abnormal conditions – ensuring the safe operation of the equipment is the top priority.

It’s mainly for environmental reasons, I guess! And the recovery is also recovery in an accident condition; where is there any venting/bleeding under normal circumstances?

The new petrochemical fire protection standards require that the exhaust gas from the safety valves of liquid ammonia spheres be recovered, which is a good thing. However, when implementing this, new safety and environmental concerns must be taken into account, and caution should be exercised when applying the principles outlined in those standards.

Right now we are undermining efforts to achieve development, but do we really have to wait until it’s absolutely necessary before realizing that sacrificing money can prevent disasters? It is our duty to do something for the environment, and it is only natural to invest more in it

The vent gas can be recovered into the low-pressure ammonia recovery system, along with hydrogen recovery equipment, which helps to save energy and protect the environment；

[3. A normal-pressure water seal tank is installed at the outlet of the safety valve, which facilitates the recovery of ammonia (ammonia is absorbed in water, while the inert gases that are not absorbed are vented to a higher altitude); however, this setup requires careful calculation of factors such as the tank’s volume, water depth, pressure settings, pipe diameter, and gas flow rate, as well as regular maintenance to ensure the safety of people in the vicinity and downwind areas and to minimize environmental pollution.]------； I wonder which manufacturers have used this method and encountered issues in actual operation? It is essentially pure gaseous ammonia that enters the water seal; it is estimated that about 600 volumes of ammonia can dissolve in 1 volume of water. Could this lead to a vacuum being created behind the safety valve, causing air to be drawn into the pipeline? Safety valves generally release fluid quite quickly; could this cause the water seal water to be flushed out of the pipeline?

Is it feasible to simply use a sink placed nearby for absorption?