Synthetic Ammonia Process Technology Exchange Area [Daily Question 2009-02-14]

The main reasons for low inlet pressure in copper pumps are: 1. The temperature of the copper melt is too low, resulting in increased viscosity and higher resistance in the inlet pipes of the copper pump. 2. The copper melt water coolers, ammonia coolers, and pipelines are blocked by impurities such as copper sulfide. 3. The structure of the copper melt ammonia cooler is unreasonable; air accumulates in some of the heat exchange tubes and cannot be completely removed, resulting in air blockages and a reduced flow area. 4. Improper handling during parking caused the heat exchange tubes of the copper melt ammonia cooler to freeze and become blocked. 5. The copper melt is contaminated with oil, has a high content of suspended particles, is viscous, and its flowability is reduced. 6. The diameter of the pipes in the recycling system is designed to be too small, resulting in a high flow rate of the copper melt and high resistance. Solution: Slightly increase the temperature of the copper melt, clear any blocked equipment or pipes, improve the filtering of the copper melt, enlarge the diameter of the system pipes, and replace the ammonia cooler used for cooling the copper melt.

The reasons for a decrease in the inlet pressure of a copper pump include: 1. An increase in the flow rate of the copper liquid, such as when an additional copper pump is used. 2. A reduction in the amount of copper liquid in the system, such as due to leakage of the copper liquid. 3. A decline in the quality of the copper liquid, resulting in an increase in its viscosity. Such as an increase in oil and suspended solids, as well as the formation of copper sulfide precipitates. 4. Clogging of inlet pipes and equipment. Issues such as blockages in the regenerator, filters, copper cyanidation tanks, or ammonia cooler coils, or the detachment of certain valve stems, can cause air to enter at the 5 inlet. Such as excessive ammonia addition to the system (which causes fluctuations in inlet pressure), or improper operation of the pump reversal function. Handling method ； 1 Reduce the copper melt flow rate appropriately while ensuring the composition of the refined gas. For example, by slightly opening the copper pump bypass line, etc., fluid is added to the system from the preparation tank. Water can also be added to the system when the composition of the copper melt is good. 3 Strengthen management to ensure the quality of copper melt. and reduce the sulfide content. 4 Some equipment can be rerouted to a bypass line in a short time. Such as filters, copper treatment tanks, etc. The addition of ammonia to the system should be done gradually, and pump operation must be carried out in a proper manner. In actual production, when a drop in pressure occurs in copper pumps, one can first slightly open the bypass valve to maintain production (while reducing the amount of refining gas from the previous stage, depending on its composition), and then identify the cause and take appropriate action!

To summarize the possible reasons briefly: the temperature of the copper melt is too low, resulting in increased viscosity and greater resistance in the inlet pipeline of the copper pump. The copper melt water cooler, ammonia cooler, and pipelines are blocked by impurities such as copper sulfide. The structure of the copper melt ammonia cooler is unreasonable; air accumulates in some of the heat exchange tubes and cannot be completely removed, resulting in air blockages and a reduction in the flow area. Improper handling during parking caused the heat exchange tubes of the copper liquid ammonia cooler to freeze and become blocked. The copper melt is contaminated with oil, has a high content of suspended particles, is viscous, and thus has reduced fluidity. The diameter of the pipes in the recycling system is undersized, resulting in a high flow rate of the copper melt and high resistance. The specific treatment methods are: appropriately raising the temperature of the copper melt, clearing blocked equipment and pipes, improving the filtration of the copper melt, enlarging the diameter of the system pipes, and replacing the copper melt ammonia cooler.

There are many reasons. Which one have you encountered? What are the steps to deal with it?

The import of copper melt containing ammonia can also lead to low pressure and an excessive amount of ammonia in the system.