Issues regarding the types of methylammonium pumps and liquid ammonia pumps

It is understood that in domestic fertilizer plants, few units use centrifugal pumps for ammonium methoxide pumps and liquid ammonia pumps; most of them employ plunger-type reciprocating pumps. Small and medium-sized units mostly use triple-plunger pumps, while many large units employ five-or seven-plunger pump systems. Please ask those who use ammonium pump or liquid ammonia pumps that are of the centrifugal pump type to share their experiences and talk about some insights gained from using centrifugal pumps! This post was last edited by Fan Zhou Wu Hu on 2009-4-18 at 12:57.]

Our factory uses plunger pumps, and a newly built plant within our group company is also using them; both ammonia pumps and ammonium pumps are centrifugal pumps. I think centrifugal pumps and piston pumps each have their advantages. Plunger pump: Relatively inexpensive; it’s easy to repair as we are used to doing so, and it has a short operating cycle. However, the maintenance costs are higher (for plungers, packing, check valves). Centrifugal pump: Relatively more expensive, with a longer operating cycle; the maintenance costs may be relatively lower

Our factory also uses plunger pumps, with five-rod and seven-rod plungers in the units. There is a certain direct relationship between the levels of outlet flow pressure and the number of times the pump needs to be repaired.

Another major advantage of using a centrifugal pump is that its outlet flow rate is stable, with no pulsations, and there is less vibration in the outlet pipeline. But the efficiency is estimated to be slightly lower than that of a piston pump. On the contrary, piston pumps have slightly higher efficiency, but their outlet flow rate is unstable, resulting in pulsations and significant vibration in the outlet pipeline.

We use three-plunger pumps, manufactured by Shanghai Dalong and Weifang Shengjian; we’ve only heard on forums that centrifugal pumps are useful. This post was last edited by lxq700918 on 2009-4-19 14:25.]

After the renovation of our plant, a new centrifugal ammonia pump and a new centrifugal methylammonium pump were installed: Ammonia pump: Manufacturer: Ebara, Japan； Level: Level 10 ； Sealing type: double-end mechanical seal ； Drive type: Motor. Operation status: Smooth operation, long service life, low maintenance requirements ； Problem: Domestic mechanical seals have a short service life and often leak ； Driven by a motor; during reverse flow, the reverse flow line vibrates significantly (rectification is in progress). Evaluation: Overall, the centrifugal pump performs well; it is easy to start and stop, eliminating the many hassle-related tasks associated with packing adjustment, which makes maintenance easier for staff. Ammonium pump: Manufacturer: Ebara, Japan ； Level: Level 6 ； Sealing type: Single-face mechanical seal ； Drive type: Turbine. Issues: Driven by a turbine; the turbine is of Elliott type. The steam seals leak frequently, resulting in lubricant emulsification and elevated temperatures in the bearing shells ； Evaluation: It operates well; as long as a vacuum is created in the turbine seal cooler, the seal leakage problem will be resolved ； By resolving the issue of leakage in the mechanical seal as well, the operation remains very stable.

These days, centrifugal pumps are widely used in the design of new factories, offering reliable and safe operation

The ammonia pump is of the piston type, while the ammonium methylate pump is of the centrifugal type. The ammonia pump is of German origin, and the ammonium methylate pump is from the United States. Due to its piston design, the ammonia pump experiences significant pipeline vibration and requires frequent maintenance； The methylammonium pump did not perform well in the previous years, with the mechanical seal leaking frequently; however, once proper operation techniques were mastered, its performance became very stable.

The liquid ammonia pumps and methylamine pumps for our 520,000-ton urea production are multi-stage centrifugal pumps manufactured by Ebara of Japan, driven by air-cooled motors with gearboxes; their condition is similar to that of the pumps on the upper floor. It has been running for 15 years and is in good condition. Domestically produced mechanical seals are of slightly lower quality, but it doesn’t have a significant impact on performance. Another commonly used type of centrifugal pump is the high-speed centrifugal pump produced by American Sundyne, which I saw at Zhongyuan Dahuahua.

We have now decided to use multi-stage centrifugal pumps. Could everyone please provide more information on the manufacturers of such pumps, their production timeframes, and their usage patterns? Thank you very much to those who have replied! This post was last edited by luomadadi116 on 2009-4-20 11:45.]