Issues with standby high-pressure coal slurry pumps
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Does any marine friend know whether there is a spare unit for the high-pressure coal slurry pump used in coal slurry gasifiers? If so, what is the process flow? Thank you!
In the pressurized gasification of water-coal slurry, there are no backup pumps; each gasifier is equipped with a dedicated high-pressure coal slurry pump. The reasons for this are as follows: economically, the investment in individual equipment is high. From a process perspective, once the shutdown system is activated, all equipment within that system comes to a stop. To restart the system, it is necessary to establish the appropriate flow rates for the coal slurry and oxygen, depressurize the system, and replace the air with nitrogen, a process that takes time. Therefore, backup high-pressure coal slurry pumps are not very useful. Additionally, considering the costs associated with equipment maintenance, these expenses increase over time, raising the costs for businesses.
Thank you! May I ask that sometimes it is a fault with the coal slurry pump itself, such as a stuck check valve in the pump or a ruptured diaphragm; if there is a backup pump, then switching to it can avoid the need to shut down the furnace, which would reduce losses significantly. So, are there no backup pumps for anything used?
Of course, there are backup units, depending on the output of the gasification furnace.
Which company is it? Is there a picture or photo? Please send it if possible.
I can tell you for sure that there is no backup pump for the high-pressure slurry pump
Generally, there is no backup pump, as the investment required for high-pressure slurry pumps is relatively high. Regarding the issue you mentioned, with a single nozzle it is necessary to stop the system for maintenance, while with multiple nozzles it is possible to continue operating under pressure after completing the maintenance.
So I would like to ask: what are the bottlenecks other than investment?
We have three furnaces, two in operation and one as a backup. In this situation, if one of them fails, can another one take its place, rather than having to install a new one?
In theory, it is possible, but in practice: 1. From a safety perspective, reversing the pump requires disabling some of the gasifier interlocks, which poses a significant risk. 2. It requires high standards for operator skills. 3. There used to be an animation on the Gasification website showing the process of switching over to a backup high-pressure coal slurry pump; please take a look and try to find it. It’s not very reasonable to have three slurry pumps in this mutual backup configuration; 1. The design of the pipelines for transferring slurry between pumps is complex. 2. If there is a problem with a slurry pump, it is entirely possible to start the hot standby furnace.
Thank you for the reply! It’s quite complex. Diaphragm pumps are different from centrifugal pumps; when reversing the flow direction, a return line is required to prevent oxygen from flowing back. Is there no precedent for this in China?