Slag tank pump selection
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The sludge tank pump draws liquid from the bottom of the clear water tank in the sludge tank, pressurizes it using the pump, and then sends it to the vacuum flash drum or the sedimentation tank. Most of the slag tanks used in Texaco’s gasification plants currently follow this process, but the flow rate and head capacity of the slag tank pumps vary. Taking furnaces with a diameter of Φ3200/3800 as an example, there are at least two configurations: 1) The slag tank pump uses a pump with a head capacity of 70 meters and a rated flow rate of 150 m3/h, with 10-inch inlet and 8-inch outlet pipes. 2: The sludge tank pump should be a model with a head of 70 meters and a rated flow rate of 35 m3/h, featuring 6-inch inlet pipes and 4-inch outlet pipes. Since slag discharge is done intermittently, only 30 cubic meters of water is used for flushing each time slag is discharged. The slag is removed twice an hour, which means less than 60 cubic meters per hour; nearly half of this amount consists of coarse slag that is removed using a slag skimmer. If the first type of sludge tank pump is used, the liquid level in the sludge tank drops very quickly. If the pump is stopped at that point, the lack of flow of slurry water can easily lead to blockages in the inlet pipes of the sludge tank pump. To address this issue, many plants have installed pipelines that supply low-pressure ash water into the sludge tank, using this low-pressure ash water to control and maintain the liquid level in the tank. This allows a continuous flow of water within the sludge tank, which helps to carry the sludge out of it. However, the downside of this approach is that it increases the load on the low-pressure ash water pumps, resulting in unnecessary waste of electrical energy. Therefore, the engineers at the design institute designed the sludge tank pump to be very small, with a rated flow rate of only 35 cubic meters per hour. While this helps to avoid adding large amounts of low-pressure ash water to the sludge tank, can the sludge in the tank actually be removed with such a low-capacity pump? Isn’t it easy to get clogged? The sludge pump in our old factory is quite large; it’s used for furnace drying on a regular basis. The sludge pump in the new factory is much smaller, and although it saves a lot of energy, it seems like there will be many problems once it’s in use. I hope everyone can discuss whether there are manufacturers of small sludge pump units, and what the performance of those units is like
I mean, the flow rates of these two pumps differ by too much. However, I personally recommend choosing the 150 model, as this allows for the timely drainage of water from the slag tank in case of an accident, such as continuous slag discharge.
Yes, I also think it’s better to choose one with high flow rate. Although it involves some waste, it can be used as a preheating water pump for the furnace when needed, so there’s no need to install a separate preheating water pump for the furnace. It can also help to remove slag water promptly during continuous slag discharge. However, the pump selected for the slag tank in this new factory is so small that I’m worried there will be many problems once operations start
Then raise your concerns about the change in a timely manner; otherwise it will cause a lot of trouble later on. 35 is too small.
The position is too low-level; the managers and the people at Tianchen Design Institute simply don’t care about our opinions. They consider it a technical improvement, arguing that if the pump capacity of the slag tank is too high, it’s not possible to send the fluid to the vacuum flash evaporation tower! Let’s wait and see after it goes into operation!