Discussion on boiler output

It's mainly due to leaks, such as the valves, flanges, gaskets, etc., on the boiler.

The process requires 10 tons of steam; a 10-ton boiler is used, with no excess capacity. Is this acceptable?

Most of the heat from the fuel supplied to the boiler is absorbed by the boiler’s heating surfaces, generating steam. This is the effective heat that is utilized. And another portion of the heat is lost; this portion of heat is referred to as heat loss. 　　The thermal efficiency of a boiler refers to the percentage of the heat input from the fuel that is useful heat. The thermal efficiency of modern large boilers is around 90%. It refers to the percentage of heat absorbed by water, steam, or heat transfer oil during the heat transfer process in a boiler or organic heat carrier furnace, relative to the total heat released upon the complete combustion of the fuel fed into the boiler. Although your boiler has a rated output of 10 tons per hour, if there are other heat losses or abnormalities during operation, it will not be able to reach this rated output and thus will not meet the production requirements. I think this is a mismatch.

Boilers designed in China these days generally have a low output capacity; although they are specified as having a capacity of 10 tons, it is difficult to achieve that level of output in practice. Therefore, when selecting such boilers, it is necessary to account for factors such as pipe pressure drop and air leakage, and it is advisable to choose a model with an output capacity that is 15–20% higher than specified.

1. There is no margin for adjustment, which is unsafe. 2. The boiler’s output may not reach 10 t/h

It shouldn’t be possible; increasing the load from 7 tons to 10 tons while ensuring stable operation means an increase in load of 42%. A 30% increase would be good.

Theoretically, it can meet the requirements; since it is used for pressure reduction while ensuring that the fuel remains unchanged, the boiler’s output will be slightly higher than necessary； However, since this unit uses manual coal feeding, it is difficult to ensure continuity in coal supply, which may result in the boiler not achieving the required output. Therefore, I suggest that this unit consider switching from manual coal feeding to coal feeding using a conveyor. If that is not possible, and continuous and stable fuel supply is necessary, it would be better to use a boiler with a higher capacity. Additionally, I believe that water-tube boilers with two boiler drums of the same tonnage operate more stably than shell-and-tube boilers with a single boiler drum, and they also have higher efficiency.

It seems that your boiler has a rated evaporation capacity of only 10 tons, and the required output is also 10 tons; the steam pressure is already close to the rated value. To meet these requirements, it is necessary to increase the furnace temperature. However, too high a furnace temperature can cause significant damage to the boiler’s heating surfaces. For long-term operation, it is necessary to add another small boiler. Or use the previous 12-15 ton boiler, with this one serving as a backup boiler.

Firstly, using a boiler with a capacity of 10T for a gas consumption rate of 10T/h is unsafe; due to the varying quality of the fuel, the output often fails to reach the rated value, and the combustion efficiency is low. As a result, problems frequently occur with the chain mechanism of the boiler during long-term operation.

It can be used, as long as any faults are promptly resolved; once it is operating smoothly, it will meet the requirements. Besides, the boiler has a 10% capacity surplus! As long as you get it tuned properly, there should be no problems! This post was last edited by wy2652 on 2009-3-5 12:50]

It should work, I guess. After all, you have boilers with a capacity of 10 tons and a pressure of 1.25 MPa, yet you are using them to produce steam at 10 tons and 1.0 MPa, thus reducing the pressure. If even this cannot be achieved, then there is a problem with their boiler design.

I agree with the view above, but considering the actual conditions of boilers in China, they may not necessarily meet your requirements; the issue of actual loss rates must also be taken into account.

Your company’s production process. 10 T/h of steam is required; the previous 10T boiler did not leave any margin, so it is likely unable to meet the production needs. A long-term, continuous and stable supply to ensure production seems unlikely; after all, it’s mechanical equipment, and mechanical failures are bound to occur during operation.

I personally think it’s not possible; production requires 10 t/h, and the boiler’s rated gas supply capacity is also 10 t/h. It will be difficult even to achieve 10 t/h with an experienced boiler operator!

I work in boiler design, and even if your company uses a new model of boiler, it’s not possible for it to achieve an output of 10 t/h, let alone operate on a long-term basis! If it is a SZL series boiler, it can also operate under overload for a short period of time! Suggestion: To add a boiler with a capacity of 6–10 tons, it is best to choose a steam boiler from the SZL series! One can use it while keeping another as a backup; it requires minimal investment yet ensures long-term operation!

To be clear, it cannot run for a long time. First, a 10t/h boiler generally cannot produce 10t/h of steam, as the coal does not meet the standards required by the boiler manufacturer. Second, it is also difficult to achieve manual coal feeding.

It’s feasible for short-term operation at full load, but stability under long-term operation is insufficient; generally, a certain margin is left. It is recommended to use a 12-ton boiler

Then why can’t the rated value of the manufacturer be used for long-term operation? What’s the point of labeling it this way if it can’t run for a long time?

I think it should work as well. Its rated capacity is 10 tons, which is just right; the error in actual operation won’t be too large. The amount of steam generated is sufficient, and the pressure of 1.25 is not high either. If it were to be 12 tons, wouldn’t the pressure increase? Would that be appropriate? Moreover, is it too costly and necessary to install a boiler with an additional 6 tons of capacity?

No, operating at full capacity for a long time carries a high risk level...... Proper selection is very important