On Line Pf-Flow Measurement MECONTROL Coal determines the absolute coal mass flow in burner pipes and the distribution of pulverised fuels from the coal mill to the burners. The density and transport velocity of the coal is independently measured within each measurement cycle. The concentration and velocity measurement are performed by a pair
The effect of a coal mill classifier speed was measured online in a 660 MWe plant. • The coal particle fineness and the coal flow distribution were monitored. • The amount of particles <75 µm varied between 66 and 74%. • The maximum coal flow deviation was reduced from 14% to 9%.
3.2. Coal Mass Flow Distribution Figure 6 shows the mass flow distribution for the four PC pipes at two different elevations from mill 20 and mill 40 respectively. The figures indicate that there is a significant mal-distribution of coal mass flow in the PC pipes, which corresponds to
Velocity of air/coal mixture in (a) mill 20 and (b) mill 40 3.2. Coal Mass Flow Distribution Figure 6 shows the mass flow distribution for the four PC pipes at two different elevations from mill 20 and mill 40 respectively. The figures indicate that there is a significant mal-distribution of coal mass flow
The coal is carried in each fuel pipe by 11.5 to 17 kg/s of air flow. The desired distribution is that fuel is evenly split among all the pipes, namely 25% of the total coal in each mill pipe, and half of that amount in each of the 8 burner pipes. It is found that at low fuel loads, the distribution deviates significantly from the desired one
Modeling and Control of Coal Mill P Pradeebha, N Pappa, D Vasanthi Department of Instrumentation Engineering, Madras Institute of Technology, Anna University, India. Email: prade [email protected],[email protected],[email protected] Abstract: The stone presents development and validation of coal mill model (including the action of
This is all controlled by the coal mill or pulveriser, and its associated feeder equipment. Operation of the coal mill can affect the ramp rate of the power station and its ability to handle rapid changes in output. For coal-fired power plants, the response time of the coal mills is critical for the overall reaction time to changing demand.
Coal Mill Dirty Air Flow Test. Balancing Coal Pipes Power Engineering, In a typical coal mill primary air pa is used to both dry the coal and transport it to the burners measuring dirty air flow or the air in a coal pipe laden with coal is of no real use in Coal Mill Dirty Air Flow Test
mill at coal-fired power plant in Malaysia. Coal flow distribution were sampled from the vertical straight PC pipes just after the pulverizer by using Dirty air pitot (DAP) and Pulverized Fuel Sampler (PFS) to measure the flow velocity and extract coal samples . To ensure isokinetic sampling, the sampling gas velocity is maintained at the same level as the gas velocity in the PC pipe. The
Dynamic effects of a varying mill classifier speed. For the first time the effect of a varying centrifugal classifier speed on coal particle size distribution and coal flow distribution between burners was monitored online in a large scale utility boiler.
on coal flow distribution. Their finding concludes that the coal flow distribution towards the boiler was significantly improved when the particle size was the smallest. They also managed to find that the maximum deviation from the average flow rate was reduced from 14% at 73 rpm to 9% at 99 rpm .
(reduction in coal particle sizing), fuel balance improves. The finer the coal, the more the two- phase mixture (coal and air) behaves like a fluid than a solid in suspension. • The more homogenous mixture of air and coal results in more even distribution between the separate burner lines. •
Problems maintaining the proper distribution of fuel to the burners related primarily to the boilers where the coal and biomass co-grinding is used. Changing the load of coal-mills and fuel type at the same time (i.e., different types of biomass) could result in less effective