Performance

 

The Performance parameter screen allows you to configure the performance of the fabric filter system.

The baghouse system is very efficient in removing particulate matter from the flue gas. Its model design is simple, requiring few parameters to characterize its effects on the overall performance of the plant. For properly designed fabric filters, the size of the system is independent of the removal efficiency.

Although the performance is determined by very few parameters, there are several design parameters necessary to determine the cost. These factors are also determined in this section. The major design parameters that can significantly impact the total system cost of the fabric filter are gas flow volume (which depends on the generating unit size), A/C ratio, the flange-to- flange pressure drop in the baghouse and the bag life.

The following parameters are available:

•Particulate Removal Efficiency: The calculated removal is set to comply with the particulate emission limit set earlier. The mass removed is then determined. If you select a spray dryer, the particulate removal efficiency applies to the combined mass of flyash and sulfur-laden wastes. This input is highlighted in blue.

•Actual SO3 Removal Efficiency: The default value is taken from the removal efficiency reported in the literature (references are below). This efficiency then determines the mass of SO3 removed from the flue gas in the collector. For more information see also:

•Hardman, R; Stacy, R; Dismukes, E "Estimating Sulfuric Acid Aerosol Emissions from Coal-Fired Power Plants", US DoE-FETC Conference on Formation, Distribution, Impact and Fate of Sulfur Trioxide in Utility Flue Gas Streams 1998 (currently available at https://web.archive.org/web/20040307161115/http://www.netl.doe.gov/publications/proceedings/98/98fg/hardman.pdf )

•Rubin, E. S. "The Importance of Sulfur Trioxide for the Toxic Release Inventory", US DoE-FETC Conference on Formation, Distribution, Impact and Fate of Sulfur Trioxide in Utility Flue Gas Streams 1998 (currently available at https://web.archive.org/web/20030416143712/http://www.netl.doe.gov:80/publications/proceedings/98/98fg/rubin.pdf)

•Solids Loading Out: This is the fabric filter output loading. It is an average value based on typical fabric filter units. The value is used to determine the particulate removal efficiency.

•Number of Baghouse Units: This is the number of baghouse units. The value is based on the gross plant size. The value must be an integer. Each unit contains several compartments. It is used to calculate the capital cost of the baghouse.

•Number of Compartments per Unit: This parameter specifies the average number of compartments used per baghouse unit. It is used to calculate the capital cost of the baghouse.

•Number of Bags per Compartment: The number of individual bags per compartment is calculated by comparing the required bag surface area to the bag dimensions and the total number of compartments. It is used to calculate the capital cost of the baghouse.

•Bag Length: Bag length generally falls into two size categories: 30-36 ft or 20 -22 ft in length. It is based on the fabric filter type and used to calculate the capital cost of the baghouse.

•Bag Diameter: Bags are generally between 2/3 and 1 foot in diameter. The value is based on the fabric filter type and used to calculate the capital cost of the baghouse.

•Bag Life: Bag life is typically between 3-5 years. The bag life values are dependent on the fabric filter type and are used to calculate the cost of the baghouse.

•Air to Cloth Ratio: The Air to Cloth ratio is the most important baghouse parameter. It is the ratio of volumetric flue gas flow rate and total bag cloth area. The calculated value is a function of fabric filter type. It is used to determine the cost and power use of the baghouse.

•Total Pressure Drop across Fabric Filter: Baghouse pressure drop (flange-to- flange) is caused by pressure losses in gas flow as it moves through the bag fabric and dust cake. Typical values range from 6 to 8 in. H2O and depend on the baghouse type selected. The value affects the power consumption.

•Percent Water in Fabric Filter Discharge: This is the water content of the collected fly ash. Fly ash disposed with bottom ash is assumed to be sluiced with water and dry otherwise. The occluded water in wet fly ash is difficult to remove, resulting in a rather high water content when the fly ash is mixed with bottom ash.

•Fabric Filter Power Requirement: The default calculation is based on the air-to- cloth ratio and the flue gas flow rate. The power accounts for the auxiliary power requirements and electro-mechanical efficiencies of fan motors.

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