Recovery Boiler - Black Liquor Dry Solids

Black Liquor Dry Solids

As fired black liquor is a mixture of organics, inorganics and water. Typically the amount of water is expressed as mass ratio of dried black liquor to unit of black liquor before drying. This ratio is called the black liquor dry solids.

If the black liquor dry solids is below 20% or water content in black liquor is above 80% the net heating value of black liquor is negative. This means that all heat from combustion of organics in black liquor is spent evaporating the water it contains. The higher the dry solids, the less water the black liquor contains and the hotter the adiabatic combustion temperature.

Black liquor dry solids have always been limited by the ability of available evaporation. Virgin black liquor dry solids of recovery boilers is shown as a function of purchase year of that boiler.

When looking at the virgin black liquor dry solids we note that on average dry solids has increased. This is especially true for latest very large recovery boilers. Design dry solids for green field mills have been either 80 or 85% dry solids. 80% (or before that 75%) dry solids has been in use in Asia and South America. 85% (or before that 80%) has been in use in Scandinavia and Europe.

Read more about this topic:  Recovery Boiler

Famous quotes containing the words black, liquor and/or dry:

    The ornament is a statuette, a black figure of a bird. I am prepared to pay on behalf of the figure’s rightful owner the sum of $5000 for its recovery. I am prepared to promise, to promise ... what is the phrase?—’No questions will be asked.’
    John Huston (1906–1987)

    The liquor of summer nights
    Accumulates in the bottom of the bottle.
    John Ashbery (b. 1927)

    Waters above! Eternal springs!
    The dew that silvers the Dove’s wings!
    O welcome, welcome to the sad:
    Give dry dust drink, drink that makes glad!
    Many fair ev’nings, many flow’rs
    Sweetened with rich and gentle showers,
    Have I enjoyed,
    Henry Vaughan (1622–1695)