Concentration of black liquor in recovery boilers
Application of viscosity measurement in black liquor concentration
Recovery processes can be optimized by burning highly concentrated solids in the recovery boiler. Viscosity control is imperative to stabilize the concentration of black liquor before entering the recovery boiler.
An unstable black liquor concentration generates waste, over consumption, increased energy supply costs, smoke emissions; and frequent maintenance operations resulting in downtime that lowers overall plant productivity.
By installing an in-line process viscometer – MIVI sensor – after the evaporator or concentrator, the black liquor solids can be regulated. The black liquor dry extract will follow the operating cycle if it is within the optimum combustion parameters; or will return to the evaporation column if it is not.
Our MIVI viscometer does not drift over time and can be mounted in any position specifically designed for each process to avoid clogging. The viscosity range of the sensor can be adapted to different black liquor compositions.
Optimization of recovery boilers by viscosity control indicates a reduction of 3 to 20% in the frequency of water washings. Installation of the MIVI process viscometer accurately controls the concentration level of black liquor and standardizes its supply for efficient combustion. Studies have shown that regular monitoring of black liquor viscosity as part of an overall optimization process can save some plants more than $1 million per year.