Study of flow characteristics of biomass and biomass–coal blends

Gravity discharge characteristics of biomass-coal blends in a hopper

Effect of moisture content on dense-phase pneumatic conveying of pulverized lignite under high pressure

Experimental investigation of pressure letdown flow characteristics in dense-phase pneumatic conveying at high pressure

The flowability properties of two carbonaceous powers (anthracite coal and petroleum coke), including angle of repose (AOR), Hausner ratio (HR) and powder compressibility (C), etc., were determined. The effects of particle size, external moisture content (MC) and power type on powder flowability properties were investigated. The results indicate that as the powder particle size increases, the AOR, HR and C decrease, respectively, and the powder flowability becomes better. As the powder external MC increases, the AOR, HR and C increase, respectively, and the powder flowability becomes worse. The anthracite coal has lower values of AOR, HR and C, and higher values of flow function (FF) than those values of petroleum coke. Therefore, anthracite coal has better flowability compared to petroleum coke. Meanwhile, there exists a good linear correlation between AOR and HR.

Experimental investigation on the flowability properties of cohesive carbonaceous powders

Influences of fluidizing velocity, flow regime, and fracture on conveying characteristics of biomass and coal were investigated at 4.0 MPa. Results indicated that mass flow rate of biomass decreased while mass flow rate of pulverized coal increased at first and then decreased with the increase in fluidizing velocity. Solid loading ratios decreased with the increase in fluidizing velocity. In the state diagram, pressure drops for biomass increased while pressure drops for pulverized coal decreased at first and then increased with the increase in conveying velocity. Start-up conveying velocity and fracture characteristics of biomass and coal were discussed and analyzed.

Comparison on Flow Characteristics of Dense-phase Pneumatic Conveying of Biomass Powder and Pulverized coal at High Pressure

Effect of Blow Tank Type and Powder Properties on Dense Phase Pneumatic Conveying Characteristics of Two Fuel Powders at High Pressure

With the aim of reducing carbon content in fly ash, fly ash recirculation with bottom feeding (FARBF) technology was applied to a 75 t/h Circulating Fluidized Bed (CFB) boiler burning mixture of coal and coal sludge. And industrial experiments were carried out to investigate the influence of FARBF technology on the combustion performance and pollutant emission characteristics of the CFB boiler. Results show that as the recirculation rate of fly ash increases, the CFB dense bed temperature decreases while the furnace outlet temperature increases, and the temperature distribution in the furnace becomes uniform. Compared with the conditions without fly ash recirculation, the combustion efficiency increases from 92 to 95% when the recirculation rate increases to 8 t/h, and the desulfurization efficiency also increases significantly. As the recirculation rate increases, the emissions of NO and CO decrease, but the particulate emission increases. The present study indicates that FARBF technology can improve the combustion performance and desulfurization efficiency for the CFB boilers burning coal sludge, and this can bring large economical and environmental benefits in China.

Experimental on Fly Ash Recirculation with Bottom Feeding to Improve the Performance of a Circulating Fluidized Bed Boiler Co-burning Coal Sludge

The effects of fluidizing gas flow rate, pressurizing gas flow rate and superficial gas velocity at the riser inlet on the pneumatic conveying characteristics such as pulverized coal mass flow rate, differential pressure, solid-gas ratio, and voidage were investigated in a top discharge blow tank pneumatic conveying system at atmospheric pressure The results indicate that as the fluidizing gas flow rate increases, the pulverized coal mass flow rate, differential pressure and solid-gas ratio increase at first and then decline, respectively As the pressurizing gas flow rate increases, the pulverized coal mass flow rate and differential pressure increase gradually, while the solid-gas ratio increases at first and then declines As the superficial gas velocity at the riser inlet increases, the pulverized coal mass flow rate and differential pressure increase gradually, while the solid-gas ratio increases at first and then declines The voidage of all the experiments is below 095, so the top discharge blow tank system can achieve dense phase conveying

Guiling Xu

Papers

Comparison on Flow Characteristics of Dense-phase Pneumatic Conveying of Biomass Powder and Pulverized coal at High Pressure

Effect of Blow Tank Type and Powder Properties on Dense Phase Pneumatic Conveying Characteristics of Two Fuel Powders at High Pressure

Experimental on Fly Ash Recirculation with Bottom Feeding to Improve the Performance of a Circulating Fluidized Bed Boiler Co-burning Coal Sludge

Study on Pneumatic Conveying Characteristics of Top Discharge Blow Tank of Pulverized Coal