LAMBDA DOSER/HI-DOSER – An excellent feeder to feed coal into reactors.

Syngas is a versatile renewable fuel. It contains mainly hydrogen and carbon monoxide. The processed syngas is converted to various essential fuels like diesel, methane, methanol, etc. It is also used to power turbines that produce electricity and has many more uses.

Syngas is produced through the autothermal gasification of carbonaceous materials like coal. The gasification through the conventional autothermal method requires the combustion of coal, which emits a massive amount of greenhouse gases like CO2. To overcome this problem, researchers from the North China Electric Power University, Beijing in collaboration with the Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing improved the conventional combined drop-tube and fixed-bed reactors (CDFR) for the steam gasification of coal, powered by the high flux solar simulator. The advantage of solar-driven gasification is that it doesn’t require biomass combustion to produce heat for the gasification process, so it limits CO2 emission.

In this lab-scale reactor, scientists tightly fixed the feeder - LAMBDA HI-DOSER- at the top of the reactor port to dose coal regularly. The coal dispensing from the powder feeder is controlled by a program done in C++ language. The entire reactor is purged with N2 gas through the gassing port of the HI-DOSER glass vessel to remove the presence of air. 

Also, researchers point out in their publication that the coal particles were excellently fed to the reactor. The continuously fed coal does not agglomerate into large particles, which provides outstanding stability for the overall gasification process and production of syngas.

DOI: https://doi.org/10.1016/j.enconman.2022.115571Tianle Dai, Cheng Xu, Qingmin Zhang, Xin Liu, Zheshao Chang, Yongping Yang. Experimental study of the solar-driven steam gasification of coal in an improved updraft combined drop-tube and fixed-bed reactor. Energy Conversion and Management, Volume 259, 2022, 115571,ISSN 0196-8904.

The advantage of LAMBDA feeder is that the motor of the driving unit is controlled with quartz-driven electronics, similarly, as it is done in electronic watches. The powder distributor is of an open spiral type (not a screw type as is sometimes used in other systems and can lead to the compacting and blocking of the dosing screw). This spiral takes the powder and pushes it to the centre where it falls out of the dosing unit.

The LAMBDA DOSER/HI-DOSER is not only for reactors, it can also be used in laminar hoods, for the dispensing of almost any powder in portions. The time-consuming conventional manual dispensing can now be quickly and simply replaced by the powder pump. The LAMBDA feeder can be connected to a weighing balance to dispense powders in portion of set weight. 

The dosing rates of the powder DOSER and HI-DOSER can be selected over a large range (3 decades), e.g., dosing range of NaCl in DOSER: 50 mg/min to 50 g/min and of HI-DOSER, the dosing rates range from 60 mg/min to 60 g/min (slow mode) and 250 mg/min to 250 g/min (fast mode), at our laboratory conditions. The feeder can also be supplied with special parts where the dispensation rate can be as low as 10mg/min. 

DOSER and HI-DOSER can get delivered with the 0.2 L, 1 L, 3 L or 6 L vessels, which can also be coated with a protective film for enhanced safety during operation and handling. 

Additional information about the LAMBDA powder feeder DOSER and HI-DOSER can be found at: www.lambda-instruments.com/powder-doser/. If you have questions or need a quotation of the DOSER/HI-DOSER powder feeder, please contact us at: sales@lambda-instruments.com