Concentration Profiles and Solids Transport above Stationary Deposit in Enclosed Conduit

Concentration profiles and overall flow parameters were measured in a 0.37-mm-sand-mixture flow above a plane stationary deposit in a pressurized circular pipe of the inner diameter of 150 mm. The new data and additional data from the literature are used to propose a tentative transport formula of the Meyer-Peter and Müller type, and a slip-ratio formula, for flows at high shear stress in enclosed conduits.     

Potential direct use of solid biomass in internal combustion engines

The direct use of dry biomass dust as a fuel in reciprocating engines could be of great interest because of the large availability of plant matter and the versatility of Internal Combustion Engines (ICE). Coal dust was used in the past and mostly in slurries because of large production during industrial era in Europe but led to many problems caused by fuel handling and wear in ICE. In comparison, biomass has a CO₂ neutral impact, and is almost ash and sulphur free. Biomass pulverization technologies are now mature and the raw material can be reduced to micronic size or even smaller. Among the various new and renewable fuels under research and development, solid raw biomass is certainly the most promising advanced biofuel. It requires no or little thermochemical or biological processing or upgrading and potentially does not generate waste, detrimental to the environment. After a general overview of the past attempts to run reciprocating engines with coal dust, this paper will assess the so far unconsidered use of dry biomass dust as a fuel in engines instead of abrasive, less volatile and more polluting coal dust.     

消泡剂和消泡机理

本文详细综述了泡沫的形成条件及构成泡沫稳定存在的因素:液膜弹性、表面粘度、溶液粘度、电双层斥力和熵双层斥力、气泡间气体的扩散;从消泡剂的进入系数和铺展系数以及憎水颗粒的去润湿作用,论述了消泡机理;讨论了构成消泡剂的功能性组份。