What is downdraft gasifier?

The downdraft gasifiers or cocurrent gasifiers are the most common type of gasifiers. In cocurrent gasifiers, biomass feedstock is fed from the top while air is passed downwards and producer gas leaves from the bottom of the gasifier. A clean mixture of combustible gases in the exit stream is obtained.

What is the meaning of entrainment?

1 : to draw along with or after oneself. 2 : to draw in and transport (something, such as solid particles or gas) by the flow of a fluid. 3 : to incorporate (air bubbles) into concrete. 4 : to determine or modify the phase or period of circadian rhythms entrained by a light cycle.

What is used in entrained gasifier?

In entrained-flow gasifiers, fine coal feed and the oxidant (air or oxygen) and/or steam are fed co-currently to the gasifier. The gasification reactions occur at a very high rate (typical residence time is on the order of few seconds), with high carbon conversion efficiencies (98-99.5%).

What is the purpose of downdraft gasifier?

A downdraft gasifier is the typical configuration used for bioenergy production. This well-established technology allows the production of syngas with low tar, due to the syngas passes through the combustion zone at high temperature and the subsequent dimensioning which in turn leads to the thermal cracking of tars.

Which of the following best indicates the process in a dual fluidized bed gasifier?

Which of the following best indicates the process in a dual fluidized bed gasifier? Explanation: The first bed in a dual fluidized bed gasifier is used for pyrolysis. The second bed is used for combustion. The second reactor provides heat by burning char provided from the first reactor.

Which is the best definition of the word entrain?

1 : to draw along with or after oneself. 2 : to draw in and transport (something, such as solid particles or gas) by the flow of a fluid. 3 : to incorporate (air bubbles) into concrete. 4 : to determine or modify the phase or period of circadian rhythms entrained by a light cycle.

What is the use of fluid or air entrainment?

Fluid or Air Entrainment. Bernoulli’s Priniciple or Effect has practical applications in the field of respiratory care in that it allows us to deliver precise oxygen concentration levels with simple devices by mixing oxygen with entrained room air.

What do you mean by entrainment in hydrodynamics?

Entrainment is the transport of fluid across an interface between two bodies of fluid by a shear induced turbulent flux.

How is water entrained in the airflow?

A spray of water droplets from the splash becomes entrained in the airflow. The formula gives a rough estimate of the amount of water that could have been entrained by this fireball. Millions of tons of this entrained water sinks, circulating back down to the south along the sea bottom.