Agitated thin film evaporators are typically used for fluids which are difficult to handle due to higher sensitivity and viscosity. Such an evaporator consists of tow key components: a jacketed shell and a rotor which rotates at high speed inside the shell. The feed is inserted into the mechanism at the top.
What is the main advantage of agitated film evaporator?
Advantages of an agitated thin-film evaporator are: Short residence time in the heated zone, measured in seconds to minutes. High heat-transfer coefficients due to the turbulence imparted by the rotor. Plug flow with minimum back-mixing.
What are the types of evaporator?
Evaporators may be classified into falling film evaporators (in which evaporation takes place from the film interface with no nucleate boiling at the wall), nucleate boiling evaporators (in which wall nucleate boiling occurs over part or all of the heat transfer surface), flash evaporators and direct contact …
What is the role of the rotor in agitated thin film evaporator?
The rotor blades spread the feed evenly on the heated surface into a thin film and further agitate the film. Heating medium passing through the jacket evaporates the volatile component in feed.
Where does the agitation take place in an agitated film evaporator?
Where does the agitation take place in an agitated film evaporator? Explanation: The agitation is carried out on the total length of the evaporator and not at parts, hence the option of agitation on the film is correct and others are incorrect (at the upper end as fluid enters rest is turbulent). 10.
How many main types of evaporator are there?
Evaporator Types. The two general types of evaporators used in today’s refrigeration systems are flooded evaporators and dry, or direct expansion (DX), evaporators.
What are evaporators used for?
Evaporators are commonly used to concentrate foods by using heat to evaporate water from the food. As the liquid is concentrated, its boiling point is elevated. Using low pressure, boiling of liquid foods (such as juices) is carried out at low temperatures and the heat labile food attributes are preserved.
What is principle of evaporator?
Evaporation is a process, which is used to separate the solid substance which is dissolved in liquid. The principle of the evaporation process is that liquid vaporizes easily, whereas solids do not. 3 (7)
What is forced circulation evaporator?
The forced circulation evaporator comprises a heat exchanger, a separator and a circulation pump. The product is sent to the exchanger where it is heated and then sent to the separator. After evaporation, the liquid portion is pumped again to be resent to the exchanger.
How does evaporator work?
The evaporator works the opposite of the condenser, here refrigerant liquid is converted to gas, absorbing heat from the air in the compartment. This causes the refrigerant to absorb heat from the warm air and reach its low boiling point rapidly. The refrigerant then vaporizes, absorbing the maximum amount of heat.
What is Agitated thin film evaporator (ATFE)?
The Agitated Thin film evaporator (ATFE) consists of two major assemblies – jacketed shell and a rotor assembly which rotates at high speed inside the shell. The feed enters evaporator at top, tangential to shell and gets distributed along the shell by the distributor.
What is the difference between flooded and falling film evaporators?
Falling film evaporators have a number of advantages over their flooded evaporator counterparts. They require a lower charge, as the entire shell (in the case of horizontal evaporators) or all the tubes (in the case of a vertical evaporator) need not be filled with liquid as a thin film is now used to cover the surfaces.
What is a high viscosity evaporator?
“ Our high viscosity units can handle products with viscosities of several million centipoise! ” An Agitated Thin Film Evaporator (ATFE), also known as Thin Film Evaporator (TFE) or Wiped Film Evaporator (WFE), consists of a jacketed shell precision machined from inside and a rotor having blades that maintain a close clearance from the shell.
How does evaporation take place in a tube?
In general evaporation takes place inside vertical tubes, but there are also applications where the process fluid evaporates on the outside of horizontal or vertical tubes. In all cases, the process fluid to be evaporated flows downwards by gravity as a continuous film.
