Q. Statement 1: In a rising film evaporator, the feed can be very viscous.
Statement 2: In a rising film evaporator, the feed cannot be heat sensitive.

View solution

Q. In a rising film evaporator, the temperature difference need not be as high as that in a falling film evaporator.

View solution

Q. Plate evaporators are used in recovering aroma from fruit juices.

View solution

Q. Statement 1: Scraped surface evaporators are used in the dairy industry.
Statement 2: Plate evaporators can be used for viscous liquids.

View solution

Q. Industry A is low on budget and is used in the sugar industry. Industry B wants to invest in a good evaporator. They are needed for meat extracts. Which evaporators will you suggest for each of them?

View solution

Q. A major reason as to why evaporators and their selection for different applications in the food industry is very important is because ______

View solution

Q. Desolventization which is done in certain evaporators is more similar to distillation than evaporation.

View solution

Q. In flashing of jams, the temperature of concentrated jam _____ on flashing. Also, the vapor pressure of the concentrated jam _____

View solution

Q. In plate evaporator, the heat transfer coefficient is high in spite of low residence time because _____

View solution

Q. Shifting of a pair of ripened apples from the store house to the vegetable cart is called mass transfer.

View solution

Q. Statement 1: When alcohol is allowed to move from chamber A to chamber B when a barrier between them is removed, it is called multi phase diffusion.
Statement 2: When oxygen is made to diffuse into the water, it’s called continuous molecular diffusion.

View solution

Q. Velocity gradient is the main driving force in mass transfer.

View solution

Q. Statement 1: A phase boundary exists between alcohol and oxygen.
Statement 2: Phase boundary varies with agitation. It is inversely proportional to the amount of agitation provided.

View solution

Q. A phase boundary between alcohol and water exists.

View solution

Q. Statement 1: Diffusion is faster than convective mass transfer.
Statement 2: Mass transfer is proportional to the area of contact.

View solution

Q. Statement 1: Resistance is inversely proportional to the inter-facial area.
Statement 2: The inter-facial area of a body is the area of the dispersed phase in a unit volume of the vessel.

View solution

Q. Ratio of equilibrium concentrations of solute A in liquid phase and gas phase i.e. CAL* and CAg* respectively is α. α is called _____

View solution

Q. Statement 1: Diffusion of gas component through the resistive film to the bulk of the liquid is the rate determining step.
Statement 2: Diffusion of gas component through the gas-liquid inter-phase is the rate determining step.

View solution

Q. In a packaging of dry grapes, the packaging material is made of polyethylene. The dry grapes have certain moisture content. Which of the following is true with respect to the diffusion of certain amount of moisture through the packing?

View solution

Q. Statement 1: Concentration is a product of diffusivity and solubility.
Statement 2: Permeability coefficient in case of food packaging can be written as product of partial pressure and solubility using Henry’s law.

View solution