Description : The suitable evaporator for concentration of foaming liquids is a __________ evaporator. (A) Long tube (B) Short tube (C) Vacuum (D) Falling film
Last Answer : (A) Long tube
Description : Viscous & heat sensitive liquids are concentrated in __________ evaporators. (A) Open pan (B) Long tube (C) Agitated film (D) None of these
Last Answer : (C) Agitated film
Description : Forced circulation evaporators are useful for the concentration of viscous, salting and scale forming liquors. Which of the following is a forced circulation evaporator? (A) Long vertical evaporator (B) Horizontal tube evaporator (C) Agitated film evaporator (D) Calandria vertical tube evaporator
Last Answer : (C) Agitated film evaporator
Description : Which is the most suitable for the concert-ration of highly concentrated solution? (A) Open pan evaporation (B) Long tube vertical evaporator (C) Agitated film evaporator (D) None of these
Last Answer : (A) Open pan evaporation
Description : Which is the most suitable for the concentration of foamy & frothy liquors? (A) Agitated film evaporator (B) Long tube vertical evaporator (C) Open pan evaporator (D) None of these
Last Answer : (B) Long tube vertical evaporator
Description : Highly viscous liquids & pastes are agitated by (A) Propellers (B) Turbine agitators (C) Multiple blade paddles (D) None of these
Last Answer : (C) Multiple blade paddles
Description : For concentrating an aqueous solution of a material like anhydrous Na2SO4, whose solubility decreases with rise in temperature, the most suitable evaporator is a __________ evaporator. (A) High pressure (B) Vacuum (C) Backward feed (D) None of these
Last Answer : (B) Vacuum
Description : Leidenfrost point is a term concerned with the (A) Condensation of the saturated vapor on a cold surface (B) Concentration of a corrosive solution by evaporation (C) Heat transfer between two highly viscous liquids (D) Boiling of a liquid on a hot surface
Last Answer : (D) Boiling of a liquid on a hot surface
Description : Which of the following is used for the concentration of rubber latex? (A) Agitated film evaporator (B) Long tube vertical evaporator (C) Short tube evaporator (D) Calandria
Last Answer : (A) Agitated film evaporator
Description : Explain with reason through which side of shell and tube heat exchanges, the following liquids are directed. (i) viscous liquid (ii) high pressure liquid (iii) corrosive liquid
Last Answer : Viscous liquid : Viscous liquid is passed through shell side Reason: because of the presence of baffles in the shell induce turbulence and hence increases heat transfer rate. High pressure liquid: High ... To avoid expensive alloy shells (in order to save the cost of expensive material for shell).
Description : Which of the following is the most suitable material of construction for evaporator & its tubes for concentrating NaOH solution to 70%? (A) Cast iron (B) Steel (C) Nickel (D) Karbate
Last Answer : (C) Nickel
Description : In case of evaporators, liquid entrainment results primarily due to (A) High vacuum in the evaporator (B) High evaporation rate (C) Foaming of the solution (D) High heat transfer rate
Last Answer : (C) Foaming of the solution
Description : Diaphragm valves are used for handling __________ fluids. (A) Corrosive (B) Viscous (C) Non-Newtonian (D) Solid suspended
Last Answer : (A) Corrosive
Description : Evaporator used for concentrating tomato juice is made of (A) Nickel (B) Brass (C) Stainless steel-glass lined (D) Cast iron-rubber lined
Last Answer : (C) Stainless steel-glass lined
Description : A backward feed multiple effect evaporator is better than forward feed for concentrating cold feed, because it provides (A) Higher economy (B) Lower capacity (C) Both (A) & (B) (D) Lower economy
Last Answer : (A) Higher economy
Description : . An evaporator while concentrating an aqueous solution from 10 to 40% solids evaporates 30000 kg of water. The amount of solids handled by the system in kg is (A) 4000 (B) 9000 (C) 4600 (D) 3000
Last Answer : (A) 4000
Description : A multiple effect evaporator has a capacity to process 4000 kg of solid caustic soda per day, when it is concentrating from 10% to 25% solids. The water evaporated in kg per day is (A) 6000 (B) 24000 (C) 60000 (D) 48000
Last Answer : (B) 24000
Description : In industrial operations fluids with temperature less than __________ are set as the limit for waste heat recovery because of the risk of condensation of corrosive liquids a. 80C b. 100C c. 120C d. 200C
Last Answer : 100C
Description : Pick out the wrong statement: (A) The capacity of an evaporator is reduced by the boiling point elevation (B) Corrosive liquid is normally passed through the tubes in a ... recompression evaporator (D) Heat sensitive materials should be concentrated in high pressure evaporators
Last Answer : (D) Heat sensitive materials should be concentrated in high pressure evaporators
Description : Helical screw agitator is used for (A) Mixing highly viscous pastes (B) Blending immiscible liquids (C) Mixing liquids at very high temperature (> 250 °C) (D) None of these
Last Answer : (A) Mixing highly viscous pastes
Description : Open pan evaporators are preferred to be used, when the solution to be concentrated is (A) Scaling (B) Highly viscous (C) Corrosive (D) Salty
Last Answer : (B) Highly viscous
Description : Forced circulation evaporators are normally used for concentrating liquids having (A) Scaling characteristics (B) High viscosity (C) Both (A) & (B) (D) Neither (A) nor (B)
Last Answer : (C) Both (A) & (B)
Description : Condensing film co-efficient for steam on horizontal tubes ranges from 5000 to 15000 Kcal/hr.m2 .°C. Condensation of vapor is carried out inside the tube in a shell and tube heat ... drop through the exchanger is desired (D) Temperature of the incoming vapor is very high
Last Answer : (B) Supersaturated
Description : Which of the following is not used as a filter medium in case of corrosive liquids? (A) Nylon (B) Glass cloth (C) Metal cloth of monel or stainless steel (D) Cotton fabric
Last Answer : (D) Cotton fabric
Description : Pick out the wrong statement. (A) Packed towers are preferred for vacuum operation, because the pressure drop through the packing is less and they (packings) also lessen the ... of liquid, problem of channelling, loading & flooding is generally encountered in packed towers
Last Answer : (C) Diameter of randomly packed tower is normally more than 1.2 metres
Description : The equipment used in the extraction of highly corrosive radioactive liquids is (A) Pulse column (B) Spray column (C) Mixer settler (D) Baffle tower
Last Answer : (A) Pulse column
Description : Multiple effect evaporation is generally recommended, when the (A) Large scale evaporation of liquor is needed (B) Corrosive liquids are to be concentrated
Last Answer : (A) Large scale evaporation of liquor is needed
Description : For evaporation of viscous solution in a multiple effect evaporator, the preferred feeding scheme is (A) Forward (B) Backward (C) Parallel (D) None of these
Last Answer : (B) Backward
Description : In case of a vertical tube evaporator, with increase in the liquor level, the __________ is increased. (A) Velocity of circulation (B) Liquor-film co-efficient (C) Both (A) and (B) (D) Neither (A) and (B)
Last Answer : (D) Neither (A) and (B)
Description : Fruit juice (a heat sensitive material) can be concentrated in a __________ evaporator. (A) Long tube (B) Falling film (C) High pressure (D) None of these
Last Answer : (B) Falling film
Description : Explain the type of multiple effect evaporator feed arrangement used for handling viscous liquid.
Last Answer : Backward feed arrangement If the liquid is very viscous, then we have to adopt backward feed arrangement. In this arrangement, the feed solution and vapour flow is in opposite direction. Fresh feed is ... Not very common as it need pump. At low values of feed temperature higher economy.
Description : Petrolatum is (A) Same as petroleum ether (B) Petroleum coke (C) A mixture of microcrystalline wax in viscous hydrocarbon liquids (D) None of these
Last Answer : (C) A mixture of microcrystalline wax in viscous hydrocarbon liquids
Description : Which of the following forced convection heat transfer equation accounts for the liquid viscosity effect for viscous liquids? (A) Dittus-Boelter equation (B) Sieder-Tate equation (C) Nusselt equation (D) None of these
Last Answer : (B) Sieder-Tate equation
Description : Pick out the wrong statement. (A) A fluid mass is free from shearing forces, when it is made to rotate with a uniform velocit (B) Newton's law of viscosity is not applicable to the ... types of bearings (D) Rise of water in capillary tubes reduces with the increasing diameter of capillary tubes
Last Answer : (B) Newton's law of viscosity is not applicable to the turbulent flow of fluid with linear velocity distribution
Description : In a gas-liquid shell and tube heat exchanger, the (A) Presence of a non-condensable gas decreases the condensing film coefficient (B) Gases under high pressure are routed through the tube side, because high pressure ... water or steam condensate remain localised to the tubes (D) All 'a', 'b' & 'c'
Last Answer : (D) All 'a', 'b' & 'c'
Description : Plate efficiency in a distillation column is reduced due to the __________ of liquid. (A) Entrainment (B) Foaming (C) Weeping & dumping (D) All (A), (B) & (C)
Last Answer : (D) All (A), (B) & (C)
Description : Foaming and priming in boiler operation can be reduced by reduction in __________ in feed water. (A) Turbidity (B) Color (Hazen) (C) Total solids (D) All (A), (B) & (C)
Description : Vacuum filter is most suitable for the (A) Removal of fines from liquid (B) Liquids having high vapour pressure (C) Liquids of very high viscosity (D) None of these
Last Answer : (D) None of these
Description : Paddle agitator (A) Is suitable for mixing low viscosity liquids (B) Produces axial flow (C) Moves at very high speed (D) None of these
Last Answer : (A) Is suitable for mixing low viscosity liquids
Description : Economy of a multiple effect evaporator is not influenced much by the (A) Boiling point elevations (B) Temperature of the feed (C) Rate of heat transfer (D) Ratio of the weight of the thin liquor to thick liquor
Last Answer : (A) Boiling point elevations
Description : Even though heat transfer co-efficient in boiling liquids is large, use of fins is advantageous, when the entire surface is exposed to __________ boiling. (A) Film (B) Nucleate (C) Transition (D) All modes of
Last Answer : Option A
Description : Which of the following is the most suitable filter for separation ofabrasive solids suspended in a corrosive liquid? (A) Sand bed filter (B) Plate and frame filter press (C) Vacuum filter (D) Batch basket centrifuge
Last Answer : (C) Vacuum filter
Description : Liquids that evaporate quickly are known as _________ liquids. A. Viscous B. Transient C. Volatile D. Light
Last Answer : ANSWER: C
Description : Which of the following liquids is most viscous? (1) Oil (2) Milk (3) Water (4) petrol
Last Answer : (1) Oil Explanation: Informally, viscosity is the quantity that describes a fluid's resistance to flow. It is dependent on temperature. Viscosity of the different fluids (in cP) is as follows: Edible Oil: 20 to 60; Milk: approximately 1.0; Water: 0.894; and Petrol: around 0.82 to 0.95 cP.
Description : The Euler's equation for the motion of liquids is based upon the assumption that (A) The fluid is non - viscous, homogeneous and incompressible (B) The velocity of flow is uniform over the section (C) The flow is continuous, steady and along the stream line (D) All of the above
Last Answer : Answer: Option D
Description : Which of the following liquids is most viscous? (1) Oil (2) Milk (3) Water (4) Petrol
Last Answer : Oil
Description : Hydrogenation of oil is carried out in a/an __________ in Vanaspati manufacturing plant. (A) Agitated vessel (B) Sieve tray column (C) Bubble cap column (D) Packed tower
Last Answer : (A) Agitated vessel
Description : Ribbon blenders are exclusively meant for (A) Blending miscible liquids (B) Non-flowing powder and thin pastes (C) Bath mixing (D) Continuous mixing
Last Answer : (B) Non-flowing powder and thin pastes
Description : Increasing the liquor level in the evaporator results in the (A) Decreased capacity (B) Increase in liquor film co-efficient (C) Decreased effect of hydrostatic head (D) Increased true temperature drop
Last Answer : (A) Decreased capacity