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 : 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 : Heat sensitive materials can be concentrated in an evaporator employing (A) Vacuum (B) High pressure (C) High residence time (D) None of these
Last Answer : (A) Vacuum
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 : 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 : . A dilute aqueous solution is to be concentrated in an evaporator system. High pressure steam is available. Multiple effect evaporator system is employed, because (A) Total heat transfer area of ... in a single effect is much lower than that in any effect in a multi-effect system
Last Answer : (B) Total amount of vapor produced per Kg of feed steam in a multiple effect system is much higher than in a single effect
Description : Vacuum is generally maintained in the vapour space of an evaporator mainly to (A) Get economical temperature difference by using moderate pressure steam (B) Facilitate forward ... (C) Concentrate heat sensitive materials (D) Achieve very high concentration of the final product
Last Answer : (A) Get economical temperature difference by using moderate pressure steam
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 : 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 : 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 : 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 : The advantage of backward feed multiple effect evaporators over forward feed units is that (A) Heat sensitive material can be handled (B) There is no additional cost of pumping ... liquid is at highest temperature (D) Equal heat transfer co-efficients exist in various effects
Last Answer : (C) Most concentrated liquid is at highest temperature
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 : Steam is routed through the tube in case of a __________ evaporator. (A) Basket type (B) Horizontal tube (C) Short tube vertical (D) Long tube vertica
Last Answer : (B) Horizontal tube
Description : A __________ evaporator employs an annular downtake. (A) Basket type (B) Horizontal (C) Long tube vertical (D) None of these
Last Answer : (A) Basket type
Description : In case of vertical tube evaporator, with increase in liquor level, the overall heat transfer co-efficient (A) Increases (B) Decreases (C) Is not affected (D) May increase or decrease; depends on the feed
Last Answer : (B) Decreases
Description : Pick out the wrong statement. (A) Economy of a multiple effect evaporator is not influenced by the boiling point elevation (B) Two identical cubes of iron and copper will have the same heat ... in the field of refrigeration (D) Finned tube heat exchangers are suitable for heating air by steam
Last Answer : (B) Two identical cubes of iron and copper will have the same heat content under the same conditions of temperature
Description : Agitated film evaporator is suitable for concentrating __________ liquids. (A) Foaming (B) Viscous (C) Very thin (D) Corrosive
Last Answer : (B) Viscous
Description : When the mixture to be distilled has a very high boiling point and the product material is heat sensitive, the separation technique to be used is __________ distillation. (A) Continuous (B) Steam (C) Azeotropic (D) None of these
Last Answer : (B) Steam
Description : Intermittent tube cleaning is possible to be done in case of a __________ evaporator. (A) Basket type (B) Horizontal tube (C) Calandria (D) None of these
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 : 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 : Black liquor generated during paper manufacture is concentrated in a (A) Single effect evaporator (B) Single effect evaporator followed by a crystalliser (C) Multiple effect evaporator (D) Multiple effect evaporators followed by a crystalliser
Last Answer : (C) Multiple effect evaporator
Description : Tubes of multiple effect evaporator used for concentration of sugar cane juice are made of (A) Nickel (B) Copper (C) Stainless steel (D) Brass
Last Answer : (B) Copper
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 : Fresh orange juice contains 12% (by weight) solids and the rest water 90% of the fresh juice is sent to an evaporator to remove water and subsequently mixed with the remaining 10% of fresh juice. The resultant product contains 40% solids. ... from 1 kg fresh juice is (A) 0.4 (B) 0.5 (C) 0.6 (D) 0.7
Last Answer : (D) 0.7
Description : Pick out the wrong statement. (A) Superheated steam is preferably not used for process heating because of its low heat transfer film co-efficient (B) In a shell and tube heat exchanger ... surface heat exchangers, when the direction of fluid flow is parallel to the axis of the tube
Last Answer : (C) S.I. unit of fouling factor is Watt/m2 .°K
Description : Pick out the wrong statement. (A) The controlling resistance in case of heating of air by condensing steam is in the air film (B) The log mean temperature difference (LMTD) for ... a pure fluid at a given pressure from liquid to vapor or vice-versa occurs at saturation temperature
Last Answer : (C) In case of a 1 - 2 shell and tube heat exchanger, the LMTD correction factor value increases sharply, when a temperature cross occurs
Description : __________ is the controlling step in a highly temperature sensitive fluid-solid non-catalytic reaction. (A) Gas film diffusion (B) Ash diffusion (C) Chemical reaction (D) None of these
Last Answer : (C) Chemical reaction
Description : Steam side heat transfer co-efficient in an evaporator is in the range of __________ kcal/hr.m2°C. (A) 10-50 (B) 100-500 (C) 1000-1500 (D) 5000-15000
Last Answer : (D) 5000-15000
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
Description : Dowtherm is a (A) High temperature heating medium (a petroleum product) (B) Product of coal tar distillation (C) Very heat sensitive material (D) None of these
Last Answer : Option A
Description : In case of a vertical tube evaporator, with increase in the liquor level, the (A) Capacity of the evaporator is decreased (B) Capacity of the evaporator is increased (C) True temperature drop increases (D) Both (B) and (C)
Last Answer : (A) Capacity of the evaporator is decreased
Description : Tubes are held between top and bottom tube sheets in Calandria type evaporator by keeping (A) Both the tube sheets fixed (B) Both the tube sheets floating (C) The top tube sheet floating and bottom tube sheet fixed (D) The top tube sheet fixed and the bottom tube-sheet floating
Last Answer : (A) Both the tube sheets fixed
Description : Very high pressure boilers are usually __________ boilers. (A) Fire tube (B) Water tube (C) Waste heat (D) Natural circulation
Last Answer : (D) Natural circulation
Description : Water-ethyl alcohol solution can be concentrated (in respect of alcohol concentration) by __________ distillation. (A) Atmospheric (B) Vacuum (C) High pressure (D) None of these
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 : Molecular distillation is (A) High temperature distillation (B) For heat-sensitive materials (C) Very low pressure distillation (D) Both (B) and (C)
Last Answer : (D) Both (B) and (C)
Description : High pressure at the bottom of a distillation tower handling heat sensitive materials results in (A) Thermal decomposition of bottoms (B) Increased relative volatility (C) Erosion of the tower (D) Very efficient operation
Last Answer : (A) Thermal decomposition of bottoms
Description : Bulk of the convective heat transfer resistance from a hot tube surfaceto the fluid flowing in it, is (A) In the central core of the fluid (B) Uniformly distributed throughout the fluid (C) Mainly confined to a thin film of fluid near the surface (D) None of these
Last Answer : (C) Mainly confined to a thin film of fluid near the surface
Description : Wrought iron is a suitable material of construction for handling __________ solutions (A) Dilute acidic (B) Concentrated acidic (C) Alkalis & alkaline (D) None of these
Last Answer : (C) Alkalis & alkaline
Description : Wrought iron is a suitable material of construction for handling __________ solutions. (A) Dilute acidic (B) Concentrated acidic (C) Alkalis & alkaline (D) None of these
Description : Air can be cooled and dehumidified by A. circulating chilled water in tube across air flow B. placing evaporator coil across air flow C. spraying chilled water to air D. all of the mentioned
Last Answer : ANSWER : D
Description : What type of steam is generated by evaporator tube of Lamont boiler ? a. Saturated steam b. Unsaturated steam c. Superheated steam d. Flash steam
Last Answer : a. Saturated steam
Description : Write construction and disadvantages of short tube evaporator.
Last Answer : Construction: It consists of number of tubes which are from 1 to 2 meters in length and from 40- 80 mm in diameter. About 1000 tubes are fitted in a vessel upto 2.5 meter or ... It is quite complicated and expensive in construction. 2. Difficult to clean. 3. Maintenance is costly.
Description : In a multipass shell and tube heat exchanger, tube side return pressure loss is equal to __________ the velocity head. (A) Twice (B) Four times (C) Square root of (D) Square of
Last Answer : (B) Four times
Description : Pick out the wrong statement. (A) Wine, rum & Vodka are prepared by the formulation of fruit juice, sugar beet & rye respectively (B) Protein catalysts are called enzymes (C) The rate ... concentration of reactants at high concentration of enzymes (D) Total sugar content in molasses is about 10%
Last Answer : (D) Total sugar content in molasses is about 10%
Description : . In a backward feed multiple effect evaporator (A) Feed is introduced in the first effect (B) Feed flows from low pressure to high pressure (C) No pumps are required between successive effects (D) None of these
Last Answer : (B) Feed flows from low pressure to high pressure
Description : Heat sensitive materials like certain pharmaceuticals and food stuffs can be dried in a/an __________ dryer. (A) Indirect tray (B) Spray (C) Freeze (D) None of these
Last Answer : (C) Freeze