Channelling is most severe
(A) In towers packed with stacked packing
(B) In towers packed randomly with crushed solids
(C) In dumped packing of regular units
Description : Plate towers are preferred to packed towers, when large temperature changes are involved, because of the reason that the (A) Packing may be crushed due to thermal expansion/contraction of the ... C) Viscosity variation of the fluids may cause channelling/flooding (D) None of these
Last Answer : (A) Packing may be crushed due to thermal expansion/contraction of the components of the equipments
Description : In a moderately sized packed absorption tower, channelling (which is most severe with stacked packings) can be minimised by taking the ratio of tower diameter to packing diameter (A) > 4 :1 (B) < 8 : 1 (C) > 8:1 (D) < 6:1
Last Answer : (C) > 8:1
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 : Which of these columns incurs the lowest pressure drop? (A) Packed column (with stacked packing) (B) Packed column (with dumped packing) (C) Bubble plate column (D) Pulse column
Last Answer : (A) Packed column (with stacked packing)
Description : Stacked packing compared to dumped packing (A) Provides poorer contact between the fluids (B) Gives lower pressure drop (C) Both (A) and (B) (D) Gives higher pressure drop
Last Answer : (C) Both (A) and (B)
Description : Channelling in a packed tower results from the (A) High pressure drop (B) Maldistribution of liquid (C) Non-uniformity of packing (D) Both (B) and (C)
Last Answer : (D) Both (B) and (C)
Description : Very tall packed towers are divided into series of beds to (A) Reduce the overall pressure drop (B) Avoid channelling (C) Reduce liquid hold-up (D) Avoid flooding
Last Answer : (B) Avoid channelling
Description : The main reason for dividing a tall packed tower into series of small towers is to (A) Minimise the overall pressure drop (B) Avoid flooding (C) Reduce liquid hold up (D) Avoid channelling
Last Answer : (D) Avoid channelling
Description : Use of raschig rings in place of crushed stones as packing in packed beds (other things being same) (A) Increases pressure drop, increases surface area (B) Increases pressure drop, decreases ... (C) Decreases pressure drop, increases surface area (D) Decreases pressure drop, decreases surface area
Last Answer : (C) Decreases pressure drop, increases surface area
Description : In an absorption column, the flooding velocity for random packing is __________ that for stacked/regular packing. (A) Greater than (B) Smaller than (C) Equal to (D) Either (A), or (B); depends on the type of packing
Last Answer : (B) Smaller than
Description : In a packed bed absorption column, the channelling will be noted by the (A) Increase in flow rate (B) Sharp drop in pressure drop (C) Sharp rise in pressure drop (D) None of these
Last Answer : (B) Sharp drop in pressure drop
Description : For a packed bed reactor; the presence of a long tail in the residence time distribution curve is an indication of: (A) Ideal plug flow (B) Bypass (C) Dead zone (D) Channelling
Last Answer : (C) Dead zone
Description : Which of the following same diameter columns gives lowest pressure drop per unit height? (A) Bubble-cap column (B) Sieve-plate column (C) Packed column (stacked)
Last Answer : (C) Packed column (stacked)
Description : The optimum moisture content in solids to be crushed/ground ranges from __________ percent. (A) 3 to 4 (B) 8 to 10 (C) 10 to 15 (D) 15 to 20
Last Answer : (A) 3 to 4
Description : Pressure drop through plate tower as compared to that through packed tower, for the same duty will be (A) Less (B) More (C) Equal (D) Either (A) or (B); depends on the packing height
Last Answer : (B) More
Description : Out of the following, the lowest packing of atoms exists in __________ crystal lattice structure. (A) Hexagonal close, packed (hcp) (B) Face centred cubic (fcc) (C) Body centred cubic (bcc) (D) Simple cubic
Last Answer : (D) Simple cubic
Description : Which of the following liquid-vapor contacting devices provides maximum contact surface area for a particular duty? (A) Sieve plate column (B) Bubble cap column (C) Randomly packed column (D) Wetted wall column
Last Answer : (D) Wetted wall column
Description : With increase in the liquid flow rate at a fixed gas velocity in a randomly packed counter current gas-liquid absorption column, the gas pressure drop (A) Decreases (B) Remains unchanged (C) Increases (D) Decreases exponentially
Last Answer : (C) Increases
Description : Pick out the correct statement. (A) Fanning friction factor is inversely proportional to Reynolds number always (B) The property of a randomly packed bed (with raschig rings) is given by the ratio of the ... the ratio of the speed of the fluid to that of sound in the fluid under conditions of flow
Last Answer : (D) Mach number is given by the ratio of the speed of the fluid to that of sound in the fluid under conditions of flow
Description : Which of the following equipments is not used in liquid-liquid extraction? (A) Pachuka tank (B) Agitated vessels (C) Centrifugal extractors (D) Packed towers
Last Answer : (A) Pachuka tank
Description : Which of the following equipments is not used for liquid dispersion? (A) Wetted wall towers (B) Packed towers (C) Venturi scrubbers (D) Agitated vessels
Last Answer : (D) Agitated vessels
Description : Pick out the wrong statement. (A) With decrease in feed temperature, the number of plates required for binary distillation decreases for a given L/V' ratio (B) The extraction per unit ... and its crosssection is wider at the bottom (D) Vander wall adsorption is also called chemisorption
Last Answer : (D) Vander wall adsorption is also called chemisorption
Description : The reason for preferring packed towers over plate towers in distillation practice is that the packed tower operation gives (A) Low pressure drop and high hold up (B) High pressure drop and low hold ... C) Low pressure drop and low hold up (D) High pressure drop and high hold up
Last Answer : (C) Low pressure drop and low hold up
Description : Use of packed towers for distillation is generally limited to the (A) Small sizes (B) Multi-component distillation (C) High pressure operation (D) Vacuum distillation
Last Answer : (A) Small sizes
Description : Which one of the following devices is not used for both the absorption as well as the liquid-liquid extraction processes? (A) Packed towers (B) Plate towers (C) Spray towers (D) Wetted wall columns
Last Answer : (D) Wetted wall columns
Description : (1) they contain free electrons Explanation: Metals typically consist of closepacked atoms, meaning that the atoms are arranged like closely packed spheres. Two packing motifs are common, one ... surrounded by six neighboring atoms. Several metals adopt both structures, depending on the temperature.
Last Answer : Helium gas is filled in ballons because (1) its atomic number is 2 (2) it is lighter than air (3) it is one of the constitutents of water (4) it is a noble gas
Description : __________ column is the most suitable for achieving the best performance for mass transfer operations involving liquid with dispersed solids. (A) Wetted wall (B) Packed (C) Plate (D) Spray
Last Answer : C) Plate
Description : A packed tower compared to a plate tower for a particular mass transfer operation (A) Incurs smaller pressure drop (B) Allows installation of cooling coils (C) Is less costly when built in large sizes/diameters (D) Is more suitable, if suspended solids are present in fluid stream
Last Answer : (A) Incurs smaller pressure drop
Description : What are the benefits of a stacked washer and dryer over separate units?
Last Answer : A stacked washer-dryer unit save a lot of space. The unit is narrower than a conventional washing machine. By sitting the dryer on top of the washer, less floor space is needed, which is excellent for small spaces, like apartments and houses in which laundry space is at a premium.
Description : A bed of spherical particles (specific gravity 2.5) of uniform size 1500 μm is 0.5 m in diameter and 0.5 m high. In packed bed state, the porosity may be taken as 0.4. Ergun's equation for the above fluid-particle ... fluidisation velocity, VOM is (A) 12 mm/s (B) 16 mm/s (C) 24 mm/s (D) 28 mm/s
Last Answer : (B) 16 mm/s
Description : A bed of spherical particles (specific gravity 2.5) of uniform size 1500 μm is 0.5 m in diameter and 0.5 m high. In packed bed state, the porosity may be taken as 0.4. Ergun's equation for the above fluid-particle system ... What is the porosity of the fluidised bed? (A) 0.2 (B) 0.5 (C) 0.7 (D) 0.8
Last Answer : (C) 0.7
Description : The following are true about the cornea: a. the stroma contains collagen fibrils of regular thickness b. the Bowman's layer contains randomly arranged collagen fibrils c. the Bowman's layer is the ... layer of the epithelium d. type I collagen is the main type of collagen found in the cornea
Last Answer : type I collagen is the main type of collagen found in the cornea
Description : Randomly assigning treatment to experimental units allows: a. population inference b. causal inference c. both types of inference d. neither type of inference
Last Answer : b. causal inference
Description : A liquid substance _______. A. has particles packed tightly together B. has definite volume C. has definite shape D. has particles arranged in a regular pattern?
Last Answer : has definite volume
Description : The work index in Bond's law for crushing of solids has the following dimensions (A) No units (dimensionless) (B) kWh/ton (C) kW/ton (D) kWh.m1/2 /ton
Last Answer : (B) kWh/ton
Description : In patients receiving massive blood transfusion for acute blood loss, which of the following is/are correct? A. Packed red blood cells and crystalloid solution should be infused to restore oxygen ... should be administered with every 5 units of packed red blood cells to avoid hypocalcemia.
Last Answer : Answer: A DISCUSSION: Patients who are suffering from acute blood loss require crystalloid resuscitation as the initial maneuver to restore intravascular volume and re-establish vital signs. If 2 to 3 liters ... when the infusion of blood proceeds at a rate exceeding 1 to 2 units every 5 minutes
Description : Cooling towers vary in size from small roof-top units to very large hyperboloid structures that can be up to ____meters tall and _____ meters in diameter, or rectangular structures that can be over 40 meters tall and 80 meters long. a. 200&100 b. 100&50 c. 200&50 d. 200 &150
Last Answer : 200&100
Description : Cooling towers vary in size from small roof-top units to very large hyperboloid structures that can be up to ____ meters tall and _____ meters in diameter, or rectangular structures that can be over 40 meters tall and 80 meters long. a. 200&100 b. 100&50 c. 200&50 d. 200 &150
Last Answer : a. 200&100
Description : _______ cooling towers use a process similar to the one found in small evaporative cooling units. a. Hyperboloid b. Tower c. Condensate loop d. None
Last Answer : a. Hyperboloid
Description : Which cooling Towers use a process similar to the one found in small evaporation active cooling units a) hyperbolic b) Tower c) condensate loop d) none of these
Last Answer : a) hyperbolic
Description : Solids may be considered to be either crystalline noncrystalline. The basic difference between them is that a crystal, in contrast to a noncrystal: w) has a sharp melting point x) has an irregular array of atoms y) exhibits double refraction z) has a completely regular atomic or molecular structure
Last Answer : ANSWER: Z -- HAS A COMPLETELY REGULAR ATOMIC OR MOLECULAR STRUCTURE
Description : What structural units up network solids?
Last Answer : Nonmetal atom
Description : During sewage treatment, effluent from which one of the following treatment units has minimum wt/vol amount of suspended solids? (a) Detritus channel (b) Primary sedimentation tank (c) Secondary sedimentation tank (d) Activated sludge process aeration tank
Last Answer : (d) Activated sludge process aeration tank
Description : any suggestions on buying a washer/dryer set? stacked vs. side-by-side?
Last Answer : stacked may be smaller. The best is a front-loading washer. They use less fuel & water & clean better.
Description : how to create a stacked form with CSS and HTML ? -How To ?
Last Answer : answer:
Description : What is Two stacked numbers appearing after a clef sign?
Last Answer : It's called a "time signature." The top number indicates howmany beats per measure, and the bottom number specifies theduration of note that gets one beat.
Description : Does Lowe's sell the stacked washer and dryer combo I am moving to a tiny apartment and I want a new set, not used.?
Last Answer : Lowe's offers a stackable unit by Whirlpool for around $1300. The unit is available in white only, and features a 2.6 cubic foot washer and a 5.9 cubic foot gas dryer.
Description : How much room does a stacked weight machine take up?
Last Answer : 14 by 14 square foot will be plenty of space.
Description : Where can I get the best deal on a stacked washer and dryer online?
Last Answer : You can I get the best deal on a stacked washer and dryer online by going to either of the folllowing websites www.ebay.com or www.Amazon.com for low prices
Description : Where can I purchase stacked washer dryer online?
Last Answer : In order to get and properly stack a stacked washed dryer one must first get a traditional model of these original specimens and then analyze it and record.