Emerging Trends in Mechanical Engineering

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2.3 Hyperbolic Cooling towers

1   The pollutants that are present depend on __________ building material, as well.
    (A)   Cooling tower
    (B)   Water tower
    (C)   Steam tower
    (D)   Fire tower

2   The presence of these pollutants can cause a series of problems. The main problems that are caused______
    (A)   are fouling,
    (B)   limestone formation,
    (C)   Corrosion and biological
    (D)   All of the above

3   Most cooling towers are capacity rated at a “standard” wet bulb temperature of ___of
    (A)   72°F
    (B)   52°F
    (C)   78°F
    (D)   75°F

4   When sizing a cooling tower the highest anticipate__________ should be used?
    (A)   Dry bulb
    (B)   Wet bulb
    (C)   Both dry and wet bulb
    (D)   None of the above

5   In ________ cooling tower there is no direct contact between the water and Air.
    (A)   Dry type
    (B)   Evaporative type
    (C)   Once through
    (D)   All of the above

6   in cooling tower, higher temperature __________ corrosion potential
    (A)   Decrease
    (B)   Increase
    (C)   Temperature has no effect on corrosion

7   Which of the following faction affect the cooling tower performance?
    (A)   The range
    (B)   Heat load
    (C)   Wet bulb temperature
    (D)   All of the above

8   In which system is Cooling of hot water is done on tray as step by?
    (A)   Mechanical draught cooling system
    (B)   Hyperbolic cooling tower
    (C)   Atmospheric cooling tower
    (D)   Wet cooling tower

9   How does the flow of air occur in natural draught cooling towers?
    (A)   Natural pressure head density between cold outside air and humid inside air
    (B)   Variation in pressure of both cold outside air and humid inside air
    (C)   Due to the given air vents and vacuum ports
    (D)   Because of difference in the volume of both the of airs

10   The first hyperboloid shaped cooling tower was introduced by the Dutch engineers Frederik van Iterson and Gerard Kuypers and built in ………..
    (A)   1918
    (B)   1919
    (C)   1870
    (D)   1920

11   Hyperbolic cooling towers are made up of high height reinforced ………structure.
    (A)   plastic
    (B)   metal
    (C)   alloy
    (D)   concrete

12   The hyperbolic cooling towers are associated with ……. and …….. power plants.
    (A)   electrical, thermal
    (B)   Nuclear, electrical
    (C)   Thermal, nuclear
    (D)   None of above

13   Wind is the prime lateral load and its combination with self-weight of the tower shell can cause the buckling instability leading to …………….failure.
    (A)   Polytrophic
    (B)   Catastrophic
    (C)   Both a) & b)
    (D)   None of above

14   Cooling efficiency of a cooling tower is significantly affected under cross-wind condition and might decrease to……… in the range of moderate to high wind velocity condition.
    (A)   50%
    (B)   25%
    (C)   75%
    (D)   90%

15   The ……….-induced response of cooling tower is the key factor to improve safety and to reduce tower crack.
    (A)   Wind
    (B)   Heat
    (C)   Water
    (D)   Steam

16   Wind load analysis can be performed following methods.
    (A)   Experiments wind pressure coefficient
    (B)   Shape factors
    (C)   wind-induced vibration coefficient
    (D)   All of above

17   The ………..used to improve the stability of the total structure HCT.
    (A)   Concrete material
    (B)   Wind properties
    (C)   Stiffening rings
    (D)   Functional structure

18   For achieving maximum buckling stability use………….parameters.
    (A)   Location
    (B)   Quantity
    (C)   Dimensions
    (D)   All of above

19   Natural draft cooling towers are mainly used in the _____.
    (A)   Steel industry
    (B)   Fertilizer industry
    (C)   Alumina industry
    (D)   Power stations

20   A better indicator for cooling tower performance is _____.
    (A)   Wet bulb temperature
    (B)   Dry bulb temperature
    (C)   Range
    (D)   Approach

21   Cooling tower effectiveness is the ratio of _____.
    (A)   Range/ (range + approach)
    (B)   Approach/ (range + approach)
    (C)   Range/ Approach
    (D)   Approach/ Range

22   The cooling water reduces the water temperature close to _____.
    (A)   Dry bulb temperature
    (B)   Ambient wet bulb temperature
    (C)   Dew point temperature
    (D)   None of the above

23   The ratio of dissolved solids in circulating water to dissolved solids in makeup water is called.
    (A)   Liquid gas ratio
    (B)   Cycle of concentration
    (C)   Cooling tower effectiveness
    (D)   None of the above

24   Which one of the following is true to estimate the range of cooling tower?
    (A)   Range = Cooling water inlet temperature- wet bulb temperature
    (B)   Range = Cooling water outlet temperature- wet bulb temperature
    (C)   Range = heat load in kcal per hour / water circulation in liters per hour
    (D)   None of the above

25   Which one of the following fill material is more energy efficient for cooling towers in case of sea water cooling?
    (A)   Splash fill
    (B)   Film fill
    (C)   Low clog film fill
    (D)   None of the above

26   L/G ratio in a cooling tower is a ratio of _____.
    (A)   Length and girth
    (B)   Length and temperature gradient
    (C)   Water flow rate and air mass flow rate
    (D)   Air mass flow rate and water flow rate

27   Normally the guaranteed best approach a cooling tower can achieve is _____.
    (A)   5°C
    (B)   12°C
    (C)   8°C
    (D)   2.8°C

28   Hyperbolic cooling towers have become design standard for all natural draft towers because
    (A)   Their structural strength
    (B)   Minimum usage of material.
    (C)   Improving cooling efficiency
    (D)   All of the above

29   Common applications of cooling towers include
    (A)   Cooling the circulating water used in oil refineries
    (B)   petrochemical and other chemical plants
    (C)   thermal power stations
    (D)   All of the above

30   The hyperboloid cooling towers are often associated __
    (A)   with nuclear power plants
    (B)   Used in some coal-fired plants
    (C)   In some large chemical and other industrial plants.
    (D)   All of the above

31   ______ type of cooling towers is structurally strong.
    (A)   Counter flow towers
    (B)   Hyperbolic towers
    (C)   Cross flow towers
    (D)   None of the above

32   Which type of cooling towers operates through a chimney or stack ___?
    (A)   Cross flow
    (B)   Counter flow
    (C)   Hyperbolic
    (D)   All of above

33   Hyperbolic cooling towers are also referred as
    (A)   Natural draft towers
    (B)   Cross flow towers
    (C)   Hyperboloid towers
    (D)   None of the above

34   _____ type of cooling towers is used with nuclear power plants.
    (A)   Cross flow
    (B)   Natural draft
    (C)   Hyperbolic
    (D)   None of above

35   Improved cooling efficiency and minimum usage of material are the key features of ______
    (A)   Natural draft cooling towers
    (B)   Cross flow towers
    (C)   Hyperbolic cooling
    (D)   All of above

36   The first hyperbolic cooling tower was built in…
    (A)   1916
    (B)   1917
    (C)   1918
    (D)   1919

37   Thermal efficiencies up to……..have been observed in hybrid cooling towers
    (A)   92
    (B)   82
    (C)   72
    (D)   62

38   Which of the following is the simplest method of cooling the condenser water?
    (A)   Spray cooling pond
    (B)   Cooling tower
    (C)   Indirect air cooling
    (D)   Hyperbolic cooling tower

39   Natural Draft or Hyperbolic towers have been used for
    (A)   Large Capacity of water
    (B)   Small Capacity of Water
    (C)   High Efficiency
    (D)   Low capital cost

40   Why is exhaust steam coming out of turbine is admitted to a steam header?
    (A)   To increase the pressure
    (B)   To decrease the velocity
    (C)   To decrease the pressure drop
    (D)   To control the pollution

41   How is air produced in mechanical draught cooling tower?
    (A)   Air Tuyeres
    (B)   Propeller fans
    (C)   Air blowers
    (D)   Louvre

42   Why is induced draught considered better than the forced draught?
    (A)   Because power requirement is high for forced draught
    (B)   Maintenance of induced draught fan is costlier
    (C)   Forced draught is less efficient
    (D)   Forced draught produces less amount of speed of air

43   Natural draft cooling tower are mainly used in
    (A)   Steel Industry
    (B)   Alumina industry
    (C)   Fertilizer industry
    (D)   Power station

44   Cooling tower effectiveness is the ratio of
    (A)   Range/ (Range + approach)
    (B)   Approach/ (range + approach)
    (C)   Range / (range – approach)
    (D)   Approach/ / (range – approach)

45   Which one of the following is true to estimate the range of cooling tower?
    (A)   Range = cooling water inlet temperature – wet bulb temperature
    (B)   Range = cooling water outlet temperature – wet bulb temperature
    (C)   Range = heat load in kcal per hour / water circulation in lines per hour
    (D)   None of the above

46   The ratio of dissolved solids in circulating water to the dissolved solids in makeup water is called
    (A)   Liquid gas ratio
    (B)   Cycle of concentration
    (C)   Cooling tower effectiveness
    (D)   None of the above

47   Cooling tower is a ______device
    (A)   Heat absorption
    (B)   Heat rejection
    (C)   Both a and b
    (D)   Neither a nor b

48   In natural draft cooling tower the air flow is obtained by___________
    (A)   Difference in air pressure
    (B)   Difference in air temperature
    (C)   Difference in air speed
    (D)   None of the above

49   In the natural draft cooling tower_________ is not required
    (A)   Fan
    (B)   Tower
    (C)   Nozzle
    (D)   None of the above

50   Which among the following are the components of natural draft cooling tower?
    (A)   Supply basin
    (B)   Reinforced concrete
    (C)   Hot water distribution
    (D)   None of the above

51   Water lost in form of liquid droplet is called as ______________
    (A)   Drift
    (B)   Water loss
    (C)   Water evaporation
    (D)   None of the above

52   The effect that takes place which results in cooling action is
    (A)   Condensing
    (B)   Heating
    (C)   Cooling
    (D)   Evaporating

53   How many times year cooling water must be cleaned
    (A)   Once a year
    (B)   Thrice a year
    (C)   Twice a year
    (D)   Four times a year

54   How many times chlorination must be carried out for cooling towers
    (A)   Twice a year
    (B)   Once a year
    (C)   Thrice a year
    (D)   None of above

55   Cooling towers operate through a ____process that efficiently cools the already cycled water to be reused.
    (A)   Heat exchange
    (B)   Heat expand
    (C)   Heat transfer
    (D)   None of above

56   In hyperboloid cooling towers the material is filled at
    (A)   Tower’s bottom
    (B)   Tower’s top
    (C)   near tower
    (D)   None of above

57   Pollution caused by cooling tower includes
    (A)   Fouling
    (B)   Limestone formation
    (C)   Corrosion
    (D)   All of above

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