MCQ’s Sand Reclamation & Control Test
Q. Thermal systems can be sufficient for reclamation of chemically bonded sands.
A. True
B. False
.
.Answer: A
Explanation: Process Chemically bonded sand uses binders to form rigid moulds by the application of heat. Reclamation of sand can be done by thermal, mechanical or wet scrubbing processes. But, thermal systems alone are sufficient for the reclamation of sands. Most of the thermal systems used are gas fired, however electrically fired thermal systems are also used widely.
Q. High degree of cleanliness can be achieved by the dry reclamation systems in reclaiming the sand.
A. True
B. False
.
.Answer: B
Explanation: Process Dry reclamation system uses the mechanical scrubbing principle to separate the clay and the organic coatings. They can be utilized with all general types of sand. However, it is not possible to achieve the degree of cleanliness by the dry reclamation systems as compared to the other types of reclamation systems.
Q. The wet reclamation systems are eco-friendly and widely used for reclaiming the sand particles.
A. True
B. False
.
.Answer: B
Explanation: Process The wet reclamation system uses wet scrubbing action to reclaim the sand. This method is quite effective in cleaning, but the cost of maintenance is very high and water discharge creates many problems which are unpleasant to the environment. These considerations have restricted their use in reclaiming the sands.
Q. Burning of organic binders can be possible in thermal reclamation systems for reclaiming the sand.
A. True
B. False
.
.Answer: A
Explanation: Process Thermal reclamation system provides heat to the sand and high temperature is achieved which is enough to burn the organic binders. These systems can be gas fired or electrically operated for the reclaiming of sand. Thermal systems are specifically suitable for organically bonded sands, but the higher temperature gas fired systems can also be utilized for the clay bonded sands.
Q. Sand reclamation is defined for repeatedly using new sand for the making of moulds in production of castings.
A. True
B. False
.
.Answer: B
Explanation: Process Sand reclamation is a physical and chemical treatment of used foundry sands so that they can be reused in making of cores and moulds for the production of casting components. The true reclamation cleans each and every single grain within the sand, whereas reconditioning is defined for the partial cleaning and treating of sand mass.
Q. After reclamation of sand, reclaimed sand should be dry at an acceptable temperature.
A. True
B. False
.
.Answer: A
Explanation: Process Proper reclamation includes many objectives like the reclaimed sand should be dry at an acceptable temperature. It should be bonded and must have moulding and core making sand properties same as that of the new sand. And the reclaimed sand should produce casting parts of good quality same to those produced by the new sand.
Q. Reclamation may improve the casting quality, but does not affect the economic expenditure.
A. True
B. False
.
.Answer: B
Explanation: Process For the increasing cost of new sand and limited availability of high quality sand sources, reclamation is very important and necessary from the economic point of view. It reduces the cost involved in making of moulds and cores by keeping the quality equal to that produced by the new sand. Reclamation makes the processes economical and environmental friendly.
Q. Thermal reclamation system removes the organic as well as the inorganic binders associated with the sand.
A. True
B. False
.
.Answer: B
Explanation: Process Thermal reclamation systems burn away and remove all the organic binders from the sand, but it does not remove the inorganic binders associated with the sand mass, which are generally fused with the sand grains. Thermal reclamation units can be either electrically operated or gas fired, depending on the degree of reclamation and convenience.
Q. In the dry reclamation system, a strong metal plate is used on which used sand is blasted to get converted into fine powder.
A. True
B. False
.
.Answer: A
Explanation: Process Dry reclamation process crushes the sand lumps into grain size, and then the binders are removed from the sand grains by the use of mechanical abrasion. Released fines particles are separated and then dry sand is prepared by crushing the sand to the metal plate by blasting which removes all the metal particles and the resulting fines are taken to a dust collector.
Q. A vigorous scrubbing action takes place in the method of wet reclamation of sand.
A. True
B. False
.
.Answer: A
Explanation: Process In wet reclamation, a scrubbing action takes place in water to dissolve binders from the sand mass. Loose clay gets suspended in the water and scrubbing action removes the clay coatings from the sand grains. Wet reclamation treats clay bonded sands very efficiently and the reclaimed sand mass is almost equal in quality and purity to new sand.
Q. In the tech thermal sand reclamation system, how many fluidized beds are used?
A. One
B. Two
C. Three
D. Four
.
.Answer: B
Explanation: Process In the tem tech thermal reclamation system, a fluidized bed plays an important role in the sand reclamation system. There are in total two fluidized beds that are used.
Q. In the tem tech thermal sand reclamation system, the recirculating air ensures what?
A. Even pressure drop
B. Even temperature drop
C. Even volume drop
D. Even loss of mass
.
.Answer: A
Explanation: Process In tem tech thermal sand reclamation system, the recirculating air ensures an even pressure drop at all its orifices.
Q. What is the heat source of fluidized bed in tem tech thermal sand reclamation system?
A. Flame heating
B. Ultraviolet heating
C. Infrared heating
D. Conduction heating
.
.Answer: C
Explanation: In tem tech thermal sand reclamation system, overall there are two beds involved in it and in them, shortwave infrared emitters are used in the beds.
Q. In tem tech thermal sand reclamation system, in the infrared heating system, which material is used in the beds?
A. Copper
B. Iron
C. Silver
D. Tungsten
.
..Answer: D
Explanation: In tem tech thermal sand reclamation system, in the heating process by shortwave infrared emitters, tungsten elements are used.
Q. What is the maximum working temperature in a fluidized bed in tem tech thermal sand reclamation system?
A. 1000°C
B. 2000°C
C. 3000°C
D. 4000°C
.
.Answer: B
Explanation: Proces In tem tech working system, there are two fluidized beds involved. The maximum working temperature in a fluidized bed in a tem tech thermal sand reclamation system is 2000°C.
Q. The infrared radiation passes through what before entering into the fluidized bed?
A. Prism
B. Concave lens
C. Quartz
D. Convex lens
.
.Answer: C
Explanation: In the tem tech thermal sand reclamation system, the infrared radiation passes through a quartz sleeve before entering the fluidized bed.
Q. Up to what accuracy can the temperature of the bed be controlled in tem tech thermal sand reclamation system?
A. ± 1%
B. ± 2%
C. ± 3%
D. ± 4%
.
.Answer: B
Explanation: The temperature of the bed can be controlled to an accuracy of ± 2%, in tem tech thermal sand reclamation system. These fluidized beds essentially need a very accurate temperature control.
Q. In tem tech thermal sand reclamation system, what is the maximum current temperature?
A. 600°C
B. 700°C
C. 800°C
D. 900°C
.
.Answer: C
Explanation: In tem tech thermal sand reclamation system, a high amount of temperature has to be maintained. The maximum current temperature is 800°C.
Q. In tem tech thermal sand reclamation system, how much is the energy conversion efficiency?
A. 75%
B. 80%
C. 85%
D. 90%
.
.Answer: C
Explanation: In tem tech thermal sand reclamation system, it is observed that the energy that is used gets reused and by other methods, the efficiency is taken up to great heights. There is a high energy conversion efficiency of 85%.
Q. One of the goal of tem tech thermal sand reclamation system, is to lower fluidization.
A. True
B. False
.
.Answer: A
Explanation: Process One of the very important goals of tem tech thermal sand reclamation system, is to lower the fluidization, to lower emissions to atmosphere.
Q. With an increase in volume of air passed, what change is seen in the permeable number?
A. Increases
B. Decreases
C. No change occurs
D. No relation among the two
.
.Answer: A
Explanation: Process With an increase in the volume of air passed, there is an increase in the permeable number, since the two have a direct relation.
Q. With an increase in height of the specimen, what change is seen in the permeable number?
A. Increases
B. Decreases
C. No change occurs
D. No relation among the two
.
.Answer: A
Explanation: Process With an increase in the height of the specimen, there is an increase in the permeable number, since the two have a direct relation.
Q. With an increase in volume of air passed, what change is seen in the air pressure measurement?
A. Increases
B. Decreases
C. No change occurs
D. No relation among the two
.
.Answer: A
Explanation: Process None.
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Q. With an increase in the height of the specimen, what change is seen in the air pressure measurement?
A. Increases
B. Decreases
C. No change occurs
D. No relation among the two
.
.Answer: A
Explanation: Process None.
Q. With an increase in area of the specimen, what change is seen in the permeability number?
A. Increases
B. Decreases
C. No change occurs
D. No relation among the two
.
.Answer: B
Explanation: Process With an increase in the area of the specimen, there is a decrease in the permeability number, since the two have an inverse relation.
Q. With an increase in air pressure measurement of the specimen, what change is seen in the permeability number?
A. Increases
B. Decreases
C. No change occurs
D. No relation between the two
.
.Answer: B
Explanation: Process With an increase in the air pressure measurement of the specimen, there is a decrease in the permeability number, since the two have an inverse relation.
Q. With an increase in air pressure measurement of the specimen, what change is seen in the air pressure measurement?
A. Increases
B. Decreases
C. No change occurs
D. No relation between the two
.
.Answer: B
Explanation: Process None.
Q. For baking standard core sand, the specimen needs to be heated at what temperature?
A. 800°F
B. 900°F
C. 1000°F
D. 1100°F
.
.Answer: C
Explanation: Process The core sand has to be baked first and brought to a comparatively high temperature. For baking standard core sand, the specimen needs to be heated at about 1000°F and above it.
Q. For how long is a specimen heated in a standard core above 1000°F?
A. 8-10 minutes
B. 10-12 minutes
C. 12-14 minutes
D. 14-16 minutes
.
.Answer: B
Explanation: Process The core sand has to be baked first and brought to a comparatively high temperature. A standard core sand bake has to be heated above 1000°F for about 10 to 12 minutes.
Q. Core hardness test includes testing of only baked cores.
A. True
B. False
.
.Answer: B
Explanation: Process In the core hardness test, the hardness of both green cores as well as the baked cores are taken into consideration.
