Bissoy
Login
Get Advice on Live Video Call
Earn $ Cash $ with
consultations on Bissoy App
A 0.5 m high bed made up of a 1 mm dia glass sphere (density 2500 kg/m<sup>3</sup>) is to be fluidised by water (density 1000 kg/m<sup>3</sup>). If at the point of incipient fluidisation, the bed voidage is 40%, the pressure drop across the bed is
A
4.4 KPa
B
2.94 KPa
C
3.7 KPa
D
None of these
Correct Answer:
4.4 KPa
Study the following information and answer the questions. Point A is 8m to the west of Point B. Point C is 4m to the south of Point B. Point D is 4m to the east of Point C. Point F is 6m to the north of Point D. Point E is 8m to the west of Point F. Point G is 2m to the south of Point E. How far and in which direction is Point G from Point A?
A
4m to the east
B
8m to the west
C
4m to the west
D
8m to the east
Study the following information and answer the questions. Point A is 8m to the west of Point B. Point C is 4m to the south of Point B. Point D is 4m to the east of Point C. Point F is 6m to the north of Point D. Point E is 8m to the west of Point F. Point G is 2m to the south of Point E. If point G is 4m to the north of Point H, then what is the distance between H and D?
A
11m
B
8m
C
6m
D
4m
Bed pressure drop in an air fluidised bed of catalyst particles (ρ
p
= 200 kg/m
3
, D
p
= 0.05 cm) of 60 cm bed depth and bed porosity of 0.5 expressed in cm of water (manometer) is
A
90
B
60
C
45
D
30
After fluidisation, the pressure drop in the fluid phase across the bed is _______ to the bed weight over unit surface of the bed cross section.
A
Equal
B
Slightly more
C
Much greater
D
Less
The pressure drop in fluidised bed on fluidisation __________ with increasing flow rate.
A
Remains same
B
Linearly increases
C
Linearly decreases
D
Remains zero
What is the correct expression for pressure drop in a fluidised bed at fluidisation?
A
ΔP=(1-∈)(ρP-ρg)gHB
B
ΔP=(∈)(ρP-ρg)gHB
C
ΔP=(1-∈)(ρP-ρg)gHC
D
ΔP=(1-∈)(ρP)gHB
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 (in SI units) is given below:
Δ P/L = 375 × 10
3
V
OM
+ 10.94 × 10
6
V
2
OM
(SI units)
If water is to be used as the fluidising medium, in actual operation, the above bed has a height = 1 m. What is the porosity of the fluidised bed?
A
0.2
B
0.5
C
0.7
D
0.8
In a Fluidised Bed Heat Exchanger with hot gas flow, at fluidisation the temperature of the bed is ________
A
Linearly Increasing
B
Uniform
C
Linearly Decreasing
D
Decreasing but not Linear
Consider the following statements.
1. Glass wool has tensile strength greater than steel.
2. Glass wool is fire proof.
3. Glass wool has high electrical conductivity and absorbs moisture.
4. Glass wool is used to prepare libre glass.
Which of the statements given above are correct?
A
1, 2, 3 and 4
B
1, 2 and 3
C
1, 2 and 4
D
3 and 4
Heat is being transferred by convection from water at 48 degree Celsius to glass plate whose surface is exposed to water at 40 degree Celsius. The thermal conductivity of water is 0.6 W/m K and the thermal conductivity of glass is 1.2 W/m K. The spectral gradient of temperature in the water at the water glass interface is 10 -4 K/m. The heat transfer coefficient in W/m2 K is
A
0.0
B
750
C
6.0
D
4.8