Biochemical Engineering

Question: The filter material used for air filtration system is/are
[A].

glass wool

[B].

glass fibre

[C].

norite

[D].

all of the above

Answer: Option D

Explanation:

No answer description available for this question.

Question: The value of K
[A].

increases with increase in air velocity

[B].

decreases with increase in air velocity

[C].

increases to an optimum with increase in air velocity and decreases on further increase of air velocity

[D].

none of these

Answer: Option C

Explanation:

No answer description available for this question.

Question: The K used in the equation for X10=2.303/K depends upon
[A].

nature of the filter material

[B].

linear velocity of the air passing through filter

[C].

both (a) and (b)

[D].

thickness of the filter

Answer: Option C

Explanation:

No answer description available for this question.

Question: The radius of the filter with a depth of 14 cm required for a volumetric airflow rate of 10 m3/min is approximately
[A].

1.6 m

[B].

0.6 m

[C].

3

[D].

6 m

Answer: Option B

Explanation:

No answer description available for this question.

Question: The X90 value for a filtration system is
[A].

the time required to reduce microbial population by 90%

[B].

the time required to traverse survivor curve by one log cycle.

[C].

the depth required to reduce population by 90%

[D].

the depth of the filter required to reduce population by 99%

Answer: Option C

Explanation:

No answer description available for this question.

Question: The efficiency of fibrous filter by combined mechanism is given by(where ηimp,ηint,ηdif are the efficiencies by impaction, interception and diffusion respectively)
[A].

1 – ηimpηintηdif

[B].

1 – (1 – ηimp)(1 – ηint)( 1 – ηdif)

[C].

1 – ( ηimpηint/ηdif)

[D].

None of the above

Answer: Option A

Explanation:

No answer description available for this question.

Question: The typical size of particles collected by diffusion mechanism is
[A].

<0.25μm

[B].

<0.5μm

[C].

<0.75μm

[D].

<1μm

Answer: Option B

Explanation:

No answer description available for this question.

Question: The collection efficiency by diffusion increases with
[A].

decreasing particle size

[B].

decreasing air velocity

[C].

both (a) and (b)

[D].

increasing particle size

Answer: Option C

Explanation:

No answer description available for this question.

Question: The interception efficiency can be expressed as (where dp is the particle diameter and Dc cylindrical collection diameter)
[A].

dp/Dc

[B].

dp x Dc

[C].

dp/Dc x 100

[D].

dpDc/100

Answer: Option A

Explanation:

No answer description available for this question.

Question: The collection efficiency by interception increases with the
[A].

increasing particle diameter

[B].

increasing air flow velocity

[C].

both (a) and (b)

[D].

increasing particle size

Answer: Option D

Explanation:

No answer description available for this question.