Agitation And Aeration

Question: The Intermig impeller is
[A].

an axial flow impeller which can be used for the culture of aerobic organisms

[B].

directed upwards rather than towards the base of the reactor

[C].

a fork shaped extensions to the impeller facilitate bubble break up

[D].

All of the above

Answer: Option D

Explanation:

No answer description available for this question.

Question: Which of the following is not classified as an axial flow impeller?
[A].

A propeller

[B].

A marine impeller

[C].

A Rushton turbine

[D].

A hydrofoil impeller

Answer: Option C

Explanation:

No answer description available for this question.

Question: A reactor has a total volume of 50,000 litres. If it has a headspace volume of 10,000 litres, then volume of liquid in the reactor will be
[A].

10,000 l

[B].

20,000 l

[C].

30,000 l

[D].

40,000 l

Answer: Option D

Explanation:

No answer description available for this question.

Question: A cylindrical reactor fitted with Rushton Turbine has a liquid volume of 100,000 litres. It has an aspect ratio (the ratio of the channel height to the width) of 2:1. The diameter of the impeller should be approximately:
[A].

1.3 m

[B].

3.3 m

[C].

5.3 m

[D].

7.3 m

Answer: Option A

Explanation:

No answer description available for this question.

Question: A cylindrical reactor has a liquid volume of 100,000 litres. It has an aspect ratio the ratio of the channel height to width of 1:1. The height of the liquid in the reactor will be approximately:
[A].

1.0 m

[B].

3.0 m

[C].

5.0 m

[D].

7.0 m

Answer: Option C

Explanation:

No answer description available for this question.

Question: The volume of liquid (VL) in a cylindrical reactor can be calculated from the liquid height (HL) and tank diameter (Dt) using the following equation
[A].

VL = 4/3 x π x HL x Dt3/8

[B].

VL= HL x π x Dt2/4

[C].

VL= HL x π x Dt2

[D].

VL= 4 x π x Dt2

Answer: Option B

Explanation:

No answer description available for this question.

Question: The reason of using a flat disk in a Turbine is
[A].

to create high shear conditions

[B].

to break up bubbles more efficiently than the impeller blades

[C].

to ensure that the bulk of the energy consumption occurs at the blades

[D].

all of the above

Answer: Option C

Explanation:

No answer description available for this question.

Question: Turbine impeller consists of flat impeller blades with
[A].

a vertical pitch welded directly to the shaft

[B].

a angled pitch welded directly to the shaft

[C].

a vertical pitch welded to a horizontal disk

[D].

a angled pitch welded to a horizontal disk

Answer: Option C

Explanation:

No answer description available for this question.

Question: Which of the following best explains the reasons for using axial flow impellers in crystallization and precipitation reactions?
[A].

Crystal and precipitates are not too small, so as to ensure easy separation of the solids from the mother liquor

[B].

Crystals and precipitates are thoroughly broken down, so as to ensure easy separation of the solids from the mother liquor

[C].

Both (a) and (b)

[D].

Axial flow impellers provide low shear, energy efficient mixing conditions

Answer: Option A

Explanation:

No answer description available for this question.

Question: In aerobic microorganisms cultures radial flow impellers are used because
[A].

they provide energy efficient high turbulent mixing conditions

[B].

they provide low shear mixing conditions

[C].

they provide high shear mixing conditions

[D].

they ensure that bubble size is maximized leading to high oxygen transfer rates

Answer: Option C

Explanation:

No answer description available for this question.