ICAR AICE-JRF/SRF Dairy Plant Design, Layout & Project Engineering: practice questions

1 · Process flow diagrams and mass balances · hard

Why do utility peaks in a dairy plant often coincide with cleaning periods?

1. Cleaning stops all production, so every utility reaches zero
2. Cleaning uses only cold water, which lowers steam demand
3. Refrigeration must be switched off whenever any line is cleaned
4. Hot detergent and rinse water are drawn while other lines keep producing

2 · Functional design and space requirements · medium

Why must clear height be considered as carefully as floor area in a dairy processing hall?

1. Higher ceilings always reduce the plant's refrigeration load
2. Tall equipment, bowl removal and overhead pipe racks need vertical space
3. Building codes everywhere fix the same height for all food plants
4. Clear height matters only for offices and laboratories

3 · Hygienic zoning and personnel flow · hard

A plant has condensation dripping from cold pipes above an open filler. Which design response addresses the cause?

1. Raise the filler's speed so less product is exposed to each drip
2. Increase the frequency of finished-product testing at the filler
3. Fit a wider drip tray under the filler to catch spilled product
4. Improve ventilation and insulate or reroute the cold pipes away from open product

4 · Hygienic zoning and personnel flow · hard

Why is hygienic zoning decided at the layout stage rather than after the building is designed?

1. Zoning only affects the colour of staff uniforms, which can change any time
2. Auditors refuse to inspect zoning that was planned after construction
3. It sets walls, air handling, drains and changing rooms, hard to alter later
4. It is decided by the equipment supplier, who must know it before ordering

5 · Pressure vessel design: codes, shells, heads and supports · easy

Compared with a cylinder of the same diameter and wall thickness, what is the membrane stress in a sphere under the same internal pressure?

1. Twice the cylinder's hoop stress
2. Equal to the cylinder's hoop stress
3. One quarter of the cylinder's hoop stress
4. Half the cylinder's hoop stress

6 · Pressure vessel design: codes, shells, heads and supports · medium

Why are flat heads rarely used on vessels with significant internal pressure?

1. They cannot be welded to a cylindrical shell at all
2. They are banned by every pressure vessel code in force
3. They bend under pressure and need very great thickness
4. They make the vessel impossible to drain completely

7 · Pressure vessel design: codes, shells, heads and supports · hard

What must a hygienic dairy pressure vessel's supports satisfy in addition to the pressure code?

1. Be painted the same colour as the vessel for easy identification
2. Allow floor cleaning beneath and avoid crevices that trap soil
3. Be made of mild steel so that they rust visibly when damaged
4. Be welded directly into the floor drain for maximum stability

8 · Equipment sizing and selection · hard

A pump moves 30 cubic metres per hour of a liquid of density 1,000 kg/m³ against a total head of 25 m with 65 percent efficiency. What shaft power is needed?

1. About 2.0 kW
2. About 4.8 kW
3. About 3.1 kW
4. About 1.3 kW

9 · Building, floors, drains and services · medium

Why are services routed through service corridors or external pipe bridges where possible?

1. Pipes in corridors need no insulation in any climate
2. It halves the length of every pipe in the plant
3. Regulations forbid any pipe inside a production room
4. Maintenance staff can work on them without entering high-hygiene rooms

10 · Installation, commissioning and validation · medium

Why are internal welds on dairy product pipelines inspected, for example with a borescope?

1. Inspection makes the pipe stronger under pressure
2. Borescopes measure the flow rate through the line
3. Internal welds determine the colour of the product
4. A poor internal weld leaves an uncleanable crevice