Chemical Engineering Department, WEC

Types of Impellers used in Centrifugal Pumps
There are 3 Main Types of Impellers used in Centrifugal Pumps: - 1️⃣ Open Impellers 2️⃣ Semi-Open 3️⃣ Enclosed

✅ Impeller design is the most significant factor for determining the performance of a centrifugal pump

1️⃣ Open Impellers The vanes free on both sides. They are structurally weak. They are typically used in small-diameter, inexpensive pumps handling suspended solids.

2️⃣ Semi-Open Impellers The vanes are free on one side and enclosed on the other. The shroud adds mechanical strength. They also offer higher efficiencies than open impellers. They can be used in medium-diameter pumps and with liquids containing small amounts of suspended solids. Because of the minimization of recirculation and other losses, it is very important that a small clearance exists between the impeller vanes &the casing.

3️⃣ Enclosed Impellers The vanes are located between the 2 discs, all in a single casting. They are used in large pumps with high efficiencies and low required NPSH, widely used pumps handling clear liquids. The closed impeller is a more expensive design not only because of the impeller, but additional wear rings are needed.

Why does the pump cavitation happen in the first place?
If the pressure in the suction line of the pump is less than the vapour pressure of the fluid, it results in the formation of bubbles and collapsing of those bubbles at the ‘eye of the impeller’ and that is termed as cavitation.

The pressure in the suction line can drop due to serval reasons.

👉🏻 The suction line has too many turns and bends (avoid that, talk to layout and piping engineers)

👉🏻 Plugged strainer or filter in the suction line (ensure the line is clean, maintenance is necessary)

👉🏻 Rusted Pipe results in friction losses (keep an eye on those and change if necessary)

👉🏻 Low level in the suction vessel (make sure that it operates at operating setpoint or close to it)

👉🏻 Damaged fittings over a period and so forth

‼️Why SHIPHON TUBE use in steam pipeline ❓‼️
A pressure gauge siphon is a simple device used to protect a pressure sensor from high-temperature media, such as steam. It can also be used to reduce the potentially damaging effects of rapid pressure changes. These low-cost devices allow systems builders to use a pressure sensor with a much lower temperature range in high-temperature applications.

Gauge Syphons are used to protect the pressure gauge from the effect of hot pressure media such as steam and also to reduce the effect of rapid pressure surges. The syphon allows condensate to form and be collected inside the syphon, preventing the hot media (hot vapors, not just steam) from coming in direct contact with the pressure instrument. Also used as freeze protector when used with proper fill fluids.

Types of gauge siphon :

Coil Syphons
U Type Syphons
Compact Gauge Syphons
Straight Pipes and 90° Elbows

Ethanol & CO2 plant

Ramzan Ethanol & CO2 Plant, new Unit Er****on near Chiniot.

System Configuration and Operating Parameters for the production of 1 m3 of enriched biomethane via biomethanation.

https://www.sciencedirect.com/science/article/pii/S0960852417315973

Head of Chemical Engineering Department & Dean of Engineering, Prof. Dr. A.K Salayria a great teacher.