Mechanical Seal Balanced – Unbalanced seal for Vessel/Reactor and Pump – Maintenancemech

Types of  Pump and its Classification 

Pump can be use for transfer fluid in term of liquid and gaseous stage from one location to other location is called pump.

Pump convert electrical energy to hydraulic energy through the action of mechanical.

TYPES OF PUMP (CLASSIFICATION OF PUMP)

There are mainly 2 types of Pumps which are classified in below diagram –(Please refer below image)

Fig - Types of Pumps

Dynamic Pump

• Centrifugal pumps
• Vertical centrifugal pumps
• Horizontal centrifugal pumps
• Submersible pumps
• Fire hydrant systems

Positive Displacement Pump

• Diaphragm pumps
• Gear pumps
• Peristaltic Pumps
• Lobe pumps
• Piston Pumps

 

Dynamic Pump Working 

The dynamic pump is a type of velocity pump in which kinetic energy is added to the fluid by increasing the flow velocity. This increase in energy is converted to a gain in potential energy (pressure) when the velocity is reduced prior to or as the flow exits the pump into the discharge pipe.

fig -Working of dynamic pump

Centrifugal pumps

Centrifugal pump is a hydraulic machine which converts mechanical energy into hydraulic energy by the use of centrifugal force acting on the fluid. These are the most popular and commonly used type of pumps for the transfer of fluids from low level to high level. It’s used in Chemical plant, pharma and agriculture industries.

1. Impeller
2. Casing
3. Delivery Pipe
4. Suction Pipe and foot strainer
5. Mechanical Seal

 

It is a wheel or rotor which is provided with a series of backward curved blades or vanes. It is mounded on the shaft which is coupled to an external source of energy which imparts the liquid energy to the impeller there by making it to rotate.

Impeller

Types of Impeller -

Open Impeller 

Semi closed Impeller and 

Closed Impeller

Open Impeller 

vanes that are attached to a center hub and mounted directly onto a shaft. Its vanes are free from both side end.

Open impellers are usually used in small, inexpensive pumps or pumps handling abrasive liquids or suspended solids.

MOC OF OPEN IMPELLER

TEFLON, SS and Cast Iron.

Semi Closed Impeller 

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 and the casing.

Closed Impeller

The vanes are located between the two discs, all in a single casting. They are used in large pumps with high efficiencies and low required Net Positive Suction Head. The centrifugal pumps with closed impellers are the most widely used pumps handling clear liquids. They rely on close-clearance wear rings on the impeller and the pump casing. The closed impeller is a more complicated and expensive design because of the impeller, but additional wear rings are needed.

The impeller blades can be:

• Backward-curved blade design (preferred design due to the negative slope of performance curve)
• Radial blade design
• Forward-curved blade design (due to positive slope conditions, this design can cause pump surge)

Efficiency Compare of Impeller

Which impeller is best efficiency

 

Closed Impeller > Semi -Closed Impeller > Open Impeller

Casing

Pump casings serve to seal off the inside of the pump to atmosphere to prevent leakage and retain pressure.

Three types of casing are used in centrifugal pump

1. Volute Casing
2. Vortex Casing
3. Casing with Guide Blades

Fig- Volute Casing

Delivery Pipe 

It is a pipe which is connected at its lower end to the out let of the pump and it delivers the liquid to the required height. Near the outlet of the pump on the delivery pipe, a valve is provided which controls the flow from the pump into delivery pipe.

Suction Pipe with Foot Valve and Strainer

suction pipe is connected with the inlet of the impeller and the other end is dipped into the sump of water. At the water end, it consists of foot value and strainer. The foot valve is a one way valve that opens in the upward direction. The strainer is used to filter the unwanted particle present in the water to prevent the centrifugal pump from blockage.

Types of Centrifugal Pump

1. Single stage pump
2. Two-stage pump
3. Multi-stage pump

Mechanical Seal 

A mechanical seal is a device that helps join systems or mechanisms together by preventing leakage containing pressure, or excluding contamination. Earlier Gland rope used in Pump due to high pressure and hazardous material drop wise leakage likely occurs.

 

Link for Other Chemical Equipment

GLASS LINE REACTOR

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