Grow Mechanical

What is balance drum and disk

What is the balance drum?

It is a device which is used to balance the axial thrust build-up by impeller. it is also used with thrust bearing which is transfer very less residual thrust load to thrust bearing.

This is the main benefit of drums. The balance drum is a circular device installed on pump rotor generally drum is installed on the discharge end side.

What is the balance disk?

Balance disk in centrifugal pump

The balance disk is use for compensate axial thrust and capable to compensate fully generated thrust load. The balance dick is used to manage axial clearance between casing and rotor disk. The balance dick is used immediately just after the last stage so it has full discharge pressure on one side of the disk.

What is balance piston?

Balance piston

The balance piston is also called the balance drum.

What is axial thrust bearing?

Thrust bearing

The residual axial thrust is always present in the system to compensate for this thrust using axial thrust bearing.

What is flange drum?

Flange drum is used in the combination of balance drum and balance disk. But principally depending on hub leeway.

What is stepped drum?

It is also used in the combination of balance drum and balance disk. But principally depending on hub leeway.

What is the difference between a balance disk and a balance drum?

Balance drum vs Balance disc

Both are used for compensate thrust load. Drum is use for managed high axial thrust and generally use in discharge end. The pressure acted on drums on both sides (left and right) and cancelled out to each other.

Balance line

The balance line is system use to compensate for generated thrust load by discharging fluids. the balance line is provided from the pump suction side to discharge side. To nullify the axial thrust generated by impeller discharge use a balance line also. Because of this back force the internal part will be damaged so a taping is given from discharge to balance drum.

Learn centrifugal pump 

Thrust load

Two types of thrust load are applied to bear axial thrust and radial thrust. Below is an example of the axial thrust mentioned. 

We will discuss boiler feed water pumps. It is also a multistage centrifugal pump. Suppose that in this pump suction pressure is 7 kg per centimetre square and discharge pressure is approx 130 kg Per centimetre Square at final outlet in 6 stage pumps.

According to this condition, in the first stage, impeller suction pressure will be around 8 kg per centimetre square due to the increase in velocity with the help of diffuser. 

The first stage of centrifugal multistage pump circulating Liquid on the periphery of casing around the Imperial Outlet. Suppose that at the impeller First stage discharge pressure is increased to around 20 kg per centimetre square. 

Due to this 20 kg Per centimetre Square in Outlet it will generate back pressure approx 20 kg/centimetre square and that force pushes the impeller assembly in backside according (Newton’s third law of motion: ‘Every action has the same and opposite reaction.). 

In the next 2nd stage, the suction pressure at inlet around 20 kg per centimetre square and discharge Pressure will be around 40 kg per centimetre square. 

Due to the same phenomena that occurred with the Second stage impeller also and the second stage discharge liquids also pushed the rotor assembly in back side after that liquid goes forward to the stage. This process is continued till the last stage. 

To balance this type of generated back Force, use three parts with pump casing, rotor assembly balance disc, balance drum, Balance line. And in the place of bearing or with the bearing to bear thrust load Thrust bearing is also provided. 

But the thrust bearing is not sufficient only for compensate hundred percent thrust load So Balance disc, balance line or balance drums used to reduce  net thrust use impeller in opposite to each other.

What is the ASTM A106 standard and its specification

Leave a Comment

Your email address will not be published. Required fields are marked *

Grow Mechanical