Electro Mechanical Drive Vs Hydraulic Drive

-


This title always flashes in every Mechanical Engineers mind along with the answer “HYDRAULIC DRIVE”.

Is this true?

If this is true, then to what extend?

Let us discuss in brief!

No doubt that comparing Electro Mechanical drive with Hydraulic drive is like comparing a Conventional car (which runs on Petrol/Diesel) with a Tesla car. Still Conventional car has advantages over a Tesla car.

In the same manner, Electro Mechanical drive has advantages over Hydraulic drive as mentioned below:

1.   Commercial

-      Price of Electro Mechanical drive is much lesser than Hydraulic drive

2.   Installation

-      Electro Mechanical drive is easy to install and needs less time to install, whereas installation of Hydraulic drive needs EXPERTS and time consuming one. Pickling of Hydraulic Pipes consumes more time and NAS (National Aerospace Standard) value of the oil to be guaranteed as per the standard before commissioning the Hydraulic drive.

3.   Maintenance

-      Electro Mechanical drive needs less or easy maintenance, whereas Hydraulic drive demands EXPERTS for repair & maintenance. Leakage of oil is a nuisance in Hydraulic Drive and NAS value of the oil to be frequently checked to avoid any major breakdown of Hydraulic drive. In addition to this, spares for Hydraulic Drive are very costly and these spares are all imported, hence sometimes the machine with Hydraulic drive remains shut down due to non-availability of spares. This has direct impact on the plant production.

On the other hand, in Hydraulic Drive the Power to Weight ratio is high compared to Electro Mechanical Drive (this helps in reducing the Counter weight in case of a Bucket Wheel Stacker Reclaimer machine).


Refer the above attached photos of both drives installed in two different machines with same configurations (capacity, material handled etc.,) and at same plant. See the size of Electro Mechanical Drive (BIG) & the Hydraulic Drive (small)!

Soft starting & Inching operation of Hydraulic Drive is easy, whereas Electro Mechanical Drive needs additional VVFD (Variable Voltage & Frequency Drive).

When multiple motors are used (Slew drive, Conveyor drive), equal load sharing is guaranteed in Hydraulic Drive, whereas Synchronising the Electro Mechanical Drive is a challenge!

Last but not the least, as a Mechanical Engineer we all know that Hydraulic Efficiency is more than Mechanical Efficiency!

TO CONCLUDE, FOR A DESIGN ENGINEER HYDRAULIC DRIVE IS THE BEST, WHEREAS FOR A PLANT OPERATION PERSONNEL (CONSIDERING PRACTICAL CHALLENGES) ELECTRO MECHANICAL DRIVE IS THE BEST.

 

***

Comments

Post a Comment

Popular posts from this blog

Stockpile configuration

-
Image
  To run any plant continuously, the basic requirement is the continuous supply of raw material. For example, to run a Thermal power-plant  or Steel plant or an Alumina plant, continuous supply of the raw materials viz., coal / iron ore / bauxite / limestone is required. Unfortunately, it is difficult to guarantee the continuous supply of raw material due to various factors viz., availability of raw material, transporting the raw material (by ship, wagon etc.,) or force majeure. Hence the solution is to store more than the required amount of these required raw materials in the plant itself. ‘Google’ defines stockpile as, ‘a large accumulated stock of goods or materials, especially one held in reserve for use at a time of shortage or other emergency’. Why the raw materials to be stacked and not dumped? It is because of the following limitations, ·        availability of space ·        quantity of material to be stored ·        equipment* used ·         p
Read more

Trapezoidal stockpile Vs Trapezoidal stockpile

-
Image
Trapezoidal stockpile can be formed in the following two methods, 1.    Without compensating the travel length of the machine. 2.    By compensating the travel length of the machine. Each method has its own advantage and disadvantage. Before comparing the advantages and disadvantages, let us discuss how a trapezoidal stockpile is formed. Without compensating the travel length of the machine: The above figure shows a trapezoidal stockpile formed without compensating the travel length of the machine. By compensating the travel length of the machine: The above figure shows a trapezoidal stockpile formed by  compensating  the travel length of the machine. Travel length compensation: To understand travel length compensation, first let us discuss how a triangular stockpile is formed with the help of a stacking mode drawing. (Stacking mode drawing: Is the drawing which defines the slewing angle, luffing angle and the travel position of the stack
Read more

Stockpile end cone correction

-
Image
Consistency is an important and inevitable factor in any process plant. To meet a consistent quality output of the product (for example steel or cement) the raw material shall be fed continuously for processing in the required ratio. Consider a case in which the raw materials are stored in the stockyard in number of layers and during reclaiming if the consistency in blending is disturbed after sometime of reclaiming. The result will be change in product quality. Case study: Form a stockpile of 40m (Width) x 12m (Height) x 250m (Length) with 6 layers and discuss the consistency (mixture of all 6 layers of material) during reclaiming operation. Machines used for stacking & reclaiming, Stacker       - Luffing Stacker or Twin Boom Stacker Reclaimer   - Bridge Scrapper Reclaimer or Barrel Reclaimer or Wheel on Bridge Reclaimer (Note: above mentioned reclaimers are with harrow arrangement) STOCKPILE: Below sketch shows a stockpile of 40m x 12m x 250m (rep
Read more