KNOW WHAT YELLOW OR WHITE STRIPS ON COACHES OF INDIAN RAILWAY MEAN !!

On 16 April, 1853, Indian Railways started its services and the first train travelled at a distance of 33 km from Mumbai to Thane. While travelling through train, you may have seen coloured coaches and different coloured stripes on the train coaches such as yellow or white etc. Have you ever thought why these coloured stripes are given to some of the train coaches, what does it mean? Let us study through this article about the stripes and about the colour coaches & their significance.

On the blue ICF coach, the lines or stripes of yellow or white colour are placed on top of the window at the end of the coach, which is actually used to separate the coach from another coach. These lines indicate the unreserved coach of the second class. When a train arrives at the station, there are many people who are confused about the General Bogie, but by looking these yellow stripes, people can easily understand that this is the General Coach. Coach with white strip shows reservation class.

Similarly, the yellow stripes on blue / red are used for the handicapped and sick people. Similarly, green stripes on the grey indicate that the coach is for women only. These colour patterns are included only for the new Auto Door Closing EMU in Mumbai, Western Railway.Similarly, the red colour stripe indicates the first-class coach.

KNOW WHY TURBOCHARGERS ARE MOSTLY USED IN DIESEL ENGINE !

Turbochargers are rarely used with petrol engines but mostly used in diesel engines.We will discuss the reason behind this in this article.

A turbo charger is a device which uses exhaust heat from an Engine to get more air into the Cylinder during Induction stroke.More air translates to increased ability to burn more fuel which in turn increases the Power output (brake horse power) of the Engine.Turbocharging is common in modern car and truck Diesel engines to produce higher power outputs, lower emissions levels, and improved efficiency from a similar capacity of engine. Turbo-Diesels in automobiles offer a higher refinement level than their naturally aspirated counterparts.

Basically turbocharger compresses the air and forces into the engine cylinder so in short, we are putting more air into cylinder which results in more power.Compression of air by TURBOCHARGER INCREASES THE PRESSURE AND TEMPERATURE INSIDE THE CYLINDER.

Now, let us take the case of Diesel Engine:

Diesel as a fuel is not as combustible as petrol. The air-fuel mixture inside the cylinder should be at higher pressures for effective combustion of diesel. To withstand higher combustion pressures a diesel engine is built with strong, heavy parts.So,heavier parts can withstand higher pressure generated by turbocharger.Also,the heavier components of a diesel engine cannot rotate at higher RPMs.Lesser RPM means lesser air intake into combustion chambers. Hence a turbo charger helps a diesel engine to get more air into the combustion chamber.

Now come to Petrol Engine:

Petrol is more combustible than diesel and hence at lower pressures combustion can take place.If we add turbocharger to petrol engine then rise in pressure inside the engine cylinder may lead to problem of knocking.Also the parts of petrol engine is lighter than diesel engine so they may not withstand the pressure rise inside the engine cylinder.These are the reasons why turbochargers are not used with petrol engines. 

Also read:

DIFFERENCE BETWEEN KNOCKING AND DETONATION EXPLAINED !!

KNOW WHY THESE EQUIPMENTS ARE USED ON THE ROOF OF FACTORIES??

 You might have seen this type of rotating equipment on the roof of factories.In this article we will discuss what is this,what is does and how it works.

These are known as roof extractors. 

In summers, high temperatures build up inside small workshops and factory units making them extremely unpleasant to work in. As a temporary measure portable fans are installed to provide relief for workers, however while portable fans cool small areas of the building, the rest remains stiflingly hot.

Roof extractor fans provide a simple, low cost method of cooling for small buildings or rooms of upto approximately 1400 cubic meter (50,000 cubic feet).

It provides ventilation, fresh air and remove stale or contaminated air.Hot air is exhausted from the building and cooler outside air is sucked in though open doors and windows. As a result the temperature inside the building is held close to the outside temperature.

Using roof extractor fans to cool buildings of upto 1400 cubic meter has proved to be a very cost effective. By rapidly removing hot air from the building and sucking cooler air in through open doors and windows, the temperature inside can be kept close to the ambient (outdoor) temperature.