Paul Edward Theroux, the famous American novelist, and traveller, once said: “The railway possessed India and made her hugeness graspable.” The Indian Railways is the world’s largest passenger carrier and the fourth-largest freight carrier (1). It is the fourth-largest railway network globally-only behind the US, Russia, and China. (2) Its immensity can be gauged from the fact that the 95,981-kilometre route length of the Indian Railways carried 8.4 billion passengers and $1.2 billion worth of freight during 2018-2019. More than 12,000 passenger trains run across the country daily and cumulatively cover a distance more than four times the earth and the moon. (3)

The Indian Railways began its journey in 1832 and has grown to become the giant it is today. As one of the primary drivers of India’s economic growth, the Indian Railways has achieved this by being financially viable, technologically brilliant, and environment friendly.

The Indian Railways has also defied the trend that many big companies face.. On the contrary,  they have cruised along and undertaken numerous initiatives to upgrade their infrastructure and quality of service.. 

These efforts have resulted in the Indian Railways achieving double-digit growth in freight traffic and doubling its freight speed on the back of massive infrastructural upgrades. Besides, new initiatives are always at play, from train control, signalling, and electrification to expansion through modern locomotives and EMUs, to name a few. 

More importantly, the Indian Railways has its goals set with social and financial objectives in mind-from efficient energy use to the new decarbonisation paradigm and aiming to become a net-zero carbon-emitter by 2030. (7)

While all this is no mean feat as the world continues to struggle with partial lockdowns, there is a lot more to come, with India projected to account for 40% of the global share of rail activity by 2050. (4) The target is achievable since the government plans to invest ₹50000 billion in railway infrastructure by 2030. (5) It has also identified many new high-speed rail corridors besides planning INR 3 trillion worth of metro rail projects across various cities over the next five years. (6)

Addressing Challenges

For the Indian Railways, maintaining the highest standards of compressed air holds critical importance. Without it, machines unexpectedly break down, demand expensive repairs, or cause uncomfortable turbulence. For rolling stock of all capacities-from locomotives to good wagons to passenger coaches, whether powered by electricity or diesel – the railways need high-quality compressed air for smooth and safe operations. Moreover, various train components, whether the braking system, doors, pantograph devices, or air suspension, rely on high-quality compressed air solutions for safety and overall reliability. The Indian Railways is also subject to a variety of constantly changing compliances and regulations.

In the 1960s, the Indian Railways took many progressive steps towards modernization and adopted 25kv AC traction for electrification. (8) While the Indian Railways urgently required compressors to modernize the braking system, it could not directly import foreign solutions because the country was hit by twin mass famines (9), and liquidity was in short supply. Besides, though the second five-year plan (1956-61) initiated industrial import policies, there was not much clarity around it. (10) However, the government was proactively piloting several initiatives to trigger domestic economic growth. It encouraged the Indian Railways to initiate production work for electric locomotives at Chittaranjan Locomotive Works and flagged off the first 1500V DC electric locomotive from Bombay in 1961. (11)

By the early 1960s, ELGi began assembling and manufacturing small compressors under the brand name ELGi Uraca. It imported only major components and either manufactured the rest in-house or procured them locally. With urgent requirements arising from the Indian Railways, and a mandate to keep costs low, ELGi opened an indigenous compressor manufacturing unit in the heart of Coimbatore. The first product supplied to the Indian Railways was a 1000 litres per minute capacity compressor driven by a battery-operated direct current (DC) motor. 

Since then, ELGi has consistently delivered a wide range of sustainable and efficient compressed air solutions to the Indian Railways. Today, 90% of Indian Railway’s electric locomotives, 65% diesel locomotives, and 60% electric multiple units (EMUs) use ELGi air compressors for braking applications and auxiliary systems. 

“The Indian Railways has been ELGi’s important customer for over five decades. Increasing urbanization and rising incomes have contributed to significant growth in the passenger segment, while freight traffic also saw a marked increase due to dedicated freight corridor investments. Our oil-free air compressors, renowned for reliability, performance, and energy efficiency, will revolutionize the way compressed air is used in the railway industry” said Dr. Jairam Varadaraj, Managing Director, ELGi Equipments.

Picture credit – https://www.toprankers.com/exams/railway-development-in-india-1854-to-now/

In business, visual cues play a key role in creating customer delight and facilitating purchase decisions. While performance & utility of the product is important on one end, aesthetics can in fact make or break your product’s future.  

One such method of “selling an aesthetic experience” to customers is Spray Painting- making it the most prevalent paint application technique due to its versatility and economic viability.  

Compressed air plays a vital role in spray painting and there are multiple methods involved in the spray painting process including Air-atomized applicators, Airless spray, and High-volume, low-pressure (HVLP) spraying.  

Let’s take a look at each of these methods: 

• Air-atomized applicators are highly flexible and can be used on almost any kind of substrate, as the equipment can be adjusted and customized to suit the needs of the operator. Air-atomized applicator consists of a traditional spray gun that combines compressed air with liquid paint to create a pressurized mist that coats the surface.  
• Airless spray propels paint particles at a lower velocity than conventional air-atomized equipment, so there is less loss of paint through overspray. In this method, rather than mixing liquid paint with compressed air, airless application equipment simply forces the liquid coating through a narrow opening to create pressure.  
• In High-volume, Low-pressure (HVLP) technique the paint is released at a lower velocity, yielding less overspray and blowback than conventional air-atomized equipment. The HVLP spray equipment utilizes spray gun atomization technology that propels large quantities of low-pressure air to the gun applicator.  
  

While there are clear visible benefits in Airless and HVLP spraying, they require advanced skill on the part of the operator, making Air-atomized spraying technique the widely preferred one. 

Design of a spray gun 

Paint applied by a spray gun must be even and should not drip, hence the nozzles of spray guns are designed for handling expanding, non-turbulent volume flow with high exit speed.  
Spray guns can also have flat, broad or round spray nozzles to suit different applications.  

Types of spray guns & the compressed air requirement 

Type of spray, consistency and quantity of paint to be applied determines the operating pressure and the nozzle diameter of the spray gun which in turn determines the compressed air requirement. Typically, spray guns require compressed air in the pressure range of 2 to 6 bar with an average air consumption ranging between 10 to 20 cfm.  

Factors to be considered when sizing your compressor: 

A reliable compressor is key to achieving high quality paint finish consistently.  

1. When it comes to sizing air compressors for painting, operating pressure and flow offered by the compressor, are the critical factors to be considered. 
2. The next critical factor to consider is the compressed air quality that the painting application demands. Quality of air is defined based on accepted levels of contaminants such as water, particles and oil. The air produced by any compressor, contains the same substances as the ambient air. This means that apart from dust particles, the RH factor in the ambient air contributes to water vapor and the oil used in the compressor for lubrication purpose also gets carried along with the compressed air. 

It is recommended that the humidity is reduced by drying the compressed air with a refrigerant dryer, and particulate filters are installed, to reduce the amount of dust particles present in the compressed air.  

An activated carbon filter can also be used to ensure there is no oil in the compressed air system. When supplementing other filters with an activated carbon filter, one achieves a quality called “technically oil-free” compressed air. 

ELGi offers a wide range of oil lubricated and oil free Reciprocating and to choose from, along with the downstream equipment to suit vast range of applications. Our extensive network of authorized channel partners across the world can help to choose the best compressor model suiting your painting applications. 

Get in touch with a compressed air expert for your needs here: https://www.elgi.com/in/contact-us/

From constraints in providing adequate treatment, to a lack of supply of medicines- Hospitals across the country were reeling from the impact of a cataclysmic crisis. The biggest challenge that the COVID-19 pandemic had brought with it, is the lack of oxygen supply to patients who need utmost critical care. More than the lack of oxygen cylinders, hospitals faced difficulty in transportation due to logistical constraints.

This is why, as a timely solution to mitigate the severe crisis, the Defence Research and Development Organisation (DRDO) had committed to set up PSA oxygen plants, which would resolve the issue of the supply constraints.

What are PSA oxygen plants and how do they function?

The air around us is composed of 78% Nitrogen, 21% Oxygen and 0.9%of Argon among trace elements of other gases. To separate oxygen from the other components of air, oxygen plants play an instrumental role.

To put it simply, oxygen plants are systems, which are designed to produce oxygen by separating it from other components of air.

In PSA oxygen plants, a technique called ‘adsorption’ is used to make this separation. This relies on the phenomenon that each gas is attracted to different solid surfaces in varying degrees.

For supplying medical oxygen, PSA oxygen plants compress the atmospheric air with an air compressor. This compressed air is then pushed under pressure through a vessel, which has a bed of zeolite, a material to which other air components have a higher degree of attraction towards, as compared to oxygen. The gas, which then comes out of the vessel, is oxygen viable for utilization on patients.

However, the basic vehicle manufacturing practice has largely remained the same. Different parts of a car, passing through production lines, are assembled by skilled workers or automated robotic processes. Air compressors are key devices that power the equipment used in vehicle assembly and the servicing and maintenance of finished products.

Choosing a suitable compressed air system for automotive applications depends on the volume and air pressure required for the concerned tools. These can vary widely across manufacturing plants and workshops:

Their distinct features can be understood in terms of:

If you plan to buy an air compressor for your industrial application, you need to mull over several factors that best suit your needs. One important consideration is the air pressure requirement of the equipment that the air compressor will operate.

The free air delivery in an air compressor is measured in cubic feet per minute (CFM). It is the amount of air generated by the air compressor at a certain pressure level. Another parameter considered along with CFM is the amount of pressure that the air compressor can offer, which is measured in bar, kg/cm2 or PSI.

For instance, small pneumatic tools usually need up to 5 CFM at 4.8-6.2 bar. Larger equipment, on the other hand, demand more than 10 CFM at 6.9-8.2 bar. Remember that when you have multiple applications with different airflow demands, you should add up their individual requirement and consider the total usage to be 40-50% higher than the obtained number. This is to ensure the air compressor doesn’t run at full capacity at all times.

Take a look at the airflow required for some common air compressor applications:

Air compressors convert normal air into its high-pressure, denser form for uses in a wide range of environments.

From small, portable models for safe supply on-the-go, to huge commercial installations that fuel complex industrial processes, they vary considerably in size and configuration to best suit all kinds of needs.

ELGi offers compressed air solutions to multiple industries, and here’s a list to name a few:

Today, let’s read about a global leading elevator manufacturer, which chose ELGi’s EG Series screw air compressors for their newest plant in Pune to achieve their ambitious production targets for market expansion in India.

Today, let us read more about a leading fuel management system provider, which enlisted the help of ELGi’s EG series compressor for their facility in Sharjah, UAE.

According to historians, it is believed that sandblasting was first patented after the observation of what appeared to be sand-laden winds. Apparently, this seemed to significantly affect objects or surfaces they met. This observation was made by none other than Benjamin Chew Tilghman – the person who invented the first air compressor.

Sandblasting is also known as abrasive blasting. It is the operation of forcibly propelling a stream of abrasive materials against a surface. It is done under high-pressure to smooth out a rough surface, roughen a smooth surface or shape the same to remove its contaminants.

The abrasive material for this operation is chosen based on the finish required on the surface.

To get the best performance from your sandblaster, you need to select the right compressor for the job.

Choosing your compressor:

Compressors and sandblasters are sized based on:

• Flow: Defined as the volume of air that the system can move in a minute, the flow is dictated by
  • Number of users
  • Hose length
  • Hose diameter
  • Nozzle size and type
• Pressure: The pressure generated by the system is dictated by media, hose length, & diameter
  One must consider both numbers to make sure the compressor and sandblaster will work together. The size of the sandblaster and nozzle will determine what size of the compressor should be used for the operation.

How sandblasters work:

To select the right size of the compressor for the operation; it is necessary to understand how exactly a sandblaster works. They clean out rough surfaces by abrading them with sand that is fired out of an air-powered gun at high velocity.

• Different types of projection systems that can throw abrasive using compressed air:
  In pressurised projection systems, both abrasive pot and air mixing champers are under the same pressure, sweeping the abrasive material along in the blast hose.
• In suction systems, compressed air is injected into the gun through a nozzle which creates a partial vacuum that sucks a mix of air and abrasive materials from the pot.
• In gravity systems, the abrasive material enters the mixing chamber by gravity and is then pushed by compressed air into the nozzle.