Shopping on line can be easy, simple and save you lots of money. It can also take a lot of your time, frustrate you, and result in unwanted purchases. Now the same can be said for regular high street shopping, but with the vast opportunity presented by the Internet it will pay you to spend a few minutes reading this and understanding how to better optimize your Roots Blower shopping experience:

1. Compare - without doubt the biggest advantage that the Roots Blower offers shoppers today is the ability to compare thousands of Roots Blower at a time. This is a great thing, but not necessarily all the time! Too much can be daunting at times so take advantage of the great comparison sites and where possible let them do the hard work for you.

2. Research - if it has been said it will be on the internet. Ignorance is no longer a justifiable reason for buying the wrong thing. Take the time to research in detail everything that you could possible want to know about

3. Testimonials - don't know anybody that has bought a Roots Blower? Wrong! If the Roots Blower is good the internet will let you know. Use the Internet as a friend and get testimonials before you buy.

4. Questions - Got a question about Roots Blower then search the Forums, FAQ's, Blogs etc. Don't be afraid to ask .....

5. Reputation - Never heard of the company selling Roots Blower? Don't worry, no reason why you should know every company in the world, but you know someone that does! Use the internet to find out what people are saying about Roots Blower and build up a picture of their reputation for sales, returns, customer service, delivery etc.

6. Returns - still worried that even after all of the above your Roots Blower wont be what you want? Check out the returns policy. There is so much competition now that someone, somewhere is bound to offer the terms that you are comfortable with.

7. Feedback - happy with your Roots Blower then let people know, after all you are depending on others people input in your buying decision, so why not give a little back.

8. Security - check for the yellow padlock on the Roots Blower site before you buy, and the s after http:/ /i.e. https:// = a secure site

9. Contact - got a question about Roots Blower, or want to leave a comment then check out the sites contact page. Reputable companies have them and respond.

10. Payment - ready to pay for your Roots Blower, then use your credit card or PayPal! Be aware of companies that don't accept them, there may be genuine reasons but given the huge amount of choice you have when buying online there is no reason at all not to buy via credit card or PayPal.

The Roots type supercharger or Roots blower is a positive Engine displacement type device which operates by pulling air through a pair of meshing lobes not unlike a set of stretched gears. Air is trapped in pockets surrounding the lobes and carried from the intake side to the exhaust. The supercharger is typically driven directly from the engine's crankshaft via a Belt (mechanical) or, in a two-stroke cycle diesel engine, by spur gears.

It is named for the brothers Philander Roots and Francis Roots, who first patented the basic design in 1860 as an air pump for use in blast furnaces and other industry applications. In 1900, Gottlieb Daimler included a Roots-style supercharger in a patented engine design, making the Roots-type supercharger the oldest of the various designs now available.

Applications is visible at the front of this GM Family II engine#LSJ in a 2006 Saturn IONOut of the three basic supercharger types the Roots has historically been considered the least Fuel efficiency. However, recent engineering developments by Eaton Corporation has resulted in a new Roots-type supercharger which yields a pump that is more efficient than all previous models. In addition, the Roots-type supercharger is simple and widely used and thus is invariably the most cost efficient. It is also more effective than alternative superchargers at developing Compression ratio at low engine Revolutions per minutes, making it a popular choice for passenger automobile applications. Peak torque can be achieved by about 2000 rpm.

All supercharger types benefit from the use of an intercooler to remove heat produced during compression. With a Roots-type supercharger, a thin heat exchanger is adapted to fit in-between the blower and the engine. Water is circulated through it to a second unit placed near the front of the vehicle where a fan and the ambient air-stream can dissipate the collected heat.

The Roots design is commonly used on two-stroke diesel engines, which require some form of forced induction as there is no intake stroke. In this application, the blower does not often provide significant compression and these engines are considered naturally aspirated; turbochargers are generally used when significant "boost" is needed. The Rootes Co. two-stroke diesel engine, used in Commer and Karrier vehicles, had a Roots-type blower but the two names are not connected.

The superchargers used on Top Fuel#Top fuel engines, funny cars, and other dragsters, as well as hot rods, are in fact derivatives of General Motors superchargers for their diesel engines, which were adapted for automotive use in the early days of the sport. The model name of these superchargers delineates their size; i.e. the once commonly used "6-71" and "4-71" blowers were designed for General Motors diesels having six Cylinder (engine)s of 71 cubic inches each, and four cylinders of 71 cubic inches each, respectively. Current competition dragsters use blowers of 14-71 design.

Roots blowers are typically used in applications where a large volume of gas must be moved across a relatively small pressure differential. This includes low vacuum applications, with the roots blower acting alone, or use as part of a high vacuum system, in combination with other pumps. Roots blowers are also used as superchargers.

Some civil defense sirens used Roots blowers to pump air to the rotor(chopper). The most well known are the Thunderbolt Siren, and ACA(now American Signal Corporation) Hurricane. These sirens are known as "supercharged sirens".

Roots blowers are also used in reverse to measure the flow of gases or liquids, for example, in gas meters.

Technical considerations Because rotary lobe pumps need to maintain a clearance between the lobes, a single stage roots blower can only pump gas across a limited pressure differential. If the pump is used outside its specification, the compression of the gas generates so much heat that the lobes expand to the point that they jam, damaging the pump.

Roots pumps are capable of pumping large volumes but as they only achieve moderate compression, it is not uncommon to see multiple roots blower stages, frequently with heat exchangers (intercoolers) in between to cool the gas. The lack of oil on the pumping surfaces allows the pumps to work in environments where contamination control is important. The high pumping rate for hydrocarbons also allows the roots pump to provide an effective isolation between oiled pumps, such as rotary compression pumps, and the vacuum chamber.

A variant uses claw-shaped rotors for higher compression.

Comparative advantages The roots pump is never used as a stand alone pump in high vacuum applications but its high pumping speed can be used to reduce the end pressure and increase the pumping speed of other vacuum pump systems in the medium to low vacuum range.

References

• (April 5, 2002). Roots Type Superchargers Explained. SuperchargersOnline.com. Accessed September 11, 2004.
• Blower Briefing. Tom Henry Racing. Accessed September 11, 2004.
• Eaton TVS Supercharger The Eaton TVS Supercharger. Accessed November 11, 2006

The term blower is used to define a device placed on engines that can not breathe on their own and is needed for scavenging and a supercharger is used on engines to boost power even though they are the same device.

External links

• Flash Animation of Roots Pump

The Roots type supercharger or Roots blower is a positive Engine displacement type device which operates by pulling air through a pair of meshing lobes not unlike a set of stretched gears. Air is trapped in pockets surrounding the lobes and carried from the intake side to the exhaust. The supercharger is typically driven directly from the engine's crankshaft via a Belt (mechanical) or, in a two-stroke cycle diesel engine, by spur gears.

It is named for the brothers Philander Roots and Francis Roots, who first patented the basic design in 1860 as an air pump for use in blast furnaces and other industry applications. In 1900, Gottlieb Daimler included a Roots-style supercharger in a patented engine design, making the Roots-type supercharger the oldest of the various designs now available.

Applications is visible at the front of this GM Family II engine#LSJ in a 2006 Saturn IONOut of the three basic supercharger types the Roots has historically been considered the least Fuel efficiency. However, recent engineering developments by Eaton Corporation has resulted in a new Roots-type supercharger which yields a pump that is more efficient than all previous models. In addition, the Roots-type supercharger is simple and widely used and thus is invariably the most cost efficient. It is also more effective than alternative superchargers at developing Compression ratio at low engine Revolutions per minutes, making it a popular choice for passenger automobile applications. Peak torque can be achieved by about 2000 rpm.

All supercharger types benefit from the use of an intercooler to remove heat produced during compression. With a Roots-type supercharger, a thin heat exchanger is adapted to fit in-between the blower and the engine. Water is circulated through it to a second unit placed near the front of the vehicle where a fan and the ambient air-stream can dissipate the collected heat.

The Roots design is commonly used on two-stroke diesel engines, which require some form of forced induction as there is no intake stroke. In this application, the blower does not often provide significant compression and these engines are considered naturally aspirated; turbochargers are generally used when significant "boost" is needed. The Rootes Co. two-stroke diesel engine, used in Commer and Karrier vehicles, had a Roots-type blower but the two names are not connected.

The superchargers used on Top Fuel#Top fuel engines, funny cars, and other dragsters, as well as hot rods, are in fact derivatives of General Motors superchargers for their diesel engines, which were adapted for automotive use in the early days of the sport. The model name of these superchargers delineates their size; i.e. the once commonly used "6-71" and "4-71" blowers were designed for General Motors diesels having six Cylinder (engine)s of 71 cubic inches each, and four cylinders of 71 cubic inches each, respectively. Current competition dragsters use blowers of 14-71 design.

Roots blowers are typically used in applications where a large volume of gas must be moved across a relatively small pressure differential. This includes low vacuum applications, with the roots blower acting alone, or use as part of a high vacuum system, in combination with other pumps. Roots blowers are also used as superchargers.

Some civil defense sirens used Roots blowers to pump air to the rotor(chopper). The most well known are the Thunderbolt Siren, and ACA(now American Signal Corporation) Hurricane. These sirens are known as "supercharged sirens".

Roots blowers are also used in reverse to measure the flow of gases or liquids, for example, in gas meters.

Technical considerations Because rotary lobe pumps need to maintain a clearance between the lobes, a single stage roots blower can only pump gas across a limited pressure differential. If the pump is used outside its specification, the compression of the gas generates so much heat that the lobes expand to the point that they jam, damaging the pump.

Roots pumps are capable of pumping large volumes but as they only achieve moderate compression, it is not uncommon to see multiple roots blower stages, frequently with heat exchangers (intercoolers) in between to cool the gas. The lack of oil on the pumping surfaces allows the pumps to work in environments where contamination control is important. The high pumping rate for hydrocarbons also allows the roots pump to provide an effective isolation between oiled pumps, such as rotary compression pumps, and the vacuum chamber.

A variant uses claw-shaped rotors for higher compression.

Comparative advantages The roots pump is never used as a stand alone pump in high vacuum applications but its high pumping speed can be used to reduce the end pressure and increase the pumping speed of other vacuum pump systems in the medium to low vacuum range.

References

• (April 5, 2002). Roots Type Superchargers Explained. SuperchargersOnline.com. Accessed September 11, 2004.
• Blower Briefing. Tom Henry Racing. Accessed September 11, 2004.
• Eaton TVS Supercharger The Eaton TVS Supercharger. Accessed November 11, 2006

The term blower is used to define a device placed on engines that can not breathe on their own and is needed for scavenging and a supercharger is used on engines to boost power even though they are the same device.

External links

• Flash Animation of Roots Pump