Author Archive
Guidelines For Selecting Plasma Cutting Machines
by Hi-Tech on Jul.24, 2010, under Mechanics
In simplest terms, plasma cutting is the process of cutting any electrically conductive metal by using high velocity of ionized gas which is delivered from a nozzle. The high pressured ionized gas which becomes the plasma, conducts electricity from the plasma cutting torch to the work piece. The plasma while coming into contact with the work piece heats and melts the material. Thus the metal pieces are cut smoothly. As plasma cutting is perfect for cutting steel and non-ferrous material, it is widely used in industries as well as by amateurs.
When you are planning to buy a plasma cutting machine, certain guidelines should be essentially followed. One of the main factors to consider is the thickness of the metal that you are cutting. Generally the plasma cutters are rated on their cutting ability and amperage. If you are cutting metal with considerably less thickness, you must consider a lower amperage plasma cutter. Likewise, you must use higher amperage machines for thicker metals. Even though the smaller amperage cutter would be capable of cutting metals of any thickness, the quality would be lacking in thicker metal cuts. The optimal cutting speed of the machine should also be considered before purchasing the cutter. A machine with high amperage would cut the metal much faster than one with low amperage.
In most plasma cutters, the pilot arc conducts high frequency electricity through the air. This electricity would interfere with computers or other equipments. So it would be better to select lift arc method that eliminates the problems of high frequency starting circuits. The plasma cutting torches consists of a number of plasma cutting consumables that would require replacement. It is recommended that a machine with lesser consumable would be long lasting and cost effective.
While purchasing plasma cutters, it would be good to make test cuts with many machines and check the quality of each cut. Here, you must look for a cutter that would offer a tight focused arc. Another quality checking method is to lift the plasma torch from the plate during cutting and check how far you can move while maintaining an arc. Generally when the pilot arc is brought close to the work metal, a transfer occurs from pilot arc to cutting arc. A plasma cutter that provides a quick, positive transfer from pilot to cutting arc at large transfer height would the best choice for getting better support during cutting.
One of the main things to be noted is the working visibility of the machine. While you are tracing a pattern, it is essential to see what you are cutting. A plasma cutting torch which is smaller and less bulky would be the best to provide working visibility. Portability is yet another thing to be noted. It is always better to go for a light weight, portable cutting machine. The most important thing is ensuring the safety features of the machine. It is highly suggested that you must buy a machine with nozzle-in-place safety sensor. This sensor makes sure that the machine won’t start unless the nozzle is in place. It is also good to look for a machine that would provide a pre-flow sequence.
Gavin Bone is an author for Plasma Cutter. He has written articles Welder. For information visit our site mig welders.
Article Source: http://EzineArticles.com/?expert=Gavin_Bone
Something About Air and Water Cooled Chillers
by Hi-Tech on Jul.23, 2010, under Mechanics
The most common compressors used in refrigeration are reciprocating, scroll, screw-driven centrifugal. With various refrigerants chillers used in industry in industrial application, chilled water or other liquid from the chiller is pumped through process. Industrial chillers are used for cooling of products and factory machinery in a wide range of industries.
They are often used in the plastic industry in plastic processing like injection molding, blow molding, extruders, laminations, p.P. Films, rigid p.V.C. Pipe, calendars, chemicals, pharmaceutical process, dyes intermediates, mineral water soda process, paper converting, coating chill rolls, plating and anodizing, lubricants/oil cooling, dairy, bakery, food products, dehumidifier, conditioned air, welding equipment, cement processing, vacuum systems, x-ray diffraction, analytical equipment, compressed air and gas cooling.
Chillers are usually small in size (cooling capacity), usually from 1 tons to 100 tons.
Central chillers generally have capacities ranging from ten tons to hundreds or thousands of tons.
Water chillers can be either water cooled or air-cooled. Water cooled chillers offer efficiencies better than air cooled is due to heat rejection at or near the air’s wet-bulb temperature rather than the higher, dry-bulb temperature but it is used in conjunction with cooling tower.
The heart of the chiller is the refrigeration compressor. This is a pump that uses electrical energy to pump refrigerant around the system. Depending on the application like size or operating temperature, a different compressor pumping technology is used. Smaller chillers use refrigeration compressors like rotary compressors, scroll compressors, and reciprocating compressors. Larger chillers use refrigeration compressor like reciprocating compressors, screw compressors, absorption compressors, and centrifugal compressors.
Article Source: http://EzineArticles.com/?expert=Sunil_Dumbre
Sheet Metal Fabrication – Know Facts About It
by Hi-Tech on Jul.23, 2010, under Fabrication
The process or system of Metal Fabrication is not new. It was developed ages ago. In the past hand tools were used in place of machinery tools to fabricate metals. Now various improved and useful technologies have evolved to complete the process successfully. Improved quality tools are created.
Technological advancements in engineering and metallurgy led to the introduction of various improved metal fabricating techniques and tools. These devices and systems are used and developed for industrial and engineering purposes. Different products with different features are created from different techniques.
Various types of products or objects are created during the metal fabrication process. Some of the most common products produced in this process are ventilation shafts, enclosures, metal cabinets, hoods, tanks, exhaust system, prototypes and tanks. Various other industries or sectors, including food storage, food dispensing, communication, computer, automotive, electronics, medical, telecommunication, aerospace, residential, pharmaceutical and construction also use metal fabrication process.
There are different types of sheet metal fabrication processes. These include
* Bending (straining)
* Annealing (heating)
* Cold rolling (shaping metal using rollers)
* Cold forming
* Forging (hammering or pressing)
* Drawing (material is forced into a die to form a cup-like shape)
* Rolling (reducing width of the material)
* Forging (pressing or hammering)
* Spinning (forms axially equal shapes)
* Extrusion (producing hollow tubes or cylindrical bars by forcing round billets via one or more dies)
No matter how small or big is your unit; the main objective should be performing Sheet Metal Fabrication process with perfection. Dedication and patience are two of the important things that help you to make the process successful.
Choosing the right metal fabricator is very essential. You need to keep in mind certain important things while selecting a metal fabrication service. Make it sure that it has stable and organized platform to give the desired layout of the sheet metal.
There are a number of sheet metal fabrication services all across the planet. It is better to opt for the one that produce quality items using latest and improved equipments or tools available in the industry, such as laser, water jet and other cutting edge technology.
If you are searching for a reputed and reliable sheet metal fabricator and laser cutting service, Garrick Engineering (garrickeng.co.uk) is the right place for you. They provide quality services with dedication and devotion. They have a team of experienced and efficient metal sheet fabricators who put much effort in providing quality service.
Article Source: http://EzineArticles.com/?expert=Ima_Johnson