Posts

Understanding Compressed Air Systems

In this day and age, it's difficult to find a manufacturing or construction business that does not use industrial compressors regularly in their daily routine. The key advantage of air compressors is that they can take the potential energy that builds up when a gas such as atmospheric air is placed under pressure and quickly convert it to kinetic energy. That energy can be used to drive small power tools such as impact wrenches or nail guns. Larger compressors are used in manufacturing when a large amount of torque needs to be applied. Most importantly, compressors are quite reliable and don't require extensive maintenance. Basic Components of Compressors compressors are similar to small internal combustion engines since they consist of a piston, a cylinder, and a connecting rod that is attached to a crankshaft. The crankshaft is driven externally, either by an electric or gas motor to rotate the shaft and move the piston up or down. The top of the piston cylinder has a valv...

Compressed Air Safety For Employees

To ensure compressed air safety when personnel are handling compressed air cylinders in the workplace (or in fact at home) all components of compressed air systems should be inspected regularly by qualified and trained employees. Operators carrying out the safety tests should individually take note of: the air receivers, the air distributions lines, the pressure regulation devices, the compressor operation and compressed Air Equipment Maintenance. Compressed air safety should be taken very seriously due to the fact that a compressed gas cylinder accident can be fatal for personnel. While it is perfectly safe to work with if the operator knows what they are doing, it can conversely be very dangerous if handled by someone who has not had the correct training or is not furnished with sufficient information. In order to guard against accidents in the workplace and to ensure a happy and healthy working environment, following are typical safety considerations that should be observed: ...

Compressed Air Energy Storage (CAES)

Compressed Air Energy Storage (CAES) is a way to store energy generated at one time for use at another time. At utility scale, energy generated during periods of low energy demand (off-peak) can be released to meet higher demand (peak load) periods. Compression of air generates a lot of heat. The air is warmer after compression. Decompression requires heat. If no extra heat is added, the air will be much colder after decompression. If the heat generated during compression can be stored and used again during decompression, the efficiency of the storage improves considerably. There are three ways in which a CAES system can deal with the heat. Air storage can be adiabatic , diabatic , or isothermic : Adiabatic storage retains the heat produced by compression and returns it to the air when the air is expanded to generate power. This is a subject of ongoing study, with no utility scale plants as of 2010. Its theoretical efficiency approaches 100% for large and/or rapidly cycled devic...

Theory of air compression 2

An air compression is a means by which one type of energy is converted to another. During this conversion certain losses occur because of the rise in temperature of the air as it compressed. In general practice, the air is stored in a receiver and heat is lost both in the receiver and pipe lines running to equipment. Since the rise in temperature of the air is a direct loss of energy. We want to keep it down to a minimum. The ideal method is to compress air isothermally but this is impossible in practice owing to lack of time necessary to affect transfer. Water jackets and inter-cooling can be used to keep the temperature down. These have the effect of reducing the compression index (n) to something less than 1.4. When air is compressed to a pressure to exceeding about 4 bar it is usual to compress it in stages, with intercooling between each stage. This considerably reduces the total amount of work required on the air. For two stages compressing, the air is compressed in the first...

Theory of air compression

Image
Air is not a perfect gas but for practical purpose the laws relative to perfect gases may be applied to it. Boyle’s law states that: The absolute pressure of a gas varies inversely as the volume, provided the temperature remains constant. p V = a constant where: p = pressure in bar, V = volume in m 3 . Charles’ law states that the volume of a gas under constant pressure, or the pressure of a gas under constant volume, varies as the absolute temperature. Therefore V varies as T, and p varies as T where T is the absolute temperature. If the two laws are combined, we get: p V / T = constant The constant is usually denoted by R and therefore: p V = R T It can be shown that the value of the constant R applicable to air is 287.0 J/(kg K). The relation between the pressure and volume of air during its expansion and compression may be represented by: p V n = R T where ‘n’ has value which depends on the addition or subtraction of heat during the process . When the te...

Opportunity of Compressed Air Savings

Approximately 10 % of all electrical power used in industry comes from compressed air. This is proof of its widespread usage but it is also evidence of the potentially large saving in costs which could be achieved if the energy management opportunities are put into practice. Normally, the purpose of compressed air systems in the industrial sectors is to deliver the necessary volume of air at the required pressure and temperature to the correct places. Compressed air is used for operating pneumatic equipments, cleaning purposes, and other general services. This is accomplished by a distribution system consisting of pipes, valves and fittings. The Compressed Air pipe work is arranged in the form of ring mains with interconnections to points of end-users. Careful evaluation of existing compressed air systems can ensure against improper operation, and poor energy utilization. Alert design, operations, and maintenance personnel, with an awareness of energy management, can achieve signif...

Compressed Air System Energy-Reduction Case Study (Part 2)

Let's continue from [ Compressed Air System Energy-Reduction Case Study (Part 1) ] Compressed Air Energy-Reduction Strategy Project Goals and Implementation Following the IAC assessment, FUJIFILM’s maintenance team formulated project goals and an implementation plan that centered on the utilization of existing facility infrastructure and equipment. The team’s implementation strategy was divided into three phases and focused on increasing the system’s storage capacity to handle production peaks and valleys; lowering air compressor operating pressure; repairing system leaks; and ultimately, operating the facility with one compressor. The team’s strategy was also aided by the company’s closure of its Orange Park, Florida, operations. This facility housed a 75 horsepower (HP) air compressor, a dryer, and a receiver, which the Dayton facility incorporated into its efforts. Project success, then, depended on the accomplishment of four specific goals: To increase system redundanc...