Saturday, January 17, 2009

Oil Vapour in Compressed Air

The quantity of oil vapour in compressed air depends on:

* Type of oil [coolant]
* End temperature after compression
* Outlet temperature of the compressed air
* Working pressure

NOTE:
Oil Vapour passes all air/oil separator elements
That is, at temperature of 100 degree Celsius, up to 5 times more oil goes through than at temperature of 80 degree Celsius.


If you have a perfectly balanced air/oil separator, then the high oil consumption, due to high oil carry-over to compressed air could be:

* Oil return (scavenging) pipe is blocked
* Oil return (scavenging) pipe too short, not of the correct length
* Oil specification wrong
* Oil vapour too high [due to high temperature]
* Oil level too high
* Air refine efficiency is bad
* Too much oil foam

Characteristic of Compressed Air

Characteristic of Compressed Air






* Compressed air is bearer of heat energy
* Compressed air can bridge certain distance
* Can be stored
* Flashed air delivers power
* Air delivers large volumes of water

Friday, January 16, 2009

Sample Service Contract

Sample Service Contract
[for your reference only, we recommend you use you own version]
1. Cover Letter
2. Service Contract
3. Schedule
4. Scope of Work

-------------------------------------------------------------------
1.
Cover Letter

Our Reference:
Date:

Dear Sirs/Madam: [customer's person name]
Proposal/Renewal of Service Contract

We take great pleasure in presenting to you the service agreement proposal. Our plan is unique in the compressed air business; design to keep your compressed air equipments operating at optimum and maximum efficiency, 365 days a year, at the lowest possible running cost.

It is a well-proven and widely recognized that, preventive maintenance that provides regular, professional service and repair, over a period of time will save you operation cost, thus providing maximum operational efficiency.

It give your compressor optimum performance, maximum productivity and financial security. With fixed maintenance [parts & labour], you will avoid hidden surprises and unnecessary breakdown of your compressor, it provide you total peace of mind to focus other more urgent task.

Our technicians are regularly trained, updated with the latest service development, and equipped with the latest tools.

We are confident that you will consider our proposal favourably.

On your approval, kindly endorse the two copies of this agreement and returned to our office with advance payment. The original copy will be returned to you after processing.

Validity of this proposal is 30 days from the date of this letter.

Assuring you of our best service.

Yours Sincerely,




--------------------------------
[Name & position]

..............................................................................................
2.
Service Contract

Our company offers service arrangement under contractual basis. This arrangement is highly recommended, not only planned service could be arranged, it also ensures the required maintenance is carried out, minimizing unforeseen breakdown.

This contractual arrangement, covers two different activities, they are:

A.
Inspection Contract;
Visit at pre-determine interval to conduct inspection and recommend any necessary service or repair necessary!

B.
Maintenance Contract;
Visit at pre-determine interval to carry out prescribed work, including periodic service.

1.
AGREEMENT


Between
[Customer name & details]

Hereafter referred to as the Customer.

2.
This Agreement cover the following equipment:

Brand:
Model:
Serial Number:
Horsepower:
Number of Units:
Installed at:
Contact Person:
Tel:
Fax:

Remarks:

3.
Validity

This agreement is valid for [..............] year(s), starting from the date [............].
This agreement can be terminated by either party in writing with one-month advance notice.

4.
Extent of this Agreement
4.1
Preventive maintenance will be carried out [...........] times a year.
4.2
The equipment covered by this agreement shall not exceed [.............] hours a year.
4.3
The inspection and maintenance of the equipment will be according to manufacturer's recommendation.
4.4
Agreement price includes labour and specific parts required for each maintenance visit, unless otherwise stated in cluase 2.

5.
The Agree price will be RM[..............] per year.
Invoice will be carried out once a year prior to the first maintenance visit. Payment must be received prior to the first maintenance visit.
{Note: Price is locked in for the year, guarantee no price increase for the year}

6.
The Responsibility and Rights of both parties.


6.1
The customer will perform the daily and weekly maintenance in accordance with compressor's instruction book. The customer here-by confirms that he has a copy of the instruction book, and ensures the compressor logbook is filled in daily.
6.2
[Company name] may contact the customer before the planned time and date for each visit. The customer will then ensure the compressor equipment is available for maintenance.
6.3.
Maintenance will be carried out during normal working hours, unless specified in clause 2. Any extra cost as a result of deviation in original schedule will be invoiced to the customer accordingly and separately.
6.4
If any major changes occur in the operation or site conditions of the compressor equipment, this agreement will become null and void. This includes factors such as ventilation, power and water supply.
6.5
[Company name ] will submit a service report on the condition of the compressor equipment to the customer after each preventive maintenance visit.
6.6
[Company name] will not accept any liability whatsoever for any bodily injury to any person, damage to property or other consequential loss, unless it can be proven that [company name] has been guilty of gross negligence.
6.7
The customer will give all necessary assistance by providing necessary lifting equipment, lighting etc.
6.8
In the event of any supplemental work arising as a result of the maintenance inspection that is not included in this agreement, [company name], however can and will carryout this work and invoice the customer separately based on customer approval and acceptance.

7
Limitation of Responsibility

7.1
[Company name] reserves the right to refuse or stop any further service if any outstanding bills are not paid.
7.2
[Company name] will not be responsible for any compressor equipment malfunction or damage if routine maintenance according o clause 6.1 is neglected or customer's failure to comply with repairs recommended by [company name].

8.
[Company name] standard warranty of 3 months or 2000 hours applies to all repair work, including part, whichever come first.


Signed for and on behalf: [customer]

Signature:
Company chop:
Name:
Position:
Date:

Signed for and on behalf: [company name]


Signature:
Name:
Position:
Date:

.............................................................................................

3.
Schedule

Average Running Hours per Year

2,000 hours +++++ 4,000 hours +++++ 6,000 hours +++++ 8,000 hours
-----------------------------------------------------------------------------------------
Y
E
A
R

1
-----------------------------------------------------------------------------------------
Y
E
A
R

2
-----------------------------------------------------------------------------------------
Y
E
A
R

3
--------------------------------------------------------------------------------------
Y
E
A
R

4
-------------------------------------------------------------------------------------
Y
E
A
R

5
------------------------------------------------------------------------------------

4.
Scope of Work

Period:
1,000/2,000 hours, Monthly visit
Scope of Work:
Measurement of temperature, condition monitoring, air jet clean coolers, motor and compressor.

-----------------------------------------------------
Period:
1,000/2,000 hours, Every 3 months
Scope of Work:
Replace oil filter, clean air filter [replace if necessary], replace compressors coolant, external air jet clean compressors, motor and coolers.

----------------------------------------------------
Period:
4,000 hours or 1 year (12 months)
Scope of Work:
Replace all items from above and, replace air/oil separator element, service moisture trap, grease main motor. Change belts if belt driven units.

-----------------------------------------------------
Period:
8,000 hours or 2 years
Scope of Work:
All of the above, plus, service oil stop valve, inlet valve, Vent valve, MPV, Replace belts.

----------------------------------------------------
Note:
Scope of works may vary for different compressors and model, based on factory's recommendation.

.............................................................................
Extended Warranty Options:
* Air end Cover: Y/N
* 5 years warranty: Y/N

Value Added Options:
* After working hours service: Y/N
* Off-day Service: Y/N

Accessories:
* Dryer service: Y/N
* Main Line Filter Service: Y/N
* Air Receiver auto-drain service: Y/N
* Others (please specified): Y/N
..........................................................

Thursday, January 15, 2009

Pre-Owned Screw Compressors' unit

Used, Ingersoll Rand Twin Screw Oil-flooded Air Compressors
Ingersoll Rand Model: XF-100
Rear View
Front View of the Ingersoll Rand XF-100 Rotary Twin Screw Oil-flooded Air Compressor.



MM 55

Side view ( Right side of the control Panel)

Control panel


Name Tag.





Front part of the compressor with electronic controller.

Pre-Owned Screw Compressors' Parts -- Heat Exchangers

Used Rotary Screw Air Compressors' Parts
[with and without warranty]

Heat Exchangers

Combined Compressed Air Cooler & Oil Cooler.
For Ingersoll Rand EP-20 & EP-25.

For Ingersoll Rand M22 & 30 Cooler ( Air 0r Oil )
Air Cooler and/0r Oil Cooler for model M22 & 30
UK made Compressors.


New and Used Screw Compressors' Parts

New and Used Screw Compressors' Parts

Unloading valve 2/2 way, high temperature and heavy duty type.

1/2" bsp connection.
Heavy duty and high temperature ---- Unloading valve and inlet valve.

Inlet air control valve, 1/4" bsp connection, 3/2 way universal. High temperature and heavy duty type.

Mechanical Automatic condensate drain.

Three used unit are available and new one can be order !!!!
Used units after repair and service ready to paint.
.
Used mechanical auto-drains

Pre-Owned Piston Compressors' parts

Used Piston Type Air Compressors Parts.


Pressure off loading valve 2/2 way !!!

 Pressure off loading valve 2/2 way - High pressure and temperature

 and inlet air valve 3/2 way universal control valve.

Universal valve for inlet air control 3/2 way. --- High temperature, heavy duty type.

Pre-Owned Piston Type Vacuum Pumps

Used Piston Type Vacuum Pumps
Ingersoll Rand T-30



Model: 15V-H10




Only two ( 2 ) units of this Reciprocating Vacuum Pumps Available.
Model: 15V- 10 horse power.

Monday, January 12, 2009

Brake Horse Power

Power and Efficiency

Brake horsepower is the input power required at the compressor input shaft for a specific speed, capacity, and pressure condition.
Motor horsepower is the nominal rating of the prime mover.

The service factor is the additional power built into an electric motor above its nominal rating - expressed as percent. Within the service factor, the brake horsepower driving an air compressor can be higher than the motor's nominal horsepower.

The power efficiency of a compressor is the ratio of the air delivered by the compressor and its input electrical requirements.

Efficiency usually is expressed as brake horsepower per 100 cfm of delivered air.

Small Reciprocating Compressor

Small Reciprocating Compressors

You do not have to hire an outside service company to work on your small reciprocating compressors. We are pleased to offer a unique book, to help you repair these compressors.

The book is easy to understand with useful information, such as the following:

• Explanations for the various components, including illustrations with exploded views.
• Simple diagrams that describe how the controls work.
• Maintenance tips on the 4 most common reasons small reciprocating compressors fail.
• An in-depth trouble shooting guide that includes specific actions to solve each problem.


Order today. The book will pay for itself – many times over the years – by eliminating the need for outside vendors to help with repairs.

Table of Contents

This book has a soft cover with 25 pages filled with material on every aspect of the small reciprocating compressor. Here is a list of the topics.

Chapter 1, Introduction
a) Compressed Air Terms
b) Definitions

Chapter 2, Types of Air Compressors
a) Reciprocating, single and multi stage
b) Rotary Vane
c) Rotary Screw
d) Diaphragm

Chapter 3, Nomenclature
a) Pumps
b) Receiver Tanks
c) Motors
d) Safety Devices
e) Accessories
This includes details on the check valve, centrifugal unloader and aftercooler.

Chapter 4, Controls
a) Starting Controls
b) Operating Controls

Chapter 5, Installation
a) Location
b) Pipe Size
c) Wire Size

Chapter 6, Trouble Shooting
a) Common Failures
b) Diagnosis
c) Correction Procedures

Chapter 7, Overhaul Procedures
a) Minor Overhaul
b) Major Overhaul

Chapter 8, Maintenance
a) Recommended Schedule
b) Reference Charts

Air System Design

Compressed Air System Design

The most economical way to have an efficient compressed air system is to start at the beginning. We can help you design a new compressed air system from scratch, redesign an older system to increase efficiency, or redesign expansion systems to fit into existing systems.

All manufacturing plants can benefit from having a specialist in compressed air involved during the design phase. Often times, engineers who execute plant designs may be great when it comes to general engineering, but are lacking experience in compressed air systems. Most design firms don't generally have compressed air specialists on staff because it is a small part of their overall business.

However, some very small mistakes related to compressed air system design could result in major losses of time, productivity and efficiency.

We are the professionals; measure and troubleshoot compressed air systems every day. We know what works and what does not work. Many of the systems we encounter in the field have problems due to incorrect piping, false pressure signals to the controllers, high-pressure loss, high velocity and turbulence to the system.

Any of these problems can lead to thousands of dollars in lost energy. Because we are not aligned with any equipment manufacturer and take no part in the sale of any compressed air equipment, we can assist our customers in evaluating and making honest recommendations for the components that are right for your operation.

For more information on compressed air system design services, contact us.

Belt Drive Failure

DO YOU KNOW?

Improper belt maintenance is the leading cause of belt drive failure.
Next in line are improper installation, and environmental factors.

typical belt tensioner as found installed in small size, Italian made Screw Air Compressors.

Air Receivers

Air Receivers

Every compressed air system needs a receiver, but the receiver alone is not always the answer to energy efficiency in the system.With its dumpy fat cylindrical shape, dull-painted exterior, lack of visible dynamic activity, and frequently hidden location, it's easy to understand why the air receiver usually is the orphan of the plant-air system family. There is confusion and controversy over its function, where it should be located, what size it should be, how it should be piped - and whether an air receiver is needed at all.

Air receivers are one of the least understood, yet potentially most useful components available to increase operating efficiency.

But an air receiver should be an integral part of any plant air system - mainly to enhance its efficiency.

Here are the classic purposes:

Contaminant removal - A bare receiver (without a pressure regulator or flow controller) adds a large volume to the piping system. This volume reduces air-flow velocity and encourages finely divided particles of liquid lubricant or condensate to drop out of the air stream. These separated liquids then can be drained from the receiver, rather than traveling with the compressed air to produce adverse downstream effects.

Pulsation dampening - A receiver installed near the compressor discharge dampens pressure pulses from positive-displacement compressors (rotary or reciprocating) to a small fraction of their original amplitude. This reduces the probability of excess compressor power or shortened service life resulting from rapid recycling of the compressor.

Pressure stabilization - A receiver combined with a pressure regulator or flow controller can create an effective pressure band or differential between the supply side and the demand side. A typical example: 95 psig in the receiver, 90 psig steady to the system. This will allow the demand side to operate at its lowest effective pressure, and therefore lowest volume demand. Stored air with a pressure differential creates volume held in reserve to cover short-term peak demands that exceed current air supply.

Controlling energy costs
When industry management began to focus on energy-cost control as a weapon for reducing production costs, energy managers soon realized that compressed air was their most expensive utility. After all, it takes 8 hp of electricity to produce 1 hp of compressed air. Air no longer was perceived as free. Its cost should, and could, be managed.

Early efforts in compressed-air cost management focused on the obvious - control of leaks and lowering usage.


Without effective storage, most unloading controls could not establish and hold enough idle time as a percent of running time. Nor could they optimize the automatic start/stop control and shut off.

Compressed Air

Compressed Air

The atmospheric pressure of air, which are measured barometrically, vary depending upon its position relative to sea level.

When air is compressed above atmospheric pressure, its characteristic is to attempt to return to its normal state. Since compression of air requires energy input, energy is then released as compressed air returns to atmospheric pressure.

Compressed air is one of the most versatile and useful forms of energy available. It is used to operate automobile lifts, inflate tires, operate tools, spray paint, many automated machinery in production plants and many other uses in all industries.

Compressed Air for Power
Compressed air is widely used for power. Internal energy stored in compressed air is directly convertible to work; no conversation from another form of energy such as heat is involved, at least not at the point of used. Pneumatic components are therefore characterized by a notably high ratio of power to weight or power to volume. Compared to equipment, which involve translational forces in a variable force field, compressed air produces smooth translation with more uniform force. Not as fast as electricity, nor as slow as hydraulic, pneumatics finds a broad field of application for which its response and speed makes it ideally suited. Where there is an overlap, the choice is often one of economics, and air is likely to hold the advantage. In addition, air doers not possess the potential shock hazard of electricity nor the potential fire hazard of oils.

The attributes of compressed air lead to its application in many different kinds of components. Pneumatic tools producing torque and rotation such as drills, brushes, nut runners and screw drives are common examples. These are generally powered by some form of rotary air motor such as the vane or lobe type, or by an air turbine. Equally common are components producing lateral motion and direct force, either steady or intermittent, with either manual or automatic control. Common examples are clamps, presses and automatic feeds. Often air pressure is used to accelerate a mass, which then exerts an impact upon an anvil, as in paving breakers and pile drivers. Common applications in industrial plants and or construction sites are air powered nailers and staplers.

In paint spraying and, to a considerate extent, in air conveying, motion is impacted essentially by the dynamic pressure of the air.

Advantages of Air Power
High ratio of power to weight in air tools contributes to low operator fatigue.
Air tools run cooler; do not generate heat in performing work.
Air tools have variable speed and toque control.
Compressed air is clean, has no fire hazard, no electric shock potential.

Pneumatic vs. Electric

Safety … Air powered equipment reduces the danger of electric shock and of fire hazard. Air tools run cooler and have the advantage of not being damaged from overload or stalling.

Lightweight … The air tool is lighter in weight and lends itself higher rate of production per man hour with less worker fatigue.

Flexibility … Due to its ability to provide a source of power by means of engine driven portable compressors, air tools can be operated in areas where other power sources are unavailable.

Cost … Due to fewer moving parts and their simplicity of design, air tools provide low cost maintenance and operation.

Pneumatic vs. Hydraulic

Safety … Unless fire resistant fluids are used, hydraulic-powered components operating near open flame or high temperatures present fire hazards. Compressed air components operate with lower system pressures. Accidental air leaks release no contaminants, as with hydraulic.

Low Initial Cost … Fewer parts make up a pneumatic system and the use of a single compressed air supply permits operation of many separate systems. Simple and less costly controls are possible with compressed air.

Flexibility … Compressed air systems provide for simpler installation, particularly where tools are frequently interchanged, such as in automotive service. Compressed air systems offer good adaptability for automation and flexibility for changing or expanding operations.

Maintenance … Pneumatics have less down time than do hydraulics, which have more complex controls and systems. Less preventive maintenance is required with air, whereas hydraulic fluids must be monitored and replaced periodically.

Leakage … Leakage in hydraulic systems results in the presence of hydraulic fluids that are dangerous to the surrounding area, whereas pneumatic system leaks do not contaminate the work area. In addition, leaks in hydraulic systems can result in complete system shutdown.

Summary
Benefits of Compressed Air:
* Easy to transport
* Easy to store
* Clean and dry
* Low weight
* Safe operation
* No accident hazard
* Rational and economical
* Simple
* Safe against overload
* Fast working medium
* Continuously graduable

Thursday, January 8, 2009

Look Beyond the Sticker Price

Look beyond the sticker price when buying an air compressor


It’s the total cost of ownership that should guide you.

When shopping for air compressors, it pays to look beyond the sticker price before you make your decision. The startling fact is that the initial price represents a mere 15% of compressor costs over a 5 to 7 year period.

Smart & savvy purchasing professionals know how to look under the hood, so to speak, when they make their choice.

ENERGY Cost
Buying an energy efficient compressor saves you tens of thousands of dollars in the long run. Compressors are not by their nature very energy efficient. In fact, it can take 7 to 8 hp. of electric power to produce 1 hp. of compressed air power. Energy costs for operating a compressor can exceed the initial cost of the compressor in the first year alone.

Efficient Operations
One way to run a compressor efficiently can be to operate the compressor in a load-no load mode. When in this mode the compressor is either running full loaded, or, when system demand is satisfied, running completely unloaded and blown down.

Of course, it's not wise having a compressor that is always unloaded. To avoid paying a premium for something that sits idle, ensure that your compressor is sized properly to match your needs--both present and in the near future.

Although load-no load is touted as a high efficiency feature, there is a catch. Unless there is a sufficient amount of air receiver capacity--including the volume of air in the piping system--this feature can be energy inefficient.

There needs to be a minimum of 10 gallons of receiver capacity for every cubic foot per minute the compressor delivers. The larger the capacity of stored air, the longer the compressor can remain blown down and operating at a reduced horsepower.

Whenever a compressor's system blows down, compressed air vents to atmosphere. In effect, you're throwing money away by discharging air, you paid money to compressed.

Partial Load
With partial loads the compressor produces compressed air at less than full capacity. The trick is to reduce compressor capacity while maintaining the minimum pressure required. Various methods are used.

Inlet valve modulation, works by controlling the position of the inlet valve that opens and closes in response to system demand. Although extremely responsive, it is the least efficient way to run a compressor partially loaded.

Another way to part load a compressor is by controlling the rotor length. A turn-valve or poppet-style valve unit opens windows up as demand decreases. The inlet valve remains fully open so the compression ratio is not affected.

Instead, the length of the rotor is shortened. At 70% capacity, a turn valve unit can achieve 78 percent brake horsepower--a 13 to 15% energy savings over inlet valve modulation.

Other ways to control the capacity on positive displacement compressors is to control the speed--rpm--through a variable frequency drive on the electric motor.

When buying an air cooled compressor, don't forget to figure in the cost of the fan motor when calculating energy costs. A 100 hp. compressor may use a 3 hp. fan. Likewise, a 500 hp. compressor uses a fan requiring 15 to 20 hp.

High efficiency motors have a higher initial cost, but, over the long run, save money. A standard motor has a 91 to 92% efficiency rating. A high efficiency motor can operate at as high as 96% efficiency.

However, the efficiency rating vary with horsepower.

For example, 50 hp. high efficiency motors have ratings from 92.4 to 93% efficiency and 200 hp. motors have efficiency ratings from 94.5 to 95% efficiency.

Coolers
The size of a compressor's cooler also plays a role in reducing costs. Controlling oil temperature in an oil-flooded rotary screw compressor is a real balancing act. If the oil temperature is too high, it preheats the incoming air. Operating a compressor with a discharge temperature of 190° F versus 175° F can cost 1-1/2 to 2% in overall efficiency, not to mention what happens to the oil.

Keeping the oil cooled and clean pays big dividends. Many people don't think of cleaning their cooler, but by cleaning it with detergent and water, and blowing it out well, the discharge temperature could drop 20° F. That doubles the life of your oil, not to mention the day-to-day efficiency of operation.

High oil temperatures mean lower oil viscosity. This results in reduced lubrication for your bearings. The life of your bearings determines the life of your compressor.

On the other hand, oil that is too cool allows condensate to form in the system. It is important & necessary to keep any water in a vapour state until it can be removed in the aftercooler--harmlessly.

Discharge oil temperatures much below 170° F may cause condensate to drop off in the oil. This increases the oil level in the system. It also causes the increase oil carryover. A thinner oil does not provide effective lubrication and internal parts can be damaged.


Bearings
The size and quality of the bearing can have an effect on the life of a compressor. Most manufacturers choose a bearing with a L10 life of 100,000 hours.

L10 life--once known as B10 life--is the theoretical fatigue life of a bearing in which 10 percent of the population of bearings will fail under ideal conditions.

Unfortunately, very few compressors operate under ideal conditions because of inconsistent or inadequate maintenance.

Experience has shown that a compressor with an L10 life of 100,000 hours needs to be overhauled every 30,000 to 32,000 hours--4 years of round the clock service.

The size of the bearing is determined by the size of the rotor. The larger the rotor, the larger the bearing. Also, as rotor size increases, rotor speed decreases.

A compressor running at a lower speed--1,500 rpm--tends to be more forgiving than one running at a high speed--3,000 rpm or more.

Contamination
In the course of daily operation, it is common to have dirt or other contaminants enter the compressor. Dirt and debris cause more damage to a compressor with small bearings running at a higher speed, than to one with larger size bearings operating at a lower speed.

Also there is a direct relationship between noise and higher speed compressors.
Low speed[rpm]=Low Noise; High speed[rpm]=Loud Noise.
Noisy compressors require either sound enclosures, a separate room, or both.

Installations
Installation costs may need to consider when purchasing your compressor. Although rotary screw compressors need only a level floor beneath them, expenses can mount when connecting a compressor to your plant air system.

Look for compressors that have piping and wiring connections near the edge of the frame. These are much easier and less expensive to install.

It is also wise to consider the labour costs involved in working on compressors. Beware of compressors whose consumable parts are not easily accessible. Look for maintenance reducing design features like simplified access to an air-oil separator and filters, as well as spin-on filters. These design features can cut maintenance time by up to 90%.

It's best to have all electrical lines in conduit--tucked out of the way--where they won't be damaged by liquids, oil spills, or chemicals found around compressors. These contaminants break down the wiring insulation, creating a safety hazard.

Price of consumable parts
Compressors with the lowest price tag may carry aftermarket - consumable parts with the highest price tags. When comparing compressors, look closely at the cost of aftermarket - consumable parts.

Maintenance
When it comes to maintaining a compressor, make sure that you have a consistent maintenance program. Including regular briefing & training of your technicians.

If you do not have the personnel to perform the maintenance, obtain maintenance agreements through a distributor that sells the compressor.

Nothing has a greater impact on the life of a compressor than a quality maintenance program.


Finally, in conclusion
When comparing compressors, be careful to compare apples to apples.

Look beyond the sticker price to the rated efficiencies, oil carryover levels, cost of aftermarket - consumable parts, ease of installation, ease of maintenance, easy availability of aftermarket parts and service support.

The initial price is important, but the real value is what you get for that price in terms of energy efficiency, reliability, and maintenance costs.

Air Dryer

Compressed Air Dryer

Two common types of dryers are refrigeration and adsorption (desiccant). When choosing a dryer, a general rule is to first select a pressure dew point that meets the requirements of the application and is 15° to 20° below the plant's lowest ambient conditions.

(A dryer's efficiency is measured as the dew point, which is the level of dryness in a compressed air system.)

Dew point determines the major difference for selecting either refrigeration dryers or desiccant models.

Refrigeration dryers cool air to a pressure dew point of 2 to 10°C, which is the effective limit on this type of dryer, as water freezes at 0° C. This style is ideal for general industrial applications in light assembly, including those that use air motors, air tools, valves, cylinders and rotary actuators, and painting and welding equipment.

When piping is installed in ambient temperatures below the dryer dew point (i.e., systems with outside piping), refrigeration dryers are not suitable.

Adsorption dryers pass air over a regenerative adsorbent material that strips moisture from the air. These types of dryers are extremely efficient and can provide a pressure dew point at 7 barg as low as -40° C. Desiccant dryers remove liquid from the compressed air system through the use of chemical beds.

A portion of the dried air is usually drawn off, passed through the chamber being regenerated, and discharged to atmosphere.

Clean Air System

How to select Air Dryer


The right air dryer for the application
Selecting the right dryer requires a combination of evaluating technical factors with actual field experience.

Factors include the type of system, size of connecting lines, water capacity, flow capacity (system size), filtration capability, construction materials (i.e., steel or copper), and safe working pressures.

For Refrigerated Compressed Air Dryer:

Step 1:
From catalogue or brochure furnish by supplier;
From Charts; Conditions (Inlet temperature & Air Pressure)
Inlet Air Temperature Co-efficient, let it be = A
Air pressure C0-efficient, let it be = B

Step 2:
To Calculate the necessary air handling capacity for the model to be select;
Therefore; Air Capacity (Air dryer) required = inlet air volume (Flow rate) / [A x B]

Step 3:
Then select the suitable air dryer for the specification above the calculated air dryer capacity.
We therefore choose the Air Dryer model with handling capacity more than the calculated figure.


Benefits from using Air Dryers
Low-pressure dew points derived from implementing air dryers helps prevent corrosion and inhibits the growth of micro-organisms within the compressed air system. Corrosion causes rust and pipe scale that, over time, breaks away and causes damage or blockage in production equipment and, in some cases, can contaminate final product and processes.

Moist air provides an ideal environment for the growth of micro-organisms. If only a few of these bacteria or viruses enter a sterile process or clean production system, damage may result, diminishing product quality or rendering a product unfit for use.

Air dryers are not the same!

Products for the filtering and drying compressed air are often selected because of their initial lower purchase cost, with little regard for the air quality they provide or the cost of operation and maintenance throughout their life cycle.

Dryer equipment with a low purchase price may turn out to be a costly investment in the long run. While initial purchase costs are important, air quality, energy efficiency, and lifetime costs are the real issues.

Poor air quality with too much moisture can damage components in the air system, as well as to end products – costing a manufacturer in terms of both money and reputation. Quality air dryers also minimize pressure loss, a major contributor to operational costs, thus reducing energy consumption.

And finally, quality air dryers last longer than lower priced models, reducing downtime and maintenance costs while contributing to increased output.

By improving air quality, lowering energy consumption, and minimizing maintenance, air dryers from leading providers can reduce the total cost of ownership and improve a manufacturer's bottom line through improved production efficiencies.

Friday, January 2, 2009

Shaft Seals

Shaft Seal
Basically, There are 2 types of seals in use on Air Compressors air end:
Lip seal & Mechanical seal.

Typical lip seal

Air End Bearing

Some Air End Bearings from our store
QJ Bearings
NU Bearings
Roller bearings

Motor Bearings

Maximize Bearing Life Cycle
Mounting and Lubrication

Mounting is one of the critical stages of bearing's life-cycle. If the bearing is installed properly using the correct method and tools, the bearings service life-time will be greatly reduced.

Lubrication is also an important step in the installation procedure. Selecting bearing grease suitable for the compressor application is critical to achieving optimum performance.

Further more, the quantity of correct grease and the lubrication method used can positively influence the service life of the bearings.

Re-Lubrication
When put into operation, the bearings require correct re-lubrication practices to optimise its performance.

Selecting the correct bearing grease and applying the right quantities at correct intervals are essential for achieving the maximum service life of the bearing.
Additionally, the re-lubrication method used can positively contribute to optimising the bearing's service life. Continuous lubrication using automatic lubricators, single or multiple-point, provides more consistent, correct and contamination-free supply than manual re-lubrication methods.
Alignment
After the bearing has been installed in an motor or pump, the set should be aligned. If it is not properly aligned, the misalignment may cause the bearing to suffer additional load, friction and vibration.

These can accelerate fatigue and reduce the bearing, as well as other machine components service life. Increased vibration and friction can greatly increase energy consumption and the risk of premature failures.




Basic Condition Monitoring
During operation, it is important to regularly inspect the condition of the bearing by performing basic condition monitoring, such as temperature, vibration and noise measurements.
These regular inspections will allow the detection of potential problems and help to prevent unexpected compressor break-down.

Consequently the compressor maintenance can be planned to suit the production schedule, thurs, increasing the plant's productivity and efficiency.

Dismounting
At some point in time, the bearing will reach the end of its service life and will have to be replaced. Although the bearing may not be used again, it is extremely important to dismount [dismantle] it correctly so that the service life of the replacement [NEW] bearing is not compromised.

Firstly, the use of proper dismounting methods and tools will help prevent damage to other machine components, such as shaft and housing, which are often re-used.

Secondly, incorrect dismounting techniques can be hazardous to the operator.

Dismounting Tools
Sample of Some of the dismounting hand tools in used!
1. Two-leg version
2. Three-leg version

Source from http://skf.com