Energy Saving Report-NEI Jaipur

Compressed Air Energy Saving M/s. National Engineering Industries Limited Page 1 18/07/2016

Contents
Topic Page No.
1. Abstract 3
2. General
 Leakage Estimation & Recommendation 4 – 6
 Cleaning /Air Blowing process & Recommendation 6 - 7
 Machinery Improvement & Air Quality 8-9
 Air Quality ` 10
 Pressure Regulation & indication 10
 Flow Measurement 10
 Staff Education & Training on Compressed Air 11
3. Observation & Recommendations 12-15
4. Conclusion 16

3rd
May, 2014
Compressed Air Energy Audit
Conducted by SMC Pneumatics (India) Pvt. Ltd
For
M/s. National Engineering Industries Ltd.– Jaipur
Rajasthan (India)
Report Prepared by: SMC Pneumatics (India) Pvt. Ltd.
Co-ordinated By: Mr. Prabhat Mathur, National Engineering Industries Ltd.
Conducted By: Chirag Naithani, SMC Pneumatics (India) Pvt Ltd
Abstract
Compressed Air usage contributes significantly to the overall energy consumed at M/s.
National Engineering Industries Ltd. production sites. In general terms this normally
exceeds 30% of the overall energy costs (based on industry statistics). Accordingly, a
reduction in the use of compressed air through efficiency improvements will realise
savings (usually significant) to NEI , and an indirect reduction in carbon emissions. In
addition, there are many additional indirect savings that will realise improved efficiencies
at M/s. National Engineering Industries Ltd..
Given the perception by many that compressed air is an inexpensive and plentiful
resource; little consideration is generally given to improvements in this area. SMC
Pneumatics has over many years been actively involved in developing products and
processes associated with the efficient usage in compressed air energy and to working
with customers to establish efficient compressed air usage practices.
It is expected that with the introduction of the recommendations introduced through an
SMC compressed air energy audit that M/s. National Engineering Industries Ltd.. will
benefit from the development of product and technologies focused on the reduction and
efficient use of compressed air. The objective of this report is to identify improvements
in an effort to reduce the adverse effects of excessive and/or unnecessary energy usage.
SMC will work closely with M/s. National Engineering Industries Ltd. to ensure that the
energy saving initiatives is ongoing and advice of further developments (as these are
developed and released). This initiative will assist M/s. National Engineering Industries
Ltd. to maintain positive trend towards reduced energy usage, and benefit from the cost
savings and improved efficiencies.

General
When considering compressed air as a source of energy it is essential that a focused
management plan is introduced to ensure:
 Processes and facilities are genuinely required
 Processes are best serviced by compressed air
 The selection of the correct components; that these are installed correctly
 Operating pressures and flow rates are established at efficient levels and
maintained.
 Operating staff can identify (and avoid) waste.
 The equipment is maintained correctly, and maintenance is planned
The survey conducted identified a number of key initiatives that, if implemented, will
provide significant cost savings to M/s. National Engineering Industries Ltd. The
initiatives are outlined below in key points, for ease of reference, with more detailed
information provided later in the document.

Each of the key points should be addressed in accordance with Plan–Do-Check-Act
(PDCA) principles. In order to benchmark performance the initial state of energy
consumption must be measured at key locations. Energy usage must be quantified at the
points of application. As each of the key points is actioned the effect can be measured
against the original (benchmarked) values and the savings and efficiencies realised.
While the initial site inspection cannot identify every instance where energy reduction
can occur, it provides a cross-section of the machinery and processes. The methods
suggested in this report can be transferred throughout the M/s. National Engineering
Industries Ltd. production processes.
Prior to describing the efficiencies that can be realised through the efficient use of
compressed air we will describe a typical factory situation.
Typical Compressed Air Usage Pattern
Air Blowing
Actuators
Leakage
Excess Demand
Compressed air is normally applied to a process without the precedence of an
engineered accurate calculation. In other words the compressed air is applied using
some factory generalisations on pressure and required flowrate. This procedure has
evolved in industry on the premise that compressed air is ‘inexpensive’. Nothing could
be further from the truth.
The perception that machinery suppliers and manufacturers have applied efficient air
consumption practices in the design is often far from accurate. Rarely is a maximum
flowrate and pressure specified by an end user in the contract considerations for
machinery. When we consider that in the purchase of a car the energy usage (fuel
consumption) is paramount in our thinking, perhaps there is a genuine requirement to
consider the energy usage in all machinery purchase contracts. This should include the
inclusion of pressure and flow measurement on all process and production machinery.
Compressed air pressure is required to develop the forces required to provide the
necessary actuation of air cylinders etc. Often the pressure is increased during the life of
a process, for no apparent reason. However it is often increased to overcome a problem;
that should be addressed using other practices. Air pressure should be benchmarked
and measured on a regular basis to ensure no unnecessary deviation.
In many instances the pressure required in a factory is standardised for all processes.
However it is often difficult to establish which model was used to establish the standard.
In fact each application is unique, and if treated as such the energy required should be
regulated to be fit for purpose, without waste.
As a source of energy for drying or air blowing product compressed air has many
applications. Provided that the airflow rates and pressures are maintained at efficient
and safe levels then energy waste from this application can be minimised or eliminated.

This use of compressed air is often the most wasteful as the degree of air blow is
normally ‘subjectively’ adjusted. It is necessary to measure both the pressure and flow
rates of air used in each blow-off application.
Pressure is form of energy!! A rule of thumb says…
“For systems in the 100 psig range is: for every 2 psi increase in discharge pressure,
energy consumption will increase by approximately 1 percent at full output flow As also
another 0.6 to 1.0 percent increase in energy consumption because of the additional
unregulated air being consumed”
“The combined effect results in a total increase in energy consumption of about 1.6 to 2
percent for every 2 psi increase in discharge pressure for a system in the 100 psig range
with 30 to 50 percent unregulated usage”
Based on the graphical representation above SMC recommends that M/s. National
Engineering Industries Ltd. addresses each of the identified areas as an individual
project. This will permit the requirements of each of these sections to be implemented
throughout the plant in a consistent and planned manner.
Yellow Project Leakage - All air leakage
Blue Project Air blowing / Air Nozzle Applications
Red Project Actuators (Machinery Improvement)
Green Project Excess Air Flow / Pressure Generation
“Given the volume of compressed air consumption at this M/s. National Engineering
Industries Ltd. site, the initial survey indicated there would be significant reduction in
energy from initiatives to use this valuable (compressed air) resource more efficiently”
A. Leakage Estimation:
For compressors that have start/stop or load/unload controls, there is an easy way to
estimate the amount of leakage in the system. This method involves starting the
compressor when there are no demands on the system (when all the air-operated, end-
use equipment is turned off). A number of measurements are taken to determine the
average time it takes to load and unload the compressor. The compressor will load and
unload because the air leaks will cause the compressor to cycle on and off as the
pressure drops from air escaping through the leaks.
Total leakage (percentage) can be calculated as follows:
Leakage (%) = [(T x 100) / (T+t)]
Where: T = on-load time (minutes), t = off-load time (minutes)
Leakage will be expressed in terms of the percentage of compressor capacity lost. The
percentage lost to leakage should be less than 10 percent in a well maintained system.

Recommendations:
 Isolate the air supply to the machine, when not in operation by installing ball
valve with rotary actuator or 2/2 process valve interlocked with operator control
panel.
B. Cleaning /Air Blowing. Throughput the plant there are a number of air
connections for general utility cleaning/air blowing. The air connections do not have
individual pressure regulation and properly sized nozzles, which is resulting in
significant amount of compressed air energy wastage:
EXISTING PROPOSED

Case Study Blow Guns
Customer : ABC
Parameters Conventional VMG
Model Customers existing model VMG11BU-02-12
Nozzle Diameter 3.74 1.5
Blow Time 10 Sec. 10 sec.
Blow Cycle 0.5 per minute 0.5 per minute
Consumption observed 250 LPM 49 LPM
Per day air consumption in M³ 20.00 3.92
No. of blow guns 90.00 90.00
Total air consumed in m³ per
day on blow guns
1800.00 352.80
Operating cost of Blow guns
in INR
1710.00 335.16
Comparative savings per day
on operating cost in INR
1374.84
Annual savings in INR 343710.00
Total Investment 187920.00
Pay Back period 137 days
Effect of improvement on savings:
Each of the ‘tube’ has a diameter of (approx) 6mm. More over energy efficient nozzles
can be employed and the pressure and flowrate at each point of application regulated to
‘as required’. A summary is shown below:
Nozzles are typically used to direct a stream of pressurised air at the product. This is
used to convey the product in many areas. Through the correct selection of nozzle with
diameter far less than that used on the machines, using much reduced pressures can
provide sufficient ‘blowing force’.

C. Machinery Improvements
The design and operation of machinery generally changes with time. This is normally
associated with the ‘localisation’ or site specific requirements that may have not been
realised at the time of machinery design or perhaps purchasing ‘off-the shelf-solutions’
that may capable of more than the required task. Accordingly it is necessary to trim the
machine to the as required situation.
During the survey carried out several features of each machine were observed to
determine where possible savings or efficiencies could be realised. With time and further
analysis additional savings and efficiencies will be realised.
Cylinder Operating Pressures.
It has been observed that the same pressure level to both loading cycles of an Actuators
(Double Acting) are being provided without even thinking that return stroke normally is
an idle stroke, which doesn’t require similar pressure:
Recommended Improvement:
The air consumption of the cylinder can be reduced by installing pressure and flow
valves. 40% of reduction can be obtained by operating the return stroke at a reduced
pressure without compromising on cycle time:
Case Study ASR/ASQ
Customer :XYZ
Parameters Conventional With ASR & ASQ
Model Customers existing
model
ASR630F-03-12S &
ASQ530F-02-08S
Cylinder Bore/ Stroke 80mm dia / 125 stroke 80mm dia / 125 stroke
Cycle of operation 15 15
Consumption observed in CFM 2.89 1.82
Per day air consumption in M³ 117.91 74.26
No. of stations 59.00 59.00
Total air consumed in m³ per
day operation
6956.81 4381.10
Operating cost in INR 6608.97 4162.05
Comparative savings per day
on operating cost in INR
2446.92
Annual savings in INR 611729.70
Total Investment 119260.00
Pay Back period 49 days

Air Quality:
“It is always recommended to maintain the PDP below 10°C
to avoid below listed problems in the facility”
1) Higher pressure requirement by actuators to do the similar job because
resistance caused by water-oil emulsion in movement of piston inside the
barrel.
2) Frequent failure of actuators & valves.
3) Increased pressure drop across filters.
4) Malfunctioning of Solenoid valves.
Recommendations:
1) Dedicated refrigerated air dryer or membrane air dryer should be placed
before every machine to remove moisture & the problems mentioned
above. We strongly recommended dedicated small air dryer to the
machines where you facing moisture problems.
2) For removing water droplets from the pneumatic parts (present in the
machine), water separator should be used.
D. Pressure Regulation and Indication.
Throughout this report continual reference is made to the pressure of the
compressed air. The cost savings indicate the considerable reduction in energy use,
when the few examples are studied. The regulation of pressure at ‘the point of
application’ permits the correct pressure to be used and this must be closely
monitored to ensure that the pressure at each point is monitored and maintained at
the ‘as required’ level. It is easy to reverse these indicated savings if no monitoring is
carried out. Who should monitor these pressures? It is suggested that the operators
should be the first monitor. If the operators can easily monitor the pressures and
understand the benefits to the company and flow on effect to all employees, then
they can accept some ownership of the efficiencies realised. To make the monitoring
process easier for all, it is recommended that the use of relatively inexpensive digital
displays be utilised. Using dual colour displays the operator can merely monitor for a
‘green’ display rather than a ‘red’ indication which indicates higher than normal
pressure.
Pressure indication should be easily displayed in an accurate format. Where it is not
easy to read the pressure it is beneficial to provide dual colour display. Here the
colour can be programmed to change (from green to Red or Red to Green) at a
predetermined pressure. For operators this provides ease of reference and also it
can be viewed at a supervisory level, where the supervisor can scan for ‘red’ or
‘green’ to indicate the status of pressure. Also the pressure indicators can be used to
provide switched outputs or Analog outputs to operate alarms, lamps or as an input
to a supervisory system or controller.
These indicators can be provided as standalone pressure measurement or can be
installed onto pressure regulators.
E. Flow Measurement.
Air volume will reduce as a result of the reduced pressure implementation. However,
as leakage can always occur it is ideal to provide for ongoing measurement and
monitoring of airflow to the various sections of the factories operated by M/s.

National Engineering Industries Ltd. Monitoring for maximum allowable flow rates is
a management tool. It will ensure energy efficiencies are maintained to acceptable
levels.
Flow measurement can be:
Total – where the plant air consumption is measured from a single point, namely; the
compressor outlet. This type of measurement is good for an overall picture but does
not discriminate between factory locations. Hence it may be difficult to identify the
exact area of inefficient / high air consumption.
Application Specific – Where the flow measurement is installed to a particular area or
process. This provides a local focus on air consumption, and will identify specific
areas of inefficient or high consumption.
Measurement of lower flow rates (typically less than 10,000 L/min) at point of
application it is beneficial to use a thermal mass flow style flow switch, sized to the
required flow rates. These contain visual displays for local observance of the flow
rates, but also provide switched outputs and pulse outputs for monitoring and
recording by PLC or supervisory system.
F. Staff Education:
Compressed air if mishandled can inflict serious injury and in some cases prove
lethal. Operators are often not familiar with the safe working practices associated
with this energy source. SMC can provide facilitated workshops to M/s. National
Engineering Industries Ltd. employees on the efficient use of compressed air and
safety associated with compressed air usage. This education would also introduce
the efficient use of compressed air to operators. SMC could schedule these
workshops to suit the requirements of M/s. National Engineering Industries Ltd.

National Engineering Industries Ltd. (Jaipur, Rajasthan)
Observation & Recommendations
During our level 1 walk through in your facility, we have observed that the leakages
are major consumer & could be tune of more than 30% of your total generation (this
figure is based on assumption & on our experience, and on actual measurement).
Air Audit conducted on the following machines using Air Audit Kit:
1. KN 705 Izumi A 297 Machine Line. No. A9:-
Total consumption : 24 CFM
Leakage : 11 CFM
Actual Consumption : 13 CFM
Blow Gun in the machine :-
Legris make Blow Gun : 10 CFM
SMC make Blow Gun : 5 CFM
Total Saving : 5 CFM
3. QTC SKF Quality technology :-
Leakage through 2/2 valve : 9 CFM
At SES - Gopalpura Jaipur
4. Ace Machine A-4 :-
Total consumption : 12.5 CFM
Leakage : 10 CFM (Including continuos Air blowing)
Actual Consumption : 2.5 CFM
5. Ace Machine A-6:-
Total consumption : 4.6 CFM
Leakage : 3.5 CFM
6. Ace Machine A-13:-
Total consumption : 13 CFM
Leakage : 11.5 CFM

We have made some observations & areas of improvement, are identified as
listed below:
 It has been observed that Water separator & Mist separator is not present in the
compressed air line,which decrease the life of all pneumatic products.
 Flow measurement or monitoring is not present in the compressed air line, which
gives no idea of how much compressed air is consumed & how much
compressed air is generated from the compressor.
 There is no U traps with auto drain is provided in the compressed air line which
help to remove line moisture & impurities present in the compressed air line.
 Pressure at each point is not monitored and maintained at the ‘as required’ level.
 Air is being supplied to the machines, irrespective of whether machine is in
operation or not, causing wastage in the form of unavoidable leakage.
 There is no flow monitoring at the machines side also which will give no idea of
actual consumption & leakage present in the machines.
 Presently some of the area conventional blow guns with 8mm diameter blow
pipe are being used for cleaning purpose, which could be consumed as high as
300 LPM or 10 CFM. Also in some areas open blowing from tube is being done,
which is on the same pressure as used in the machine. Pressure regulation is not
being done at any area.
Air Leakage :
Air leakage is difficult to assess unless flow measurement is carried out.
Estimates will be used in an attempt to quantify the volume of air leakage. Given
that a 1mm (diameter) hole constitutes a relatively small leak in practical terms
we will base our estimates on a comparison with this ‘gauge’. Below is a table
that highlights the costs associated with various diameter (equivalent) leaks
There were few areas in the factory where leakage was not present. Typically it
occurs at screwed connections, poor fitting hose and component failure (seals etc).
With the background noise that occurs in a typical factory many leaks are not readily
‘audible’ unless the machinery is not operating (lunch breaks, before start etc). This
is the ideal.
A 1.0mm diameter hole in an air system operating at 8 Bar is likely to discharge air to
atmosphere at 51 LPM. This single leak is likely to cost around Rs.18,727 per
annum for an 8400 hour operating year. Ten such leaks (not unrealistic in a factory)
operating at 168 hours per week will cost directly around Rs. 1,87,270 per year.

A maintenance program will rectify leakage that is reported, however the operator is
the best tool to identify the leakage. Here education on the benefits of repairing
leakage will be necessary.
While a zero leakage rate is preferable, it is rarely achieved. The above shows a
relatively small leakage rate for a factory complex of the size of NEI. Realistic leakage
would be well in excess of these values.
This demonstrates both the cost and also the need to regulate air to the ‘as required’
pressure at the point of application. This point cannot be over-stressed.
Recommendations by SMC:
1) It is always recommended that there should be 1/100 slope in compressed air
main line & after the certain length U-traps should be provided. All U-traps need
to be equipped with auto drain at the bottom.
2) It has been observed that Water Separator & Mist separator is not present in the
compressed air line, which decrease the life of all pneumatic products. These
product should be installed in the compressed air line.
3) It has been observed that there were no shut off valves in machines to cut
compressed air supply when machine is not in use. Isolate the air supply to the
machine, when it is not in operation by installing ball valve with rotary actuator or
2/2 process valve interlocked with operator control panel.
4) It has been observed that open blowing is continuously done in machines which
will consume most of the compressed air, In order to rationalise that, special
nozzle should be mounted on the tube where open blowing is done.
5) Reduce the line pressure to the minimum acceptable level. This can be done by
reducing the discharge pressure settings or by use of pressure regulators on
major branch lines.
6) SMC PU tubes are manufactured with 1st
grade plastic & are in transparent colour.
We recommend use of such transparent tubing (For visibility of moisture &
impurities present in compressed air) along with quality fittings with thread
sealant.
7) Maintain good air quality in the system - contaminants or moisture in the air
system cause increased leakage and equipment malfunction.
8) Accurately estimate the correct air pressure for the system, for example blowing
application required minimum compressed air pressure. Over pressurization
results in higher compressed air leakage and higher energy costs.
9) Air Auditing at regular interval (at the time of preventive maintenance) is
recommended to fix & remove leakages in machines.

Misc. Recommendations:
Further Recommendations for National Engineering Industries
Ltd. to implement Energy Saving:
 Replacement of manual drains with auto drains.
 Place small flow meter in each single line to check the continuos flow rate
of the line & consumption of the process.
 Use of energy saving series 2/3 port valves (low power consumption).
 Use compact manometer in line to check differential pressure or measure
air blow rate.
 Use of S coupler which feature energy saving by pressure loss reduction.
 Monitoring differential pressure across the filters with properly graduated
differential pressure gauges.
 For different levels of operating pressure use Pressure Booster in single
line to boost air pressure & regulator to regulate.

Conclusion
This report highlights some of the costs associated with compressed air usage at the
M/s. National Engineering Industries Ltd.– Jaipur, Rajasthan Site. While in the time
available it was not possible to access all areas with sufficient time to identify all
cost savings, as the process of undertaking some of the recommendations herein
progresses, other areas will become obvious.
Based on estimates from this initial site survey, it is quite clear that M/s. National
Engineering Industries Ltd. will benefit from a substantial reduction in compressed
air energy costs. This will contribute to the overall reduction in carbon emissions
resulting from the energy to generate the required power. With a commitment to
realize both the cost savings and the ongoing improvements in the carbon footprint,
M/s. National Engineering Industries Ltd. can demonstrate these savings at all sites.
SMC having completed the initial assessment detailed in this report can work with
M/s. National Engineering Industries Ltd. to ensure the recommendations is
implemented. Following the introduction of energy saving measures detailed a
further assessment should be conducted and the results quantified with further
measurements. In order that this energy saving project is successful it is necessary
that the process operators and maintenance personnel accept some ownership. The
training offered by way of the facilitated workshops will assist the operators etc to
gain an appreciation of the benefits to the environment and the benefits to M/s.
National Engineering Industries Ltd. personnel of reducing the compressed air
energy consumed at NEI sites.
SMC is pleased to partner with M/s. National Engineering Industries Ltd. in an effort
to provide these substantial energy cost savings. The initial air flow measurements
done in NEI will be possible to quantify the savings for the site. Implementing air
audit as an internal project to undertake the necessary plant improvements will
provide a planned and managed approach with clear measurement of the resulting
savings.

Energy Saving Report-NEI Jaipur

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