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White Paper: Compressed Air Cost Savings for Small Food Processing www.hitachi-america.us/airtech HITACHI AMERICA, LTD. Air Technology Group 5808-Q Long Creek Park Drive, Charlotte, NC 28269 Tel: 704.494.3008 x28 www.hitachi-america.us/airtech; [email protected] Hitachi Industrial Equipment Systems Co., Ltd. White Paper: Compressed Air Cost Saving for Small Food Processing With recent trends and consumer concerns for food safety, many food processors are considering and adopting the use of oilfree compressed air for their food manufacturing process. One of the major concerns is the capital investment of oil free air compressors, as typically oil free compressors are significantly more expensive than lubricated units (sometimes called OilBath, Oil Flooded or OilInjected). A possible alternative for those who want to avoid the high initial investment of an oil free compressor may be a lubricated compressor with food grade lubricant. As consumers become more and more sensitive for food safety, food grade lubricant may not be in their best interest if the air comes into contact with the product or packaging materials during the manufacturing process. Oil free compressors can and do eliminate the issue and provide the best air quality (Class 0 Certification, ISO8573.1). An OilFree Compressor when properly applied can provide financial savings. Here are a few concepts to be aware of during the design of an air compressor system. Knowledge of the actual “point of use” pressure requirement by the manufacturing equipment is essential. Typically, pneumatic equipment requires 40 to 70 psig to operate. In order to fulfill plant wide needs of air, many companies tend to choose air compressors with a design pressure of 125psi. This higher design pressure is to accommodate for air pressure drops and still be able to achieve 90 to 100psig. Many applications such as air blowing, air knifes, cylinder movement, etc. may not necessarily require a high pressure supply. All plant equipment should be researched to determine the correct amount of pressure required. Applying a 100psi air compressor instead of a 125psi air compressor can save up to 10% of the operation cost. (Below graph 1) Graph1. The theoretical power to adiabatic air compression

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White Paper: Compressed Air Cost Savings for Small Food Processing

www.hitachi-america.us/airtech

HITACHI AMERICA, LTD.Air Technology Group

5808-Q Long Creek Park Drive, Charlotte, NC 28269 Tel: 704.494.3008 x28 www.hitachi-america.us/airtech; [email protected]

Hitachi Industrial Equipment Systems Co., Ltd.

White  Paper:  Compressed  Air  Cost  Saving  for  Small  Food  Processing  

With  recent  trends  and  consumer  concerns  for  food  safety,  many  food  processors  are  considering  and  adopting  the  use  of  oil-­‐free  compressed  air  for  their  food  manufacturing  process.  

One  of  the  major  concerns  is  the  capital  investment  of  oil  free  air  compressors,  as  typically  oil  free  compressors  are  significantly  more  expensive  than  lubricated  units  (sometimes  called  Oil-­‐Bath,  Oil-­‐Flooded  or  Oil-­‐Injected).  A  possible  alternative  for  those  who  want  to  avoid  the  high  initial  investment  of  an  oil  free  compressor  may  be  a  lubricated  compressor  with  food  grade  lubricant.    

 As  consumers  become  more  and  more  sensitive  for  food  safety,  food  grade  lubricant  may  not  be  in  their  best  interest  if  the  air  comes  into  contact  with  the  product  or  packaging  materials  during  the  manufacturing  process.  Oil  free  compressors  can  and  do  eliminate  the  issue  and  provide  the  best  air  quality  (Class  0  Certification,  ISO8573.1).  

 An  Oil-­‐Free  Compressor  when  properly  applied  can  provide  financial  savings.  Here  are  a  few  concepts  to  be  aware  of  during  the  design  of  an  air  compressor  system.  Knowledge  of  the  actual  “point  of  use”  pressure  requirement  by  the  manufacturing  equipment  is  essential.  Typically,  pneumatic  equipment  requires  40  to  70  psig  to  operate.  In  order  to  fulfill  plant  wide  needs  of  air,  many  companies  tend  to  choose  air  compressors  with  a  design  pressure  of  125psi.  This  higher  design  pressure  is  to  accommodate  for  air  pressure  drops  and  still  be  able  to  achieve  90  to  100psig.  Many  applications  such  as  air  blowing,  air  knifes,  cylinder  movement,  etc.  may  not  necessarily  require  a  high  pressure  supply.  All  plant  equipment  should  be  researched  to  determine  the  correct  amount  of  pressure  required.  

 Applying  a  100psi  air  compressor  instead  of  a  125psi  air  compressor  can  save  up  to  10%  of  the  operation  cost.  (Below  graph  1)    

 

 

 

 

 

 

 

 

Graph1.  The  theoretical  power  to  adiabatic  air  compression    

White Paper: Compressed Air Cost Savings for Small Food Processing

www.hitachi-america.us/airtech

HITACHI AMERICA, LTD.Air Technology Group

5808-Q Long Creek Park Drive, Charlotte, NC 28269 Tel: 704.494.3008 x28 www.hitachi-america.us/airtech; [email protected]

Hitachi Industrial Equipment Systems Co., Ltd.

A  10%  savings  of  the  daily  operating  cost  is  a  huge  financial  benefit.  The  energy  consumption  of  the  use  of  a  30HP  compressor  with  a  6,000  hour  operating  schedule  a  year  is  $17,000  a  year.  The  annual  savings  will  be  $1,700  just  by  lowering  the  air  pressure  at  the  source.  

 Another  valuable  point  is  that  the  typical  plant  air  leak  load  is  around  10~20%.  Lowering  the  plant  air  pressure  from  125psi  to  100psi  provides  a  benefit  in  the  reduction  of  air  consumption;  leakage  will  be  reduced  by  up  to  18%.  (Below  graph  2)    In  addition  to  the  reduced  daily  energy  consumption;  an  overall  reduction  in  the  size  of  the  air  compressor  required  may  be  obtained.  

   

 

 

 

 

 

 

 

 

 

 

Graph2.  Air  leakage  from  hole  *1  Air  Temperature  is  68F  *2  Depends  on  the  inner  surface  friction  of  the  bore    

Many  other  methods,  such  as  proper  maintenance,  larger  air  storage,  pressure  regulators,  etc.  will  also  provide  opportunities  to  save  energy.  

 

Industry  Movement  and  Application  

Countries  such  as  Japan  and  their  major  automotive  manufacturers  that  consume  significant  energy  have  started  applying  techniques  to  lower  their  entire  plant  air  pressure.  One  technique  is  by  using  small  booster  compressors  for  the  equipment  that  requires  higher  pressure.  

White Paper: Compressed Air Cost Savings for Small Food Processing

www.hitachi-america.us/airtech

The  following  shows  an  example  of  this  type  of  application.    

Typical  example  of  compressed  air  installation  as  described  below.  (Air  Treatment  excluded)    

 

 

 

 

 

 

 

 

 

One  example  of  the  more  energy  efficient  models  is  as  follows:  

 

 

 

 

 

 

 

 

*Booster  means  Booster  compressor  or  Booster  valve  

 

 

 

 

   

   

 

 

 

 

 

Air  Compressor (125psi)

Air Receive

r

(Pressure  reducing  valve)

Air  Compressor (125psi)

70psi

100psi

   

   

 

 

 

 

 

Air  Compressor (100psi)

Air Receive

r

Booster  Equipment

Air  Compressor (100psi)

70psi

More  than  100psi

 

White Paper: Compressed Air Cost Savings for Small Food Processing

www.hitachi-america.us/airtech

HITACHI AMERICA, LTD.Air Technology Group

5808-Q Long Creek Park Drive, Charlotte, NC 28269 Tel: 704.494.3008 x28 www.hitachi-america.us/airtech; [email protected]

Hitachi Industrial Equipment Systems Co., Ltd.

 

A  second  option  would  be  separate  systems:  

Line1  

 

 

 

 

Line2  

 

 

 

 

In  either  of  these  examples,  operation  can  be  optimized  and  significantly  save  energy  cost.  

 

Many  smaller  food  processors  continue  to  have  a  tight  initial  investment  budget.  One  way  to  overcome  such  financial  challenges  is  to  use  single  stage  oil  free  compressors.  A  typical  oil  free  compressor  uses  two  stages  of  compression  within  the  design  (2  air-­‐ends/compression  modules).  Advances  in  technology  have  enabled  the  design  and  manufacturing  of  single  stage  designs,  with  a  typical  maximum  pressure  of  100psi.  Naturally  single  air-­‐end  compressors  have  lower  initial  cost  and  also  less  maintenance  cost  due  to  the  reduction  of  components  (Below  Graph  3).  A  further  reduction  in  energy  cost  may  be  achieved  if  a  variable  speed  drive  compressor  is  utilized  (Below  Graph  4).  

 

 

 

 

 

 

Fig.  1  The  difference  between  1-­‐stage  and  2-­‐stage  by  simplified  model  

70psi    

   

 

Air  Compressor (100psi)

Air Receive

r

100psi    

   

 

 

 

 

Air  Compressor (125psi)

Air Receive

r

White Paper: Compressed Air Cost Savings for Small Food Processing

www.hitachi-america.us/airtech

HITACHI AMERICA, LTD.Air Technology Group

5808-Q Long Creek Park Drive, Charlotte, NC 28269 Tel: 704.494.3008 x28 www.hitachi-america.us/airtech; [email protected]

Hitachi Industrial Equipment Systems Co., Ltd.

     

 

 

 

 

 

 

 

 

 

                     Graph3.  Total  Cost  Comparison*                                                                                                    Graph4.  Total  Cost  Comparison*                                                        (2-­‐stage  vs1-­‐stage)                                                                                                              (2-­‐stage  Fixed  Speed  vs  1-­‐stage  VSD)  *The  vertical  axis  means  the  value  of  the  model  to  be  compared  if  the  total  cost  of  2-­‐stage  compressor  is  100%.    *6,000hr  operation  a  year    *Approximately  70%  load  operation  of  2-­‐stage  compressor  *Electricity:  $.10  per  kWh    

Consumers  are  becoming  more  and  more  sensitive  related  to  food  safety  and  health.  Integration  of  oil  free  air  compressors  to  food  processing  is  a  growing  trend  to  address  certain  aspects  of  food  safety.  With  proper  design  and  application,  the  usage  of  oil-­‐free  compressed  air  is  not  limited  to  the  larger  organizations  offering  “peace  of  mind”  to  even  the  smallest  food  processor.  

 

 

 

 

 

By:  Larry  M  Cooke  

                Contributing  Writer:  Shawn  Okita