Knowledge
   
  Tank systems
  Pasteurisation systems
  Water for injection systems (WFI)
  Drying and evaporation
  Filtration systems
  CIP systems
  Utility systems
 

 

 

 
 

Tank systems

There are a wide range of tank systems, typical applications being:

  • Silo tanks - for intermediate storing of product before, during and after processing
  • Balance tanks - for ensuring constant pressure in the system
  • Mixing tanks - for agitation, mixing and blending of the product
  • Pressure tanks - for ensuring the optimal pressure conditions

 

 

 


 

Pasteurisation systems

    The pasteurisation system removes harmful organic bacteria in a product by heating it up to a specific temperature, and then cooling the product rapidly.

Pasteurization

     Pasteurization and correct cooling are some of the most important processes in the treatment of milk and other liquid food products. When done correctly, these processes will prolong the shelf life of liquid foods and beverages.

Temperature ranges

Typical temperature ranges:

  • Fruit juice at 80-95°C for 15-30 seconds
  • Beer and wine at 72°C for 30 seconds
  • Regular milk at 72-75°C for 15-20 seconds
  • Whipping cream at 80-95°C for 10 seconds


 

Water for injection systems (WFI)

     The pharmaceutical and bio-pharmaceutical industries demand high purity water systems, being reliable and consistently providing the required water for injection (WFI) and purified water (PW) to meet established standards.

WFI and PW definitions

     WFI is typically stored and circulated in a hot water system at temperatures between 70-90°C.

     PW is typically stored and circulated at ambient temperature. To keep bacteria under control, ambient systems are sanitised at regular intervals - normally done by elevated temperature or ozonisation.

Pharmaceutical water system

     A pharmaceutical water system ensures that there are no risks for cross contamination between different media (e.g. cooling/heating media, equipment lubrications etc) and the water.

     The piping and equipment must be flushable and should not contain any stagnant areas. The product contact surface must not be reactive, additive or absortive.


 

Drying & evaporation

Why carry out evaporation? The typical reasons are:

  • Reduce costs for storage and transportation
  • Reduce the cost of drying - why evaporation always is done before drying
  • Reduce water activity to increase microbiological and chemical stability
  • Recover valuable substances and by-products from waste streams

 


 

Filtration systems

There are two main types of filter systems:

  • Dead-end filtration
  • Cross-flow filtration

Dead-end filtration

     Dead-end filtration works according to the same principles as a coffee filter, soaking up all components in the fluid that are too big to pass through the filter.

Cross-flow filtration

     Cross-flow filtration systems commonly use membranes where the fluid feed is passing through a membrane bed, trapping solids in the filter and letting the filtrate being released at the other end.

     The feed flows tangentially across the surface of the filter, rather than into the filter, being a continous process - unlike the dead-end filtration, where the process will typically be a batch process.

     In membrane filtration systems the pressure is a critical factor. Alfa Laval offers a wide range of components fit for high-pressure duties.

 


 

CIP SYSTEM

     Clean-in-place (CIP) is a method of cleaning the interior surfaces of pipes, vessels, process equipment, filters and associated fittings, without disassembly.

     Up to the 1950s, closed systems were disassembled and cleaned manually. The advent of CIP was a boon to industries that needed frequent internal cleaning of their processes. Industries that rely heavily on CIP are those requiring high levels of hygiene, and include: dairy, beverage, brewing, processed foods, pharmaceutical, and cosmetics.

     The benefit to industries that use CIP is that the cleaning is faster, less labor-intensive and more repeatable, and poses less of a chemical exposure risk to people. CIP started as a manual practice involving a balance tank, centrifugal pump, and connection to the system being cleaned. Since the 1950s, CIP has evolved to include fully automated systems with programmable logic controllers, multiple balance tanks, sensors, valves, heat exchangers, data acquisition and specially designed spray nozzle systems. Simple, manually operated CIP systems can still be found in use today.

     Depending on soil load and process geometry, the CIP design principle is one of the following:

  • Deliver highly turbulent, high flow-rate solution to effect good cleaning (applies to pipe circuits and some filled equipment).
  • Deliver solution as a low-energy spray to fully wet the surface (applies to lightly soiled vessels where a static sprayball may be used).
  • Deliver a high energy impinging spray (applies to highly soiled or large diameter vessels where a dynamic spray device may be used).
  • Elevated temperature and chemical detergents are often employed to enhance cleaning effectiveness.


   

Utility systems

     Utility systems are used for heating and cooling of water and/or steam in the customer’s processes.

Heat exchangers

     Operating a food processing plant requires large quantities of thermal energy to heat various products, detergent solutions etc. Heat is transferred to the product through the use of heat exchangers by the heating medium, typically water or steam.

Hot water vs. steam system

     The installation cost of a hot water system is slightly lower than in a steam system. The hot water system is also easier to regulate and its operation is more straightforward. The disadvantage is that heat transfer in a hot water system is lower than the one in a steam system.