Prerequisite prior to using a retort, or an oven, or a bath
How do we go about achieving heat distribution tests ?
Once the heat is on
Objective of the test
Who performs those tests?
Pharmaceutical Industry
Example of thermocouple distribution
Sensors location
Steam retort
How long should the vent last
More broadly, heat distribution tests are required :
To summarize
Tests performed on several types of retorts

 

A retort, an oven or a bath should be designed such that every containers receive the same thermal process

HOWEVER, before using a retort, an oven or a bath to process food products, heat distribution tests should be undertaken by a specialist in that field so as to verify the efficacy of both the design and the hook-up of the equipment.

 

The procedure goes as follows:

  • Load the retort/oven/bath with filled containers (filled with water or actual product, or a product substitute (a clay or bentonite suspension for example)
  • As the retort/oven/bath is being loaded, spread thermocouples or wireless loggers at several locations throughout the load

 

The procedure goes as follows:

  • Temperature is recorded regularly by every thermocouple or wireless loggers
  • So as to ensure temperature uniformity in every point of the load.

 

The temperature must be uniform throughout the load within one minute after process is started.

 

A thermal process specialist.

 

The requirements presented here for the food industry apply just as well to the pharmaceutical industry.

 

in a vertical retort and a horizontal retort

autoclave vertical autoclave horizontal

 

Normally, the temperature sensors will be located outside the containers, in between each others.

Emplacements des sondes

 

Steam retorts are a special case since they contain lots of air when the door or lid of the retort is closed. And we know that air is a good insulator.

IF THE THERMAL PROCESS IS TO TAKE PLACE IN A STEAM ONLY ENVIRONMENT, THE AIR MUST BE RID OF.

The vent cycle is in fact designed to evacuate the air from the retort.

 

The answer lies in the heat distribution test.

EACH SYSTEM WILL HAVE ITS OWN VENT CYCLE.

 

  1. To develop or validate a vent procedure;
  2. To determine whether there is a cold or slow heating zone in the retort;
  3. For any new installations;
  4. Whenever a modification is made in the processing area that could affect the heat distribution

 

Heat distribution tests are a prerequisite to sterilizing or pasteurizing a food product in a retort (or oven, or bath, etc).

Heat distribution tests enable the thermal process specialist to set-up operating procedures so as to guide the user

These operating procedures must be followed by the operator for every batch.

 

Developex has performed tests on several types of retorts

Allpax immersion and Stock immersion

Allpax en immersionStock en immersion

Lubeca immersion and Barriquand, water cascading

Lubeca en immersionBarriquand en ruissellement

or a steam-air Lagarde

Lagarde air-vapeur

Crateless steam retort, Malo

Malo, autoclave vapeur sans panier

Steam only FMC continuous cooker, Sterilmatic

Sterilmatic de FMC