Procedures guidelines guideline for assessing the appropriate cleaning intervals for tetra therm aseptic sterilisers

Procedures & Guidelines Guideline for assessing the appropriate cleaning intervals for Tetra Therm Aseptic Sterilisers FSQ-588012-0101 Guideline for assessing the appropriate cleaning intervals for Tetra Therm Aseptic sterilisers Table of contents Introduction Cleaning-efficiency depends on several factors Checklist for determining cleaning intervals Some commonly encountered terms .4 Aseptic Intermediate Cleaning .4 Final Cleaning In Place Records Tubular Heat Exchangers (TTA Flex, TTA Primo) General guidelines Practical approach Plate Heat Exchangers (TTA Maxi) General guidelines Practical approach 10 Direct steam injection (TTA VTIS, TTA PLUS ll) 11 General guidelines 11 Practical approach 12 Appendix 13 Checklists 13 FSQ-588012-101 Page of 15 Guideline for assessing the appropriate cleaning intervals for Tetra Therm Aseptic sterilisers Introduction Cleaning-efficiency depends on several factors Factor Possible effect Quality of raw product (air content, microbial enzymes, undissolved ingredients, salt content) Stability Type and configuration of equipment Running time restriction Type of product Type of deposits (protein / fat / minerals) Running time before cleaning Thickness of deposits Cleaning solution additives Type of alkaline and acid Concentration of circulating media Hardness of water Cleaning time Cleaning result Cleaning temperature Cleaning liquid flow rates Because of all these factors it is not possible to state precisely how long a UHT plant can be run before it is necessary to clean The configuration of the processing equipment will also influence the type of cleaning problems encountered Checklist for determining cleaning intervals The following guidelines will help to establish the optimum running time and when ‘Aseptic Intermediate’ (AIC) and ‘Final Cleaning In Place’ (Final CIP) should be carried out It should be noted that it takes time to find the optimum production-cycle and it requires the co-operation of a motivated team The exercise will have to be repeated until desired result has been achieved However the benefits will be: • An increased running time (and therefore a better ratio of production to down time) • Easier production planning • A reduced risk of producing defective product • Increased life time of equipment (especially valid for PHE) • Decreased consumption of detergents (due to decreased frequency of cleaning) The checklists found in the appendix will assist you in determining the production hours between cleaning (AIC / Final CIP) FSQ-588012-101 Page of 15 Guideline for assessing the appropriate cleaning intervals for Tetra Therm Aseptic sterilisers Some commonly encountered terms The common name for deposits in a product pipe as a result of the differential heating is ‘fouling’ The heat differential will be the result of the difference of temperature between the heating medium and the product being processed This is usually referred to as ‘Delta-temperature’ ( ∆-t) The pressure differential between two points in the process is usually referred to as ‘Deltapressure’ ( ∆-p) Aseptic Intermediate Cleaning An aseptic intermediate clean (AIC) is carried out under production conditions i.e production temperature, flow and pressures are maintained during AIC The product is purged out with water and this warm rinse is typically followed by a 20 minute alkali step The AIC is then completed by a warm rinse A typical example of the aseptic intermediate cleaning steps are as follows, although times and other parameters will depend on the particular installation and verification of the cleaning effectiveness Step Medium Warm Pre-rinse Water Alkali Cleaning NaOH Water Warm rinse Time Temperature measured in the holding-cell Temperature measured at the return (reaching prod temp.) ~ 137 ºC ~ 40 ºC 1.5% - 2,5 % ∗ 20 ~ 137 ºC ~ 70 oC To electrical conductivity of supply water 10 ~ 137 ºC Concentratio n ~ 40 ºC ∗ Reference should be made to specialist supplier’s recommendation Pure or formulated detergents may be used Note! • It is not recommended to carry out more than two (2) Aseptic Intermediate Cleaning cycles within the planned production time • Normally AIC is not carried out with acid This is because the aggressive nature of the acid at these elevated temperatures will effect the plant material FSQ-588012-101 Page of 15 Guideline for assessing the appropriate cleaning intervals for Tetra Therm Aseptic sterilisers Final Cleaning In Place Depending on the kind of soil every step of a cleaning operation has an optimum operating temperature In general, for cold surfaces, alkali and acid cleaning are performed at 60-80ºC However, in UHT-process equipment, cleaning is performed at a higher temperature than traditional cleaning Typically the alkali clean will be approx 137 ºC and the acid clean approx 105 ºC, measured in the holding-cell The product is purged out with water and this warm rinse is typically followed by a 50 minute alkali step After that another warm rinse typically followed by a 30 minute acid step The Final CIP is then completed by a warm rinse plus a final rinse at ambient temperature A typical example of the final cleaning steps are as follows, although times and other parameters will depend on the particular installation and verification of the cleaning effectiveness Step Medium Concentratio n Time Temperature measured in the holding-cell Temperature measured at the return (reaching prod temp.) ~ 137 ºC ~ 40 ºC ~ 70 oC Warm Pre-rinse Water Alkali Cleaning NaOH 1.5% - 2,5 % * 50 ~ 137 ºC ~ 105 ºC Warm rinse Water To electrical conductivity of supply water Acid Cleaning HNO3 1-1,5 % * 30 ~ 105 ºC ~ 105 ºC Water To electrical conductivity of supply water Warm rinse Final rinse Water ~ 40 ºC ~ 60 ºC ~ 40 ºC 10 Ambient ∗ Reference should be made to specialist supplier’s recommendation Pure or formulated detergents may be used FSQ-588012-101 Page of 15 Guideline for assessing the appropriate cleaning intervals for Tetra Therm Aseptic sterilisers Records A Production record is to be filled in by the equipment operator It shall be completed at least every hour during production The reporting interval shall be shorter if the raw product quality is poor and the production record shall contain all applicable production and cleaning parameters A Laboratory record is important to track problems due to dirty equipment This record shall include information on raw material and finished product quality The purpose of these records is to be able to trace the effects of the relationship between production activities and the product attributes FSQ-588012-101 Page of 15 Guideline for assessing the appropriate cleaning intervals for Tetra Therm Aseptic sterilisers Tubular Heat Exchangers (TTA Flex, TTA Primo) Fouling will occur in: • The protein stabilisation section where product is usually heated to between • 85 °C – 100 °C • In the final heater section where the temperature is at its highest • In the pre-cooling section where the temperature starts high and is decreased from say,137 °C to 80 °C The thickening of the deposit is indicated by an increasing ∆t between the temperature at the inlet to the holding cell on product side and temperature at the inlet to heater on hot water side These two are normally indicated by TT 44 (Product temperature) and TT (hot water temperature) As the thickness of the deposit increases the more difficult it is for the heat in the heating medium to transfer to the product The temperature of the hot water has therefore to increase to provide enough heat for the product temperature to reach it’s set point, indicated by TT 44 The thickening of the deposit is also indicated by an increasing pressure (normally indicated by PI 3) before the heating section This is because the cross sectional area of product pipe decreases as the fouling occurs The product flow will remain unchanged but the velocity will increase The result of this is that there will be a decreased holding time in the holding cell General guidelines It is important to note that different filled products have different fouling characteristics during processing This will result in different cleaning interval requirements All tests should be made using a standard set-up, e.g product, hot water flow, equipment configuration etc An acceptable ∆-t can be °C – 10 °C higher than the ∆-t for clean equipment For example if the temperature at the start of production at TT 44 is 137oC and at TT it is141°C then a rise to say, 146 – 151°C at TT can be accepted before cleaning is considered necessary The Pressure difference is dependant on capacity (a low capacity gives a low pressure drop) A pressure gauge with a low reading span makes reading easier for low pressure drops/low capacities (0-10/25 bars) An acceptable ∆-p can be 0,5 – bar higher than the ∆-p for clean equipment For example if the pressure at the start of production is bar at PI 3, an acceptable rise would be to 5,5 – 10 bar at PI before cleaning is considered necessary FSQ-588012-101 Page of 15 Guideline for assessing the appropriate cleaning intervals for Tetra Therm Aseptic sterilisers Practical approach A practical approach to achieve optimum production/cleaning time for sterilisers equipped with tubular heaters • The operator should complete a production record at regular, short intervals • When the ∆-t and the pressure reach their critical levels and it is time to clean, the equipment should be stopped • Open the pipe from outlet of the heating section to holding cell • Measure and record the thickness of the deposits • Re-assemble the pipe and run the CIP • Record CIP parameters during the clean –Temperatures, chemical concentrations, time for each step and flow rates • After the CIP, re-open, the outlet pipe from the heating section • Measure and record cleaning result It should be noted that it may also be difficult to clean the protein stabilisation section and the first part of cooler after the holding cell These should be checked in a similar manner If the cleaning result is satisfactory then increase the set point for critical values of ∆-t and pressure for next production This will effectively increase the production time before the next clean After the next production repeat the assessment process as described above Product quality has a significant impact on the running times and it is only possible to increase production time if the product quality is in control and is consistent FSQ-588012-101 Page of 15 Guideline for assessing the appropriate cleaning intervals for Tetra Therm Aseptic sterilisers Plate Heat Exchangers (TTA Maxi) This equipment is sensitive to fouling in the final heating section where the temperature is high The thickness of deposits is indicated by an increasing ∆-p (pressure difference) between the product before and after the heating section The pressure is normally indicated by PI This happens because the distance between plates decreases as fouling takes place The product flow will remain unchanged but the velocity will increase The result of this is that there will be a decreased holding time in the holding cell General guidelines It is important to note that different filled products have different fouling characteristics during processing This will result in different cleaning interval requirements All tests should be made using a standard set-up, e.g product, hot water flow, equipment configuration etc The Pressure difference is dependant on capacity (a low capacity gives a low pressure drop) As a guide a maximum of 1.5 bar difference would indicate that the plant is ready for cleaning FSQ-588012-101 Page of 15 Guideline for assessing the appropriate cleaning intervals for Tetra Therm Aseptic sterilisers Practical approach A practical approach to achieve optimum production/cleaning time for sterilisers equipped with plate heaters • The operator should complete a production record at regular, short intervals • When the pressure reaches its critical level and it is time to clean, the equipment should be stopped • Open the pipe from the outlet of the heating section to holding cell It may be necessary to open the complete heating section • Measure and record the thickness of the deposits • Re-assemble the equipment and run the CIP • Record CIP parameters during the clean –Temperatures, chemical concentrations, time for each step and flow rates • After the CIP, re-open, the plate heat exchanger • Measure and record cleaning result Note! There is risk associated with opening PHE in terms of damage to gaskets and plates This should only be done if considered to be absolutely necessary A comparison of pressures and temperatures between different productions can be made at start of production If the cleaning result is satisfactory then increase the set point for the critical value of pressure for the next production This will effectively increase the production time before the next clean After the next production repeat the assessment process as described above Product quality has a significant impact on the running times and it is only possible to increase production time if the product quality is in control and is consistent FSQ-588012-101 Page 10 of 15 Guideline for assessing the appropriate cleaning intervals for Tetra Therm Aseptic sterilisers Direct steam injection (TTA VTIS, TTA PLUS ll) This equipment is sensitive to fouling in the final heating section where the temperature is high An increasing opening of the steam valve indicates the thickness of deposits This occurs because of fouling on the steam-injector, the temperature-transmitter (TT 44), and constant pressure valve (V.30) The opening of the steam valve is indicated directly on the valve and, if applicable, on operators display As fouling takes place, the product flow will remain unchanged but the velocity will increase The result of this is that there will be a decreased holding time in the holding cell General guidelines It is important to note that different filled products have different fouling characteristics during processing This will result in different cleaning interval requirements All tests should be made using a standard set-up, e.g product, hot water flow, equipment configuration etc Use the steam valve as the indicator for the commencement of cleaning An acceptable maximum opening of the steam valve is 75% before cleaning needs to be started FSQ-588012-101 Page 11 of 15 Guideline for assessing the appropriate cleaning intervals for Tetra Therm Aseptic sterilisers Practical approach A practical approach to achieve optimum production/cleaning time for sterilisers equipped with steam injection • The operator should complete a production record at regular, short intervals • When the steam valve reaches its critical level and it is time to clean, the equipment should be stopped • Open the pipe from the outlet of the heating section to holding cell Check for fouling of the steam injector Measure and record the thickness of the deposits • Re-assemble the equipment and run the CIP • Record CIP parameters during the clean –Temperatures, chemical concentrations, time for each step and flow rates • After the CIP re-open the equipment • Measure and record cleaning result If the cleaning result is satisfactory then increase set point for critical values for opening of the steam valve for next production This will effectively increase the production time before the next clean After the next production repeat the assessment process as described above Product quality has a significant impact on the running times and it is only possible to increase production time if the product quality is in control and is consistent FSQ-588012-101 Page 12 of 15 Guideline for assessing the appropriate cleaning intervals for Tetra Therm Aseptic sterilisers Appendix Checklists FSQ-588012-101 Page 13 of 15 Guideline for assessing the appropriate cleaning intervals for Tetra Therm Aseptic sterilisers FSQ-588012-101 Page 14 of 15 Guideline for assessing the appropriate cleaning intervals for Tetra Therm Aseptic sterilisers FSQ-588012-101 Page 15 of 15 [...]... Page 12 of 15 Guideline for assessing the appropriate cleaning intervals for Tetra Therm Aseptic sterilisers Appendix Checklists FSQ-588012-101 Page 13 of 15 Guideline for assessing the appropriate cleaning intervals for Tetra Therm Aseptic sterilisers FSQ-588012-101 Page 14 of 15 Guideline for assessing the appropriate cleaning intervals for Tetra Therm Aseptic sterilisers FSQ-588012-101 Page 15 of... different cleaning interval requirements All tests should be made using a standard set-up, e.g product, hot water flow, equipment configuration etc Use the steam valve as the indicator for the commencement of cleaning An acceptable maximum opening of the steam valve is 75% before cleaning needs to be started FSQ-588012-101 Page 11 of 15 Guideline for assessing the appropriate cleaning intervals for Tetra Therm. . .Guideline for assessing the appropriate cleaning intervals for Tetra Therm Aseptic sterilisers Direct steam injection (TTA VTIS, TTA PLUS ll) This equipment is sensitive to fouling in the final heating section where the temperature is high An increasing opening of the steam valve indicates the thickness of deposits This occurs because of fouling on the steam-injector, the temperature-transmitter... for fouling of the steam injector Measure and record the thickness of the deposits • Re-assemble the equipment and run the CIP • Record CIP parameters during the clean –Temperatures, chemical concentrations, time for each step and flow rates • After the CIP re-open the equipment • Measure and record cleaning result If the cleaning result is satisfactory then increase set point for critical values for. .. of the steam valve for next production This will effectively increase the production time before the next clean After the next production repeat the assessment process as described above Product quality has a significant impact on the running times and it is only possible to increase production time if the product quality is in control and is consistent FSQ-588012-101 Page 12 of 15 Guideline for assessing. .. for Tetra Therm Aseptic sterilisers Practical approach A practical approach to achieve optimum production /cleaning time for sterilisers equipped with steam injection • The operator should complete a production record at regular, short intervals • When the steam valve reaches its critical level and it is time to clean, the equipment should be stopped • Open the pipe from the outlet of the heating section... temperature-transmitter (TT 44), and constant pressure valve (V.30) The opening of the steam valve is indicated directly on the valve and, if applicable, on operators display As fouling takes place, the product flow will remain unchanged but the velocity will increase The result of this is that there will be a decreased holding time in the holding cell General guidelines It is important to note that different filled