Technical Manual
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- 6.2.3 Operation of CIP (Cleaning-in Place) Stage
- The following steps are carried out during CIP and must be monitored closely and done manually
Operation Procedures for MICRODYN AQUADYN® UA860 Modules
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Form-No: TM-WW002 // Revision: A // Date: Oct. 10, 17
and the dosing pump is started to dose the required chemicals into the back flush line. EBF is normally performed with less than 50 ppm free chlorine for 30 to 90 seconds. 3) Once the chemicals are in the UF modules, the back flush pump is stopped and a soak timer is started. The soak timer is typically set between 5 to 20 minutes. 4) When the soak timer has elapsed the chemicals are rinsed out of the UF rack and mem- brane modules. The rinsing of the chemicals is carried out in the finishing step, whereby the back flush pump is operated at the designated back flush flux rate, as per usual without chemical dosing. Time duration must be adjusted during the plant start-up to ensure that all chemicals are completely removed from the membrane modules and system.
Figure 12: Introduction of chemicals to the system during EBF 1 step
= Manual, automatic or non-return valve Feed/CIP return/WW Feed Product
Pre-strainer BF/CEB inlet BF / CEB / CIP w aste w ater Waste w ater CIP return & BF/CEB discharge Air supply for Air Scouring Air supply / CIP feed Blow er
UF permeate Feed tank UF permeate tank BF / CEB
Feed/CIP Back flush pump pump
Chemical dosing sets UA860 Perm.
CIP / WW tank membrane
Chem 1 Chem 2
Operation Procedures for MICRODYN AQUADYN® UA860 Modules
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Form-No: TM-WW002 // Revision: A // Date: Oct. 10, 17
Figure 13: Introduction of chemicals to the systems during EBF 2 step 6.2.3 Operation of CIP (Cleaning-in Place) Stage When there is fouling and scaling that cannot be removed by hydraulic cleaning and EBF, a CIP can be performed. This may happen due to upsets in the water quality or due to difficult operating conditions such as ineffective pre-treatment or incorrect chemical doses. The major difference is that the CIP requires a CIP tank. Additionally; the time taken to perform a CIP is typically much longer than for hydraulic cleaning or EBF. The CIP is normally done only on the feed side and does not involve the permeate side of the membrane module. This means that CIP is specific in targeting exterior of fibers, whereas EBF in specific in cleaning fibers from inside-out. Thus, both procedures may complement each oth- er well, depending on the nature of the anticipated fouling. A CIP cycle is typically carried out once every few months. In certain feed water conditions the CIP may be as frequent as on a weekly basis. The following points are important and should be taken care of before performing the CIP. 1) The CIP should be performed if periodic hydraulic cleaning and EBF is unable to recover perfor- mance adequately. The CIP should be considered effective if it recovers minimum 75% of the membrane performance. 2) The chemicals to be used must be as per recommended in chapter 5.2. 3) The water used to prepare the CIP cleaning solution must be free of particles and have an al- calinity <70mg/l (tap water or permeate may be used). This is especially valid for caustic and = Manual, automatic or non-return valve Feed/CIP return/WW Feed Product
Pre-strainer BF/CEB inlet BF / CEB / CIP w aste w ater Waste w ater CIP return & BF/CEB discharge Air supply for Air Scouring Air supply / CIP feed Blow er
UF permeate Feed tank UF permeate tank BF / CEB
Feed/CIP Back flush pump pump
Chemical dosing sets UA860 Perm.
CIP / WW tank membrane
Chem 1 Chem 2
Operation Procedures for MICRODYN AQUADYN® UA860 Modules
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Form-No: TM-WW002 // Revision: A // Date: Oct. 10, 17
cleaning. 4) Typical CIP time may take up to 12 hours but should not exceed this time. 5) The CIP solution must be fed only from the feed side of the membrane modules to prevent any substances that can cause scaling or fouling ending up in the permeate side of the membrane module during the recirculation. 6) Always isolate the UF rack undergoing CIP from other UF racks and/or other up and down stream processes. 7) Replace the fine screen at the entrance of the UF system by a finer pre-screen of about 5 to 10 µm. 8) Prepare the CIP solution in a separate CIP tank and check the concentration by measuring the pH value (or free chlorine if using NaOCl) to confirm sufficient chemical is added to the clean wa- ter.
9) Please note that the ratio of the CIP cleaning tank to the entire volume inside the cleaned system (amount modules, piping, CIP tank) needs to be considered for appropriate calculation of the CIP cleaning solution. It may be required to adjust the pH and concentration after the total system is mixed.
The following steps are carried out during CIP and must be monitored closely and done manually: 1) The CIP tank must be filled first with water before the addition of any chemicals. 2) The chemicals must be properly mixed. After the mixing, it should be checked that the concentra- tion of the solution is as per the targeted values. It is important that the solution concentration does not exceed the maximum limits set according to APPENDIX - MICRODYN AQUADYN ®
UA860 data sheet. 3) To prevent a contamination, the feed tank and product/back flush tank must be isolated from the system by closing the valves on the feed line and back flush line. 4) The chemical solution is drawn into the UF system if the individual rack is equipped with a feed pump or pushed into the UF rack by a CIP pump as part of the CIP system. The process should be monitored that the recirculated solution is passed through the entire system, always check the concentration of the recirculated chemical solution is the same as that entering the system. 5) While the solution is recirculating and entering via the feed port of the membrane module, the air scouring can be operated intermittently during soaking to enhance the cleaning effect. 6) The cleaning solution is recirculated and soaked for 30 to 180 min. As a standard you may start with 60 min. However, the CIP strategy needs to be adjusted and optimised for each plant. 7) The water can then be flushed back to the CIP tank after this is done. Take samples of the return water to check if there is still sufficient concentration of cleaning chemical in the CIP water. If the water turns dirty, replace the chemical solution and repeat the cycle. 8) Once the cleaning is deemed effective, always drain and dispose of the chemicals safely. Then clean the tank and top up again with clean water before rinsing the membrane modules. 9) Do a backflush of the membrane modules at 80 to 100 LMH for 30 to 180 s dependent on dirti- ness of reject.
Operation Procedures for MICRODYN AQUADYN® UA860 Modules
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Form-No: TM-WW002 // Revision: A // Date: Oct. 10, 17
Figure 14: CIP mode Shut Down 6.3 UF systems are typically designed to run continuously. If shut down is required and exceeds more than one week a chemically enhanced back flush (EBF) is necessary: 1) Execute first a hydraulic cleaning cycle. 2) Perform a EBF with 100 ppm NaOCl as described in chapter 6.2.2 3) At shut down the water in the module is replaced with permeate or drinking water by back flush to prevent bacterial growth. 4) After back flush, all valves on the UF rack are closed in order to isolate the UF rack. 5) Take note that at no point the fibers should be allowed to dry out as this would cause an ir- recoverable deterioration of performance. 6) This cleaning procedure shall be repeated every week when modules are not operated in filtration mode. 7) The module must be stored in an upright position and free of any oxidizing agents during the system shutdowns. Longer shut down times should be discussed with a MICRODYN-NADIR specialist and we rec- ommend adding preservative solution.
= Manual, automatic or non-return valve Feed/CIP return/WW Feed
Product Pre-strainer BF/CEB inlet BF / CEB / CIP w aste w ater Waste w ater CIP return & BF/CEB discharge Air supply for Air Scouring Air supply / CIP feed Blow er UF permeate Feed tank UF permeate tank BF / CEB Feed/CIP
Back flush pump
pump Chemical
dosing sets UA860
Perm. CIP / WW tank membrane Chem 1
Chem 2 Operation Procedures for MICRODYN AQUADYN® UA860 Modules
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Form-No: TM-WW002 // Revision: A // Date: Oct. 10, 17
Operating and Cleaning Logs 6.4 Operation and cleaning logs are important for tracking operating conditions and to optimize op- erations. In Appendix - Operation and Cleaning Record Logs are three record forms for moni- toring of cleaning. Failure to furnish this information when requested shall render the warranty void. The first is for the operation record form which is used to collect the data during normal filtration and hydraulic cleaning. The second and third are the maintenance/cleaning record forms which records the data during EBF and CIP. The data should be recorded from the moment the modules are put into operation, the custom- er is required to maintain complete and continuous documentations of the operating conditions and the amount of time the plant is operated and cleaned. Use of chemicals for feed water pre-treatment and EBF / CIP must be monitored closely. This information should also be recorded. The forms provide a guide to the required information for tracking the performance of the mem- brane modules but should not be a limit of any additional information required.
Troubleshooting 6.5 In case of operational issues at some plants a general troubleshooting is recommended to vari- fy that no common issues are the reason for this. In general, please take recommendations according to the data sheet into account (Appendix 7.2). In addition, the proper function of plant especially of all pumps, valves, blowers and sen- sors must be validated for instance by regular calibration. Issue Recommendation Low effect of chemical Clean- ing Bleach stock con- centration - It is recommended to check the bleach stock concen- tration due to its degradation once a month in colder regions or weekly in warmer regions (tests available i.e. from Hach Lange)
Delivery of chemi- cal - Make sure that the required chemical is pumped into the system (metering of pump, check volume removed from stock tank)
Biofouling - Use bleach or hydrogen peroxide Scaling - Use acids at low pH according to data sheet, mostly pH of 2 is sufficient - Check the total alkalinity of the influent, at high alkalini- ty (hard water) more frequent acid chemical cleanings are required Chemicals - Chemicals used should be approved for membrane compatibility Enhanced back- flush (EBF) - Consider the volume of piping for the dosing time that the chemical is entering the modules - Increase dosing time, soaking time, chemical concen- tration or frequency between EBFs Operation Procedures for MICRODYN AQUADYN® UA860 Modules
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Form-No: TM-WW002 // Revision: A // Date: Oct. 10, 17
Issue Recommendation CIP
- Check the turbidity of the reject flow after CIP per- formed. Increase flow and/or time of backflush if turbid- ity is high - Increase recirculation time, soaking time, chemical concentration, temperature or frequency between CIPs - Do cleaning in two steps and renew the chemical solu- tion in between for removal of accumulated particles - Use a fine strainer bag during CIP recirculation to prevent accumulation of particles during CIP Performance High Pressure - Note that the pressure is temperature-dependent (high temperature low pressure) - Check inproper pre-treamtment - Check design for - Additional backpressure which increases feed pressure. - Check for high pressure loss due to inproper design of piping etc. - Make sure that no air is accumulated in the fibers by venting Effluent quality - Disinfect piping and all tanks - Measure turbidity or Silt Density Index (Please check Troubleshooting Measuring Silt Density Index TSG-T- 010 for more information) Inproper pretreat- ment
- Clean and improve pre-treatment - If additives are dosed, check the dosing rate and prop- er function, overdosage must be avoided Influent quality - Check the influent quality parameter in particular BOD, COD, TSS, total alkalinity and make sure that no sub- stances are entering the modules which may decrease performance - At higher influent concentrations than designed, the performance may be significantly less
Low effect of hy- draulic cleaning - If effect of backflush is low, increase first the flow if possible - If flow must be decreased due to high pressure, in- crease the time to obtain the same volume than used before
Malfunctions Water hammer - In most cases the element needs to be replaced - Check all safety shutdown scenarios again if reason for malfunction is unknown Too high tempera- ture pH or chemical cleaning concen- tration out of range TMP
Appendices
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Form-No: TM-WW002 // Revision: A // Date: Oct. 10, 17
Appendices Appendix – Basic P&ID of MICRODYN AQUADYN ® UA860 Plant 7.1
Appendices
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Form-No: TM-WW002 // Revision: A // Date: Oct. 10, 17
Appendix – MICRODYN AQUADYN ® UA860 Data Sheet 7.2 Appendices
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Form-No: TM-WW002 // Revision: A // Date: Oct. 10, 17
Appendices
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Form-No: TM-WW002 // Revision: A // Date: Oct. 10, 17
Appendix - Operation and Cleaning Record Logs 7.3
Appendices
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Form-No: TM-WW002 // Revision: A // Date: Oct. 10, 17
Appendices
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Form-No: TM-WW002 // Revision: A // Date: Oct. 10, 17
Appendix – Module Preservation Procedure 7.4
1. Prepare the required volume of sodium meta-bisulphite (SMBS) 35%. The target concen- tration of SMBS in the preservative solution is 4.5%. Table 1 shows the correct dosage of SMBS for typical preservative volumes:
35% SMBS [L] 0.37 1.85 3.7 9.25 14.8 Preservative Solution [L] 4 20
40 100 160 Table 1: Preservative solution
2. Use proper PPE when handling the SMBS. 3. Use a clean and empty tank for the mixing. 4. Fill 50% of the required preservative solution volume into the mixing tank. Slowly add the concentrated SMBS 35%. Fill the mixing tank up with water to the required volume as per table 1. The preservative is now ready to use for cartridge preservation. EXAMPLE: Preparation of 100L of preservative solution a. Fill in 50L of water b. Add in 9.3L of 35% Sodium Metabisulphite c. Fill up to the 100L mark with water d. Ready to use 5. Add 4L of the preservative solution to each MICRODYN AQUADYN ® UA860 membrane module through the feed/reject port using a hose and/or a hopper. 6. Upon completion of adding the preservative solution, proceed to insert the PVC plug to prevent evaporation of the preservative solution. 7. Discard any leftover preservative solution, it can not be stored.
Appendices
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Form-No: TM-WW002 // Revision: A // Date: Oct. 10, 17
Appendix – MICRODYN AQUADYN ® UA860 Single Packing Procedure 7.5
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