Operation and Maintenance Manual for

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LC Manual 11/02 Rev. 3 SYSTEM MAINTENANCE d. The chemical feed system is turned on to inject concentrated sanitant into the feed water. The sanitant is diluted by the feed water to the recommended concentration. e. The system is left running for 30 to 60 minutes. f. The chemical feed pump and the RO system are shut down, and the sanitant solution is allowed to sit in the system (optional). g. The chemical feed system is disconnected and the RO is operated with product diverted to drain until all residual sanitization chemicals are flushed from the system. h. A new prefilter is installed in the system prefilter housing. 3. Static Soak Method This sanitization method may be used in combination with either recirculation or continuous injection sanitization for heavily bio-fouled systems. In this method, sanitant is introduced into the system and then the system is shut down. The membranes are allowed to soak in the sanitant solution for a period of time ranging from as little as 30 minutes up to several days (check with USFilter, Technical Support Department at the number provided on the cover of this manual for recommended maximum soak time). 4.3 CLEANING THE RO MEMBRANES A. General Information This section includes general guidelines for developing a cleaning procedure for your particular application. When RO systems have adequate pretreatment and are properly operated, they do not require frequent cleaning. In time, however, the RO membranes can become fouled to a point where system performance is adversely affected, resulting in diminished product output or salt rejection. When the normalized product flow rate drops by 15% and/or the salt passage rises noticeably, this may indicate fouling of the RO membranes and a need for cleaning. However, other factors such as temperature decreases, or malfunctioning pretreatment systems, pressure controls and pumps may also cause these conditions. It is important to rule out these factors before cleaning the system. Clean the membranes if the system performance (based on flow rate or salt rejection) decreases because of membrane fouling. A 15% increase in the feed to reject differential pressure also indicates that cleaning is needed. Membrane foulants include colloidal materials such as aluminum and silica compounds precipitated metal hydroxides of iron and manganese, biological films, and calcium or magnesium carbonate scale. The type of cleaning solution (See Table 4-2) depends on the type of foulant present (organic compounds, metal hydroxides, Ca/Mg carbonates, etc.). The need for frequent cleaning (once a month or more), may indicate that pretreatment is inadequate. USFilter 4-5
SYSTEM MAINTENANCE LC Manual 11/02 Rev. 3 B. Factors to Consider when Cleaning RO Membranes 1. Cleaning skid required. An accessory cleaning skid consisting of a tank and recirculation pump is required to effectively clean the system. The tank and pump should be of materials compatible with the cleaning chemicals. Plastic tanks and sealless (magnetic drive) plastic pumps are recommended. A tank capacity of 10-20 gallons is sufficient for the LC series RO systems. 2. Use RO product water for cleaning and rinse solutions. Use RO product water to prepare cleaning solutions, and as flush water between each cleaning step. If RO product water is not available, use softened filtered tap water. Completely flush the system between applications of different cleaning solutions. 3. Increase flow rates and decrease pressure. During cleaning, reject flow rates should be as high as possible without exceeding the maximum design flow of the system. The flow rate should be 3 - 5 gpm per vessel for the LC series RO systems during cleaning. Pressure should be kept at a minimum during cleaning. Transmembrane pressure keeps foulants within or on the membrane surface during cleaning. The RO pump should be off during cleaning. 4. Optimum temperature during cleaning: The RO membrane cleaning solutions should be maintained at an elevated temperature if possible. Cold water reduces the effectiveness of the cleaning solution. Do not exceed the following temperatures during cleaning: pH Range Maximum Cleaning Temperature 2-10 50°C (122°F) 1-11 35°C (95°F) 1-12 30°C (86°F) 4-6 USFilter
Page 1 and 2: USFilter 10 Technology Drive Lowell
Page 3 and 4: This manual discloses information i
Page 5 and 6: TABLE OF CONTENTS SECTION DESCRIPTI
Page 7 and 8: LC Manual 11/02 Rev. 3 INTRODUCTION
Page 9 and 10: LC Manual 11/02 Rev. 3 INTRODUCTION
Page 11 and 12: LC Manual 11/02 Rev. 3 SYSTEM INSTA
Page 13 and 14: LC Manual 11/02 Rev. 3 SYSTEM INSTA
Page 15 and 16: LC Manual 11/02 Rev. 3 OPERATING IN
Page 21 and 22: SYSTEM MAINTENANCE LC Manual 11/02
Page 23: SYSTEM MAINTENANCE LC Manual 11/02
Page 31 and 32: TROUBLESHOOTING LC Manual 11/02 Rev
Page 33 and 34: LC Manual 11/02 Rev. 3 WARRANTY 6.1
Page 35 and 36: APPENDIX LC Manual 11/02 Rev. 3 7.1
Page 41 and 42: APPENDIX LC Manual 11/02 Rev. 3 RO
Page 45 and 46: Product Description/Equipment Speci
Page 47 and 48: Process Water Systems General Speci
Page 49 and 50: Process Water Systems Low feed pres
Page 51 and 52: Process Water Systems Skid Cleaning
Page 53 and 54: Series 1, 2 & 3 Pumps Page 1 of 2 [
Page 55 and 56: Product Information FILMTEC Membran
Page 57 and 58: USFilter USFilter USFilter USFilter
Page 59 and 60: Conventions and Symbols ii Special
Page 61 and 62: Table of Contents iv MC10 Overview
Page 63 and 64: Specifications The MC10 incorporate
Page 65 and 66: ! The MC10 may be configured to use
Page 67 and 68: Installation 2 Environmental The MC
Page 69 and 70: I/O The wiring diagram for the inpu
Page 71 and 72: Operation 3 Controls The MC10 is ho
Page 73 and 74: Sequence The normal startup and shu
Page 75 and 76:
7 Perm Divert TD Sec 8 High Temp SP
Page 77 and 78:
Time Delays Time delays and deadban
Page 79 and 80:
Important Please note: • Temperat
Page 81 and 82:
Troubleshooting 5 The MC10 Reverse
Page 83 and 84:
Type of Problem Possible Cause or S
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