Toray UF
Instruction
Manual“HFUG-2020AN”(type AN)

Last updated March 2023

06-G-MB2-HFUG-2020AN-230330

Toray UF

NoticeThe data and information contained in this document are based upon rigorous technicaltesting by Toray, and is to the best of our knowledge reliable. Toray cannot control designand operating conditions, and consequently Toray does not assume any liability for results
obtained or damage incurred through the application of the information provided herein.
No liability, warranty or guarantee of final product performance by Toray is implied by the
information provided in this document.
This manual supersedes all previous versions. Technical modification of products or
production technology may necessitate changes to information in this manual without priornotice. Please verify that your version of the manual is the latest version available by either
contacting Toray, or checking online at www.water.toray.

Terms and Conditions of Use
When using this document, please read the Terms and Conditions of Use below thoroughly and agree to them before using
this document. By using this document, you agree to all of the Terms and Conditions of Use outlined here. The Terms andConditions of Use are subject to change without prior notice, so please check with Toray for the latest Terms and Conditionsof Use before using the document.
1.

Intellectual Property Rights
The content in this document is protected by copyright laws in respective countries and relevant treaties. Accordingly,
the document's information may not be reproduced, altered, or distributed without permission in writing from Toray. We
permit downloading this document through Toray's website as a PDF file, stored on a personal computer, and printed
out for customers' personal use. However, we prohibit transferring this document to any other websites or printed media.
The material contained in this document may not be used without permission from the copyright holder for any otherpurpose that exceeds the scope permitted under copyright law.

2.

Trademarks
The "TORAY" company name used in this document is a trade name, and the names of products manufactured by
Toray are trademarks or registered trademarks. Toray's trade names and trademarks are protected under the JapaneseTrademark Law, the Unfair Competition Prevention Law, and other legislation. The trade name and trademarks may not
be used or reproduced without express permission from Toray.

3.

Disclaimer
Toray takes all reasonable care in updating the information in this document. However, Toray makes no representation
and warranty of any kind, either express or implied, including without limitation, any implied warranties concerning theaccuracy, usefulness, suitability, or fitness for a particular purpose of the information in the document.
Toray shall not be responsible or liable for any losses or damage incurred due to the use of the information in thisdocument. The information in this document is subject to change without prior notice, and Toray reserves the right tosuspend or discontinue the publication of this document.

4.

Availability of Goods and Services
The goods and services contained in this document are not available in all countries and regions. Goods and services
may also be supplied under different trademarks in different countries. We ask that you contact your nearest Toray
representative office if you wish to use the goods and services shown or implied in this document.

5.

Proper Law and Court of Jurisdiction
This Terms and Conditions of Use shall be governed by and construed according to the laws of Japan. Any and all
disputes arising out of or relating to this document shall be brought to the Tokyo District Court Tokyo, Japan.

Instruction Manual

06-G-MB2-HFUG-2020AN-230330

Toray UF

Contact Information
Toray Industries, Inc. — UF & MBR Membrane Products Department (Global Headquarters)
Nihonbashi Mitsui Tower, 1-1, Nihonbashi-Muromachi 2 chome, Chuo-ku, Tokyo, 103-8666
Japan
Tel: +81-3-3245-4542 Fax: +81-3-3245-4913
Toray Membrane USA, Inc. (TMUS)
13435 Danielson Street, Poway, California 92064 USA
Tel: +1-858-218-2360 Fax: +1-858-218-2380
Toray Membrane Europe AG (TMEU)
Grabenackerstrasse 8b, Muenchenstein 1 CH-4142, Switzerland
Tel: +41-61-415-8710 Fax: +41-61-415-8720 E-mail: info.tmeu.mb@mail.toray
Toray Asia Pte. Ltd. (TAS)111 Somerset Road, #14-22 - #14-27, Singapore 238164, Republic of Singapore
Tel: +65-6226-0525 Fax: +65-6226-0509
Toray BlueStar Membrane Co., Ltd. (TBMC)
Zone B, Tianzhu Airport Industrial Zone, Beijing 101318, China
Tel: +86-10-8048-5216 Fax: +86-10-8048-5217
Toray Membrane Middle East LLC (TMME)PO Box 20279, Dammam 31952, Kingdom of Saudi Arabia
Tel: +966-13-568-0091 Fax: +966-13-568-0093
Toray Advanced Materials Korea Inc. (TAK)
Korea Toray R&D Center 7, Magokdonng-ro 10-gil, Gangseo-gu, Seoul 07790, Republic of
Korea
Tel: +82-22-3279-7389 Fax: +82-2-3279-7088

website: www.water.toray

Instruction Manual

06-G-MB2-HFUG-2020AN-230330

TORAY UF

TABLE OF CONTENTS
I.

Introduction ................................................................................................................... 1
1.

Characteristics of Toray "HFU series" Membrane Module ........................................... 1

2.

About “type AN” ........................................................................................................... 2

3.

Applications of Toray "HFU series" Membrane Module ................................................ 2II.

For Your Safety ............................................................................................................. 3
1.

Safety Instruction for Unpacking and Installation ......................................................... 42.

Safety Instruction for Filtration Operation .................................................................... 6

3.

Safety Instruction for Chemical Cleaning ..................................................................... 84.

Safety Instruction for Disposal ..................................................................................... 9

5.

Warranty Claims .........................................................................................................10

6.

Warranty Policy .......................................................................................................... 11

III.

Specifications of Toray “HFU Series” Membrane Module .............................................12IV.

Configuration of Toray “HFU Series” Membrane Module (type AN)...............................15

V.

Installation ....................................................................................................................16

VI.

Operation .....................................................................................................................19

1.

Filtration .....................................................................................................................192.

Backwash and Air-scrubbing ......................................................................................21

3.

Toray Maintenance Cleaning ......................................................................................23

4.

Basic Trans-Membrane Pressure Calculation .............................................................26

5.

Temperature Correction Factor ...................................................................................27

6.

Performance Recording .............................................................................................28

VII. Chemical Cleaning .......................................................................................................29
VIII. Storage of Membrane Module ......................................................................................33
1.

Storage of New Membrane Module ............................................................................33

2.

Storage of Membrane Module after Use .....................................................................33

3.

Replace Preservative Chemical .................................................................................34

Instruction Manual

06-G-MB2-HFUG-2020AN-230330

TORAY UF

I.

Introduction

Toray PVDF Hollow Fiber Membrane Module "HFUG series" is a pressurized hollow fiber UF(Ultra Filtration) membrane module developed with polymer science and membrane fabrication
technologies accumulated over decades of successful membrane manufacturing at Toray
Industries, Inc.
The membrane material is Polyvinylidene fluoride (PVDF). The nominal pore size of themembrane is 0.01 micrometers.
The module, which is permanently potted in its casing, is pressure-driven which provides equal
filtrate quality to submerged modules, while offering greater TMP range for more flexible plant
operation. Maximum operating pressure is 300 kPa (43.5 psi). The flow direction is outside-in,which is more suitable for higher turbidity water treatment because of the air-scrubbing
effectiveness. Additionally, outside-in modules can remove suspended solids more effectively
at higher recovery rates compared to inside-out fibers.

1. Characteristics of Toray "HFUG series" Membrane Modules(1) High Filtration FluxHFUG series provides high filtration flux and stable operation for the filtration of various
raw water sources. The membrane is made with a special spinning method, which enableshigh permeability and high fouling resistance.
(2) Excellent Water Quality
HFUG series provides very good water quality for the filtrate, extremely low turbidity since
the membrane has 0.01 micrometers nominal pore size. HFUG series is recommended tobe applied to the tertiary treatment of sewage water and RO pretreatment in desalination.
(3) High Mechanical Strength
The membrane of HFUG series has very high mechanical strength because it is made of
PVDF with the special spinning method developed by Toray. HFUG series provides highintegrity and durability under recommended operating conditions.
(4) High Chemical Durability
The membrane material of HFUG series is PVDF, which allows to clean the membranewith high concentrations of chlorine and with high concentrations of acid resulting in better
cleaning and longer sustainable membrane flux rates.
Instruction Manual

06-G-MB2-HFUG-2020AN-230330
1 of 34

TORAY UF

2. About “type AN”“Type AN” is a module type whose housing is sealed with an improved cap. All connecting
parts of "Type AN" modules are identical to those of "Type N" modules, so existing "Type N"
modules can be replaced with "Type AN" modules.

3. Applications of Toray " HFUG-2020AN " Membrane Module

Drinking Water Production



Tertiary Treatment

RO Pretreatment

Industrial Water Production

Reuse of Industrial Wastewater

Instruction Manual

06-G-MB2-HFUG-2020AN-230330
2 of 34

TORAY UF

II. For Your Safety

Please be sure to read and follow the instructions below before using HFUG-2020AN.
This manual should be retained for future reference.



Follow the safety precautions as they are intended to protect operators and equipmentfrom various risks such as physical harm and/or property damage. The following tableshows a level of potential risk for each indicated symbol.
This symbol indicates an imminent hazardous situation which
will result in serious injury or death when the instruction is notobserved.
This symbol indicates a potentially hazardous situation which
will result in serious injury or death when the instruction is notobserved.
This symbol indicates a potentially hazardous situation whichmight result in injury or property damage when the instruction
is not observed.



The following table explains the information to be noted.

“Prohibited”
Prohibited!

Instruction

This symbol indicates a prohibited action or procedure.

“Instruction”
This symbol indicates an important action or procedure which
has to be taken without fail.

Instruction Manual

06-G-MB2-HFUG-2020AN-230330
3 of 34

TORAY UF

1. Safety Instruction for Unpacking and Installation!

Instruction

Be sure to wear safety gear such as rubber gloves and safety glasses for unpacking.
The membrane is packaged in sodium hypochlorite solution (Max. 200 mg/L as Cl2).
If the solution happens to splash onto the skin, wash the affected part with runningwater. If the solution happens to get in the eyes or mouth, wash the affected partwith sufficient amounts of clean running water for more than 15 minutes and see
the doctor immediately.

!

Instruction

Be sure to wear safety gear such as a helmet to protect your head and safety shoes
to avoid injury due to falling of related parts or equipment, such as module, etc.

The preservative solution should be drained out before using the modules. After
that, fill tap water or equivalent quality water into the modules to prevent the hollow
Prohibited

fiber membrane from drying out. Do not allow the modules to dry even for a few
hours.

The membrane modules should not be frozen.
Prohibited

Be careful not to damage or dent the modules during handling.
Prohibited!

Instruction

Be sure to wear protective appropriate gloves to avoid injury of hands by packing
box of the modules.

Instruction Manual

06-G-MB2-HFUG-2020AN-230330
4 of 34

TORAY UF!

Instruction!

Instruction

Housing type joints and screw are applied to connect the modules of HFUG2020AN to the piping. Follow the instruction of the connection provided by the
supplier at the connection point. Wrong connections may damage the modules.

When connecting and unconnecting the modules to the piping, be sure to secure asufficient working space, and take care not to catch and hurt fingers.

Keep the connection surface free of any dirt or oils.

!

Prohibited

Be sure to install the modules vertically for effective air scrubbing.

Instruction

Instruction Manual

06-G-MB2-HFUG-2020AN-230330
5 of 34

TORAY UF

2. Safety Instruction for Filtration Operation!

Instruction!

Instruction!

Instruction!

Instruction!

Instruction!

Instruction

Flush all the piping out with clean water and make sure no debris is remaining in
the piping prior to connecting the modules.

Confirm that the preservative chemical in the modules is completely drained out
before starting the filtration operation. The preservative chemical is harmful tohumans.

Flush the modules at low pressure, filling from the bottom, and vent to remove any
air from the modules. Air left in the modules may cause water hammer and may
result in damage to the membrane.

Prior to use, make certain modules are flushed. Filtrate water should be drained
unless it meets the required quality.

Protect modules from direct sunlight and ultraviolet light. Ultraviolet light candegrade module housing and membranes.

Constantly monitor filtrate water quality such as turbidity and/or the number ofparticles during filtration, and stop the operation if abnormal water quality isdetected.

Instruction Manual

06-G-MB2-HFUG-2020AN-230330
6 of 34

TORAY UF

Do not exceed the maximum applicable pressure of 300 kPa (43.5 psi). Higher
pressures can damage the modules. Do not exceed the maximum temperature of
Prohibited

40 deg C (104 deg F). The higher temperature damages the modules.

Do not freeze the membrane modules.
Prohibited!

Instruction!

Instruction!

Instruction

The operating conditions, including the filtration flux and the periodical physicalcleaning, must be properly set up otherwise the trans-membrane pressure may rise
too quickly. The operation range is described in the latter section of this manual.

Make sure air tubes or connected pipes are properly fixed. Otherwise, the tubes orconnected pipes may be blown away or behave violently during air-scrubbing.

Do not overfeed air to the modules. Excessive scrubbing air damages themembranes and/or shortens the membrane life.
The air flow rate should be within the range below for each module type.
HFUG-2020AN: 4.8 – 9.0 Nm3/h (2.8 – 5.3 scfm)
The maximum required air pressure during the air-scrubbing for inside of themodule will be 40 kPa (6 psi).

!

Instruction

At the integrity tests, such as Pressure Decay Test (PDT) or Diffusive Air Flow (DAF)
Test, keep the air pressure below 130 kPa (18.9 psi). Keep the source air pressure
lower than 200 kPa (29 psi), to prevent excess air inflow. All the air used for air
scrubbing and integrity testing must be dry oil-free air..

Instruction Manual

06-G-MB2-HFUG-2020AN-230330
7 of 34

TORAY UF

3. Safety Instruction for Chemical Cleaning!

Instruction

Take special precautions when handling chemicals during chemical cleaning. Wear
the safety gear such as safety glasses and protective appropriate gloves. If
chemicals come in direct contact with your skin or your clothes, treat the contactedpart appropriately based on the SDS.

Do not mix sodium hypochlorite with acid. Such mixture generates toxic chlorine
Prohibited!

Instruction!

Instructiongas.

Stop operation whenever any anomaly occurs with the equipment or any signs ofan anomaly are observed.

In the chemical cleaning, strictly follow the procedure described in the latter sectionof this manual. Otherwise you may damage the modules or negatively affect themembrane performance.

Instruction Manual

06-G-MB2-HFUG-2020AN-230330
8 of 34

TORAY UF

4. Safety Instruction for Disposal!

Instruction

Apply a service of a qualified waste disposing company when disposing of themodules. Use the appropriate facilities in which hydrogen fluoride (HF) gas can be
neutralized when the module is to be incinerated. HF gas is generated with theincineration of membrane.

Instruction Manual

06-G-MB2-HFUG-2020AN-230330
9 of 34

TORAY UF

5. Warranty Claims
UF modules that are damaged due to improper loading, shipping, handling, or storing shall not
be covered by Toray Industries, Inc.’s warranty. Therefore, it is very important that the customer
firmly follows instructions of loading, shipping, handling, and storing of the UF modules
mentioned in this Instruction Manual.
UF modules which are in their original sealed package can be stored for 12 months from thedate they were shipped from Toray’s factory or warehouse. If they are stored for longer than
12 months, the warranty will become void unless otherwise Toray Industries, Inc. agrees.

Instruction Manual

06-G-MB2-HFUG-2020AN-230330
10 of 34

TORAY UF

6. Warranty Policy
Full and proper compliance with this Instruction Manual is a mandatory required thing for theclaims under the warranty. In case of making a warranty claim, the customer automaticallyagrees to provide Toray Industries, Inc. with the information about operation mode, recording
performance data of UF systems.
Kindly please contact Toray Industries, Inc. if the customer wishes to deviate from any of theprocedures or specifications mentioned in this Instruction Manual and request written approvalin advance. Otherwise, the customer has a risk of invalidation for any warranty claims that they
may make in the future.

Instruction Manual

06-G-MB2-HFUG-2020AN-230330
11 of 34

TORAY UF

III. Specifications of Toray “HFUG-2020AN” Membrane Module
Table 1. Specifications of membrane *1)
Membrane Material

PVDF (Polyvinylidene fluoride)

Nominal Pore Size *2)

0.01 micrometers

Trans-Membrane

Maximum *3)

300 kPa (43.5 psi)

Pressure

Normal Operation

Lower than 200 kPa (29.0 psi)

Storage and Operating1 – 40 deg C

Temperature Range(34 – 104 deg F)

Operating pH Range

1 – 10*1): Note that the specifications are subject to change without notice.
*2): Estimation from removal of model particles.
*3): TMP (Trans-Membrane Pressure) should be below 300 kPa (43.5 psi) at any time even during thefiltration.

Table 2. Feed water limits *1), *4)

Turbidity
TSS

Intermittent Peak *5)

200 NTU

Continuous Maximum

50 NTUIntermittent Peak *5)

200 mg/L

Continuous Maximum

50 mg/LOzone

Not detected

Pretreatment Filter Mesh Size

Smaller than 200 micrometers
1 – 40 deg C

Temperature Range(34 – 104 deg F)

pH Range

1 – 10Maximum Feed Pressure

300 kPa (43.5 psi)*1): Note that the specifications are subject to change without notice.
*4): If you have any concerns about design, please contact us.
*5): The duration time should be less than 48 hours and the occurrence frequency should not exceed
more than once a month.

Instruction Manual

06-G-MB2-HFUG-2020AN-230330
12 of 34

TORAY UF

Table 3. Cleaning limits *1)
Cleaning pH Range

0 – 12
1– 40 deg C

Cleaning Temperature Range(34 – 104 deg F)

Maximum Concentration of NaClO as Cl2

3,000 mg/L (10 < pH < 12)

Maximum NaClO Exposure

1,000,000 mg/L hours(Lifetime contact time) as Cl2
Maximum Acid Contact Time

1,000 hours (pH > 0)*1): Note that the specifications are subject to change without notice.

Table 4. Specifications of modules *1)
Module Type
Membrane Surface Area
(Outer Surface)

HFUG-2020AN
90 m2(969 ft2)

Diameter

216 mm(8.50 inches)

Dimensions

WeightMaterials

LengthFull of Water
Drained
Housing
Potting
Top

Connections

Bottom2,160 mm
(7.087 ft.)
92 kg (203 lbs)
49 kg (108 lbs)
PVC and/or equivalent
Epoxy and/or equivalent
Housing type joint
80A
Housing type joint
80A
Housing type joint
65A

Side
Max. Feed
Water FlowMax.
Backwash
Flow
OperatingConditions

15 m3/h (66 gpm)
16.8 m3/h (74 gpm)

Max. Air Flow

9.0 Nm3/h (5.3 scfm)

Filtration
MethodOutside to inside, dead end

Max. Inlet
Pressure

300 kPa (43.5 psi)

Maximum
Temperature

40 deg C (104 deg F)*1): Note that the specifications are subject to change without notice.
Instruction Manual

06-G-MB2-HFUG-2020AN-230330
13 of 34

TORAY UF



Handle and operate the modules within the ranges andthe limits indicated in Table 1 to 4. Operation out of theseranges or limits may damage the modules and affectfiltration performance.

Instruction Manual

06-G-MB2-HFUG-2020AN-230330
14 of 34

TORAY UF

IV. Configuration of Toray “HFUG-2020AN” Membrane Module(1): Filtrate Outlet / Inlet of Backwash Water(2): Air Outlet / Backwash Water Outlet(3): Feed Water Inlet / Air Inlet / Drain Outlet

Connections
Pipe fitting outer
diameter
mm (in)(1)

89.1 (3 1/2”)(2)

76.3 (3”)(3)

89.1 (3 1/2”)

Connectors
Housing typejoint 80A
Housing typejoint 65A
Housing typejoint 80A

Fig. 1. Type: HFUG-2020AN

Instruction Manual

06-G-MB2-HFUG-2020AN-230330
15 of 34

TORAY UF

V. Installation
The standard procedure to install membrane modules is described below.
1.

Unpack membrane module from a wooden box or corrugated box.
Be sure to wear protective appropriate gloves to avoid
injury of hands by packing box of the modules.

2.

Remove a plugging plate from each nozzle of the module.

3.

Drain out the preservative solution from the module.


Wear rubber gloves and safety glasses when you drain
the preservative chemical. Note that the preserving
chemical is sodium hypochlorite solution (Max. 200 mg/L
as Cl2). If this solution splashes onto your skin, wash theaffected part with running water. If the solution gets inyour eyes or mouth, wash the affected part with enoughamounts of running water for over 15 minutes and see
the doctor immediately.

4.

Put the module vertically on the pedestal in the module rack. Fix the module upright withthe hanging hook and/or the supporting belt. (see Fig. 2).

Instruction Manual

06-G-MB2-HFUG-2020AN-230330
16 of 34

TORAY UF

Fig. 2. Typical example of the membrane module installation

Do not drop the module.

Use equipment such as chain blocks, a crane, or aforklift truck when you handle the module. The HFUG2020AN module is too heavy to handle by hand.

Take care not to catch and hurt fingers.

Be careful not to install the module upside down.
Confirm the module is installed in the right direction.



Do not overtighten the module with the hanging hook
and/or the supporting belt, or you may damage themodule.



Do not allow the hollow fiber membranes to dry even fora few hours, especially in summer.

5.

Do not freeze the module.

Connect the piping to each connection point of the module with Housing type joints(HFUG-2020AN) (see Fig. 4). The maximum fastening power of the Housing type joints
should not exceed 40 Nm. When you tighten or loosen the Housing type joints, makecertain to maintain sufficient space prior to the work and be careful not to injure one’s
fingers or other body parts.

Instruction Manual

06-G-MB2-HFUG-2020AN-230330
17 of 34

TORAY UFKeep the connection surface free of any dirt or oils.



Follow the instruction below when storing the modules.
A wrong use may cause the damage to the module.

6.

Air inject should be located just beneath the bottom nozzle of the module to inlet air
completely to the module. Please refer to the below photos (see Fig. 3). Also, a checkvalve is necessary to the air piping to avoid water reverse flow.

Good location for air inject

Poor location for air inject
Good location for check valve

Fig. 3. Typical example of the air pipe installation

Make sure air tubes or connected pipes are properly
fixed. Otherwise, the tubes or connected pipes may be
blown away or behave violently during air scrubbing.

7.

Make sure that the module is installed vertically.


If the module is not installed vertically, the effect of the
air scrubbing would be reduced, and an effective
filtration will be impaired.

Instruction Manual

06-G-MB2-HFUG-2020AN-230330
18 of 34

TORAY UF

VI. Operation
1. Filtration(1) Check that all piping is connected appropriately and flushed out prior to the operation. Fig.
4 shows a typical example of membrane pipe connection.

Fig. 4. Typical example of membrane pipe connection(2) Make sure the feed water valve (V-1), the drainage valve (V-3), and the valve for the
scrubbing air (V-2) are “closed”.
(3) Make sure the filtrate water valve (V-5) is opened. Open the air exhaust valve (V-4).
(4) Gradually open the feed water valve (V-1) and fill the feed water to the module to purge
any air out.
Do not open the feed water valve (V-1) quickly, or waterhammer may occur, and the module could be damaged.

Instruction Manual

06-G-MB2-HFUG-2020AN-230330
19 of 34

TORAY UF(5) Confirm that the air is out of the module, and then close the air exhaust valve (V-4).
(6) Set appropriate volume of filtrate water flow.
Do not exceed 300 kPa (43.5 psi) to avoid damage tothe module.



Operating conditions including the filtration flux and thephysical cleaning should be properly set up to observe
the rise of trans-membrane pressure (Details aredescribed in the next session). Please contact us for any
technical support if necessary.

(7) When stopping the operation, gradually close the feed water valve (V-1).

Instruction Manual

06-G-MB2-HFUG-2020AN-230330
20 of 34

TORAY UF

2. Backwash and Air-scrubbing
The physical cleaning with backwash followed by air-scrubbing should be carried out
periodically and automatically for the continuous filtration. The frequency of the physicalcleaning mainly depends on the raw water quality (Typical frequency is once every 30 minutes
for the surface water filtration. Please contact us if you need any technical support). Fig. 5.
shows a typical example of the flow diagram for backwash and air-scrubbing.

Fig. 5. Flow diagram for backwash and air-scrubbing(1) Close the feed water valve (V-1) and stop the feed water pump.
(2) Open the air exhaust valve (V-4).
(3) Close the filtrate water valve (V-5) and open the backwashing valve (V-6) to feed back thefiltrate water from the backwashing tank to the membrane module. During backwash, thechemical feed pump can be operated to dose chemical to the backwash water. The
chemical is usually sodium hypochlorite, and the dosing rate should be up to 50 mg/L as
Cl2.
The flow rate of backwash water is set up in advance for 1.0 to 1.5 times the filtrate flow
rate. Do not exceed Max. Backwash Flow described in Table 4.
Instruction Manual

06-G-MB2-HFUG-2020AN-230330
21 of 34

TORAY UF(4) After backwashing for a fixed time (normally 30 seconds, up to 60 seconds), close thebackwashing valve (V-6) and stop the backwashing pump.
(5) Open the air exhaust valve (V-4) and the air-scrubbing valve (V-2) for air-scrubbing for a
fixed time (normally 30 seconds, up to 60 seconds).


The air flow rate for air-scrubbing should be within therange below. Excessive air flow rate may damage thehollow fiber membrane.

HFUG-2020AN: 4.8 – 9.0 Nm3/h, normally 6.0 Nm3/h(2.8 – 5.3 scfm, normally 3.5 scfm)
The maximum required air pressure during the airscrubbing for the inside of the module will be 40 kPa (6psi).

(6) Close the air-scrubbing valve (V-2) and open the drainage valve (V-3).
(7) Close the drainage valve (V-3) after the water is all drained out.
(8) Run the feed water pump and open the feed water valve (V-1).
(9) Close the air exhaust valve (V-4) after the air is purged from the module.



Constantly monitor filtrate water quality during filtrationand stop the operation if abnormal water quality isdetected. In that case, check the integrity of the elementwith PDT (Pressure Decay Test) or DAF (Diffusive AirFlow) Test. The test procedure is provided as thetechnical information by Toray.

Instruction Manual

06-G-MB2-HFUG-2020AN-230330
22 of 34

TORAY UF

3. Toray Maintenance Cleaning
Instead of chemical dosing for every backwash, soaking the membrane in a chemical solution
several tens of minutes a day is also effective for membrane performance retention. This
process is called Toray Maintenance Cleaning (TMC). The TMC is usually held following the
backwash and air-scrubbing which does not contain the chemical dosing. The frequency andsoaking time of the TMC mainly depends on the raw water quality (Normally once a day for 20
minutes. Please contact us if you need any technical support.). Fig. 6 shows a typical example
of flow diagram for the TMC.

Fig. 6. Flow diagram for the TMC(1) Open the air exhaust valve (V-4) and the drainage valve (V-3).
(2) Open the backwashing valve (V-6), run the NaClO feed pump and the backwashing pump
to feed the chemical enhanced backwash water to the membrane module. The chemical
is usually sodium hypochlorite, and the dosing rate should be up to 300 mg/L as Cl2 for
TMC.
The flow rate of backwash water is set up in advance for 1.0 to 1.5 times the filtrate flow
rate. Do not exceed Max. Backwash Flow described in Table 4.

Instruction Manual

06-G-MB2-HFUG-2020AN-230330
23 of 34

TORAY UF(3) As soon as the NaClO is detected in the drainage water, close the drainage valve (V-3).
NaClO diluted with UF filtered water is applied to TMC cleaning solution usually. In thiscase, if the filtered water contains a lot of organic matter, NaClO will be consumed by theorganic matter, which may result in a substantial decrease of cleaning efficiency. Pleasecontact us if there is such concern.
(4) After making sure water comes out from the upper part of the side nozzle of the membrane
module, stop the NaClO feed pump, close the backwashing valve (V-6), and stop the
backwashing pump.
(5) Soak the membrane in the chemical for a fixed time (normally 20 minutes). And then, open
the air-scrubbing valve (V-2) for a fixed time (normally 60 seconds).


The air flow rate for air-scrubbing should be within therange below. Excessive air flow rate may damage thehollow fiber membrane.

HFUG-2020AN: 4.8 – 9.0 Nm3/h, normally 6.0 Nm3/h(2.8 – 5.3 scfm, normally 3.5 scfm)
The maximum required air pressure during the airscrubbing for the inside of the module will be 40 kPa (6psi).

(6) Close the air-scrubbing valve (V-2), open the drainage valve (V-3) to drain the chemicalfrom the membrane module.
(7) Close the drainage valve (V-3), open the backwashing valve (V-6), and run the
backwashing pump (normally 30 seconds). Stop the backwashing pump, close thebackwashing valve (V-6), and then open the air-scrubbing valve (V-2) (normally 30
seconds). Repeat this procedure until the overflow water meets the required water quality.
(8) Repeat the process of (6) to (7) until the overflow water meets the required water quality.
(9) Make sure the air-scrubbing valve (V-2) and the backwashing valve (V-6) are “closed” andthe backwashing pump is “stopped”.

Instruction Manual

06-G-MB2-HFUG-2020AN-230330
24 of 34

TORAY UF

Constantly monitor filtrate water quality during filtrationand stop the operation if abnormal water quality isdetected. In that case, check the integrity of the elementwith PDT (Pressure Decay Test) or DAF (Diffusive AirFlow) Test. The test procedure is provided as thetechnical information by Toray.

Instruction Manual

06-G-MB2-HFUG-2020AN-230330
25 of 34

TORAY UF

4. Basic Trans-Membrane Pressure Calculation
To calculate accurate Trans-Membrane Pressure (TMP), it is necessary to involve the height
difference of inlet and outlet pressure gauges (see Fig. 7).
Example calculation of TMP (The specific gravity of water is set to 1)
TMP = (Pin - Hin) - (Pout - Hout)= (70 - 10) - (20 - (- 25))
= 60 - 45= 15 kPa

Fig. 7. Basic TMP calculation
Note, the following formula may also be used:
TMP = Pin - Pout - total delta H= 70 - 20 - (10 – (- 25)) = 15 kPa

Instruction Manual

06-G-MB2-HFUG-2020AN-230330
26 of 34

TORAY UF

5. Temperature Correction Factor
The permeability of the membrane is influenced by temperature mainly because the waterviscosity changes with temperature. It is necessary to eliminate the temperature effect with thetemperature correction factor (TCF) shown in Fig. 8 to evaluate the permeability correctly.
A Trans-Membrane Pressure (TMP) measured at some real temperature can be converted to
25 deg C corrected TMP with multiplying by TCF at real temperature.
A filtrate flow rate measured at some real temperature can be converted to 25 deg C correctedfiltrate flow rate with divided by TCF at real temperature.

1.6
1.4

温度補正係数 (-)

1.2
Temperature

1.0

correction

0.8

factor

0.6
0.4
0.2
0.0
0

10
20
30
Feed watertemperature
膜供給水温度(℃)(deg C)

40

Fig. 8. Temperature correction factor (TCF)
The equation for calculating TCF at a temperature (T deg C) is as follows.
TCF =0.0008902 / (0.01257187 x EXP((1－0.005806436 x (273.15 + T)) /(0.001130911 x (273.15 + T) - 0.000005723952 x (273.15 + T) x (273.15 + T))) / 1000)

Instruction Manual

06-G-MB2-HFUG-2020AN-230330
27 of 34

TORAY UF

6. Performance Recording
To effectively evaluate the current UF system performance, including quick recognition ofundesirable trends in operation and appropriate countermeasures, it is necessary to compare
current operating performance data with a performance data which were recorded at the firstplaced in service. Log the data which is concerned about the UF operation and must include
regular information on: flow, trans-membrane pressure, contractually specified feed water
quality parameters and temperature, and elapsed time since start-up (days). The data might
be captured and logged automatically every 2 seconds to help optimize the UF operation
system.

Instruction Manual

06-G-MB2-HFUG-2020AN-230330
28 of 34

TORAY UF

VII. Chemical Cleaning
The chemical cleaning should be carried out to remove foulants accumulated in the membranepores or sticking to the membrane surface.


Carry out the chemical cleaning before the transmembrane pressure rises to 200 kPa (29.0 psi), or themodulefiltration

performance

could

be

reducedsignificantly.



Follow the instruction described in this manual when you
carry out the chemical cleaning. If you use theunacceptable chemicals or perform the cleaning alteredfrom the recommended procedure, the membrane could
be seriously damaged.



Pay full attention when handling chemicals and be sure
to wear the safety gear such as glasses and gloves.
The chemicals used for the chemical cleaning areharmful to people. If chemicals directly contact yourskin, your eyes, or other body parts, take theappropriate treatment as stated in its SDS.



Do not mix sodium hypochlorite with acid. Such mixture
generates toxic chlorine gas.



Stop operations when any instrumental anomalies
occur, or any sign of anomalies are observed.

Instruction Manual

06-G-MB2-HFUG-2020AN-230330
29 of 34

TORAY UF

Fig. 9. Flow diagram for chemical cleaning(1) The flow diagram for cleaning simultaneously both outer surface and inside of hollow fiber
membranes is shown in Fig. 9. The flow diagram can be changed case by case. Pleasecontact us for further information if necessary.
(2) Open the chemical return valve and then open the chemical feed valve.
(3) Run the chemical feed pump to start for chemical circulation. Then, open the chemical
permeate valve to let the chemical pass through the membrane.
(4) Circulate the chemical for a fixed time.
(5) Stop the chemical feed pump.
(6) Drain the chemical and rinse the cleaning line and the module thoroughly with productwater.

Instruction Manual

06-G-MB2-HFUG-2020AN-230330
30 of 34

TORAY UFTake appropriate measures to prevent the mis-operationor accidents that could cause the chemicals to get into
the product water. Check the piping and correctly
position of each valve before starting the chemicalcleaning.

(7) The standard conditions for chemical cleaning are shown in Table 5.
The concentration and the circulation time shown in Table 5 should be observed.
Otherwise, the membrane module may get damaged and/or the life of membrane may
be shortened.



The cleaning temperature should be 20 to 40 deg C.

The circulation flow rate for each type of the module is as follows.
HFUG-2020AN: 62.5 L/min (16.5 gpm)

Table 5 Standard conditions for chemical cleaning

Pollutants

Chemicals

Inorganic substances

Citric acid *6)

Maximum

Circulation

Concentration

Time (hr)

3.0 wt%1-33,000 mg/L
Organic substances

Sodium hypochlorite

as Cl2

1-3(10 < pH < 12)*6): Besides citric acid, hydrochloric acid (with the maximum concentration of 1.0 mol/L), oxalic acid(with the maximum concentration of 1.0 wt%), sulfuric acid (with the maximum concentration of 0.05
mol/L), and nitric acid (with the maximum concentration of 0.1 mol/L) are acceptable.

Instruction Manual

06-G-MB2-HFUG-2020AN-230330
31 of 34

TORAY UF



In the case of cleaning with acid and with sodium
hypochlorite alternately, rinse the cleaning line and themodule with clean water thoroughly after each cleaning.
Use product water for rinsing and make sure that pH of
the water in the module is in the range between pH 6.5
and 7.5 after rinsing.



Do not use any other chemicals than those indicatedabove.



Do not mix sodium hypochlorite with acid. Such mixture
generates toxic chlorine gas.

!

The chemical cleaning should be done at least once a year. Otherwise, the module
filtration performance could be reduced.

Instruction

Instruction Manual

06-G-MB2-HFUG-2020AN-230330
32 of 34

TORAY UF

VIII.

Storage of Membrane Module

Follow the instruction below when you store the modules.



Be careful not to freeze the modules.

1. Storage of New Membrane Module
Keep the modules in the original packing in a dark and cool place (1 to 40 deg C). Avoid
direct sunlight and moisture.

2. Storage of Membrane Modules after Use(1) Short-term, or temporary shutdown or storage
In the case of the suspension of operation for less than four days, stop the feed water andkeep modules full of water. Keep the modules at 1 to 40 deg C.
If suspended from four days to less than eight days, fill the module with the chemical
described in Table 6. Use filtrate quality water. Keep the modules at 1 to 40 deg C.
Table 6. Conditions for storing membrane modules for less than eight days

Maximum Storage Period

Chemical7 daysSodium hypochlorite

Instruction Manual

Concentration of the
Chemical
20 mg/L as Cl2

06-G-MB2-HFUG-2020AN-230330
33 of 34

TORAY UF(2) Long-term storage
First, carry out a chemical cleaning with sodium hypochlorite. Fill the module with thechemical described in Table 7. Use filtrate quality water. Follow the instructions shown in
Table 6.
Keep the modules sealed with the aqueous chemical solution shown in Table 6 or Table 7.
If removing modules from the system, seal them and store out of direct sunlight. Keep themodules at 1 to 40 deg C.
Table 7. Conditions for storing membrane modules for more than seven days

Storage Period

Preservative Chemical *8)

Concentration of the
ChemicalSodium hypochlorite

10 mg/L as Cl2 *9)

Sodium bisulfite

1,000 mg/L

More than 7 days

*8): Select either sodium hypochlorite or sodium bisulfite chemical solution.
*9): Be careful not to exceed the sodium hypochlorite contact upper limit shown in Table 3.



Rinse the module thoroughly with clean water after thechemical cleaning with sodium hypochlorite and fill themodule with sodium bisulfite solution. Toxic chlorine
gas is generated in the case of mixing sodium
hypochlorite with sodium bisulfite without first flushingwith water.

3. Replace Preservative Chemical
Check the pH value of sodium bisulfite solution as the preservative and replace the chemical
if the pH is below three (3.0). Sodium bisulfite solution with a pH of 3 to 6 is active for thepreservation. Sodium bisulfite reacts with oxygen and forms sulfuric acid which results in alower pH. In case that sodium hypochlorite is being used as the preservative, replace it if thesodium hypochlorite concentration is less than 0.1mg/L as Cl2.

Instruction Manual

06-G-MB2-HFUG-2020AN-230330
34 of 34

Toray specializes in the development and manufactureof innovative membrane technologies. We offer an
integrated approach using our RO, NF, UF, MBR, andantiscalant products to solve water and process treatment
challenges. Contact us today to find out how Toray canhelp maximize water recovery, achieve high water quality
for water reuse, lower energy requirements, and minimize
life cycle costs. TORAY, experts in RO, NF, UF and MBR.

www.water.toray