정수장 효율향상 고도처리기술․Improvement of drinking-water treatment plant and advanced

water treatment technology

역세척 효율 및 구조적 안전성 향상을 위한 평탄형

하부구조 유공블럭 여과지 시스템의 개발

Development of Flat Bottom Filter for Leopold Underdrain

System to Improve Structural Stability

고 려 대 학 교

환 경 부

과제번호: 061-051-027

- 1 -

제 출 문제 출 문제 출 문제 출 문

환경부장관 귀하환경부장관 귀하환경부장관 귀하환경부장관 귀하

본 보고서를 “역세척 효율 및 구조적 안전성 향상을 위한 평탄형 하부

구조 유공블럭 여과지 시스템의 개발 에 관한 연구 의“ ” 보고서로 제출합

니다.

년 월 일2007 12 14

주관연구기관명 고려대학교 산학협력단:

연구책임자 최 승일:

연 구 원 장 홍진:

조 영희:〃

조 중현:〃

유 계형:〃

맹 민수:〃

김 륜호:〃

경 국현:〃

유 양수:〃

임 진형:〃

김 승현:〃

- 3 -

보고서 초록보고서 초록보고서 초록보고서 초록

과제번호 061-051-027 과제구분 실용화기술

연구사업명 차세대 핵심환경기술개발사업

대분야명 만족도 높은 먹는 물

중분야명 정수장 효율향상 고도처리기술․연구개발

과제명

국문명역세척 효율 및 구조적 안전성 향상을 위한 평탄형 하부구조유공블럭 여과지 시스템의 개발

영문명Development of Flat Bottom Filter for LeopoldUnderdrain System to Improve Structural Stability

연구책임자 최승일총연구기간

참여연구원수

총 명: 11

내부 명: 5

외부 명: 6

총

연구개발비

정부 천원: 290,000

기업 천원: 99,600

계 천원: 389,600

연구기관명

및

소속부서명

고려대학교 산학협력단 참여기업명 주 디아이 엔바이로( )

국제공동연구 상대국명 : 상대국연구기관명 :

위 탁 연 구 연구기관명 : 연구책임자 :

요 약보고서

면수138

여과지 하부구조를 현재의 중앙부 오목 구조에서 평탄형 구조로 개조하고 유공블록

의 공기배관을 각 열마다 배치하는 구조에서 스트레이너 형의 공기주입방식으로 변경

시켜 여과지 하부구조를 단순화하여 효율적이고 안정적인 하부구조를 설계하기 위해

검증하고 조사하였다 본 연구에서는 을 통한 예비 실험과정과 를. Lab scale Pilot plant

이용한 실제 여과지의 크기로 적합성을 평가하였으며1/10 CFD(Computational Fluid

를 이용한 실제 정수장 여과지 크기로 도형화하여 안정성 및 효율성을 검토Dynamics)

하였다 다양한 별로 모형의 적합성을 분석하였으며 여과지 분배조에서 격벽과. case

오리피스와의 수리분석을 통해 균등한 역세척의 효율을 긍정적으로 평가 할 수 있었으

며 이로 인해 시공성의 편리성과 안정성을 확보하게 되었다.

색 인 어한글 유공블럭 여과지 바닥구조 역세척 분배, , , ,

영어 Leopold block, Filter, Underdrain structure, Backwash, Distribution

- 5 -

요 약 문요 약 문요 약 문요 약 문

제 목제 목제 목제 목....ⅠⅠⅠⅠ

역세척 효율 및 구조적 안전성 향상을 위한 평탄형 하부구조 유공블럭 여과지

시스템의 개발

연구개발의 목적 및 필요성연구개발의 목적 및 필요성연구개발의 목적 및 필요성연구개발의 목적 및 필요성....ⅡⅡⅡⅡ

연구의 목적연구의 목적연구의 목적연구의 목적1.1.1.1.

본 연구는 시공의 용이성과 구조적 안정성을 위한 평탄형 바닥구조와 여과지 내부에

공기분배관의 설치가 없는 새로운 형태의 여과지를 개발하는 것이다.

연구의 필요성연구의 필요성연구의 필요성연구의 필요성2.2.2.2.

유공블럭을 사용하는 여과지의 바닥은 여과지의 중앙부에 오목한 골을 형성하여 역세

척 수 공급관을 매설하도록 되어있는데 중앙부의 오목한 골을 시공하기 위해서는 여과지

의 하부바닥 콘크리트의 타설시에 여러 번 끊어서 타설을 하여야 하므로 시공에 시간이

걸리며 완공 후에 여과지를 운전함에 있어서도 부등침하와 구조적 응력결집으로 균열이,

발생되어 누수문제가 발생될 가능성이 없지 않다 또한 유공블럭을 사용함에 있어서 공기.

공급을 위한 배관은 각 블럭의 열마다 설치하여야 하므로 여과지 하부집수부의 수중에

공기배관이 지나가야 하며 시공시 주공기관으로부터 공기공급관을 각 열마다 연결하여야,

하는 복잡한 구조를 가지고 있어 시공기간이 오래 소요되는 문제가 있다 그러므로 유공.

블럭을 사용하는 여과지 하부집수거 구조를 현재의 중앙부 오목구조형에서 평탄바닥형으

로 개조하고 공기분배를 위하여 각 유공블럭의 각 열마다 설치하던 공기배급관을 스트레,

이너 형의 공기주입방식으로 변경하면 여과지 하부구조가 단순하여 질 뿐 아니라 오랜

사용 후에도 기능적 결함이 발생되지 않게 된다.

- 6 -

연구개발의 내용 및 범위연구개발의 내용 및 범위연구개발의 내용 및 범위연구개발의 내용 및 범위....ⅢⅢⅢⅢ

본 연구를 통한 기술의 궁극적인 목표는 그림 과 같았던 여과지 하부의 중앙통로< 1>

를 들어 올려서 그림 와 같이 하는 것이며 또한 하부집수거에 설치되었던 공기헤더< 2> ,

관과 공기분배관을 제거함으로써 그림 과 같이 여과지의 하부집수거 내에 공기배관< 3>

을 전부 제거하는 것이다.

그러나 하부집수거 내에서 공기배관을 제거하고도 공기와 물을 균등하게 분배하기 위

해서는 몇 가지 기술이 선결되어야 한다 첫째는 평탄한 바닥에 이중수로를 구성하기 위.

한 격벽의 설치기술이다 이를 위하여 오리피스가 있는 격벽을 설치하여 격벽내로 물이.

유입되도록 한다 유입된 물은 오리피스를 통하여 격벽과 유공블럭 사이의 공간으로 흘러.

나가고 이때 오리피스를 통한 손실수두로 인하여 격벽내의 수위보다 격벽과 유공블럭 사,

이의 수위가 낮아지는 이중수로를 구성하게 된다 이때 격벽에 설치하는 오리피스는 적절.

한 직경 뿐 아니라 오리피스와 유공블럭 유입슬리브와의 위치도 이중수로의 원활한 구축

을 위하여 매우 중요한 요인이 된다.

그림 기존 여과지의 오목형 하부집수 및 역세수 분배통로< 1>

- 7 -

그림 평탄형 여과지의 하부집수관 및 역세수 분배통로< 2>

둘째로는 공기를 주입할 때 공기가 물을 말단부로 밀어 물이 말단부로 쏠리는 현상을

극복하지 못하면 유입부로부터 말단부까지 물의 균등분배가 어렵다 그러므로 하부집수거.

의 상부에 압력실을 설치하여 압력실로 주입된 공기가 압력실 바닥의 오리피스를 통하여

분배될 수 있도록 함으로써 공기의 주입으로 인한 물의 밀림현상을 극복하여야 한다 셋.

째로는 유공블럭의 공기와 물의 유입슬리브의 직경조절 기술이다 역세척시 물과 공기를.

유입시키면 물은 말단부에서 속도수두가 없어지면서 수위를 높이게 되고 유입공기는 유,

입부에서 공간을 차지하게 된다 만약 유공블럭의 물과 공기 유입슬리브의 직경이 유입부.

와 말단부에서 동일하다면 물과 공기의 균등분배가 되지 않는다 그러므로 물 유입슬리브.

의 직경은 유입부에서 크고 말단부에서 작게 하고 공기 유입슬리브는 유입부에서 작고, , ,

말단부에서 크게 하여 슬리브를 통한 손실수두가 전체적인 수두의 균형을 안배하도록 하

여야 한다.

격벽격벽격벽격벽

그림 공기헤더관과 공기분배관을 제거한 신기술 여과지 하부구조< 3>

- 8 -

연구개발결과연구개발결과연구개발결과연구개발결과....ⅣⅣⅣⅣ

하부집수거의 중앙수로에 오리피스가 있는 격벽을 설치하여 이중수로를 형성하였다 하.

부집수거 내에 격벽을 설치하여 역세척수가 우선 중앙의 수로로 공급되면 중앙수로에서

격벽의 오리피스를 통하여 격벽과 유공블럭 사이의 수로로 물이 흐른다 이때 오리피스의.

손실수두로 인하여 중앙의 수로와 옆의 수로사이에 수두의 차이가 발생하게 된다 격벽의.

오리피스 면적이 여과지 면적의 약 인 경우에 역세척수를 의 속도로 투입0.4% 0.3m/min

하면 약 정도의 수위차이가 발생된다 이중수로에서 수두의 차이가 발생되므로, 10 cm .

공기는 격벽이 없을 때 전체 물을 밀어내리는 것보다 손쉽게 격벽과 유공블럭 사이의 수

로로 진입하여 유공블럭의 공기 유입오리피스를 통하여 유공블럭으로 진입하게 된다 그.

러므로 하부집수거의 중앙에 격벽과 격벽오리피스를 적정한 면적비로 설치하여 이중수로

의 수위차를 형성함으로써 공기와 물의 역세척시에 공기와 물이 동시에 유공블럭으로 순

조롭게 투입될 수 있도록 하였다 또한 격벽의 오리피스는 직경 뿐 아니라 그 위치도 매.

우 중요하다 그러므로 의 모사를 통하여 격벽의 오리피스는 유공블럭 슬리브의 상. CFD

하좌우의 중간에 놓이도록 함으로써 이러한 문제를 해결하였다.

역세척 공기가 유입될 때 하부집수거에서 종방향을 따라 하부집수거 내의 물이 밀리면

서 역세척수가 하부집수거의 유입부와 최종단에서 균등한 수면을 형성하지 못하는 현상

은 중앙집수거의 상부쪽에 압력실을 형성하여 공기를 압력실로 유입시킴으로서 극복하였

다 이러한 구조로서 공기는 일단 압력실로 유입되어 압력실의 바닥판에 조성한 오리피스.

를 통하여 하부집수거에 유입되게 됨으로써 하부집수거에서 물의 밀림을 방지하게 되었

다 압력실을 통한 공기의 유입에 대한 평가는 실험과 실증실험을 통하여 검증하였. Lab

다.

유입부의 유공블럭과 말단부의 유공블럭에 균등하게 물과 공기가 공급되는 것은 유공

블럭의 공기와 물 유입오리피스 공경에 다소의 조정이 필요하다 유공블럭의 오리피스에.

대한 조정이 없으면 유입부는 공기가 축적되어 수위를 낮추고 말단부에서는 반대로 공기,

가 적어서 수위가 높아지며 공기압을 가지는 공기층의 형성에 문제가 생긴다 그러므로, .

유입부의 공기 오리피스의 공경은 축소하고 물 유입오리피스의 공경을 증가시켜 유입부,

와 말단부에서 물과 공기의 균압이 형성되도록 하였다 규모의 실증플랜트에서는 말. 1/10

단부의 공기 유입오리피스 공경은 유입부의 공경의 배로 하였으며 물 유입오리피스의2 ,

공경은 유입부에서 말단부의 배가 되도록 함으로써 전 수로 길이를 통하여 비교적 균일2

한 수면경계층을 형성할 수 있었다.

- 9 -

연구개발결과의 활용계획연구개발결과의 활용계획연구개발결과의 활용계획연구개발결과의 활용계획....ⅤⅤⅤⅤ

본 연구에서 평탄형 바닥구조의 여과지가 개발되면 참여기업은 여과지 하부구조의 설

계도를 변경하여 엔지니어링 회사에 제공할 것이며 참여기업은 년에 유공블럭의 국2004

내 제작 계약을 체결하여 추후 중국을 포함하여 아시아와 동남아시아 지역의 유공블럭

수요를 충당할 것으로 예상하고 있다 본 연구의 성공으로 여과지의 기능이 향상되면 추.

후 독자적인 구조의 여과지와 유공블럭으로써 플랜트 수출에 일익을 담담하게 될 것이다.

- 11 -

S U M M A R Y

. SubjectⅠⅠⅠⅠ

Development of Flat Bottom Filter for Leopold Underdrain System to Improve Structural

Stability

. Objectives and necessity of researchⅡⅡⅡⅡ

1. Objectives

This study had been focused on the development of a flat bottom filter for Leopold block

underdrain system.

2. Necessity of study

Until now the underdrain structure has been consisted of trench type bottom. However the

structure need relatively long construction period and high cost. And the trench type structure

at the bottom could be a reason for leakage due to the uneven sedimentation or breaking of

waterproof film. Furthermore air distribution line for the underdrain system need to be

connected from the air header pipe to each row of Leopold block. Since the air pipes are

submerged in the underdrain corridor, the chlorine contained water would cause corrosion

around the welding points of the air pipes. The corrosion might cause deterioration of the

water quality. Therefore the usual structure of the filter bottom need to be rehabilitated. The

alternatives to solve this trouble is to develop the flat bottomed filter structure without

submerged air header and distribution pipe.

. Contents and scope of researchⅢⅢⅢⅢ

The objectives of his study were ultimately changing the structure of the filter bottom to

from as well as to remove the air header pipe and distribution pipes

- 12 -

such as shown in the .

Conventional structure of filter for underdrain and backwash

New bottom structure of filter

격벽격벽격벽격벽

New arrangement of the air pipe for backwash

- 13 -

The research has been focused on 3 issues. First, the technology of installing the baffle to

form the double waterway. It could be achieved by punching orifice with proper diameter and

position on the wall of the baffle. If the headloss due to the orifice is proper, the water level

between the baffle and the Leopold block wall may be much lower than the water level

between the baffle. Therefore the proper diameter and number of the orifice should be very

important to form the double waterways.

Secondly, the needed technology is prevention of the air pushing the water at the end of

the corridor. This uneven distribution of air and water pressure could be overcomed by

installing the pressure balancing chamber at the top of the central corridor. The second

mission of the research is to develop a technique to distribute air pressure evenly throughout

the length of the central corridor.

Thirdly, the needed technology is the method of adjusting the diameters of the air and

water sleeves on the Leopold block wall. When the water and air were supplied during the

backwash, the velocity head of the water may be converted to the pressure head resulting in

the more water pushed in the end rows of the underdrain block. Therefore it is needed to

adjust the diameter of the water sleeve small and diameter of the air sleeve large at the end

of the corridor. The research need to develop the proper methods to achieve all three

technology for even distribution of water and air throughout the flat bottomed filter.

. Results of research and developmentⅣⅣⅣⅣ

The research has been conducted stepwise through lab scale modules, pilot scale model and

CFD modelling. The lab scale experiments figured out the basic parameters for flat bottom,

no submerged air distribution system. The pilot plant experiment confirmed the results

obtained by lab scale experiments. Finally the CFD modelling examined various change of the

design parameters and their applicability.

This research has been succeeded to find out the design parameters for flat bottom without

air distribution pipes in the underdrain corridor. The installation of pressure balancing chamber

at the top of the underdrain corridor make the air injection possible without pushing the water

at the end of the underdrain corridor.

Forming the double waterways has been achieved by installing baffles with orifices in the

middle of central underdrain corridor. When the total area of orifice was about 0.4% of filter

- 14 -

bed area, the headloss reached about 10 cm. If the total orifice area is less than 0.4% of the

filter bed, the difference of the water level was proper to form doulbe waterways. The

importance of orifice at the baffles is not only diameter but also position. If the position of

orifices in baffles is matched to the water sleeves position on the Leopold block wall, the

backwash water would be injected directly to Leopold block. In that case, the distribution of

the water to all rows of Leopold block could not be achieved. The orifice on the baffle

should be located between the air and water sleeves on the Leopold block wall.

To equally distribute water and air to Leopold block from the entrance to the end of the

long underdrain corridor, the adjustment for diameter of air and water sleeves in Leopold

block were required. The ratio of diameter for air and water sleeves on the Leopold block

wall should be rated 1:2 along the corridor axis and should be arranged inversely. If not,

even distribution of backwash water and air throughout the underdrain corridor have not been

achieved. By making the diameter of air sleeves at the entrance one half of that at the end,

the even distribution was observed. And vise versa for the water sleeves.

. Plan of application for results of this research.ⅤⅤⅤⅤ

The result of the study will be used to rehabilitate the old filters if they install the

Leopold blocks. Also the technology could be offered when a new filter adopting Leopold

block underdrain system.

- 15 -

C O N T E N T SC O N T E N T SC O N T E N T SC O N T E N T S

Submission LetterSubmission LetterSubmission LetterSubmission Letter ···································································································································································································································································································································································································································· 1111

AbstractAbstractAbstractAbstract ···················································································································································································································································································································································································································································································································· 3

SummarySummarySummarySummary ············································································································································································································································································································································································································································································································ 5

Summary in EnglishSummary in EnglishSummary in EnglishSummary in English ········································································································································································································································································································································································································ 11

Contents in EnglishContents in EnglishContents in EnglishContents in English ············································································································································································································································································································································································································ 15151515

ContentsContentsContentsContents ········································································································································································································································································································································································································································································································ 23232323

Chapter 1. IntroductionChapter 1. IntroductionChapter 1. IntroductionChapter 1. Introduction ···················································································································································································································································································································································································· 31313131

Phrase 1. Objectives of the Study ······················································································· 31

Phrase 2. Necessity of the Study ························································································· 31

Phrase 3. Scopes of the Study ······························································································ 33

Chapter 2. Current Status of Internal and External TechnologyChapter 2. Current Status of Internal and External TechnologyChapter 2. Current Status of Internal and External TechnologyChapter 2. Current Status of Internal and External Technology ········································ 35353535

Phrase 1. Current Status of Research ················································································· 35

1. Domestic ································································································································ 35

2. Overseas ································································································································ 35

Phrase 2. Difference of domestic and overseas technology ·········································· 35

Chapter 3.Chapter 3.Chapter 3.Chapter 3. Experiments and ResultsExperiments and ResultsExperiments and ResultsExperiments and Results ································································································································································································································································ 37373737

Phrase 1. Theoretical Approach ···························································································· 37

1. Factors of Affecting Backwash of Sandfilter ····························································· 39

2. Mudball Analysis ················································································································ 43

3. Regular Maintain ················································································································ 44

4. Underdrain Block ················································································································ 45

Phrase 2. Experimental Approach ························································································· 48

Phrase 3. Experiments and Results ······················································································ 50

1. Lab Scale Test ···················································································································· 50

2. Pilot Plant Test ··················································································································· 87

3. CFD Test ······························································································································ 94

4. Summary of the Experiment ························································································· 110

Phrase 4. Economy and Analysis of design ······································································ 131

1. Economical Efficiency of Flat Bottom Underdrain System ·································· 131

- 16 -

2. Specification of Design and Operation ······································································· 133

Chapter 4. Completion and ContributionsChapter 4. Completion and ContributionsChapter 4. Completion and ContributionsChapter 4. Completion and Contributions ························································································································································································································ 137137137137

Phrase 1. Outcome of Expectations ··················································································· 137

1. Technological Side ············································································································ 137

2. Environmental Side ·········································································································· 137

3. Economical Side ················································································································ 137

Phrase 2. Achievement ··········································································································· 138

Phrase 3. Outcome of Study ································································································ 138

Chapter 5. Plans for UtilizationChapter 5. Plans for UtilizationChapter 5. Plans for UtilizationChapter 5. Plans for Utilization ···································································································································································································································································································· 141141141141

Chapter 6. ReferencesChapter 6. ReferencesChapter 6. ReferencesChapter 6. References ···················································································································································································································································································································································································· 143143143143

- 17 -

Comparison of water and air of backwash ············································· 63

Phenomenon of backwash in 3rd model ··················································· 66

Formation of pressure in 4th model ·························································· 72

Phenomenon of initial pressure in 5th model ·········································· 78

Range of water pressure and air pressure of 5th model ···················· 78

Range of water pressure and air pressure of 6th model ···················· 82

Range of water pressure and air pressure of 7th model ···················· 83

Abstract of lab scale test ············································································· 86

Results and operation condition of 1st 2nd Pilot Plant～ ······················ 88

Results and operation condition of 3rd 9th Pilot Plant～ ···················· 89

Results and operation condition of 10th 15th Pilot Plant～ ················ 91

Results and operation condition of 16th 20th Pilot Plant～ ················ 92

Results and operation condition of 21th 28th Pilot Plant～ ················ 93

Abstract of pilot plant test ········································································· 94

Range of water pressure and air pressure of 4th model ················ 121

Range of water pressure and air pressure of 7th model ················ 122

Results and operation condition of 3rd 9th Pilot Plant～ ·················· 124

Result and condition of Pilot Plant after adjustment of diameter 126

Result and condition of Pilot Plant after adjustment of air inflow127

Result and condition of Pilot Plant after adjustment of 14

50 mm diameter～ ······················································································· 128

Reduction of construction expenses ······················································· 132

Reduction of construction period ····························································· 132

Method of air and water backwash ······················································· 134

- 18 -

Diagram of front filter ················································································· 32

Diagram of plane filter ················································································· 32

Front diagram of flatness filter ································································· 33

Flatness diagram of plane filter ································································ 33

Existing filter of concavity underdrain and backwash distribution

line ····················································································································· 37

Flatness filter of underdrain and backwash distribution line ············ 37

New technology filter removed air head line and air distribution

line ····················································································································· 38

Change of water quality with time off after backwash ····················· 43

Strainer type ··································································································· 47

Verbal type underdrain system ·································································· 47

Leopold Universal S type underdrain system ········································ 47

Flow chat of flatness underdrain filter ···················································· 48

Pump, Flowmeter, Airmeter ········································································ 49

Air Maker and Compressor ········································································ 49

1st module bore a orifice in battle removed with air distribution ·· 50

Structure design and 1st module ······························································ 51

2nd module by water supply room and dispersal room removed

baffle ················································································································· 53

Design drawing and flow principle of 2nd module ······························ 54

2nd module and Air space ·········································································· 54

3th module with baffle and double baffle ··············································· 56

Front of 3th module, side and whole figure ·········································· 57

Detail design drawing of 3th module, front ··········································· 58

Side of 3th module and baffle design drawing ····································· 59

Air-orifice pitch change in Leopold ······················································· 59

Drain of inequable air ················································································· 61

Channel formation of baffle ······································································ 61

Air space formation in Leopold ······························································· 62

Air space by uniformity of water supply room ·································· 62

- 19 -

Pressure circulation line of inner pressure distribution ···················· 63

Leopold due to balance and Leopold due to unbalance ···················· 63

Backwash over unbalanced baffle by wave ········································· 64

4th module ····································································································· 68

4th module design drawing ······································································· 69

Front view of the 4th model ···································································· 70

Plane view of the 4th model ···································································· 70

Side view of the 4th model ······································································ 71

Equal distribution of air in the 4th model ··········································· 73

Inequable distribution of air in the 4th model ···································· 73

The 5th model included by the circulation space of pressure ········ 75

Circulation pathway of air for equal distribution of pressure ········ 75

Theory of the distribution of pressure ·················································· 76

Plane and side view of the 5th model ·················································· 77

Back view of central catchment basin and circulation

space of pressure in the 5th model ······················································· 77

Situation of unequally discharging air to filter ··································· 79

Situation of occuring disparity of pressure between front and

back side in the block ················································································ 79

Picture and operating situation of the 6th model ······························· 81

Change of central pathway in the 7th model ······································ 82

Schematic of the 7th model ······································································ 83

Central pathway in the 8th model ·························································· 84

Schematic of the 8th model ······································································ 84

Picture of entire and central pathway in the 8th model ·················· 85

Front and back appearance at operating time of the 8th model ··· 85

Plane and side view at operating time of the 8th model ················ 86

Picture of entire and central pathway in the actual plant ·············· 88

Air orifice and pipe classified by diameter ·········································· 89

Water orifice classified by diameter ······················································· 90

Before and after picture of incoming air pipe changed ···················· 91

Front and rear picture of forming air layer after changing

incoming air pipe ························································································· 92

- 20 -

Air and water orifice classified by diameter ······································· 93

Formation of air and water in block after changing pipe and

orifice ·············································································································· 94

CFD Grid System ························································································ 95

Adjustment for interval of orifice ··························································· 95

Flow field in plane ······················································································ 95

Flow field in side ························································································ 95

Ratio of velocity classified by section in CFD ··································· 96

Ratio of pressure classified by section in CFD ·································· 96

350.000 m3/day capacity filter ··································································· 96

The 2nd CFD model ··················································································· 97

The 2nd Grid System ················································································· 97

The 2nd adjustment for interval of orifice ··········································· 97

Initial situation of the 2nd CFD ······························································ 98

CFD 2nd result ····························································································· 98

CFD 3rd interim result ··············································································· 99

CFD 3rd result ····························································································· 99

CFD 4th interim result ············································································· 100

CFD 4th result ···························································································· 100

CFD phase 5th, 6th, 7th ·········································································· 101

5th (r:35mm) ······························································································· 101

6th (r:40mm) ······························································································· 101

7th (r:45mm) ······························································································· 101

5th (r:35mm) ······························································································· 101

6th (r:40mm) ······························································································· 101

7th (r:45mm) ······························································································· 101

CFD 8th, 9th Orifice in baffle ································································ 102

8th water surface from distribution basin center ····························· 102

9th water surface from distribution basin center ····························· 102

CFD 8th, 9th ······························································································· 103

CFD distribution basin ············································································· 103

With Leopold block ··················································································· 104

Without Leopold block ·············································································· 104

- 21 -

With Leopold block ··················································································· 104

Without Leopold block ·············································································· 104

CFD 11th ······································································································ 105

CFD 12th ······································································································ 105

CFD 14th ······································································································ 106

CFD 16th ······································································································ 106

A phase of inlet(2nd, 3rd, 4th, 5th, 11th, 12th) ································ 107

A phase of inlet(14th, 16th) ···································································· 107

Pressure distribution in baffle hole ······················································· 107

Pressure difference in baffle hole ·························································· 108

Flow distribution in baffle hole ····························································· 108

Flow difference in baffle hole ································································ 109

Height of water surface distribution from Leopold block ·············· 109

Comparison of height of water surface distribution from

Leopold block ······························································································ 110

Detail design drawing of 3th module, front ······································· 111

The condition which air pushes the water and it goes out ········· 111

Channel formation of baffle ···································································· 112

Air space by uniformity of water supply room ································ 112

Attempt of distribution of air pressure ··············································· 113

Phenomenon of partition adapting to pressure room ······················· 114

Adjustment of location of air inflow ···················································· 114

Back and forth side after adjustment of air pipe ···························· 115

Flowing Principal and Drawing of 2nd model ·································· 115

Feature of waterway of partition ························································ 117

Feature of 8th model ·············································································· 117

Drawing Leopold block of sandfilter ·················································· 119

Model of 4th Lab test ············································································ 120

Adjustment of location of air inflow in 7th model ························ 122

Feature of 8th model ·············································································· 123

Adjustment of entrance sleeve and diameter of orifice ················ 125

First and last of air inflow ··································································· 126

Back and forth side after adjustment of air pipe ·························· 127

- 22 -

Model of CFD sandfilter, underdrain and Leopold block ·············· 129

Expression double waterway according to diameter of orifice ··· 130

Expression double waterway according to location of orifice ···· 130

Distribution of flux in Hole of Partition ··········································· 131

Distribution of height in entrance of underdrain block ················ 131

Cross section of sandfilter ···································································· 135

Specification of underdrain of sandfilter ··········································· 135

Specification of flat bottom sandfilter setting for new

technology ·································································································· 136

Air pipe and partition of installation setting for new

technology ·································································································· 136

- 23 -

목 차목 차목 차목 차< >< >< >< >

제 출 문제 출 문제 출 문제 출 문 ·················································································································· 1111

보 고 서 초 록보 고 서 초 록보 고 서 초 록보 고 서 초 록 ······································································································ 3

요 약 문요 약 문요 약 문요 약 문 ·················································································································· 5

SummarySummarySummarySummary ·············································································································· 11

ContentsContentsContentsContents ··············································································································· 15151515

목 차목 차목 차목 차 ······················································································································ 23232323

본 문본 문본 문본 문 ······················································································································ 31

제 장 연구개발과제의 개요제 장 연구개발과제의 개요제 장 연구개발과제의 개요제 장 연구개발과제의 개요1111 ········································································································································································································································································································ 31313131

제 절 연구개발의 목적1 ············································································································ 31

제 절 기술개발의 중요성 및 필요성2 ···················································································· 31

제 절 연구개발의 범위3 ············································································································ 33

제 장 국내외 기술개발 현황제 장 국내외 기술개발 현황제 장 국내외 기술개발 현황제 장 국내외 기술개발 현황2222 ································································································································································································································································································ 35353535

제 절 연구개발대상 기술의 국내 외 현황1 ․ ········································································ 35국외1. ········································································································································· 35

국내2. ········································································································································· 35

제 절 국내외 기술과의 차별성2 ······························································································ 35

제 장 연구개발수행 내용 및 결과제 장 연구개발수행 내용 및 결과제 장 연구개발수행 내용 및 결과제 장 연구개발수행 내용 및 결과3333 ························································································································································································································································ 37373737

제 절 이론적 접근 방법1 ·········································································································· 37

여과지 역세척에 영향을 미치는 인자 및 대책1. ····························································· 39

머드볼 분석2. (Mudball) ········································································································· 43

정기적 유지관리3. ··················································································································· 44

하부집수장치4. ························································································································· 45

제 절 실험적 접근 방법2 ·········································································································· 48

제 절 연구개발내용 및 결과3 ·································································································· 50

- 24 -

1. Lab scale test ······················································································································ 50

2. Pilot plant test ····················································································································· 87

3. CFD test ······························································································································· 94

핵심사항4. ······························································································································· 110

제 절 경제성 및 설계 분석4 ·································································································· 131

평탄형 하부구조 여과지 시스템 경제성1. ······································································· 131

설계시방서 및 운전절차서2. ······························································································· 133

제 장 목표 달성도 및 관련분야에의 기여도제 장 목표 달성도 및 관련분야에의 기여도제 장 목표 달성도 및 관련분야에의 기여도제 장 목표 달성도 및 관련분야에의 기여도4444 ···································································································································································· 137137137137

제 절 기대성과1 ······················································································································· 137

기술적 측면1. ························································································································· 137

환경적 측면2. ························································································································· 137

경제적산업적 측면3. ․ ········································································································· 137제 절 목표달성도2 ··················································································································· 138

제 절 기여도3 ··························································································································· 138

제 장 연구개발결과의 활용계획제 장 연구개발결과의 활용계획제 장 연구개발결과의 활용계획제 장 연구개발결과의 활용계획5555 ································································································································································································································································ 141141141141

제 장 참고문헌제 장 참고문헌제 장 참고문헌제 장 참고문헌6666 ···························································································································································································································································································································································································· 143143143143

- 25 -

표 차례표 차례표 차례표 차례< >< >< >< >

표 역세척 공기량과 수량의 변화에 따른 역세상황의 비교< 3.3.1> ································ 63

표 차 모형에서 물과 공기의 주입에 따른 역세척 상황< 3.3.2> 3 ···································· 66

표 차 모형에서 물과 공기의 주입에 따른 압력의 형성< 3.3.3> 4 ···································· 72

표 차 모형에서 공기주입시 초기압력 발생상태< 3.3.4> 5 ·················································· 78

표 제 차 모형에서 공기압과 수압의 분포에 따른 역세척 현상< 3.3.5> 5 ························ 78

표 제 차 모형에서 공기압과 수압의 분포< 3.3.6> 6 ······························································ 82

표 제 차 모형에서 공기압과 수압의 분포< 3.3.7> 7 ······························································ 83

표 요약< 3.3.8> Lab scale test ······························································································· 86

표 차 현장 플랜트 운전조건 및 결과< 3.3.9> 1 2～ ·························································· 88

표 차 현장 플랜트 운전조건 및 결과< 3.3.10> 3 9～ ························································ 89

표 차 현장 플랜트 운전조건 및 결과< 3.3.11> 10 15～ ···················································· 91

표 차 현장 플랜트 운전조건 및 결과< 3.3.12> 16 20～ ···················································· 92

표 차 현장 플랜트 운전조건 및 결과< 3.3.13> 21 28～ ···················································· 93

표 요약< 3.3.14> Pilot plant test ···························································································· 94

표 차 모형에서 물과 공기의 주입에 따른 압력의 형성< 3.3.15> 4 ································ 121

표 차 모형에서 공기압과 수압의 분포< 3.3.16> 7 ······························································ 122

표 차 현장 운전조건 및 결과< 3.3.17> 3 9 Pilot Plant～ ·············································· 124

표 물 유입오리피스 직경 조정 후 현장 운전조건 및 결과< 3.3.18> Pilot Plant ······ 126

표 공기 유입구를 압력실로 변경 후 현장 운전조건 및 결과< 3.3.19> Pilot Plant ·· 127

표 물 유입슬리브의 직경을 로 한 운전조건< 3.3.20> 14 50 mm Pilot Plant～

및 결과 ·················································································································· 128

표 공사비 절감내역< 3.3.21> ·································································································· 132

표 공사기간 절감내역< 3.3.22> ······························································································ 132

표 공기와 물의 역세척 방법< 3.3.23> ·················································································· 134

표 공기와 물의 역세척 방법< 4.2.1> ···················································································· 138

- 26 -

그림 차례그림 차례그림 차례그림 차례< >< >< >< >

그림 여과지 정면 개요도< 1.2.1> ···························································································· 32

그림 여과지 평면 개요도< 1.2.2> ···························································································· 32

그림 평탄형 여과지 정면 개요도< 1.2.3> ·············································································· 33

그림 평탄형 여과지 평면 개요도< 1.2.4> ·············································································· 33

그림 기존 여과지의 오목형 하부집수 및 역세수 분배통로< 3.1.1> ································ 37

그림 평탄형 여과지의 하부집수관 및 역세수 분배통로< 3.1.2> ······································ 37

그림 공기헤더관과 공기분배관을 제거한 신기술 여과지 하부구조< 3.1.3> ·················· 38

그림 역세척 후 휴지시간에 따른 여과수질의 변화< 3.1.4> ·············································· 43

그림 스트레이너 형< 3.1.5> ······································································································ 47

그림 자구형 하부집수장치< 3.1.6> ·························································································· 47

그림 레오폴드 형 하부집수장치< 3.1.7> (Leopold Universal S) ······································· 47

그림 평탄형 하부구조 여과지 모형의 흐름도< 3.2.1> ························································ 48

그림 장치의 펌프 유량계 공기유량계 모습< 3.2.2> , , ·························································· 49

그림 와< 3.2.3> Air Maker Compressor ··············································································· 49

그림 공기분배관을 제거하고 격벽에 오리피스를 뚫은 차 모형 모형도< 3.3.1> 1 ········ 50

그림 구조별 설계도와 차 모형의 모습< 3.3.2> 1 ·································································· 51

그림 격벽을 제거하고 블록으로 송수실과 분산실을 도입한 차 모형< 3.3.3> 2 ············ 53

그림 차 모형의 설계도면과 흐름 원리< 3.3.4> 2 ·································································· 54

그림 차 모형 측면과 블록의 공기층 형성 모습< 3.3.5> 2 ·················································· 54

그림 격벽과 중벽을 설치하여 안정성을 도모한 차 모형 구조< 3.3.6> 2 3 ······················ 56

그림 차 모형의 앞면 측면 그리고 전체모습< 3.3.7> 3 , ······················································· 57

그림 차 모형의 앞면 상세 설계도< 3.3.8> 3 ·········································································· 58

그림 차 모형의 측면 과 격벽 설계도< 3.3.9> 3 ···································································· 59

그림 유공블럭내 오리피스 높이 변화< 3.3.10> Air- ···························································· 59

그림 불균등한 공기의 배출 모습< 3.3.11> ············································································ 61

그림 격벽의 수로 형성 모습< 3.3.12> ···················································································· 61

그림 블록내 공기층 형성< 3.3.13> ·························································································· 62

그림 송수실의 균등하게 형성된 공기층의 모습< 3.3.14> ·················································· 62

그림 내부압력 분배를 위한 압력순환 관< 3.3.15> ······························································ 63

그림 양 쪽의 균형을 이룬 블록과 불안정한 블록< 3.3.16> ·············································· 64

- 27 -

그림 파장에 의해 불균형하게 격벽을 넘치는 역세척수< 3.3.17> ···································· 64

그림 차 모형 모형도< 3.3.18> 4 ································································································ 68

그림 차 모형 설계도< 3.3.19> 4 ································································································ 69

그림 차 모형 정면< 3.3.20> 4 ···································································································· 70

그림 차 모형 평면< 3.3.21> 4 ···································································································· 70

그림 차 모형 측면< 3.3.22> 4 ···································································································· 71

그림 차 모형의 공기 균등분배< 3.3.23> 4 ·············································································· 73

그림 균등한 공기층을 형성하지 못한 모습< 3.3.24> ·························································· 73

그림 압력순환공간을 가진 차 모형 모형도< 3.3.25> 5 ························································ 75

그림 압력 균등 분포용 공기순환통로< 3.3.26> ···································································· 75

그림 압력분배 원리< 3.3.27> ···································································································· 76

그림 차 모형 앞면과 측면 사진< 3.3.28> 5 ············································································ 77

그림 차 모형의 중앙집수부와 압력순환통로 뒷모습< 3.3.29> 5 ········································ 77

그림 공기가 여과지로 불균형하게 배출되는 모습< 3.3.30> ·············································· 79

그림 블록내 유입부와 말단부의 압력차 발생< 3.3.31> ······················································ 79

그림 제 차 모형도 실제사진 및 실험 모습< 3.3.32> 6 ························································ 81

그림 차 모형 중앙통로의 변화< 3.3.33> 7 ·············································································· 82

그림 차 모형 개요도< 3.3.34> 7 ································································································ 83

그림 차 모형 중앙통로< 3.3.35> 8 ···························································································· 84

그림 차 모형 개요도< 3.3.36> 8 ································································································ 84

그림 차 모형 전체모습 중앙통로 모습< 3.3.37> 8 , ······························································· 85

그림 차 모형 실험중 중앙통로 앞 뒤< 3.3.38> 8 / ·································································· 85

그림 차 모형 실험 측면 정면< 3.3.39> 8 / ················································································ 86

그림 현