게시판 > 질답게시판

스테파노 Stefano

12-11-07 19:46

(1) (탱크에서 직접 혼합시험한 것이 아니라) "각각의 시료를 채취하여 혼합된 시료"를 언급하는 것으로 봅니다.

(2) Jet Fuel을 on-test blend와 off-test blend를 겸하여 성공한 사례를 누가 자신의 이력소개에서 소개하고 있습니다.
출처: http://2200parkway.blogspot.kr/search?q=off-test

< Quote/>
2. Discuss a professional project which challenged your analytical skills.
While engineering is by nature an analytically challenging profession, I am able to single out one project that was particularly challenging. Three years ago, I was asked to determine why we were unable to meet a product specification unique to export jet fuel. It was assumed this question could be answered easily by “finding out what others do.” Unfortunately, “others” were not in the export jet fuel market; this time, we in the Richmond Refinery were the pioneers.
After consulting my counterparts at other Chevron refineries, our technical experts in the home office, several jet fuel experts in the home office, and several jet fuel experts throughout the petroleum industry, I realized I would have to solve the problem on my own. This problem was especially difficult to solve because the specification was sensitive to the synergistic effects of different sulfur species in the jet fuel components. Because we use several components to blend jet fuel, I set out to identify a blend of jet components which would not result in synergistic effects. This recipe would be used for export jet fuel.
I had many different combinations of jet fuel components hand-blended together and tested for this specification. Using this method I was unable to produce even one off- test result. I then attempted to duplicate the recipes of actual off-test blends to produce an off-test result. If I could not produce an off-test blend, the results of the on-test hand blends would be suspect. I was again unable to produce an off-test result.
A careful review of the data revealed that the material used in the hand blends had been sampled from the piping leading to the jet tanks while the off-test results for the actual blends were sampled at the tanks. I began to suspect a problem with the tanks themselves. After additional testing, I confirmed that this was in fact the problem. I recommended a solution which was quickly implemented. This project has resulted in profits of tens of millions of dollars for the refinery over the last several years.
</Unquote>

(1) (탱크에서 직접 혼합시험한 것이 아니라) "각각의 시료를 채취하여 혼합된 시료"를 언급하는 것으로 봅니다.

(2) Jet Fuel을 on-test blend와 off-test blend를 겸하여 성공한 사례를 누가 자신의 이력소개에서 소개하고 있습니다.
출처: http://2200parkway.blogspot.kr/search?q=off-test

< Quote/>
2. Discuss a professional project which challenged your analytical skills. 
While engineering is by nature an analytically challenging profession, I am able to single out one project that was particularly challenging. Three years ago, I was asked to determine why we were unable to meet a product specification unique to export jet fuel. It was assumed this question could be answered easily by “finding out what others do.” Unfortunately, “others” were not in the export jet fuel market; this time, we in the Richmond Refinery were the pioneers. 
After consulting my counterparts at other Chevron refineries, our technical experts in the home office, several jet fuel experts in the home office, and several jet fuel experts throughout the petroleum industry, I realized I would have to solve the problem on my own. This problem was especially difficult to solve because the specification was sensitive to the synergistic effects of different sulfur species in the jet fuel components. Because we use several components to blend jet fuel, I set out to identify a blend of jet components which would not result in synergistic effects. This recipe would be used for export jet fuel. 
I had many different combinations of jet fuel components hand-blended together and tested for this specification. Using this method I was unable to produce even one off- test result. I then attempted to duplicate the recipes of actual off-test blends to produce an off-test result. If I could not produce an off-test blend, the results of the on-test hand blends would be suspect. I was again unable to produce an off-test result. 
A careful review of the data revealed that the material used in the hand blends had been sampled from the piping leading to the jet tanks while the off-test results for the actual blends were sampled at the tanks. I began to suspect a problem with the tanks themselves. After additional testing, I confirmed that this was in fact the problem. I recommended a solution which was quickly implemented. This project has resulted in profits of tens of millions of dollars for the refinery over the last several years.
</Unquote>

龍鳳 yongbong

12-11-08 10:02

인용해주신 내용중에 off-test result, actual off-test blends, on-test hand blends, hand blends 등의 용어가 나오는데,
Tank에 Mixer를 두어야 하는 이유를 설명하는 과정에서 나오는 것을 추측을 해보면
on-test (hand) blend 는 Tank에서 직접 섞지 않고 Sample을 채취해서 Blending을 하는 것이고
off-test blend는 Tank에 직접 "the addition of a component" 하면서 Blending을 하는 것으로 보입니다.

저보다 더 꼼꼼하게 찾아보신 것 같아 부끄럽습니다...감사드립니다.

PS.
질문에 "off-test"의 의미를 문의드린것인데, "off-blend"라고 써 버렸네요..

스테파노 Stefano

12-11-08 21:45

<A careful review of the data revealed that the material used in the hand blends had been sampled from the piping leading to the jet tanks while the off-test results for the actual blends were sampled at the tanks.>

위에서 다시 인용한 내용으로 미루어 판단해 보면 (on-test) hand blends는 jet-fuel tank로 연결된 piping에서 시료를 취해 혼합한 것이고 off-test blends는 (연결 pipe가 아니고 보내오는 출처에 해당하는) 원래의 각각의 tank들에서 시료들을 취해 혼합한 것으로 봅니다.

결국 "on"은 "Jet Fuel Blend Tank에 가까이 연결된 Piping"에서 시료를 취했다는 말이고 "off"는 Piping이나 Blending Tank가 아니고 여기서 "멀리 떨어져 있는 각각의 Tank"에서 시료를 취한 것이라고 귀결되는것 같습니다.

龍鳳 yongbong

12-11-09 10:47

답변 감사합니다.

근데, 제 나름의 결론은 조금 다른데요...
Mixer와 off-test blend를 연결 시키려면, 사전 test 없이 Blending Tank에서 직접 투입하고, Blending Tank에 있는 Mixer로 섞어 가면서 결과를 확인한다는 의미가 아닐까 생각해 봅니다.

스테파노 Stefano

12-11-09 12:05

여러 정황을 고려하여 판단하는 것은 판단자의 몫이겠으나 원래의 질문에서 인용한 글귀,
<To allow for re-mixing after the addition of a component to adjust an off-test blend.>로 돌아가 실제상황을 연상해보면..

Blening Tank에 투입 필요량을 넣어준 다음 "Mixer"로 잘 혼합하여 균일하개 해주고나서 시료를 채취해 분석해봐야 목표로 정했던 이전의 off-test blend 품질에 도달했는지 그렇지 않은지 평가가 가능할 수 있을 것이므로 투입-혼합-시료채취-분석의 과정에서 Sampling전 균일하게 혼합하기위해 Mixer를 사용하겠지요. 대형 탱크에서 Test 없이 미리 적당히 섞어 Blending하고 Mixing 해가면서 품질을 정확히 맞추어 간다는 것은 대단한 모험이 될 것입니다.

실제로 정유공장의 Blending에 종사하는 분이 있다면 실제 적용하는 사례를 예를 들어 도움을 주면좋겠습니다.