ESCO NEWS OCCASIONAL NEWS AND INFORMATION FROM ESCO ENGINEERING NO. 10, May 1997 ESCO Engineering, 179 Lansdowne Avenue, Kingsville, Ontario N9Y 3J2, Ph: (519) 733-3122; Fax (519) 733-6094 ESCO PROJECTS Some recent Esco projects illustrate the wide range of work carried out: - design and supply of a SS pickling tank for copper alloy strip. - 48000 cfm fume exhaust system for a wire pickler. - slag cement handling system - kiln off-gas pollution control system. - installation engineering for food packaging systems - three fumeless picklers - copper smelter ventilation design - utilities design for evaporator system - stress analysis for certification of pressure vessels and piping - food process equipment and piping layout for major plant expansion. FUME EXHAUST TIPS #7 Maintenance Like other plant equipment, a fume exhaust system will not work well unless it is maintained. Generally, such systems don't need a lot of maintenance, as there are few moving parts - mostly, it is a matter of keeping the system clean. Remember, a fume exhaust system is designed to prevent noxious fumes and dust from escaping into the workspace, so it is inevitably going to get dirty if it does its job properly. Here are some pointers for fume exhaust system maintenance: - repair mechanical damage to hoods and ducts as soon as possible. Unrepaired FRP will deteriorate quickly, and unnecessary holes reduce useful draft by drawing air from areas that do not need to be controlled. - repair leaks that drip acid immediately - check fan belts weekly for tightness and wear. - check weekly that the scrubber circulating pump is pumping - not just running, but actually pumping! - check the scrubber make-up water supply flowmeter at least once a shift, and make sure the meter stays clean. - install a differential pressure gauge across the scrubber, and monitor it daily. Increasing pressure drop could indicate plugging. A decrease could be due to reduced air flow or collapsed packing or plates. - wash the hoods out weekly, and the ducting monthly. - inspect the fan annually for mechanical damage, deterioration of the FRP, and leakage, especially at flanges, inspection ports and access openings. - inspect the scrubber annually for deterioration of the shell, mechanical damage, plugging of packing, plugging of nozzles (test them, don't just look!) and plugging or deterioration of the demister Next time - What are the benefits? FREEBIES! Coming soon: Neil Stone, our chief engineer, is presenting a paper on hydrochloric acid fume scrubbers, with special reference to the effect the new Clean Air Act rules for HCl will have on scrubbers, at the 1997 AISE Annual Convention in Cleveland, Ohio, Sept 29-Oct 2. If you cannot be there, copies of the paper will be available after the Convention. NEW EQUIPMENT We were so pleased with our inkjet plotter, we bought a second one! We find that using colour for construction and tender plots is a tremendous help in explaining the scope of work, especially when it involves additions or modifications to existing plant. THE VIEW FROM THE FIELD WHEN ALL ELSE FAILS, READ THE INSTRUCTIONS! The caption above is not so much a joke these days, as a matter of routine. There seems never to be enough time to do things right the first time which leads very often to instructions being ignored. However, in the past we have experienced cases in which some serious damage was done to expensive equipment as a result of ignoring instructions, not because of strict time constraints, simply because that has become the norm. What is it then, that causes people to ignore instructions? Is it pride, is it "know it all" or just "who cares?" It could be any of these, but most cases, it is a combination of pride, tradition and confusion. The instructions are quite clear but the terminology is unfamiliar. Perhaps the operator/assembler "thought" that according to his knowledge and experience it should be the way he always does it. Such additional information as schematics and neatly drawn diagrams are also often ignored. The new nomenclature may not be familiar to the situation, so the manufacturer adds a well-drawn explanatory diagram. We never find out why the instructions were ignored, but it leads us to think about instructions in general. Is there enough thought given to writing instructions? Are instructions written above the readers heads? Are instructions written for obvious and easy aspects of the operation while ignoring the important and more complicated? As in the case of instructions for operating a tea kettle, where the first instruction said: "Plug the cord into a suitable electric outlet" and not a word about what to do when the switch pops out. The habit to try it first and then read the instructions can be to a great extent eliminated, by writing instructions that are short, to the point, cover important aspects and in a format readable by anyone. The writer of instructions, whether professor, engineer or technologist must put him/herself into the shoes of the person eventually reading them. All of this will not prevent ignoring of instructions that are kept in some file in the supervisors office. Make copies and give them to all of the people involved in construction, startup, operation and maintenance. TANK EMISSIONS Our spreadsheet for calculating vapor losses from pickling tanks into the exhaust air remains much in demand. If you need to do such calculations, to meet the new reporting requirements, call or fax us for a copy - it's free. The spreadsheet will calculate HCl, nitric/HF and water losses for both open and closed tanks. Unfortunately, sulfuric acid losses are purely mechanical, and not possible to predict . The spreadsheet is available for download from our website. INTERNET NEWS E-mail addresses: jnstone@mnsi.net (Neil Stone) pblokr@mnsi.net (Pete Blokker) fhasler@mnsi.net (Fred Hasler) pas@mnsi.net (Paul Stone) Mail is usually checked once a day, so if you need an urgent reply, use fax or phone. Check out our home page at: http://www.mnsi.net/~pas/esco.htm This contains information about Esco, copies of this, and all previous newsletters, and the opportunity to download our open tank emissions spreadsheet. In addition, there is some humor, and quite a few links to sites of interest