1、 GUIDE FOR EXHAUST EMISSION ABATEMENT OCTOBER 2013 NOTICE NO. 1 July 2017 The following Rule Changes were approved by the ABS Rules Committee on 7 June 2017 and become EFFECTIVE AS OF 1 JULY 2017. (See http:/www.eagle.org for the consolidated version of the Guide for Exhaust Emission Abatement 2013,
2、 with all Notices and Corrigenda incorporated.) Notes - The date in the parentheses means the date that the Rule becomes effective for new construction based on the contract date for construction. (See 1-1-4/3.3 of the ABS Rules for Conditions of Classification Offshore Units and Structures (Part 1)
3、.) SECTION 3 EGC SELECTIVE CATALYTIC REDUCTION SYSTEMS 9 SCR System Equipment (Revise Paragraph 3/9.5, as follows:) 9.5 SCR Reductant System (1 July 2017) Exhaust emission abatement systems using SCR technologies usually use an ammonia reductant introduced as a urea/water solution into the exhaust s
4、tream, prior to the catalyst blocks. For automotive and land-based engine applications, this reductant solution is typically a 32% urea solution meeting the ISO 22241 standard (AUS 32). A specific marine engine urea standard utilizing a 40% (AUS 40) urea solution has been developed by ISO (18611 ser
5、ies). The SCR manufacturer is to detail the specification of the reductant solution(s) appropriate for use with the SCR system and any specific installation considerations that may be applicable for storage, handling, and use of the reductant. Urea is typically not classified as dangerous according
6、to MSDS but can be an eye, skin, and respiratory irritant, and hence there is a need for the provision of appropriate safety features and personnel protective equipment. The key fluid media components of the SCR reductant system typically comprise reductant storage tank, pumps, filters, dosing units
7、, and injectors with associated control system. The specific requirements for SCR reductant system components using urea as a reductant are given under 3/11.3 of this Guide. Arrangements using alternative reductant solutions, such as aqueous ammonia or anhydrous ammonia, will be considered on a case
8、-by-case basis. ABSGUIDE FOR EXHAUST EMISSION ABATEMENT .2013 1 Notice No. 1 July 2017 11 SCR System Piping 11.3 Reductant Piping Systems Urea Solution (Revise Subparagraph 3/11.3.3, as follows:) 11.3.3 Arrangement of the Urea Storage Tank (1 July 2017) i) The urea storage tank is not to be situated
9、 where spillage or leakage therefrom can constitute a hazard by falling onto combustibles or heated surfaces and is to be located in a well-ventilated area away from heat sources. The urea storage tank may be located within the engine room. If installed in a separate compartment, the area is to be s
10、erved by an effective mechanical supply and exhaust ventilation system providing not less than 6 air changes per hour which is independent from the ventilation system of accommodation, service spaces, or control stations. In addition, if located in a separate compartment, the ventilation system is t
11、o be capable of being controlled from outside the compartment and is to be maintained in operation continuously except when the storage tank is empty and has been thoroughly air purged. If the ventilation stops, an audible and visual alarm is to be provided outside the compartment adjacent to each p
12、oint of entry, and inside the compartment, together with a warning notice requiring the use of such ventilation. Alternatively, where a urea storage tank is located within an engine room a separate ventilation system is not required when the general ventilation system for the space is arranged so as
13、 to provide an effective movement of air in the vicinity of the storage tank and is to be maintained in operation continuously except when the storage tank is empty and has been thoroughly air purged. Where urea based ammonia solution is stored in integral tanks, the following are to be considered d
14、uring the design and construction: a) These tanks may be designed and constructed as an integral part of the hull, (e.g. double bottom, wing tanks). b) These tanks are to be coated with appropriate anti-corrosion coating and cannot be located adjacent to any fuel oil and fresh water tank. c) These t
15、anks are to be fitted with but not limited to level gauge, temperature gauge, high temperature alarm, low level alarm. ii) The urea storage tank is to be protected from excessively high or low temperatures applicable to the particular urea concentration of the solution (e.g., above 30C and below 0C
16、for a 40% solution). Depending on the operational area of the vessel, this may necessitate the fitting of heating and/or cooling systems. The physical conditions recommended by applicable recognized standards (such as ISO 18611-3) are to be considered to avoid impairment of the urea solution during
17、storage. iii) Every pipe emanating from a tank containing urea, which, if damaged, would allow urea to escape from the tank, is to be provided with a manual closing valve located directly on the tank. iv) The urea storage tank is to be provided with vent pipes complying with 4-6-4/9 of the Steel Ves
18、sel Rules, and the outlets are to terminate in a safe location see 4-6-4/9.3.5(b)ii) of the Steel Vessel Rules in the weather and arranged to prevent entrance of water into the urea tank. The vents are not to be subject to deterioration due to the concentrations involved and the arrangement is to be
19、 such that the potential source of moisture from the vents does not present any danger to the crew or vessel. Alternatively, the tanks are to be fitted with appropriately sized pressure/vacuum valves. 2 ABSGUIDE FOR EXHAUST EMISSION ABATEMENT .2013 Notice No. 1 July 2017 v) The urea storage tank is
20、to be provided with temperature and level monitoring arrangements. High and low level alarms together with high and low temperature alarms are to be provided. vi) Urea storage tanks are to be arranged so that they can be emptied of urea, purged and vented. (Revise Subparagraph 3/11.3.5, as follows:)
21、 11.3.5 Personnel Protection (1 July 2017) For the protection of crew members, the vessel is to have on board suitable protective equipment consisting of large aprons, rubber gloves with long sleeves, rubber boots, coveralls of chemical-resistant material, dust respirator, and tight-fitting chemical safety goggles or face shields or both. Eyewash and safety showers are to be provided. The location and number of these eyewash stations and safety showers are to be derived from the detailed installation arrangements. ABSGUIDE FOR EXHAUST EMISSION ABATEMENT .2013 3
