CHAPTER 7 AUXILIARY MACHINERY
Information related to much of the auxiliary machinery aboard ship is provided in Engineman 3 amp; 2, NAVEDTRA 10541 (current revision). This chapter provides additional information on the care and maintenance of compressed air systems and equipment, auxiliary boilers, hydraulic systems, distilling plants and pressure valves.
COMPRESSED AIR SYSTEMS
Qualifications for lower rates require that you know not only the purpose and principles involved, but also the operation and performance of routine maintenance on many auxiliary systems and units which use compressed air. As an EN, you have already used compressed air for such jobs as starting diesel engines, blowing out and cleaning various units, and operating numerous pneumatic tools. When working with any of the three types of compressed air systems (low, medium, and high pressure), you have probably found that the principal source of many troubles is to be found in the compressor. Even though the design and capacity of compressors vary, the maintenance procedures are essentially the same for all of them. However, the care and maintenance of high pressure compressors require additional safety precautions and adherence to procedures recommended by the manufacturer.
Because of your past experience, parts of the following discussion will serve only as a review, while other portions of the discussion will benefit you in your study for advancement, and will be helpful when you are called upon to train others.
To avoid unnecessary damage to equipment, always use proper tools and take all necessary precautions. The correct use of proper tools should be kept constantly in mind when a machine of any kind is being serviced. Remember, the im-proper use of tools and methods may cause serious casualties to both machinery and personnel.
Although rugged and dependable, modern auxiliary machinery is not designed to withstand abusive treatment. Gasketed joints, pipe joints, and bolts are designed to safely withstand the strain required for a tight connection when the specified torque is applied with the correct tool. Whenever a joint or bolt cannot be tightened without the use of an oversized wrench or wrench handle extension, there is usually something wrong with the assembly.
Pounding on a wrench to acquire additional force usually results in damage to the equipment. Use of a wrench extension is likely to distort the gasketed surface or twist off the bolt without achieving a tight joint. The application of any force in excess of the force prescribed usually results in breakage.
CARE AND MAINTENANCE OF AIR COMPRESSORS
To keep the shiprsquo;s air compressors operating efficiently at all times and to prevent as many troubles as possible, it is necessary to know how to care for air intakes and filters; how to main-tain and replace air valves; how to take care of air cylinders, pistons, and wrist pins; how to adjust bearings and couplings; and how to properly maintain the lubrication, the cooling, the control, and the air systems.
Air Intakes and Intake Filters
The satisfactory operation of any compressor is based on a supply of clean, cool, dry air. To
aid in keeping the air supply clean, filters are fitted to compressor intakes. Unless inspected and cleaned regularly, these filters become clogged and cause a loss of capacity.
Filter elements should be removed from the intake and cleaned either with a jet of hot water or steam, or by immersion in a strong solution of sal soda. The filter body should be drained and replaced. Filter elements of the oil-wetted type should be dipped in a clean, medium viscosity oil after cleaning and the excess oil should be drained from the elements before replacing them on the filter intakes. Gasoline or kerosene should not be used for cleaning air filters because of the explosive fumes which may collect in the com-pressor or air receiver.
Dehydrators
On some ships, compressed air is used for the operation of missile system components and with automatic controls for boilers. In order to pre-vent failure of these systems, moisture and lubricants from the compressor must be kept at a minimum. Blowing down the compressor separators prevents most of this, but still some moisture is carried over.
To aid in the removal of the moisture and lubricants, two types of dehydrators are generally used: type I refrigerant dehydrators and type
II dehydrators using a desiccant of either silica gel or activated alumina, and containing electric heating coils for reactivating the desiccant when it becomes saturated with moisture. Type II dehydrators are normally installed in pairs so that one can always be in service while the other is be-ing reactivated.
Air Valves
Air inlet and discharge valves are vital parts of a compressor and should receive careful atten-tion. When these valves leak, the compressor capacity is reduced and results in an unbalanced stage pressure.
There are several symptoms which signify that an air valve is not functioning properly. A devia-tion from normal intercooler pressure may indicate a leaking or broken valve. A defective inlet valve above the intercooler will cause a rise in pressure in the intercooler, while a defective
discharge valve below the intercooler will cause a decrease in the intercooler pressure. An unusu-ally hot valve cover is a sign of valve trouble.
Dirt is generally the cause of leaking valves. The source of valve trouble can usually be traced to dirty intake air; the use of excessive or improper cylinder oil; or excessively high air temperature, resulting from faulty cooling. A periodic inspec-tion and cleaning of valves and valve passages will minimize and perhaps prevent the occurrence of air valve troubles. The frequency for cleaning valves must be determined for each installation.
The air valves are easily access
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CHAPTER 7 AUXILIARY MACHINERY
Information related to much of the auxiliary machinery aboard ship is provided in Engineman 3 amp; 2, NAVEDTRA 10541 (current revision). This chapter provides additional information on the care and maintenance of compressed air systems and equipment, auxiliary boilers, hydraulic systems, distilling plants and pressure valves.
COMPRESSED AIR SYSTEMS
Qualifications for lower rates require that you know not only the purpose and principles involved, but also the operation and performance of routine maintenance on many auxiliary systems and units which use compressed air. As an EN, you have already used compressed air for such jobs as starting diesel engines, blowing out and cleaning various units, and operating numerous pneumatic tools. When working with any of the three types of compressed air systems (low, medium, and high pressure), you have probably found that the principal source of many troubles is to be found in the compressor. Even though the design and capacity of compressors vary, the maintenance procedures are essentially the same for all of them. However, the care and maintenance of high pressure compressors require additional safety precautions and adherence to procedures recommended by the manufacturer.
Because of your past experience, parts of the following discussion will serve only as a review, while other portions of the discussion will benefit you in your study for advancement, and will be helpful when you are called upon to train others.
第7章辅助机械
与船上大部分辅助机械有关的信息是在 engineman 3 amp;2、navedtra 10541 (目前修订) 中提供的。本章提供有关压缩空气系统和设备、辅助锅炉、液压系统、蒸馏厂和压力阀的维护和保养的其他信息。
压缩空气系统
较低费率的资格要求您不仅知道所涉及的目的和原则, 而且知道许多使用压缩空气的辅助系统和设备的日常维护的操作和性能。作为一个轮机员, 您已经使用压缩空气来完成启动柴油发动机、吹灭和清洗各种装置以及操作众多气动工具等工作。当使用三种压缩空气系统中的任何一种 (低、中、高压) 时, 您可能会发现许多故障的主要来源是在压缩机中。尽管压缩机的设计和容量各不相同, 但所有压缩机的维护程序基本上都是一样的。但是, 高压压缩机的保养和维护需要额外的安全预防措施, 并遵守制造商建议的程序。
由于你过去的经验, 下面的部分讨论将只是一个回顾, 而讨论的其他部分将有利于你的学习进步, 并将有助于当你被要求培训他人。
To avoid unnecessary damage to equipment, always use proper tools and take all necessary precautions. The correct use of proper tools should be kept constantly in mind when a machine of any kind is being serviced. Remember, the im-proper use of tools and methods may cause serious casualties to both machinery and personnel.
Although rugged and dependable, modern auxiliary machinery is not designed to withstand abusive treatment. Gasketed joints, pipe joints, and bolts are designed to safely withstand the strain required for a tight connection when the specified torque is applied with the correct tool. Whenever a joint or bolt cannot be tightened without the use of an oversized wrench or wrench handle extension, there is usually something wrong with the assembly.
Pounding on a wrench to acquire additional force usually results in damage to the equipment. Use of a wrench extension is likely to distort the gasketed surface or twist off the bolt without achieving a tight joint. The application of any force in excess of the force prescribed usually results in breakage.
CARE AND MAINTENANCE OF AIR COMPRESSORS
To keep the shiprsquo;s air compressors operating efficiently at all times and to prevent as many troubles as possible, it is necessary to know how to care for air intakes and filters; how to maintain and replace air valves; how to take care of air cylinders, pistons, and wrist pins; how to adjust bearings and couplings; and how to properly maintain the lubrication, the cooling, the control, and the air systems.
为避免对设备造成不必要的损坏, 请务必使用适当的工具并采取一切必要的预防措施。在维修任何类型的机器时, 都应时刻牢记正确使用适当的工具。记住, 不正确地使用工具和方法可能会给机械和人员造成严重的伤亡。
现代辅助机械虽然坚固耐用, 但其设计并不能承受长期疲劳。当使用正确的工具施加指定的扭矩时, 密封接头、管接头和螺栓的设计能够安全地承受紧密连接所需的应变。每当连接或螺栓不能收紧而不使用超大扳手或扳手手柄延伸, 通常有问题的组装。
敲击扳手以获得额外的力通常会导致设备损坏。使用扳手扩展可能会扭曲垫片表面或扭曲螺栓, 而不会达到紧密的关节。施加任何超过规定的力的力通常会导致断裂。
空气压缩机的保养与保养
为了保持船舶的空气压缩机在任何时候都能高效运行, 并防止尽可能多的故障, 有必要知道如何照顾进气口和过滤器;如何维护和更换气阀;如何照顾气缸、活塞和曲柄销;如何调整轴承和联轴器;以及如何正确维护润滑、冷却、控制和空气系统。
Air Intakes and Intake Filters
The satisfactory operation of any compressor is based on a supply of clean, cool, dry air. To
aid in keeping the air supply clean, filters are fitted to compressor intakes. Unless inspected and cleaned regularly, these filters become clogged and cause a loss of capacity.
Filter elements should be removed from the intake and cleaned either with a jet of hot water or steam, or by immersion in a strong solution of sal soda. The filter body should be drained and replaced. Filter elements of the oil-wetted type should be dipped in a clean, medium viscosity oil after cleaning and the excess oil should be drained from the elements before replacing them on the filter intakes. Gasoline or kerosene should not be used for cleaning air filters because of the explosive fumes which may collect in the com-pressor or air receiver.
Dehydrators
On some ships, compressed air is used for the operation of missile system components and with automatic controls for boilers. In order to pre-vent failure of these systems, moisture and lubricants from the compressor must be kept at a minimum. Blowing down the compressor separators prevents most of this, but still some moisture is carried over.
To aid in the removal of the moisture and lubricants, two types of dehydrators are generally used: type I refrigerant dehydrators and type
进气和进气滤清器
任何压缩机的令人满意的运行都是基于清洁、凉爽、干燥的空气供应。为有助于保持空气供应清洁, 过滤器安装在压缩机进气口。除非定期检查和清洁, 否则这些过滤器会堵塞, 并导致容量损失。
过滤元件应从进气口取出, 用热水或蒸汽喷射清洗, 或浸入强烈的苏打水溶液中清洗。应排水更换过滤体。油湿型滤芯清洗后应浸入干净、中等粘度油中, 多余的油应该从这些元件中排出, 然后再在滤清器进气口上更换。汽油或煤油不应用于清洁空气过滤器, 因为可能会在压缩机或空气接收器中收集爆炸性烟雾。
干燥器
在一些船舶上, 压缩空气用于导弹系统部件的操作, 并对锅炉进行自动控制。为了防止这些系统发生排风前故障, 必须将压缩机的水分和润滑剂保持在最低限度。吹下压缩机分离器可以防止大部分的情况, 但仍有一些水分被携带。
为了帮助去除水分和润滑剂, 通常使用两种类型的脱水机: i 型制冷剂脱水机和类型
II dehydrators using a desiccant of either silica gel or activated alumina, and containing electric heating coils for reactivating the desiccant when
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