Presentation1

Main Points Related to Internship at Attock Refinery Limited.

ABSTRACT. I’m Ali Usman Saqib, student of BS. Mechanical Engineering at UET, Taxila. I have done a 4-week internship at Attock Refinery Limited. This was my first experience of an industry, and it went excellent. ARL provides a friendly environment that persuades learning process. This Presentation depicts what I have learnt during the period of my internship, the tasks performed and the practical knowledge I have gained during my internship at ARL. The report briefly explains the different aspects of Plant Maintenance at ARL..

Plant Maintenance – III(PM-III). My first week was with PM-III, I worked with the Plant Maintenance - III (PM-III) Section. This section focuses on maintaining critical units involved in processing various refinery products. PM-III Units: Hydrogen Unit Diesel Hydro De-Sulfurization Unit (HDS) Amine Unit Sour Water Stripper Sulfur Recovery Unit H2S Safety Protocols: All PM-III units handle Hydrogen Sulfide (H2S) gas, which is highly toxic. I thoroughly reviewed H2S characteristics, required Personal Protective Equipment (PPE), and safety protocols to prevent accidents. Air Compressors. I learned about air compressors, their function of increasing gas pressure, and their similarities to pumps. Reverse Osmosis Plant: This unit utilizes the principle of reverse osmosis, a process where a solvent (typically water) flows through a membrane in the opposite direction of natural osmosis due to applied pressure. The ARL plant has a capacity of 36 cubic meters per hour..

DHDS Diesel Hydro desulfurization (DHDS) is a catalytic chemical process widely used to remove sulfur (S) from diesel fuel. Catalysis is the increase in the rate of a chemical reaction due to the participation of an additional substance called a catalyst. Sulfur removal is an exothermic reaction. Hydro Treating is an established refinery process for reducing sulfur, nitrogen and aromatics while enhancing certain number, density and smoke point. Hydro cracking process by which the hydrocarbon molecules of petroleum are broken into simpler molecules, as of gasoline or kerosene, by the addition of hydrogen under high pressure and in the presence of a catalyst. Minimum required hydrogen purity for DHDS unit is 70%..

WTH (Workshop, Transport and HVAC) We were assigned to the Workshop, Transport, and HVAC department for 2 days. Here's what I experienced: Workshop: I observed various fabrication processes, including machining, milling, welding, forging, fitting, and casting. Drinking Water Chiller: I studied the cooling system, which consists of: Evaporator: Where the refrigerant absorbs heat to transform from a liquid to a gas. Compressor: Raises the pressure and temperature of the refrigerant gas. Condenser: Where the hot, high-pressure gas releases heat and condenses back into a liquid. Expansion Valve: Reduces the pressure of the liquid refrigerant, allowing it to absorb heat again in the evaporator..

Plant Maintenance – I I was assigned to work in Plant Maintenance – I (PM-I) section for the first one week. Following plants come under Plant Maintenance - I: Distillation Unit Downstream Unit Distillation Unit HBU – I (HB word from Howe-Baker International the design and manufacturing company) HBU – II Downstream Units: Isom Reformer Cooling Towers Flare Area Parts of Heat Exchanger: Tubes: Carry the fluid that needs to be heated or cooled. Shell: Encases the tubes and holds the other fluid. Baffles: Direct fluid flow and support tubes..

Plant Maintenance-II I was assigned to work in Plant Maintenance – II section for the next 3 days. Following are the plants in PM-II Heavy Crude Unit (distillation unit) LUMMUS (distillation unit) Merox Boiler House (5 Boilers) Reverse Osmosis Plant (RO Pant) Steam Generation System (SGS) Compressor Room Type of Maintenance Generally, 2 types of maintenance are carried out in ARL. Corrective Maintenance: Carried out in case of any breakdown, emergency plant shutdown. Generally, includes replacing bearings, mechanical seals etc. It is mostly discouraged Preventive Maintenance: Carried out on periodic basis for early detection of possible failures. Is mostly carried out based on running hours e.g., 4000, 8000, 16000 etc. Vibrational level, oil level, sound, mechanical seal leakage and temperatures are generally checked. Necessary to avoid breakdown. Pump A device which uses energy to move liquid from lower to higher elevation or same elevation. Types of pump 1). Positive displacement pump 2). Reciprocating Pump 3). Rotary Pump.

Possible fault symptoms in Heat Exchangers were studied: Deviation of differential pressure of inlet and outlet (∆ P) Deviation of differential temperature (∆ T) Impurities in product Brief overview of Heavy Crude Unit (HCU) was given. It consists of Atmospheric Distillation Tower: Vacuum Distillation Tower Vessels’ Piping System Heat Exchangers Pumps Overhead Condensers De-Salters Overview of SGS Plant SGS Boiler Capacity = 26 ton per hour Design Pressure = 254 kg/cm2 Working Pressure = 234 kg/cm2.

Power plant A power plant is an industrial facility used to generate electricity by converting various energy sources such as fossil fuels, nuclear, solar, or wind into electrical power. At Attock Refinery Limited, power plants often utilize steam turbines and generators fueled by natural gas or oil to supply energy for refining operations and nearby communities. Types of power plants Two power plants are available at attock refinery limited Three Engines with plant number 1 and engine # 1,2,3. Three plants with plant number 2 and engine # 4,5,6. Capacity Three engines are with capacity of 2.5MW each.Three engines are with capacity of 6MW each. Production of these power plants is 25MW but its consumption is half about 12MW.13MW is stand by and will be used on need base. Fuel used The fuel that is using in refinery by these power plants is Heavy Fuel Oil (HFO). It come from How Beaker Unit-I(HBU-I) and Heavy Crude Unit(HCU). HFO is very viscous hence it is not use for start-up and stop the Power plant. Diesel is used for this process for start and stop. However, due to its high viscosity and challenging combustion properties, it is not suitable forstarting up or shutting down power plants..

Engine An engine is a machine designed to convert various forms of energy into mechanical power, which can then be used to perform work. In the context of Attock Refinery Limited, engines arevital components in various applications, driving mechanical systems and providing the necessary power for numerous operations. 12 cylinder engines are using here. For example, diesel engines are commonly used in backup power generators to ensure continuous operation during power outages. Gas turbines, another type of engine, are employed in cogeneration systems to produce both electricity and heat, optimizing energy efficiency within the refinery. In maintaining the reliability and efficiency of Attock Refinery Limited’s operations, ensuring seamless production and energy management. Consumption of oil in Engine The oil using for running of engine is 8-10 litres per minute. Continuously supply is provided for running of an engine. Boiler are running by exhaust gases of an engine. Engines are stopped or done maintenance after approximately 2000 hours. For cooling engines At Attock Refinery Limited, cooling of an engine is typically achieved using water-based cooling systems, which include a combination of water and antifreeze circulated through the engine to absorb and dissipate heat. Additionally, air-cooled systems may be used for smaller engines, utilizing fans and radiators to manage temperature..

Off-site Maintenance(OSM) I was sent to Utility and Off-site maintenance (U & OSM) Section for the last 2 days. This section looks after the maintenance of all areas outside the battery limit of plants, storage tanks and all piping system leading crude oil to plants from storage tanks and products from plants to storage tanks. The Offsite Maintenance Department at Attock Refinery Limited is responsible for ensuring the reliability and efficiency of all equipment and infrastructure not directly located within the main processing units. This department oversees the maintenance of pipelines, storage tanks, loading and unloading facilities, and other critical auxiliary systems that support the refinery's operations. Their tasks include routine inspections, preventive maintenance, troubleshooting, and repair work. The department plays a vital role in minimizing downtime and maintaining the overall safety and operational integrity of the refinery by promptly addressing any issues that arise and implementing best practices for equipment upkeep. Through their diligent efforts, the Offsite Maintenance Department contributes significantly to the refinery's productivity and operational excellence. Following areas are included: CMS (Crude metering station) PMS (Product Metering station) AB (Asphalt Bitumen) PMB (Polymer Modified Bitumen) ETP (Effluent treatment plant) Crude come from outside to the refinery at following two main stations. Crude metering unit(CMU) Crude decanting unit(CDU).

Types of Tanks By Roof: 1). Fixed (Dom, Umbrella, Cone) 2). Floating (Internal and External Roof) (For volatile products) By Bottom 1). Cone Up 2). Cone Down 3). Flat Parts of a floating roof: 1). Floats 2). Seal 3). Sheet 4). Rim plate 5). Primary Seal Tank Parts: 1). Roof 2). Bottom 3). Foam line and foam chamber 4). Tangential stairways 5). Side-Entry Mixer 6). Railing Parts of floating head 1). Primary seal 2). Secondary seal 3). Inter- shoe plates seal 4). Shoe plate 5). Counterweights 6). Foam Dam 7). Panton (hollow chambers to maintain buoyancy force) 8). Anti-rotating device 9). Rim-vent 10). Gauge pipes.

Main Points Related to Internship at Attock Refinery Limited.