Boiler Feed Water & Components PDF

**WHAT IS BOILER FEED WATER?** Boiler feedwater is an essential part of boiler operations. The feed water is put into the steam drum from a feed pump. In the steam drum the feed water is then turned into steam from the heat. After the steam is used, it is then dumped to the main condenser. From the...

**WHAT IS BOILER FEED WATER?** Boiler feedwater is an essential part of boiler operations. The feed water is put into the steam drum from a feed pump. In the steam drum the feed water is then turned into steam from the heat. After the steam is used, it is then dumped to the main condenser. From the condenser it is then pumped to the cascade tank. From this tank it then goes back to the steam drum to complete its cycle. The feed water is never open to the atmosphere. This cycle is known as a closed system or Rankine cycle **Boiler Diagram** **THE MAIN COMPONENTS OF A BOILER** **Burner ** One of the most important parts of a boiler is the burner. This is where the mixing of the air with the fuel source happens, resulting in the combustion which provides the necessary heat to heat up the fluid. The burner provides heat input by combustion of a heat source. In other words, it initiates the combustion reaction within the boiler.  The way this particular component operates is that thermostats will send messages to the burner electronically when the system needs to produce heat. And then, fuel will pump, by a filter mechanism, to the boiler from an outside source --- usually an adjacent fuel tank. A nozzle on the burner turns this fuel into a fine spray and ignites it, which creates the reaction in the combustion chamber.  **Combustion Chamber** As the name suggests, a combustion chamber is the part of a boiler in which the fuel/air mix burns. For this reason, the combustion chamber is usually cast iron, and the temperatures inside will rise to several hundred degrees. This process usually occurs in a very short amount of time. **Cascade tank** - A vessel steam system cascade tank, also known as a hot well, is a part of the boiler feed water system. It is a tank that receives the condensate (water) from the steam heating system and filters out any foreign substances such as rust, oil, or dirt. **Economizer** - An economizer is a heat exchanger used for heating the feed water before it enters the boilers. The economizer recovers some of waste heat of hot flue gases going to the chemistry and thus it helps in improving the boiler efficiency. **Safety Valve** - The principle type of device used to prevent overpressure in plant is the safety or safety relief valve. The safety valve operates by releasing a volume of fluid from within the plant when a predetermined maximum pressure is reached, thereby reducing the excess pressure in a safe manner. **Feed water pump -** This pump delivers feed water to the boiler to balance steam demand and maintain desired water levels. **2 Types Of Boilers** **1. fire tube boiler** is a type of boiler in which hot gases pass from a fire through one or more tubes running through a sealed container of water. The heat of the gases is transferred through the walls of the tubes by thermal conduction, heating the water and ultimately creating steam. **2. water tube boiler** is a type of boiler that uses water that is circulated through tubes that are surrounded by hot combustion gases. The water is heated by the combustion gases and turns into steam, which can be used to power turbines or other machinery. **What is a feed water pump?** A feed water pump is a type of pump that supplies water to a boiler to produce steam. For industrial purposes, a feed pump supplies a liquid for further processing **PROPERTIES OF BOILER FEEDWATER** - **pH** Normal pH level of Boiler is from 7.0 - 14.0. Controlling the PH of water is the first step towards boiler treatment. pH below 7 the solution is acidic and above 7 it's alkaline. Boiler feedwater should always be alkaline. - **Hardness** The main purpose of controlling hardness is to prevent scale formation building on the interior surface. This can be done by keeping hardness values low. - **Oil and Fats** - **Dissolve oxygen** - **[Chloride Ion]** It causes generation of scale formation. The more the chloride ions, the more the scale formation. Therefore, it is necessary to limit it as low as possible. The problem with chloride ions is that high degree of dissolution makes it difficult to remove them at a later stage. - **Phosphates** - **Corrosion** **The importance of Boiler** **Steam Generation:** - The primary role of feed water is to be converted into steam within the boiler. This steam is then used for various purposes, such as heating, powering turbines, or driving industrial processes. **System Efficiency:** - The quality of the feed water impacts the efficiency of the boiler. Impurities in the water can lead to scaling, corrosion, and reduced heat transfer efficiency, which can affect the overall performance and energy consumption of the system. **Boiler Longevity:** - Properly treated feed water helps prevent damage to the boiler. Issues like scale buildup and corrosion can lead to reduced lifespan and increased maintenance costs. **Sampling of boiler feed water** is an important procedure for ensuring the water quality meets the necessary standards for efficient and safe boiler operation. **Objectives of the Boiler Water Testing** 1\. To monitor the condition of the boiler water 2\. To control the chemical dosing of the boiler **Cooling System** It controls temperatures and pressures by transferring heat from hot process fluids into the cooling water, which carries the heat away. **Engine cooling water** Engine cooling water is a vital fluid used to regulate engine temperature. It absorbs heat from the engine. **Effect of high temperature in the engine** - Due to high temperature, the piston would seize in cylinder and stop the engine. - Lubricating quality of the oil inside the cylinder would be destroyed. - Preignition of fuel mixture which cause engine knocking as well as loss of power. **Quality of Cooling Water** The cooling water of the engine should be only distilled water with proper treatment, which is necessary for keeping effective cooling and preventing corrosion of the system. Though the distilled water matches best to the requirements for cooling water, it is necessary to add corrosion inhibitor. Because untreated distilled water absorbs carbon dioxide from the air and then becomes corrosive. **Sea water** or **fresh water** contaminated by sea water even in small amount is not allowed to be used as cooling water of the engine due to high risk of severe corrosion and deposits formation in the system. **Rainwater -**is heavily contaminated and highly corrosive in general, which is also not recommended as cooling water. Tap water (drinking water) is not recommended as cooling water due to risk of chalk deposit formation inside the cooling system. However, if the distilled water, for example from fresh water generator, is not available, tap water may be used as cooling water after softening and some other treatments according to the ingredients. **Corrosion prevention** is essential for extending the lifespan of materials and structures, particularly metals. Here are some common methods for preventing corrosion. **Basic corrosion prevention methods** **The common methods for prevention of corrosion include:** a\) Filtration of solid suspended impurities & particles from water b\) Removing dissolved oxygen from the boiler feedwater c\) Maintaining alkaline conditions in the boiler water d\) Keeping the boiler internal surfaces clean e\) Protecting boilers during out of service periods f\) Using a chemical treatment to counteract corrosive gases in steam and condensate systems **Open recirculating systems** are the most widely used industrial cooling design. These systems consist of pumps, heat exchangers, and a cooling tower. The pumps keep the water recirculating through heat exchangers.  **Once-through systems.** In once-through systems, the cooling water passes through heat exchange equipment only once. The mineral content of the cooling water remains practically unchanged as it passes through the system. **Closed recirculating systems** It uses the same cooling water repeatedly in a continuous cycle. First, the water absorbs heat from process fluids, and then releases it in another heat exchanger. In these systems, an evaporative cooling tower is not included.  **1. Plate type heat exchanger** This type of exchanger is designed with multiple parallel sets of plates which are being compressed to form the cooler unit, allowing fluid to pass between lines on the plate to the outlet holes. Furthermore, the exchanger gasket is placed on both side ends of the plate, which separates both substances from mixing up. Use of Plate type heat exchanger Plate exchanger is mostly used for lube oil and engine jacket water cooling. From my experience, the plate type seems to be the best exchanger in the terms of cooling effect and/or easy maintenance. In the terms of cleaning, it seems difficult and takes time. \"Plate **2. Shell and tube heat exchanger** Shell and tube exchanger is designed with a bundle of tubes, which are placed inside the shell. This type of heat exchanger is being used on board the ship mainly on the steam condenser, jacket water cooling, as well as lube oil cool.