The economizer is a bunch of horizontal water tubes usually located in the back pass or second pass (after the primary superheaters and reheaters) of the boiler through which the feed water enters the boiler to absorb the residual heat from the exhaust flue gas and transfer it to the steam production cycle. This process helps in improving
Symptoms: Aggressive localized boiler tube corrosion and loss of tube wall.Pits can act as stress-concentration sites which can be initiation points for stress-related corrosion mechanisms. Causes: Oxygen pitting occurs with the presence of excessive oxygen in boiler water.It can occur during operation as a result of in-leakage of air at pumps, or failure in operation of preboiler water
We claim: 1. A water-tube boiler comprising: a. an elongated water drum disposed at a lower level and extending generally horizontally along a first longitudinal axis, one end of said water drum being disposed adjacent a front end of said boiler, the other end being disposed adjacent a rear end thereof;
sectional and modular heating boilers 1- Describe the water circulation in a longitudinal drum straight tube boiler. 2- Describe four-drum, three-drum, and two-drum bent tube boilers and the advantages of a bent tube boiler compared to a straight tube boiler. 3- Describe the construction of the A type, D type, and O type and the advantages
travel over the outside surfaces of the tubes and transfer their heat to the water within the tubes. WATERTUBE BOILERS Longitudinal Straight Tube Boilers Fig. 1 illustrates one of the earliest straight tube boilers. The drum runs longitudinally in relation to the tubes. The straight inclined tubes run between
You can't use your boiler any more and you shouldn't try to repair it if there is a lap-seam crack in a longitudinal riveted joint in the boiler's shell, drum or pressure vessel. Boilers should have less than 1? times the maximum working pressure which can be measured with a hydrostatic pressure test.
(b) Tube ends or weld necks may be fusion welded to the drums of water-tube boilers without expanding or flaring. (c) Where pipe is used for tubes in water tube boilers, it may be screwed instead of rolled and flared. The ends of stub tubes may be closed by either forge or fusion welding.
A cross drum straight tube boiler a) could not have higher capacity than a longitudinal drum unit b) was usually only of single pass design c) could have more inclined tubes than a longitudinal drum unit d) is a very popular design in today's plants e) was internally fired
A circulator on the boiler side of the bypass raises the return water temperature. A circulator on the system side of the bypass lowers the supply water temperature. Boiler manufacturers emphasize bypass lines today—and with good reason. Boilers are relatively small now. Their heat exchangers are much more efficient than are those in older
The tube hole pattern, or "pitch," varies the distance from one tube to the other as well as the angle of the tubes relative to each other and to the direction of flow. This allows the fluid velocities and pressure drop to be manipulated to provide the maximum amount of turbulence and tube surface contact for effective heat transfer.
What is a steam trap? A steam trap is a device that removes condensate from a steam system. A typical steam system will have many steam traps - they are placed at 50-150' intervals in straight pipe, after every heat exchanger (where the work gets done), and at every location where there is a change of elevation or pressure.
A steam drum is used without or in the company of a mud-drum/feed water drum which is located at a lower level. A boiler with both steam drum and mud/water drum is called a bi-drum boiler and a boiler with only a steam drum is called a mono-drum boiler. The bi-drum boiler
ISA SYMBOLOGY. The symbology for the identification of the measurement and control instrumentation on the flow and process diagrams and on the P&ID (Piping & Instrument Diagram), commonly called P&I (Piping & Instrumentation), is generally compliant with the Standard ISA (Instrumentation Society of Automation) identified as S.5, that is composed of identification codes and graphic symbols.
A pressure vessel is a container designed to hold gases or liquids at a pressure substantially different from the ambient pressure.. Pressure vessels can be dangerous, and fatal accidents have occurred in the history of their development and operation. Consequently, pressure vessel design, manufacture, and operation are regulated by engineering authorities backed by legislation.
FWASDR. -- Foster Wheeler 8-Drum. Express-Type Boiler. FWH -- Foster Wheeler Header-Type Boiler. FWPFS -- Foster Wheeler Pressure-Fixed Supercharged Boiler. FWSFD -- Foster Wheeler Single-Furnace D-Type Boiler. FWSHC -- Foster Wheeler Superheat Control Boiler. FW2DR -- Foster Wheeler 2-Drum Boiler, FW2DRS -- Foster Wheeler 2-Drum Superheat
In most cases a small water tube boiler can change loads at ~20% per minute when increasing or decreasing load. The larger the unit, the slower the boiler can change load. This is based on both
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In this arrangement (Figure 1), the steam generated at start-up in the HP drum and the IP drum of the HRSG is sent directly to the condenser after being attemperated with spray water from the
Water Tube Water tube boilers have a heating surface that consists of a large number of relatively small-diameter tubes that contain the water. The heat is applied to the external side of the tubes. Other Other unlisted technology types. Search Logic:
Scotch marine boiler is a famous boiler, the first one having been installed in a ship in about 1862 and up until around 1900 was practically the only type boiler found aboard merchant or Navy ships. At that time water tube boilers began to come into use but for a number of years the Scotch marine still remained the dominant boiler.
Regardless of the type of boiler deaerator, each functions generally in the same way. When water passes from the feed water tank into the boiler deaerator, it enters through the inlet water connection. The water flows through a heating and venting section that is filled with steam.
(The term tube bank is often used, in the literature, to denote a crossflow situation and bundle to indicate longitudinal flow, however this convention is far from universal.) The flow may be single-phase or multiphase : boilers and condensers containing tube banks find a wide range of applications in industry, in addition there may be
Different types of valves we use in boiler room here are some example. Ball valve; Gate valve; Globe valve; Check valve; All these valves have the application in the purpose for controlling and isolation or creating backflow on a process.
BOILER FEEDWATER Feed water have a low mineral content, a low chloride content, a low dissolved oxygen content and a pH of above 7-8. As the purpose of the boiler is to evaporate water, the low
A water tube boiler is such kind of boiler where the water is heated inside tubes and the hot gasses surround them. This is the basic definition of water tube boiler. Actually this boiler is just opposite of fire tube boiler where hot gasses are passed through tubes which are surrounded by water.. Advantages of Water Tube Boiler. There are many advantages of water tube boiler due to which
flow of steam leaving the boiler drum. Maintaining liquid level in the boiler steam drum is the highest priority. It is critical that the liquid level remain low enough to guarantee that there is adequate disengaging volume above the liquid, and high enough to assure that there is water present in every steam generating tube in the boiler.
Longitudinal (Long) Drum, Straight Tube boiler generates 5,000 to 80,000 pounds of steam per hour with design pressures ranging from 160 to 325 psi. The maximum size of a longitudinal (long) drum boiler is limited because steam and water circulating in tubes from the front and back headers are connected to the steam drum in circumferential rows.
The industrial watertube boiler typically produces steam or hot water primarily for industrial process applications, and is used less frequently for heating applications. In the watertube design, tubes contain steam and/or water and the products of combustion pass around the tubes. Typically, watertube designs consist of multiple drums.
The Babcock & Wilcox boiler is built in two general classes, the longitudinal drum type and the cross drum type. Either of these designs may be constructed with vertical or inclined headers, and the headers in turn may be of wrought steel or cast iron dependent upon the working pressure for which the boiler is constructed.
The boilers are aft of the engine room. They are oil-fired, sectional water-tube, single cross-drum marine boilers built by the Foster Wheeler Corporation. These are the boilers that powered the boat when she was built. They were state of the art at that time. Heat passed around water-filled tubes in the boiler, heating it and assuring circulation.
Under this category, the Babcock Wilcox water-tube boiler is discussed as under. 28.2.1. Babcock Wilcox Water-Tube Boiler Features and characteristics. This boiler is. a stationary. longitudinal drum, externally fired, natural circulation, water tube boiler. It is suitable for all types of fuels.
For boilers using an automatic water feeder valve, the most-common cause of low boiler water level is failure to properly clean and maintain the water feeder valve, and the most-common cause of failure of the LWCO safety control to function is the same: failure to clean and flush the valve as specified by the manufacturer.
A tube sheet is a portion of a boiler drum, or header perforated for the insertion of tubes. (14) Ligament. The ligament is the section of metal between the holes in a tube sheet. (i) Longitudinal ligament. A longitudinal ligament is the minimum section of metal between two tube holes on a line parallel with the axis of the drum.
boiler tubes. Fly ash erosion, is a significant boiler tube failure concern, occurs in the regions with high local flue gas velocities, with high ash loading, and with abrasive particles such as quartz Corrosion: Deterioration and loss of material due to chemical attack. There are two basic categories in boiler tubes:
number of tubes and their orientation, tube design and geometry, box design, number of tube passes and furnace cells, etc., but all require decoking the furnace tubes at some time. Coker furnaces built prior to the early 1990's were normally the single fired type. Today's coker furnaces are typically double fired furnace designs like those
Mech302-HEAT TRANSFER HOMEWORK-10 Solutions 4. (Problem 10.52 in the Book) A vertical plate 2.5 m high, maintained at a uniform temperature of 54oC, is exposed to saturated steam at atmospheric pressure. a) Estimate the condensation and heat transfer rates per unit width of the plate.
I think your piping system will take care of the derating of your boiler(s) - if carryover in your steam drum doesn't. Your boiler(s) are designed to operate at a given pressure and the internal water circulation patterns are a function of that pressure (range).
The boiler water is evaporated continuously and the relative pure steam leaves the boiler drum. This mechanism is leads to concentration of boiler water with more dissolved solids. Since the solubility of various dissolved solids is limited based on the operating pressure, it is necessary to limit the concentration of dissolved solids in the boiler water.
Define boiler. boiler synonyms, boiler pronunciation, boiler translation, English dictionary definition of boiler. boiler water-tube boiler n. 1. An enclosed vessel in which water is heated and circulated, either as hot water or as steam, for heating or power.
The typical water content in these boilers is around 11/4 to 13/4 pounds of stored water for t every pound of steam per hour for which the boiler is rated. This water content is a function of the convection tube spacing which dictates the boiler pressure vessel diameter. It is also related to one of the design standards that has developed over