1 Jan Abstract. Energy management programs are vital to the economic life of any industry and heat recovery boilers play a dominant role in those. Waste heat boiler deskbook. Front Cover. V. Ganapathy. Fairmont Press, Jan 1, – Technology & Engineering – pages. Covers the design and application of waste heat boilers for industrial, cogeneration and municipal solid waste applications. Real-life case studies aid the.
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This book offers useful information on design and off-design performance aspects of Heat recovery systems and components such as superheaters, evaporators and economizers, which are elaborated by over 65 fully worked out examples. In-Une and Staggered Tube Bundles.
The reason is that with the same oxygen content entering the burner, more fuel is being fired thus reducing the excess air leaving the stack; also, with an increase in inlet gas temperature the exit gas temperature from a HRSG with an economizer usually decreases. Greater ash quantities may be generated and the fly ash and bot: Reference 26 79 Waste Heat Boilers Rapper drive shaft.
The boiler designed in Example 1 has to operate under the following conditions: In this type of boilers, the hot gas stream which could be at very high pressure flows inside the tubes, while low pressure saturated steam is generated outside the tubes. How to compute the fuel requirements and oxygen consumption for gas wsate exhaust boilers?
Using the methodology discussed in Appendix E, the following data were arrived at: A shut down cleaning may be necessary.
Cost of pump desobook and economics plays a role in pump sizing. The operating cost has to be considered in making the decision as it increases significantly from 15 to 45 kW. Maximum heat recovery compatible with considerations of high and low temperature corrosion is the objective of the flue gas waste heat boiler. Heat recovery scheme with reciprocating engine. Figure shows the scheme. If we add to this a multipressure HRSG situation or the presence of bliler radiant section with different operating parameters and fuel firing, the design procedure would be indeed difficult without a computer.
The best that can be done is watse use a multi-pass design with different tube sizes in each pass. Ammonia is injected upstream of the catalyst and is mixed with the gas stream Waste Heat Boiler Deskbook 40 – 9 5 4 1 9 5 I. Figure 31 shows the various configurations that are feasible for a single pressure system. As the gas velocity increases the surface area reduces and gas pressure drop increases significantly.
Waste heat boiler deskbook – V. Ganapathy – Google Books
The advantage is that the catalyst can be located beyond the evaporator and ahead of the economizer and splitting up of the evaporator is avoided. Since the gas stream has particulates, bare tubes are preferred for the heat transfer surfaces unless the particulate concentration is very low. The front end of the boiler has several rows of wide spaced slag screen tubes, which helps minimize bridging of tubes by molten slag; this is a combination of several salts of sodium and potassium which have low melting points.
A subroutine calculates the enthalpy. Steam bubbles if any should be easily removed with this configuration. More information on finned tubes and their optimization can be found in Appendix A. The design of the heat recovery boiler will also be affected by the presence of chlorine and alkali salts, as discussed earlier. The gas flow remains nearly constant, while the steam production and the water flowing through the economizer increases, depending on the extent of firing.
The boiler has a fully water cooled radiant section of membrane wall design followed by a convection bank and economizer.
Determine U at the average gas temperature. Tube outer diameter is 2 in. Figure shows a water tube boiler for a large tpd sulfuric acid plant. The next set of data to be fed in are: Presented below is an analysis and a chart that may be used to perform quick estimates of oxygen depletion and fuel consumption. Depending on the type of incinerator and the velocity of combustion air in the combustion zone, ash particulates can get carried away with the flue gas; this could be on the order of a 0.
The gas density at the exit is: A large water cooled membrane wall radiant section may be required to cool the gases below the fusion points of eutectics before entering the convection section. This design occupies a small floor space. There are several correlations for determining the convective heat transfer coefficient he, see Reference 1. Compute the gas specific volume. Since on-line cleaning is difficult with these boilers, they have to be shut down and cleaned more often than water tube boilers if the incoming gas has slagging tendencies.
Waste heat boiler deskbook
Sulfidation attack on steels can result at high temperatures. Both may be used to burn RDF alone or in combination with other fuels such as wood chips, sewage sludge, coal or tires. Due to the high gas inlet temperature lnd resulting heat flux, the design consists of a few rows deskbooo bare tubes followed by tubes with low fin density and then tubes with high fin density. Its effect on U as explained above is not significant.
With smaller tubes, one needs fewer for the same duty. The efficiency of the HRSG system increases with a decrease in stack gas temperature and mass flow, as will be shown in Chapter 4. The boiler is slightly inclined to dskbook draining. Heat losses thrqugh casing may be evaluated using the program described.