Furnace Maintenance

The alert mechanic informed the operations supervisors of the failures. Operations shut down the furnace. Maintenance mechanics replaced the bolts with the properly-specified high-strength stud bolts prior to any serious releases. 

The instrument operated successfully for a period of over six months (from July to December 2005) with no user intervention for alignment or cleaning of any internal optical components. The only maintenance that occurred during this period was brushing material buildup from the ends of the probes during furnace maintenance shutdowns. This procedure required five minutes of effort. The maximum allowable time between cleanings was not determined however, the system was operated successfully for periods of up to four weeks without cleaning. 

Steam may also be supplied to municipalities. However, the supply of this heat/steam cannot be guaranteed in all cases for instance during flue gas system or glass furnace maintenance. 

EFFECT OF COAL AND MULTIFUEL FIRING ON INDUSTRIAL BOILER DESIGN Effect of Design Parameters on Boiler Sizing Oil/Gas Capability Stoker or Pulverized Coal Furnace Maintenance... 

In addition, NDT plays an important part in industrial maintenance. During plant shutdowns for instance, many thousands of ultrasonic wall thickness measurements are taken on piping, vessels, furnace tubes etc. All these thickness readings have to go into extensive data bases, and this process is, thanks to modem computers and data loggers, ever more automated. 

Historically, internal scrapers or paddles were used in some designs, and loose rails were used in others to break up any caking material which formed. The nature of these designs mechanically limited the furnaces to relatively small sizes producing about 3000 t/yr. High maintenance costs were also involved. 

Eig. 8. Cost of electricity (COE) comparison where represents capital charges, Hoperation and maintenance charges, and D fuel charges for the reference cycles. A, steam, light water reactor (LWR), uranium B, steam, conventional furnace, scmbber coal C, gas turbine combined cycle, semiclean hquid D, gas turbine, semiclean Hquid, and advanced cycles E, steam atmospheric fluidized bed, coal E, gas turbine (water-cooled) combined low heating value (LHV) gas G, open cycle MHD coal H, steam, pressurized fluidized bed, coal I, closed cycle helium gas turbine, atmospheric fluidized bed (AEB), coal J, metal vapor topping cycle, pressurized fluidized bed (PEB), coal K, gas turbine (water-cooled) combined, semiclean Hquid L, gas turbine... 

Granular materials are shipped raw or calcined and usually have been ground to a specified screen si2e or si2e distribution. The additives depend on the apphcation and service conditions. These materials are used in constmction, repair, or maintenance of furnaces and vessels. Refractory mortars are used to lay brick of the same composition. These are manufactured wet premixed or dry. 

Equipment-maintenance reduction, as in filtration of engine-intake air or pyrites furnace-gas treatment prior to its entry to a contact sulfuric acid plant... 

Steel mills Blast furnaces charging, pouring CO, fumes, smoke, particulates (dust) Good maintenance, seal leaks use of higher ratio of pelletized or sintered ore CO burned in waste-heat boilers, stoves, or coke ovens cyclone, scrubber, and baghouse... 

Easy maintenance access must be provided. Removable roof panels for access to furnace subassemblies are desirable. Water-cooled equipment, electrode, and roof movement mechanisms, etc. all require overhead access for proper maintenance. 

Velocity flame stoppers have been used for feeding waste fuel gas to furnace burners when the gas can become flammable due to contamination with air. They have also been used for feeding waste or depleted air streams to furnaces when the air streams can become contaminated with flammable gases (Howard 1982). It should be noted that a furnace pressure transient may render this device ineffective and consideration should be given to providing an upstream detonation flame arrester. In this arrangement a demand will only be placed on the detonation flame arrester when the velocity flame stopper fails. Therefore, detonation flame arrester maintenance should be minimal. 

In wet-back boiler designs the rear wall of the furnace and the point at which the first-pass exit gases reverse direction is surrounded by water thus, no combustion chamber refractory is required and maintenance costs are reduced. 

Adsorptive cathodic stripping voltammetry has an advantage over graphite furnace atomic absorption spectrometry in that the metal preconcentration is performed in situ, hence reducing analysis time and risk of contamination. Additional advantages are low cost of instrumentation and maintenance, and the possibility to use adapted instrumentation for online and shipboard monitoring. 

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