Abstract: A flow of air is provided from a hot air main into a combustion chamber at a time when a burner is firing into the combustion chamber to heat a bed of regenerative media. The flow of air into the combustion chamber helps to keep products of combustion from flowing into the hot air main. In preferred embodiments, sensors sense pressure in the combustion chamber and the hot air main. A controller shifts a valve back and forth within a range of open conditions to regulate the flow of air in response to the sensed pressures.
August 7, 2012
August 1, 2013
John N. Newby, Todd A. Miller, Thomas F. Robertson, Bruce E. Cain
Abstract: A scrap metal recycling furnace system comprises a dry hearth furnace, a closed well furnace, an afterburner chamber, a regenerator, a safety cooler and a fume purification plant operably interconnected by a plurality of conduits to form a system wherein exhaust gases from each component of the system can be selectively supplied to at least one other component of the system.
Abstract: An air heating apparatus for air that is to be supplied to a blast furnace. The apparatus includes a number of separate air heater devices connected together in series flow relation so that the total temperature increase is the sum of the heating actions produced in the individual devices. Each device includes a tube-shell heat exchanger and a plurality of burner units oriented around the shell to direct flames against outer surfaces of the tubes.
Abstract: A hot blast stove installation for heating cold blast to form hot blast includes a plurality of hot blast stoves each alternately operable during a heating phase and a blowing phase, a cold blast main for supplying cold blast to respective of the stoves during the blowing phases thereof, and combustion air and fuel gas mains for supplying combustion air and fuel gas to respective of the stoves during the heating phases thereof. The cold blast in the cold blast main has a relatively high temperature compared to ambient temperature, for example a temperature of from 100.degree. C. to 300.degree. C. A heat exchanger is connected to the cold blast main to remove heat from the cold blast therein prior to the supply of the cold blast to the stoves, thereby reducing the men and/or maximum waste gas temperature in the stoves during the heating phase of operation thereof.
Abstract: A system for preheating air being fed to a continuous fired furnace by means of high temperature waste gases exhausted from the furnace. The system includes two pairs of interconnected regenerators. The regenerators of one pair are alternately connected by means of a reversing valve to an ambient air inlet and a waste gas exhaust stack, and the regenerators of the other pair are alternately connected by means of a second reversing valve to the furnace's waste gas outlet duct and combustion air inlet duct.
Abstract: An apparatus for regulating the feed or delivery of hot air in the tuyere stock of a shaft furnace, and a tuyere stock which incorporates such a regulating apparatus is presented. The regulating apparatus may be used in conjunction with a tuyere stock for a shaft furnace (the structure of which is well known) and consists of an articulated pipe connecting a large circular conduit to a nozzle and which is fitted internally with a refractory lining having an internal channel therethrough for the passage of air. The regulating apparatus of the present invention comprises a valve substantially in the form of a disc which is adapted to operate in a spherical portion of the internal channel described above. The disc is removably mounted on the end of a rod, the rod being rotatably and hermetically mounted in a tubular support integral with the wall of the tuyere stock and connected on the outside thereof to a mechanism which serves to pivot both the rod and the valve about the longitudinal axis 0 of the rod.
November 7, 1984
Date of Patent:
May 13, 1986
Paul Wurth S.A.
Pierre Mailliet, Gilbert Bernard, Marc Calmes
Abstract: The burner means for a blast furnace stove having a vertical shell, a combustion chamber adjacent the inside wall of the shell and checkers in the shell includes a generally horizontal first tube extending from the outside of the shell into communication with the combustion chamber, a ceramic tube within the first tube spaced therefrom, and a ceramic nozzle at the inner end of the ceramic tube extending upwardly at an angle between 45.degree. and 90.degree.. Air of fuel gas passes within the first tube around the ceramic tube and the other of the air or fuel passes within the ceramic tube with the gas and air mixing and burning upwardly in the combustion chamber.
Abstract: A method of and a device for blast heating is described, employing separate indirect heat exchangers for combustion air and fuel gas fed to a regenerator and flue gases discharged from the regenerator. The indirect heat exchangers share heat-transfer liquid recirculating in a circuit in which an auxiliary heat exchanger is connected. In the latter exchanger, the temperature of transfer liquid is increased by combustion of partial streams of combustion air and fuel gas branched off downstream of the indirect heat exchangers. The temperature is increased to such a value which preheats the fuel gas to a temperature at which a substitution of fuel gas of a low calorific value, such as waste gas from a blast furnace, for fuel gas of high calorific value, is made possible.
Abstract: In a support construction for a hot blast main which is connected by respective branches to the outlets of a plurality of hot blast stoves of a blast furnace, the main is suspended on each stove by means of a rod system secured to a stiffened transitional region between the wall and dome of the stove and having an outer end located above the main. The main is suspended from this outer end, to which at least one strut extends from the stove wall adjacent the hot blast outlet. A travelling crane track is secured to the lower side of the rod systems so as to extend above valves incorporated in the hot blast branches. Thus these valves can easily be removed and replaced.
Abstract: A blast stove having adjoining combustion and checker chambers, for use with a blast furnace. A support structure, mounted within the checker chamber, supports tiers of interlocked checkerbricks. The support structure includes vertically extending columns which loosely engage a series of transversely extending girders. The girders supportively engage a plurality of grid bar assemblies, each assembly including a plurality of grid bars maintained in a spaced relation by transverse rods and spacers welded to the bars and further including interlocking apparatus for engaging the underlying girders and an adjacent grid bar assembly. The grid bar assemblies support a plurality of grid shoes having grid assembly engaging grooves for interlocking the grid shoes to the grid bar assemblies. The top surface of the grid shoes include recesses which receive bosses located on the underside of the checkerbricks so that the first layer of checkerbricks, is engaged by the shoes.
Abstract: Arrangement for preparing dry hot compressed air to be supplied to blast furnace, wherein a heat exchanger and a dehydrater assembly comprising a gas permeable regenerative moisture absorbing rotor are arranged in the air passage from blower to hot air furnaces so that the hot compressed air from the blower may be used to heat the dehydrated air and to regenerate the rotor. Air leakage between regenerating and dehydrating zones in the dehydrater is prevented by sealing those clearances where otherwise such leakage would occur by packing elements to form sealed spaces and externally introducing dry pressurized air into each of said spaces.
Abstract: Assembly for dehydrating atmospheric air at the input side of a blower for supplying air to a blast furnace comprising at least one gas permeable rotor containing a regenerative moisture absorbent wherein a hot combustion gas obtained by burning a waste gas from the blast furnace is utilized for regenerating the absorbent and wherein means for regulating the relative humidity of the moist air to be dehydrated, which does not need any external heat source, is provided to avoid deliquescence of the absorbent. The rotor preferably comprises a layer containing the absorbent and a layer of an adsorbent capable of adsorbing impurities contained in the air.
Abstract: Intercrystalline stress corrosion of the walls of heat exchangers employed to produce hot air for injection into a blast furnace, particularly the wall of the passage interconnecting the combustion and heat exchange chambers, is avoided by eliminating pressure differentials across the walls. Also, the walls of the heat exchanger are heated to a temperature above the condensation point of deleterious vapors present or formed in the apparatus to thereby further minimize the possibility of occurrence of stress corrosion.
September 10, 1975
Date of Patent:
May 10, 1977
S.A. des Anciens Etablissements Paul Wurth
Abstract: A hot blast stove apparatus comprising a hot blast stove having a discharge passage for hot blast gases, and a temperature equalizer material in the passage such that the hot blast gases discharged from the hot blast stove, gradually lowering in temperature with lapse of time, are continuously supplied with heat from the equalizer material and the hot blast gases discharged from the passage are at an equalized temperature.
Abstract: A method is disclosed for the improved operation of heating stoves for blast furnaces. This method is comprised of a combined use of an independent source of compressed air and potential and thermal energy of air remaining in the heating stoves at the end of a period of cooling. The purpose of this method is to reduce the time of filling of the ready to go on -- wind stoves by compressed air; to stabilize the operating conditions of the blast furnace; to save coke; to save the fuel spent on heating the stoves.