Kiln loading

According to Ono, Kawamura, and Soda (1968), alite birefringence is a function of maximum temperature in the kiln load the higher the temperature, the larger the birefringence. Birefringence in Ono s method is measured on alite crystals in clinker particles mounted in RI oil and observed in transmitted, polarized light. 

Seaman (1951) developed an approximation for the theoretical residence time of a shallow bed (lightly loaded kiln) and a theoretical relationship for the kiln volumetric flow rate for deep beds (heavily loaded kilns). Nonetheless, no clear definition has ever been given for the range of operation encompassed by the two cases of kiln loadings. Seaman s approximations led to the conclusion that kilns should be considered heavily loaded when the fractional cross sectional fill of solids exceeds approximately 5 percent. 

Fig. 6. Pilot-scale kiln results for a fill fraction of 0.08% at 0.5 rpm and an initial toluene loading, on a dry, calcined, montmorillonite clay adsorbent, of 0.25 wt %, at A, 790°C B, 330°C and C, 190°C. The soHd lines are model fits using equation 24. The model simultaneously fits to all of the data (24).

The shuttle kiln consists of a firing chamber with two or more kiln cars on which the bricks to be fired are set. While one load of brick is being fired, a second is being set. Somewhat similar is the beU top or top-hat kiln which is raised and lowered above and over the kiln cars to be fired. These kilns are more expensive to operate than tunnel kilns but provide flexibiUty in burning conditions and production schedules. 

Use prescrubbers/condensers/kilns to reduce load in duct... 

For engineered uses the allowable stresses arc slightly lower, for kiln-dried lumber slightly higher. For slion-ienn loads, such as wind, earthquake, or impaci, higher unit stresses arc allowed... 

Fireclay bricks are used in kilns, malleable-iron furnaces, incinerators, and many portions of metallurgical furnaces. They are resistant to spalling and stand up well under many slag conditions but are not generally suitable for use with high-lime slags or fluid-coal-ash slags or under severe load conditions. 

The capacity of regeneration furnaces is selected so that they operate 80-90% of the time. In multiple-hearth furnaces the loading is 70-80 lb/(sqft)(day). In countercurrent direct fired rotary kilns, a 6% volumetric loading is used with 45 min at activation temperature. 

Gerhards (57) reviewed the results of 12 separate studies on strength properties of fire-retardant-treated wood conducted at the FPL and other laboratories. He concluded that modulus of rupture (MOR) is consistently lower and modulus of elasticity (MOE) and work to maximum load are generally lower for fire-retardant-treated wood than for untreated wood if fire-retardant treatment is followed by kiln drying. The effect may be less or negligible if the fire-retardant-treated wood is air dried instead of kiln dried. The most significant loss was in work to maximum load, a measure of shock resistance or brashness, which averaged 34 percent reduction. 

Kraft pulp mills Digesters batch and continuous Multiple-effect evaporators Recovery furnace Weak and strong black-liquor oxidation Smelt tanks Lime kiln Mercaptans, methanol (odors) H2S, other odors H2S, mercaptans, organic sulfides, and disulfides h2s Particulates (mist or dust) Particulates (dust), H2S Condensers and use of lime kiln, boiler, or furnaces as afterburners Caustic scrubbing and thermal oxidation of noncondensables Proper combustion controls for fluctuating load and unrestricted primary and secondary air flow to furnace and dry-bottom electrostatic precipitator noncontact evaporator Packed tower and cyclone Demisters, venturi, packed tower, or impingement-type scrubbers Venturi scrubbers... 

Dust from the kiln is largely captured in a suspension preheater that which is not is removed by an electrostatic precipitator before the gas passes up the chimney. The flow of gas is aided by an exhaust fan. The dust is as far as possible returned to the system by mixing with the raw meal or with the fuel (insufflation), though the extent to which either is possible may be restricted by its content of alkali sulphates or chlorides, which if high could lead to an unduly high recirculating load, conducive to the formation of deposits or undesirably high concentrations in the clinker. 

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