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Show concept. It incorporates an underfeed stoker which operates fuel-rich producing a low heating value gas and an integral burner which produces a hot exhaust gas stream. The system is refractory-lined with no provision for heat removal. Thus, it can tolerate wet fuel and can produce a low excess air exhaust at a temperature of up to 2600°F. Low excess air and high gas temperatures will result in a high boiler efficiency. The gasifier and burner sections are designed with tangential air entry to reduce particulate emissions. Most of the char and ash particles entering the burner are centrifugally separated from the gas and returned to the gasifier. Thus, particulate control equipment may not be required. A number of Lamb-Cargate units have been installed and are currently operating with lime kilns, lumber kilns and waste heat recovery boilers. However, there have been no modifications of oil/gas-fired industrial boilers. Process Selection Based upon the above characteristics, the Lamb-Cargate Wet Cell was selected as the wood firing process to be utilized in this conversion. The use of a separate combustor solves potential problems with ash handling in the boiler. The Lamb-Cargate unit produces a high temperature exhaust gas stream resulting in a high combustion and boiler efficiency. The operation of this process has also been proven at a number of installations and has exhibited a rapid response time to changes in load demand or fuel composition. LAMB-CARGATE SYSTEM Description A diagram of the Lamb-Cargate system is shown in Figure 4. Wood is burned in a two stage process using two refractory lined combustion chambers, one located directly above the other. In the lower, or primary, chamber the wood is gasified with substoichiometric quantities of air. The gases produced in this chamber are then burned in the upper, or secondary, chamber with the injection of additional air producing hot, relatively clean exhaust gas. The controlled application of combustion air to both chambers results in low excess air levels and, therefore, high exhaust gas temperatures in the 28-12 |