System and method of curing concrete products in a kiln

Abstract

A system for curing concrete products resident in a kiln, in particularly for producing high strength building blocks from relatively dry green concrete, controls temperature and humidity in the kiln as a function of time in the curing cycle from a water pool heated by underwater grates near the upper water surface. Heated air and air/CO.sub.2 mixture also is circulated in the kiln during relevant portions of the curing cycle. Accelerated evaporation from the water well is induced by ruffling the water surface with the circulated air with enough intensity that the grates are uncovered to quickly evaporate water films wetting the grate surfaces. A baffle structure thus directs circulating air into the water surface. Individual grates are heated at critical times during the heating cycle in a manner to control temperature of different zones within the kiln by means of circulating hot liquids, such as oil. For example the temperatures at each grate may respond to thermostats controlling liquid flow valves for the respective grates. The comprehensive system may be automatically controlled by a computerized control system during curing cycles as a function of time to provide critical curing conditions including: (1) early cooling during exothermic reactions in the green concrete, (2) intermediate humidification to prevent drying of the partly cured concrete, (3) providing CO.sub.2 rich heated circulating air for curing the concrete and (4) heating with dry air near the end of the curing cycle for drying out the concrete.

Dependencies are inferred from the claim text.