Method for curing concrete products

Claim 1

The method of rapidly curing concrete products in a machine including a circular, endless tunnel having a circular track therein, a plurality of interconnected racks movably mounted upon the track for carrying a plurality of the products to be cured, means for rotating the racks in an indexing manner and in a timed manner hereinafter defined, each rack having a solid divider panel with a peripheral seal for coaction with each of a plurality of seals secured about the interior of the tunnel in arcuately spaced relation to form with each coaction a substantially hermetical sealed wall thereby forming a plurality of continuously formed hermetically sealed stations within the tunnel, the method comprising the steps: loading at least one of the products onto a first rack at a first station within the tunnel, said first station open to the atmosphere; moving the first rack to the next adjacent station within the tunnel, said next station being a second station automatically sealed by coaction of the rack seals with the tunnel seals, while repeating the loading action at the first station on a second rack; introducing a superheated steam and carbon dioxide into the second station and maintaining the temperature within said second station at a range of 175° to 250° F. for approximately 12 minutes; moving said first rack to a third automatically sealed station adjacent to said second station while simultaneously repeating the action at said previous stations; introducing a non-superheated steam into the third station and maintaining the temperature therein at a range of 195° to 200° F. for approximately 60 minutes; moving said first rack to a fourth automatically sealed station adjacent said third station while simultaneously repeating the actions at said previous stations; exposing the first rack in said fourth station to ambient air from external the tunnel for approximately 12 minutes; moving said first rack to a fifth automatically sealed station adjacent said fourth station while simultaneously repeating the actions at said previous stations; forcing ambient air from external the tunnel into said fifth station for approximately 3 minutes; moving said first rack to a sixth station adjacent said fifth station, said sixth station being exposed to the atmosphere; and unloading the rapidly cured products from the first rack at the sixth station, while simultaneously repeating the actions at said previous stations.

Claim 2

The method of rapidly curing concrete products in a machine including a circular, endless tunnel having a circular track therein, a plurality of interconnected racks movably mounted upon the track for carrying a plurality of the products to be cured, means for rotating the racks in an indexing manner and in a timed manner hereinafter defined, each rack having a solid divider panel with a peripheral seal for coaction with each of a plurality of seals secured about the interior of the tunnel in arcuately spaced relation to form with each coaction a substantially hermetical sealed wall thereby forming a plurality of continuously formed hermetically sealed stations within the tunnel, the method comprising the steps: loading at least one of the products onto a first rack at a first station within the tunnel, said first station open to the atmosphere; moving the first rack to the next adjacent station within the tunnel, said next station being a second station automatically sealed by coaction of the rack seals with the tunnel seals, while repeating the loading action at the first station on a second rack; introducing a superheated steam and carbon dioxide into the second station and maintaining the temperature within said second station at a range of 175° to 250° F. for approximately 12 minutes; moving said first rack to a third automatically sealed station adjacent to said second station while simultaneously repeating the action at said previous stations; introducing a non-superheated steam into the third station and maintaining the temperature therein at a range of 195° to 200° F. for approximately 60 minutes; moving said first rack to a fourth automatically sealed station adjacent said third station while simultaneously repeating the actions at said previous stations; exposing the first rack in said fourth station to ambient air from external the tunnel for approximately 12 minutes; moving said first rack to a fifth automatically sealed station adjacent said fourth station while simultaneously repeating the actions at said previous stations; forcing ambient air from external the tunnel into said fifth station for approximately 3 minutes; moving said first rack to a sixth station adjacent said fifth station, said sixth station being exposed to the atmosphere; and unloading the rapidly cured products from the first rack at the sixth station, while simultaneously repeating the actions at said previous stations.