Liquid cryogen delivery and injection control apparatus

A delivery apparatus for delivering liquid cryogen to a chilling application, comprising:

• a liquid cryogen feed tank (21);
• a liquid cryogen conduit (23) in fluid communication between the liquid cryogen feed tank and the chilling application (51);
• a flowmeter (31) in communication with the liquid cryogen conduit for controlling a quantity of liquid cryogen to be delivered from the liquid cryogen feed tank to the chilling application through the liquid cryogen conduit;
• a flow control valve (45) in communication with the liquid cryogen conduit for controlling a speed of delivery of the liquid cryogen to the chilling application;
• wherein the chilling application uses the liquid cryogen to produce an exhaust gas (61);
• a device (41) for measuring a temperature of the exhaust gas, the temperature measuring device selected from the group consisting of a thermocouple and a resistance temperature detector (RTD), and in operative communication with a controller (43);
• an actuated valve (27) associated with the liquid cryogen conduit and in communication with the controller, the actuated valve configured to receive another signal from the controller;
• wherein the controller is in communication with the temperature measuring device, the flow control valve and the actuated valve, and the controller is configured to receive a signal corresponding to the temperature of the exhaust gas from the temperature measuring device to regulate the flow control valve to vary the speed of delivery of the liquid cryogen through the liquid cryogen conduit and to regulate the actuated valve to pulse a flow of the liquid cryogen at exhaust gas temperature dependent intervals to the chilling application in response to the temperature of the exhaust gas without changing the heat transfer rate of the chilling application.