초록 ▼

A nitrogen generation control system and method are provided for controlling levels of nitrogen and oxygen in a controlled atmosphere within a container for perishable goods. The nitrogen generation control system has a nitrogen generator that controllably generates an amount of nitrogen, while rele

A nitrogen generation control system and method are provided for controlling levels of nitrogen and oxygen in a controlled atmosphere within a container for perishable goods. The nitrogen generation control system has a nitrogen generator that controllably generates an amount of nitrogen, while releasing oxygen as an off gas. The nitrogen is injected into the container to create a controlled environment. A sample analyzer subsystem is connected to the container to extract a sample of gases from the controlled environment and analyze the oxygen content. The control system further includes a cascaded, dual control loop controller coupled to the nitrogen generator and sample analyzer subsystem. The controller has a nitrogen generation control loop to control the amount of nitrogen generated by the nitrogen generator in response to variation between the oxygen released during nitrogen generation and a reference amount of oxygen. The controller also has a container atmosphere control loop to control the reference amount of oxygen used as a control input to the nitrogen generation control loop in response to variation between the actual oxygen content in the container and a preselected oxygen level desired to be present in the container.

대표청구항 ▼

A method for controlling a level of oxygen in a controlled environment, the controlled environment comprising gases which include nitrogen and oxygen, the method comprising the following steps: providing a desired level of oxygen within the controlled environment; controllably generating a stream of

A method for controlling a level of oxygen in a controlled environment, the controlled environment comprising gases which include nitrogen and oxygen, the method comprising the following steps: providing a desired level of oxygen within the controlled environment; controllably generating a stream of nitrogen having an oxygen component; controllably setting a reference amount of oxygen to be present in the nitrogen stream; monitoring the amount of oxygen that is actually present in the nitrogen stream; adjusting the amount of nitrogen being generated based upon variation between the monitored amount of oxygen and the reference amount of oxygen; injecting the nitrogen into the controlled environment; extracting a sample of gases from the controlled environment; analyzing actual oxygen content in the extracted sample; and adjusting the reference amount of oxygen to be present in the nitrogen stream based upon variation between the actual oxygen content in the controlled environment and the desired level of oxygen in the controlled environment.