Electric pressure canner with digital control
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Solution Overview
Problem
Traditional pressure canners lack reliable temperature control during the canning process, leading to inefficient heating and potential survival of bacteria and microorganisms due to mechanical pressure relief systems and external heat sensor placement, which can result in temperature fluctuations.
Innovation Solution
A digital pressure canner with a non-contact thermal sensor that measures internal steam temperature in real-time, communicating this data to a temperature control system to maintain consistent temperatures, reducing overshoots and undershoots, and incorporating a mechanical safety device for audible or physical indicators of sufficient canning conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a mechanical pressure relief system is used to indicate sufficient pressure, then the canning process can be monitored, but the temperature control becomes unreliable leading to large fluctuations
Solution Approach 1:
The patent replaces the mechanical pressure relief system with a digital control system that uses a thermal sensor to directly measure steam temperature. This substitution eliminates the indirect monitoring method (pressure relief indicating pressure) and provides direct temperature measurement, thereby improving temperature control reliability and monitoring accuracy simultaneously.
Solution Approach 2:
The patent implements a feedback control system where the thermal sensor continuously measures the actual steam temperature inside the canner and communicates this information to the control system. The control system then adjusts the heating element based on this feedback to maintain the desired temperature, resolving the contradiction between reliable temperature control and accurate monitoring.
2Reliability
If the heat source is set at maximum output level to ensure sufficient temperature, then sterilization is achieved, but temperature overshoots occur leading to energy waste
Solution Approach 1:
The digital control system with thermal sensor provides real-time temperature feedback, allowing the heating element to be adjusted dynamically. When the desired temperature is reached, the system reduces heating power accordingly, preventing overshoots and energy waste while maintaining sterilization effectiveness throughout the canning process.
Solution Approach 2:
The patent transitions from a static maximum-power heating approach to a dynamic heating control system that continuously adjusts power output based on real-time temperature measurements. This dynamic adjustment ensures the minimum necessary power is used at each moment to maintain sterilization temperature, eliminating energy waste from overshoots.
3Measurement precision
If a non-contact thermal sensor is used to measure internal steam temperature, then real-time temperature control is achieved, but the device complexity increases
Solution Approach 1:
The patent replaces complex mechanical temperature measurement and control mechanisms with a simpler digital system using a non-contact thermal sensor. This sensor optically measures steam temperature without mechanical contact, and the digital control system processes this information electronically, reducing overall mechanical complexity while improving measurement precision.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Ensures consistent maintenance of necessary temperatures to kill bacteria and microorganisms, enhancing safety and efficiency by minimizing temperature fluctuations and optimizing heating element operation.
Implementation Method 1
a non-contact thermal sensor adapted to measure an internal steam temperature within the pressure canner
Implementation Method 2
a heating element... By measuring internal steam temperature in real-time, the temperature control is able to control a heating element
Implementation Method 3
As the vessel is heated, the water begins to boil, which turns to steam
Implementation Method 4
the water begins to boil, which turns to steam and the pressure within the vessel begins to rise
Data Source
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AI summary
A digital pressure canner and related methods of operation that provide for improved safety and consistency during a food canning process by reducing temperature over and undershoot. The digital pressure canner includes a digital control operating with inputs from digital sensors to accurately control the canning temperature during the canning process. By reducing over and undershoot of canning temperatures, foods within the pressure canner are maintained at temperatures sufficient to kill any bacteria or microorganisms for the entire canning cycle. In order to verify operation of the digital canner at sufficient canning temperatures, mechanical safety devices, for example, a pressure relief valve can be utilized in conjunction with digital controllers and sensors to provide audible and visual feedback to a user during the canning process.