Furnace having regulated flow rate of inerting gas
US5795147A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 11, 1996 |
| Grant date | Aug 18, 1998 |
| Priority date | — |
| Expiry date | Jun 11, 2016 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF27D2019/0006
- WIPO fieldThermal processes and apparatus
- WIPO sectorMechanical engineering
Abstract
A furnace, for instance a reflow soldering oven, in which oxygen concentration is either directly or inferentially sensed within central processing and either one or both of the inlet and outlet sections of the furnace. Signals generated by these sensors are processed in a PID controller to generate a control signal to control the flow rate of inerting gas into the central processing section, thereby to at least inhibit ingress of air into the central processing section. The PID controller is programmed such that its integral error term is set equal to a time average of the oxygen concentrations of the central processing section less an oxygen concentration set point desired for the central processing section. The proportional and differential error terms are set equal to a time average of the concentrations of the central processing section and one or both of the inlet and outlet sections of the furnace less the oxygen concentration set point.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.