Patent · US Expired

Solid fuel furnace

US4517903A · kind A · utility

23Cited by
3References
16Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJun 1, 1983
Grant dateMay 21, 1985
Priority date
Expiry dateJun 1, 2003

Classification

  • Technology area (CPC F)Mechanical Engineering; Lighting; Heating
  • CPC primaryF24H3/088
  • WIPO fieldThermal processes and apparatus
  • WIPO sectorMechanical engineering

Abstract

A furnace using pelletized wood as a fuel and a system for controlling the operation of the furnace are described. Pelletized wood stored in a hopper is fed into the combustion chamber of the furnace from an elevated position; and combustion of the pelletized wood is controlled by microprocessor-based circuit which receives input signals representative of the interior and exterior temperatures of the building, the air flow and the level of fuel in the combustion chamber and processes this information in accordance with a predetermined program to switch the furnace into one of two modes. In the `low` mode, the exterior temperature is below a certain value for example, 0.degree. C., but the interior temperature is above it. In this case a fire is maintained in the combustion chamber in anticipation of the interior temperature falling beneath this value. If it does fall beneath this value the fan is switched to a `high` mode and to promote vigorous combustion so that the heat output is sufficient to warm the building. A novel method of manufacturing a heat exchange element for use in the furnace is also described.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.