GB1535931A - Gas cookers - Google Patents

Abstract

1535931 Hot-plate gas cookers; burners SCHWANK GmbH 26 Aug 1975 35153/75 Headings F4W and F4T A gas cooker comprises radiation burners 65 each with a perforated ceramic burner plate, a common glass ceramic plate 64 spaced above the burners, a sensing device 77 and a valve 69 for interrupting gas flow to the burners when the temperature of the plate 64 and/or the exhaust gases exceeds a predetermined value, a solenoid valve 73, and a power control device 72 operative to periodically open and close the valve 73 to permit and prevent gas flow to the burners, thereby to prevent overheating of the plate 64. The device 72 is variable to adjust the duration of the open and closed periods of valve 73. The sensing device 77 is in circuit with a flame failure detecting thermocouple 76. The burner 65 is part of a burner assembly having an ignition burner 74, and the valve 69 is adjustable to supply gas to either burner 74, 65 or to both. As shown in Fig. 3, the burner assembly may include plenum chambers 32a, 33a associated with a common perforated ceramic plate 31 having an unperforated region 31c, the chambers being supplied with gas via nozzles 37, 38 and venturi tubes 35, 36, combustion air being drawn in via openings 41, 42. The chambers 32a, 33a may be concentric and circular or side by side and rectangular, (Figs. 5, 6). The venturi tubes 35, 36 may be replaced by a single tube subdivided into two passages by a longitudinal partition (82, Fig. 9). The burner assembly shown in Fig. 13 comprises a liquid filled gas flow control thermostat 89 in resilient contact with the glass ceramic plate 102. A wall 85 made of ceramic fibres surrounds the burner plates 83, 84 and includes an exhaust gas outlet. An insert (87a, Fig. 12) on the edge of the burner plate 83 may define an ignition burner. Each burner plate may comprise circular recesses 98 in its gas outlet surface, through passages 99 regularly spaced about and bisected by the perimeter wall of each recess, through passages 100 extending through the centre of each recess and through passages 101 centrally between adjacent recesses 98. The glass ceramic plate is spaced 10 to 15 mm. from the upper surface of each burner.