| 摘要 |
The invention relates to a multiple actuator for the combined gas/air regulation of a combustible gas-air mixture in a combustion heat producer according to the servo principle. In the case of this actuator the regulating valve and the safety valve (8) are in each case designed as double seat valves. The regulating valve is arranged at the input of the gas flow to the multiple actuator and has, at the lower end of the valve stem, a diaphragm disc which is provided at its margin with a circumferential sealing control diaphragm (2). The diaphragm disc can be acted upon on its lower side by the control pressure pst and on its upper side by a central space pressure pm from a central pressure space (7), the central space pressure being less than or equal to the input pressure pe of the inflowing gas flow at the input. The input pressure pe of the gas flow can act, via a longitudinal bore in the valve stem of the regulating valve, on the control pressure space (4) whose upper boundary is formed by the underside of the diaphragm disc of the regulating valve. The control pressure space (4) can be acted on at the other side by the burner pressure pbr via a control valve (12) which can be actuated by the first regulating diaphragm (13), on one side of which the burner pressure pbr is present. In this way, a lower sensitivity of the regulating system with respect to rapid pressure fluctuations on the burner side and a lower dependency of the valve functions on the input pressure are achieved. In addition, the energy which is present in the gas pressure can, as a result, be utilised in an optimum fashion for the control pressure. <IMAGE> |
