| abstract |
The invention relates to a metering device for metering an easily combustible material, in particular acrolein acetal, from a source or a storage container (20) into a vacuum line (38), comprising: a displacement pump (26) operated via a compressed air motor (28), the pumping capacity of which can be controlled; and a pressure-sustaining and pressure-controlling valve (35), arranged between the displacement pump (26) and the vacuum line (38), the dimensionless delivery head H/Ho [mWs/1mWs] of which is associated with the dimensionless delivery capacity Q/Qo [m 3 /h/1m 3 /h] according to formula: {H/Ho} = {C1 * (Q/Qo)} 0 ' 333 , wherein H = hydraulic pressure at the input of the pressure-sustaining and pressure-controlling valve, Ho = 1 mWS, C1 = constant for the pressure-sustaining and pressure-controlling valve, Q = hydraulic flow rate, and Qo = 1m 3 /h. |