Process for the preparation of cyclic diketones

将可以从备有流量控制装置的气体供给设备正确且迅速地按所需要的流量比Q#-[1]/Q#-[2]向腔室内分流供给规定流量Q的处理气体。具体地说，从备有流量控制装置的气体供给设备通过多个分支供给线和固定于其末端的喷淋板按规定的流量比Q#-[1]/Q#-[2]向减压的腔室(C)内分流供给规定流量Q的气体之际，在前述多个分支供给线(GL#-[1]、GL#-[2])上加装压力式分流量控制器(FV#-[1]、FV#-[2])，并且靠来自使流量大的一方的压力式分流量控制器的控制阀(CV)的开度全开的分流量控制盘(FRC)的初期流量设定信号，开始前述两个分流量控制器(FV#-[1]、FV#-[2])的开度控制，通过分别调整前述控制阀(CV)的下游侧压力P#-[3]′、P#-[3]″，通过设在喷淋板(3、4)上的节流孔(3a、4a)，按由式Q#-[1]＝C#-[1]P#-[3]′和Q#-[2]＝C#-[2]P#-[3]″(式中，C#-[1]、C#-[2]是取决于节流孔的断面积或节流孔上游侧的气体温度的常数)表达的所需要的分流量Q#-[1]、Q#-[2]向前述腔室(C)内分流供给总量Q＝Q#-[1]+Q#-[2]的气体。 A method for supplying a specified quantity Q of processing gas while dividing at a desired flow rate ratio Q1/Q2 accurately and quickly from a gas supply facility equipped with a flow controller into a chamber. When a specified quantity Q of gas is supplied while being divided at a desired flow rate ratio Q1/Q2 from a gas supply facility equipped with a flow controller into a reduced pressure chamber C through a plurality of branch supply lines and shower plates fixed to the ends thereof, pressure type division quantity controllers FV1 and FV2 are provided in the plurality of branch supply lines GL1 and GL2. Opening control of both division quantity controllers FV1 and FV2 is started by an initial flow rate set signal from a division quantity control board FRC for fully opening the control valve CV of the pressure type division quantity controller having a higher flow rate and pressures P3' and P3" on the downstream side of the control valve CV are regulated thus supplying a total quantity Q = Q1 + Q2 of gas while dividing into the chamber C through orifice holes (3a, 4a) made in shower plates (3, 4) at desired division quantities Q1 and Q2 represented by formulas Q1 = C1P3' and Q2 = C2P3" (where, C1 and C2 are constants dependent on the cross-sectional area of the orifice hole or the gas temperature on the upstream side thereof).