A portion of the reactor effluent leaving the Ethanol Dehydration Reactor Feed/Effluent Exchanger is used in the Stripping Column Reboiler, E-3310 (Dwg. 5248-X-103A), to reboil the bottoms of the Stripping Column, T-3310 (Dwg. 5248-X-103A). The remainder of the reactor effluent is sent to the Ethanol Feed Vaporizer where it is cooled to 118°C. The ethylene-steam mixture from the Ethanol Feed Vaporizer is mixed with flash vapor from the Dehydration Excess Steam Condensate Drum, V-31230, and with vapor from Stripping Column Reboiler Condensate Drum, V-3310 (Dwg. 5248-X-103A). This combined vapor stream is fed to the Dehydration Excess Steam Condenser, E-31230, where it is cooled to 60°C.The ethylene-rich vapor from the Dehydration Excess Steam Condenser is sent to the Ethylene Compressors, C-3310A/B (Dwg.5248-X-103B).

离开乙醇脱水反应器进料/出料换热器的一部分反应器流出物被用于汽提塔再沸器内（E-3310，图号5248 – X- 103A），使汽提塔（T-3310，图号5248-X-103A）底部再沸腾。其余反应器流出物被送至乙醇进料汽化器，在此被冷却至118°C。来自乙醇进料汽化器的乙烯蒸汽混合物与来自脱水过剩蒸汽冷凝液罐（V-31230）的闪变水汽及来自汽提塔再沸器冷凝液罐（V-3310，图号5248 -X-103A）的蒸汽相混合。这种混合蒸汽流被送至脱水过剩蒸汽冷凝器（E-31230）内，在此被冷却至60°C。来自脱水过剩凝汽器的富乙烯水汽被送至乙烯压缩机（C – 3310A/B，图号5248 -X-103B）。

In the case of the cycle gas differential flow alarm, the alarm point will automatically increase at its fixed ratio below the process flow as the process flow is increased. However, the alarm point will not decrease when the process flow is decreased unless the “reset” push-button for the alarm is pressed. Failure to reset the alarm point when reducing the process flow could result in a shutdown because the alarm point would remain at a value equal to the set ratio below the maximum process flow which has been obtained. Consequently, when deliberately reducing cycle gas, the “reset” push-button should be pressed and held until the new process flow has stabilized. The alarm point tracks the process flow while the push-button is pressed. Upon release of the “reset” push-button, the alarm point is reset to the fixed ratio below the new lower process flow.

在循环气体流量差报警的情况下，随着工艺流程的增加，报警点会按照工艺流程以下的固定比例而自动增加。但当工艺流程降低时，报警点将不会减少，除非按下报警用的“复位”按键。工艺流程降低时，未复位报警点可能会导致停机，因为报警点将保持在一个与低于已经获得的最大工艺流程的设定比例相当的值上。因此，当故意减少循环气时，应按下“复位”按键按下并保持直至新的工艺流程已趋于稳定。当按下按键时，该报警点会跟踪工艺流程。一旦松开“复位”按键，报警点将被复位至低于新的较低工艺流程的固定比例。

The Purification Column is provided with tandem safety valves which provide pressure relief for the entire Ethylene Oxide Purification Section. The design pressure is set significantly higher than the normal operating pressure to minimize the possibility of an accidental EO release. Redundant high-pressure interlocks cut off feeds to the EO Reaction Section and all heat sources to the Ethylene Oxide Purification Section far below the relieving pressure. Rupture discs with “tell-tale” pressure switches are provided for EO service relief valves to eliminate fugitive emissions. The temperature level of all concentrated EO heating media is limited to assure that the temperature of all surfaces in contact with concentrated EO vapor is kept well below the established safety limits.

净化塔配备有串联安全阀，为整个环氧乙烷净化工段卸压。设计压力被设定为大大高于普通工作压力，以将发生环氧乙烷泄漏事故的可能性降至最低。冗余高压连锁切断了向环氧乙烷反应工段的供料，以及供至远低于泄放压力的环氧乙烷净化工段的所有热源。环氧乙烷服务安全阀配备有带“指示器”压力开关的破裂片，以消除无组织排放。需要对所有浓缩环氧乙烷加热介质的温度范围进行限制，以确保与浓缩环氧乙烷蒸汽接触的所有表面温度被控制在规定的安全范围以下。

Start Evaporator bottoms flow and slowly increase to 1.7 times the estimated EO content of the Glycol Reactor feed. Make small (1%) changes in bottoms flow to obtain a stable Evaporator bottoms temperature of 182 to 186°C. Do not put the steam flow controller in cascade with the temperature at this time. As the EO production increases the bottoms flow must be increased proportionately. Make small changes to the steam flow controller in an effort to stabilize the trend of the Evaporator bottoms level.

开启蒸发器底流，慢慢将其增至乙二醇反应器进料中预计环氧乙烷浓度的1.7倍。对底流做一些细微（1%）调整，以便获得一个稳定的蒸发器底层温度——182°C到186°C之间。此时，请勿将蒸汽流控制器与温度串联。由于环氧乙烷生产增加，底流也必须成比例增加。对蒸汽流控制器做一些细微的调整，以稳定蒸发器底部水位的趋势。

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