循环水排污水系统讲义

循环水排污水系统讲义

一、简介系统设备组成及流程：

Water source coming from CW blowdown water→ Mechanical stirring clarification pond→ Clarification pond → Clarified water pump → Mechanical filter → Ultrafiltration device → Ultrafiltration pond→Reverse osmosis water feeding pump → Reverse osmosis device → Fresh water basin → Fresh water pump →Processing system of boiler feeding water。

水源来自循环水排污水→机械搅拌澄清池→澄清水池→澄清水泵→机械过滤器→超滤装置→超滤水池→反渗透给水泵→反渗透装置→淡水池→淡水泵→锅炉补给水处理系统。

二、Mechanical stirring clarification pond

机械搅拌澄清池

Technical principle工艺原理

由于循环水中存在大量Ca (HCO3)2 投加石灰去除暂时硬度和部分镁离子/氨氮/等离子，反应方程如下：

1)Remove the temporary hardness:

去除暂时硬度：

Ca (HCO3)2 + Ca (OH) 2 = 2CaCO3↓+ 2H2O

Mg (HCO3)2 + Ca (OH) 2 = 2CaCO3↓+ Mg (OH) 2 + 2H2O

2)Remove the CO2 in the water to reduce erosion:

去除水中的CO2，减少腐蚀：

CO2 + Ca(OH)2 = 2CaCO3↓+ H20

3)Neutralize the superfluous coagulant, promote coagulating effect and work as coagulant

aids:

中和过量的混凝剂，增强混凝效果，起到助凝剂的作用：

4Fe2+ +4(OH)- + O2 + 2H2O = 4Ca2+ + 4Fe(OH)3↓

4）Remove the colloidal silicon in the water

去除水中胶体硅：

H2SiO3 + Ca(OH)2 = CaSiO3↓+ H2O

三、机械搅拌澄清池运行监督

1) Effluent of the mechanical stirring clarification pond: TUB<5NTU; PH value should be controlled at 10.1-10.3, if it is over 10.3, the dosing amount of the lime should be reduced or mud discharge be carried out.

机械搅拌澄清池出水：TUB<5NTU;PH 控制在10.1-10.3，如PH超过10.3 应降低石灰投加量，或进行排泥。

加硫酸时控制pH符合反渗透进水要求即可，现规定为6.5---8.5.

过滤器用次氯酸钠泵冲程、频率根据超滤出水余氯控制，一般为<0.1mg/l即可,注意：余氯高将造成还原剂的及杀菌剂的浪费及反渗透的运行风险，当还原剂加药泵故障时，余氯进入反渗透将造成不可逆转的伤害。

四、超滤化学反洗时的监督

进酸时pH控制2.5，进碱时控制pH为12，超滤反洗次氯酸钠泵冲程、频率最大即可。

五、Supervision about reverse osmosis device operation

反渗透运行监督

1) Record the reading of every pressure meters every 2 hours.

每隔2h记录一次各压力表的读数。

2) Record the reading of product water flowmeter, thick water flowmeter and product water conductivity analyzer every 2 hours.

每隔2h记录一次产品水流量表、浓水流量表的读数和产品水电导率表的读数。

3）Record the PH value of RO inlet, electrical conductivity, temperature and remnant chlorinity every hour and record the SDI value of RO inlet every 4 hours.

每隔1h记录一次RO进水pH值、电导率、温度和残余氯含量，每隔4h监测一次RO进水的SDI值。

4) Every time when start the RO device, the inlet valve should be opened slowly for preventing the reverse osmosis membrane from being damaged by the sudden high pressure.

每次启动RO设备时，应缓慢开启进水阀，以防止反渗透膜因受瞬间的过高压力而遭到破坏。

5) Pay attention to static back pressure valve and it is forbidden the side pressure of pure water is higher than the pressure of the inlet (strong brine) side.

操作中应注意静背压，不允许净水侧压力高于进水（浓盐水）侧的压力。

6) Whether in operation or not, the dehydration of the reverse osmosis membrane must be paid attention to, because if the reverse osmosis membrane dehydrates it will lead to irreversible damage.

不论在运行或停运时，都必须注意防止反渗透膜的脱水现象，因为反渗透膜一旦脱水，会造成不可恢复的损伤。

7)反渗透控制指标：反渗透进水流量=90T/h,淡水流量55-60T/h，浓水流量25-30T/h,进水