The biological filter automatic control system is the core control link of the BAF process automation system, and is also the main process part of the entire sewage treatment plant.
Filter state is divided into normal operation, backwash, standby, fault and other states, online filter on the filter is mainly dissolved oxygen detection instrument, flow meter and filter pressure differential detection instrument.
1, normal work control
When the filter is in normal working condition, the aeration valve and water inlet regulating valve are opened, the other valves are closed, aeration operation is performed, and the entire filter tank is automatically operated. The core control parameters are the speed of filtration, the level of dissolved oxygen in the effluent, and the control of the operating cycle.
In order to make the influent water volume of the filter tank appropriate and evenly distributed to each filter tank, the most perfect control method is to control the automatic adjustment of valves and flow meters, and control the opening degree of the valves on the inflow branch pipe according to each filter flow data. , so that the flow of incoming water is the same as the preset flow rate.
In order to ensure biological activity, biological aerated filters need to be backwashed regularly. Under normal conditions, the backwash cycle of a primary filter is between 16-36h (this process is provisionally set for 24h), and the secondary filter backwashing period is between 24-48h ( This process is tentatively scheduled 36h), the operating personnel can adjust the data set in the PLC according to the actual situation. When the inter-filter material is suspended due to the interception of the role, leading to increased head loss of the filter bed, this time using a differential pressure meter to measure the size of the filter pressure difference, as an important indicator of the filter recoil, the bottom of the process When the differential pressure meter reading exceeds 0.9 Mpa, backwashing is performed. In addition, the current value can also be used to control. When the current value of the fan exceeds 10% of the rated current, backwashing is performed.
The order of priority is as follows: current value - pressure value - period value
There is another kind of consideration, human intervention, to generate a backwash signal.
2, backwash control
When the filter backwash conditions need to stop the normal work, to be queued to enter the backwash conditions (according to the order of the proposed backwash applications, pay attention to only one backwash tank at a time). The backwash procedure is a three-stage flush: gas flush, air-water mix flush, and water rinse.
The process is as follows: close the inlet water control valve - close the aeration fan - close the aeration fan outlet valve - open the backwash flushing gate - open the backwash inlet valve - start the backwash blower - open backwash Inlet valve - open and reverse flush pump - stop reverse flush fan - off reverse flush inlet valve - off reverse flush pump - off reverse flush inlet valve - off reverse flush drain gate - open inlet valve - Open aeration inlet valve - open aeration fan, this time the filter began normal work. details as follows:
(1) Air-washing phase: Close the water inlet and aeration valve, open the backwash air inlet valve, start the backwash air blower, and perform air-washing. The purpose is to loosen the filter layer and expand the filter layer. The air-wash intensity is 12— 18L/(m2·s), time is 3--5min.
(2) Gas-water combined backwash: The backwash pump is started to perform gas-water combined backflushing. The purpose is to flush suspended solids and aging microorganisms on the filter material. The backwashing strength is (5-6L/m2. s), the time is 5-8 min.
(3) Water rinsing: Turn off the backwashing fan and the back flushing inlet valve and rinse with water. The purpose is to flush out suspended matter on the surface of the filter material and the aging biofilm for 3 - 5 minutes.
3, standby state
The aeration biological filter system will be designed according to conservative data, plus the seasonal changes in the influent water volume of the wastewater treatment plant is also very large, so the filter pool is often idle and standby. At this time, the control system should arrange the filter work according to how much time each filter and equipment is idle, so that each filter and equipment can get roughly the same repair time.
Reminder: The period for flushing the aerator is approximately six months to one year. It is usually the case that the filter does not work and it is most suitable before the backwash.
4, fault status
If the aeration biological filter malfunctions during the operation or if it is repaired once a year, it must be turned off for maintenance. It is required that the maintenance of a single filter does not affect the normal operation of other filters.
Power Meter Socket
Power Meter is a monitoring and testing instrument which determines the power consumption of a connected appliance and the cost of the electricity consumed.
Built-in 3.6V rechargeable Batteries ( . The purpose of the batteries is to store the total electricity and memory setting
Resetting
If an abnormal display appears or the buttons produce no response, the instrument must be reset. To do this,
press the RESET button.
Display Mode
Entire LCD can be displayed for about 1 minute and then it automatically gets into Model. To transfer from
one mode to the other, press the FUNCTION button.
Mode 1: Time/Watt/Cost Display Display duration(how long) this device connect to power source.LCD on first line shows 0:00 with first two figures mean minutes(2 figures will occur while occur at 10 min) and the rest shows seconds. After 60mins, it displays 0:00 again with first two numbers meas hour(2 figures will occur at 10hours)and the rest shows minutes. The rest can be done in the same manner which means after 24 hours, it will re-caculate. LCD on second line displays current power which ranges in 0.0W 〜 9999W. LCD on third line displays the current electricity costs which ranges in O.Ocost 〜 9999cost. It will keep on O.OOcost before setting rate without other figures.
Mode 2: Time/Cumulative electrical quantity Display Display duration(how long) this device connect to power source.
LCD on first line shows 0:00 with first two figures mean minutes(2 figures will occur while occur at 10 min) and the rest shows seconds. After 60mins, it displays 0:00 again with first two numbers meas hour(2 figures will occur at 10hours)and the rest shows minutes. The rest can be done in the same manner which
means after 24 hours, it will re-caculate. LCD on second line displays current cumulative electrical quantity which ranges in 0.000KWH 〜 9999KWH without other figures. LCD on third line displays"DAY"- "1 'Will be showed on numerical part(the other three figures will be showed at carry) which means it has cumulated electrical quantity for 24hours(one day). The rest can be done in the same manner untill the maximal cumulative time of 9999 days.
Mode 3: TimeA^bltage/Frequency Display LCD on first line displays the same as Mode 1 dones. LCD on second line displays current voltage supply (v) which ranges in 0.0V 〜 9999V .LCD on third line displays current frequency (HZ) which ranges in 0.0HZ 〜 9999Hz without other figures.
Mode 4: Time/Current/Power Factor Display LCD on first line displays the same as Mode 1 dones.LCD on second line displays load current which ranges in 0.0000A 〜 9999A. LCD on third line displays current power factor which ranges in 0.00PF 〜 LOOPF without other figures.
Mode 5:Time/Minimum Power Display LCD on first line displays the same as Mode 1 dones. LCD on
second line displays the minimum power which ranges in 0.0W 〜 9999W. LCD on third line displays character of "Lo" without other figures.
Mode 6: Time/Maximal Power Display LCD on first line displays the same as Mode 1 dones. LCD on second line displays the maximal power which ranges in 0.0W 〜 9999W. LCD on third line displays character of "Hi" without other figures.
Mode 7: Time/Price Display LCD on first line displays the same as Mode 1 dones. LCD on third line displays the cost which ranges in O.OOCOST/KWH 〜 99.99COST/KWH without other figures.
Overload Display: When the power socket connects the load over 3680W, LCD on second line displays the''OVERLOAD[ with booming noise to warn the users, (selectable choice)
Supplemental informations:
1: Except [OVERLOAD[ interface, LCD on first line display time in repitition within 24hours.
2: LCD on first line, second line or third line described in this intruction take section according to two black lines on LCD screen. Here it added for clarified purpose.
3. Mode 7 will directly occur while press down button "cost".
4. [UP"&"Down" are in no function under un-setting mode.
Setting Mode
1. Electricity price setting
After keeping COST button pressed lasting more than 3 seconds(LCD on third line display system defaults price, eg O.OOCOST/KWH ),the rendered content begins moving up and down which means that the device
has entered the setting mode. After that, press FUNCTION for swithing , then press "UP"and "DOWN" button again to set value which ranges in OO.OOCOST/KWH 〜 99.99COST/KWH. After setting all above, press COST to return to Mode7 or it will automatically return to Mode7 without any pressing after setting with data storage.
Power meter socket, Energy meter socket, Energy meter cost socket, Power meter cost socket, Energy power meter socket
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