Energy conservation renovation of humidifying tower systemDate: 2019-07-23 Views:
1. Humidifying tower system operation problem
The humidifier tower specifications for a company's 2800t/d grog production line are ∅8.5mX34m, with a designed maximum processing capacity of 460000m cubed/h, inlet flue gas temperature of 325 ° c, and outlet flue gas temperature of 120 ° c ~ 150 ° c.The humidifying spray system of humidifying tower adopts high pressure return flow, with the maximum water injection volume of 24t/h, 10 nozzles, working pressure of the nozzles of 3.3mpa, equipped with 2 multi-stage pumps DG25 -- 50*10, motor power of 75kW, one for use and one for backup.When the temperature of the process system changes, the return water is controlled by adjusting the opening of the backwater valve of the humidifier tower, so as to control the quantity of water spraying in the humidifier tower.
Since the humidifier tower was put into use, there have been many failures, and the water back cannot be effectively regulated and controlled. The pump has been running at full load, with the current reaching about 125A, and the energy consumption is very high.
2. Problem analysis and judgment
(1) the spray system of humidifying tower requires high water pressure, the maximum head of the pump is 522m, and the speed of the pump is up to 2950r/min, so the pump is easy to wear, and the shaft seals at both ends of the pump often leak, resulting in the pressure of the spray gun at the top of the humidifying tower cannot reach the design value of 3.3mpa, so the spray gun atomization effect is poor.When the backflow valve is open for an hour, it is easy to cause the wet bottom of the humidifying tower.When the opening degree is large, it is easy to cause high inlet temperature of dust collector and lead to excessive emission.
(2) when the temperature of the process system needs to be adjusted, the backwater valve opens wider and the water spraying pressure is low, so the spray gun is easy to be blocked, and the spray gun cannot be atomized, resulting in the wet bottom of the humidifying tower for many times.
(3) the pump selection is relatively old with high energy consumption, and the power of each motor is 53kW higher than that of the company's phase ii 5000t/d production line.
3 treatment measures
To one-time solve the problems existing in the system of humidifying tower, after comprehensive consideration decided to issue the humidifying tower spray system into a double fluid spray system, the system adopts the two-fluid nozzle, spray gun pipes for double pipes, has the certain pressure of compressed air and clean water after spray gun pipes to the nozzle at the same time, under the action of compressed air, the water is atomized into water mist, rapid evaporation at high temperature, to take away heat to achieve the effect of cooling and humidification.
Transformation of make full use of the original equipment and facilities, and does not need to be removed the original pipeline, the original water supply pipeline remains as a new system of water supply pipeline, the original return piping as a new system of compressed air pipeline, just put the original spray gun system into a new double fluid spray gun system, the old pump replacement for the new type of low pressure water pump, the pump power is 15 kw, flow after 24 m/h, lift 120 m, compared with the old pump power directly reduce the 60 kw.
4. Transformation effect
Before the transformation, the pump was basically running at full load, with the running current around 125A.After the transformation of the new type of water pump, the operating current is about 17A. Compared with the previous operating condition, 24h operation every day can save about 1450kWh of electricity every day.
Four dual-fluid spray guns are needed, which require 0.3mpa to 0.4mpa compressed air of about 8Nm ^ 3 / min, and the energy consumption of the compressor is about 551kWh per sky.The energy saving effect is immediate. According to the annual operation of 180d and the electricity cost of 0.67 yuan per kWh, the annual electricity cost can be saved about (1450-551)*0.67*180=108419.4 yuan.