The exhaust humidity is too low (the exhaust air volume in the hood is too large)
Influencing factors : ① High energy consumption of cadres; ② Heat recovery low heat transfer efficiency.
Possible causes : ① Humidity measuring instrument failure; ② The exhaust air volume is too large (the intake valve is opened too large or the fan speed is too high); ③ The inlet air valve of the exhaust fan may be stuck in the open position and not act; ④ Moisture may leak into the plant from the top of the hood; ⑤ Evaporation of cadres is lower than the design value.
Solution : ① Check the position of the inlet air valve of the exhaust fan/the frequency setting and function of the frequency conversion fan are appropriate; ②Check whether the setting value and function of the automatic measurement system are appropriate; ③ Check the tightness of the upper part of the hood.
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The hood zero is too high (the hood supply is too small relative to the hood exhaust volume)
Influencing factors : ①High energy consumption of cadres;②Condensate may be generated on the inner surface of the hood and on the hood skeleton
Possible causes : ① There is a failure in the air volume measuring instrument; ② The exhaust air is too large (the exhaust valve is too large and the exhaust fan speed is too high); ③ The air supply volume is too small (the intake valve is too small close to the full close or stuck in the closed position, the fan speed is too low); ④ the blower does not work; ⑤ The heat exchanger and steam heater on the air supply side are blocked; ⑥ The air supply pipe is blocked or leaked.
Solution : ① Check the function of the fan and the condition of the impeller; ② Check the tension of the fan belt; ③ Check the position of the fan inlet air valve and the status of the fan frequency; ④ Check the position of the air valve on the air duct; ⑤ Check the setting value and function of the automatic measurement system; ⑥ Check the cleanliness of the air supply - gas heat exchanger and steam heater; ⑦ Check the cleaning condition of the air duct.
The supply air temperature is too low
Influencing factors : Condensation may occur on the inner surface of the hood and on the hood skeleton.
Possible causes : ① the steam heater is broken; ② No steam enters the steam heater; ③ Steam heater drainage is not smooth; ④ The supply air temperature is set incorrectly, or the temperature measurement is invalid.
Solution : ① Check the steam heater status; ② Check the function of the supply air steam heating system; ③ Check the temperature measuring instrument and temperature setting.
Shandong Fengxin Technology Development Co., Ltd. is a company specializing in the development, research and production of paper ventilation, drying, energy saving technology and equipment, and has achieved good results in the field of paper ventilation, drying and energy saving for many years. Fengxin closed air hood system design mainly includes the drying part closed air hood, air hood in various functions of the blower, waste heat recovery device, paper machine mesh moisture, high-speed Yanke hot air hood, all kinds of coating drying boxes, workshop ventilation system and supporting equipment.