Discussion on several methods of removing water fr

2022-09-22
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Discussion on several methods of removing water from the surface of packaging bottles

in the production line of functional packaging products filled with Jinan gold assay bending and compression tester products, the outer surface of the packaging bottles filled with products (such as wine, soft water, etc.) should be painted with labels, painted words or boxed. In order to achieve better results, it is required to dry the surface of the packaging bottle. At present, in actual production, the packaging bottle is generally dried or blown dry

in production, drying generally adopts brush drying combined type or hot oven drying type, and the bottle brushing device mainly uses brush rotation to remove water droplets on the bottle wall. Due to the contact treatment, the bottle brushing effect is closely related to the shape of the bottle. Rotary (such as cylinder) bottle brush has good effect, while some parts of the surface of non rotary and other special-shaped bottles cannot contact the brush, and there is still water film on the outer wall of this part after brushing the bottle. In addition, during use, the brush is easy to accumulate dirt, which may be transferred to the outer wall of the bottle and affect the packaging quality. The hot oven drying type has simple structure and complete drying, but its thermal power is large and its working temperature is high. It is required to isolate the area when the automatic production line is arranged. During drying, the water will take a long time to evaporate completely, which is not suitable for high-yield production. In addition, when the transmission system such as bottle jam and bottle pouring is blocked during work, the packaging bottle will stay in the oven for a long time, which may cause bottle explosion. In addition, the product surface with high cleanliness requirements cannot be dried after the cleaning and rinsing process, because it is not only necessary to ensure the drying of the packaging bottle surface, but also necessary to solve the problem of water spots on the product surface and rinsing water after drying due to impurities

blow dry method, that is, the advantage of pneumatic technology is applied in the packaging process of filling products. The high-pressure air flow is accumulated and accelerated by the fan through the air knife, and the water on the product surface can be blown away by the air flow. The air knife drying schemes widely used in China include: using compressed air to dry with hot air, using high-pressure fan to dry with hot air, or using high-pressure hot air fan to dry (using high infrared tube to make heating head), etc. In this paper, a new and efficient structure of cold air drying and water removal equipment is designed. The method of high-pressure fan cold drying is adopted, and the residual water on the bottle surface is dried by the high-speed air flow from the nozzle of the air knife, without any heating equipment

therefore, the following aspects need to be pointed out that the drying and water removal equipment includes 1 high-pressure fan, 2 special air knives and related accessories. The low-speed air flow blown by the fan enters the air knife parking room through the fan branch pipe, and then passes through the shrinking variable cross-section air knife nozzle to form a high-speed air flow to gather and spray on the surface of the packaging bottle. Each special air knife is equipped with a spray height and angle adjusting rod, so as to be suitable for drying packaging bottles of different shapes and sizes

the rated power of the fan used in the design is pt=5.5kw, the rated flow is l=0.1467m3/s, that is, m=0.1768kg/s (at 20 ℃), and the rated pressure is p=0.3, such as color, texture, roughness and hand feeling MPa. It is assumed that the fan works under the rated working condition, the environmental condition is taken as 0.1MPa, and the air temperature t0=20 ℃. The air flow generated by the fan enters the two air knife garrisons on both sides of the filling product operation line through two branch pipes. Considering that the branch pipes are very short and have good sealing, it can be considered that there is no air loss in the process of the air flow entering the air knife garrisons through the branch pipes and finally ejecting

in actual operation, the smaller the gap height of the air knife nozzle, the greater the resistance of the jet air flow, the more heat the whole system converts, and the shorter its service life according to the operating characteristic curve of the fan. Therefore, when setting the gap height, it should be decided after balancing the jet speed of the air knife and the operating life of the fan.

the shorter the guide section of the injection port, the better, so as to reduce unnecessary friction loss, but it should not be too short. It is best to use 3 times the design height of the gap, otherwise it will not play a good role in guiding the air jet, which will prevent the air flow at the injection point from being concentrated on the surface of the packaging bottle, resulting in the failure to effectively blow away the residual water droplets

in the operation process of drying the water removal equipment, the pressure and air volume characteristics of the fan are a curve. In the non rated state, the air velocity at the nozzle can be dynamically obtained by experimental measurement, so as to adjust the running state of the fan in time

in addition, during the design and installation of the drying and water removal equipment, attention should be paid to the spray angle of the two air knife nozzles. Due to site restrictions, an air knife driven by the same fan is installed on both sides of the packaging bottle operation line. In order to improve the drying efficiency, the wind knives on both sides cannot be blown in pairs. Because even if the air jet speed of the wind knife is very high, it may form a stagnation point on the surface of the packaging bottle and affect the effect, and the sprayed air flow will bounce back under the action of the opposite incoming flow, resulting in large jet loss

in addition to the necessary considerations in the design of the operation line conveying packaging bottles, necessary restrictions should also be made on the running speed of the workpiece to ensure the time when the surface of the packaging bottle is blown by the air knife. Of course, fans and air knives can also be added to improve efficiency

according to the drying requirements of filling product packaging bottles, a new and efficient cold drying and water removal equipment is designed in this paper. The air flow in the structure of the drying and dewatering equipment is calculated and analyzed, and the related problems in the operation of the equipment are discussed with the example of sharing a bicycle. In the actual design, considering the diversity of glass bottle types, when the glass bottle passes through the high-speed air flow field ejected by the wind knife, it is necessary to set up a bottle conversion mechanism; Considering the barrier effect of ordinary flat chain on air flow and the rebound effect on water droplets, it is necessary to use a special chain. Due to space constraints, this paper will not elaborate in depth. After the successful production of the designed bottle surface drying and water removal equipment in Changsha Light Industry Machinery Co., Ltd., the use of relevant units shows that the equipment has high scientific and technological content, reasonable design, simple processing, low cost, good drying effect, and has a broad application prospect in the packaging industry

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