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The influence and selection of altitude on the equipment fan of the glass deep-processing industry.

1. Preface

The glass industry in all countries in the world has developed rapidly along with economic growth. The deep processing rate of flat glass products in some developed countries has reached about 70%, and the proportion is still growing. Glass deep-processing products are already the most common way to use glass. The deep processing is mainly through tempering, interlayer, and insulating processes to change the relevant properties of the glass to achieve diversified use requirements. In the process of automatic deep processing of glass, almost every process involves the use of fans. Whether the power of the fans is suitable, will directly affect the production efficiency and product quality of the automation factory, and it is a link that must be paid attention to when investing in automation equipment.

2. The use and influence of fans in glass deep processing

The glass deep processing industry mainly produces and processes toughened glass, laminated glass, hollow glass, bulletproof glass, and fireproof glass. These products involve the use of fans such as conveying wind power and vacuum adsorption in the production process. Influence the introduction.

2.1 The use and influence of fans in glass cutting

At present, glass cutting mainly adopts automatic glass cutting machine operation mode. The cutting machine involves the use of fans, mainly on the upper platform, vacuum suction cups are needed to absorb the original glass pieces, and then transported to the cutting table for cutting. The cutting table and the unloading table use the fan. Bottom-up blowing air on the table makes the glass in a suspended state on the table so that the operator saves effort and safely carries out the glass load and unload jobs. When selecting the fan, the cutting table and the unloading table can be equipped with suitable fans to meet the requirements. What needs to be considered is the problem of the vacuum pump on the upper platform, which has a greater impact on the overall cutting machine. The impact is more obvious, and the principle to be considered in use is similar to that of a fan, so we will analyze it together here. The configuration of the vacuum pump needs to meet the needs of the vacuum chuck, which can smoothly absorb the original glass sheets of different sizes that meet the production requirements. LIJIANG Glass once investigated some glass processing enterprises located in the central part of the United States. The average altitude of this area is about 1890 m. The cutting machine was purchased without consideration of the altitude. And increase the power of the vacuum pump, the vacuum pump of the loading table cannot meet the glass weight required by the contract, and the problem can be solved after replacing the corresponding fan according to the altitude. Whether the cutting can be carried out smoothly depends on the power selection of the fan.

Figure 1 The equipment fans from automatic glass cutting machine 1

Figure 1 The equipment fans from automatic glass cutting machine 1

2.2 The use and influence of fans in glass grinding and washing

Clean and water-free glass after edging is a necessary condition for entering the tempering furnace. During the edging operation, after the glass is washed and dried in the glass washing machine, there are a lot of water droplets attached to the surface. It needs to be blown dry quickly with the help of a fan to remove the remaining water droplets. . For example, the remaining water droplets on the glass after washing will have the following effects: cause the glass to bond after mounting, resulting in time-consuming and laborious separation; the dirt attached to the water droplets entering the tempering furnace will also pollute the ceramic spokes, increasing the frequency of cleaning the tempering furnace High; there are water droplets left on the coated glass after washing. First, the traces left by the water droplets after drying cannot be eliminated after tempering, resulting in unqualified appearance quality. When the power of the fan is not up to the requirement, to remove the water droplets, it can be handled by reducing the film washing speed, but this will affect the production efficiency and increase the production cost. Whether the edge grinding and film washing fan can meet the requirements has a great influence on the grinding and washing process. If the power of the fan meets the requirements, the residual water droplets on the glass will be easily removed. On the glass, this can lead to reduced edging speeds and subsequent failures. During the grinding and washing process, the use of the fan also involves blowing the water remaining on the glass after the glass is edged. The edging machine also needs to increase water replenishment, increasing water consumption, and large particles of glass powder brought into the brush may also cause scratches on the glass. Choosing a fan with suitable power can remove residual sewage from edging as much as possible, ensure the quality of film washing and reduce water consumption.

Figure 2 The equipment fans from automatic horizontal glass washing machine 1

Figure 2 The equipment fans from automatic horizontal glass washing machine 1

2.3 The use and influence of fans in tempered glass processing

The tempering glass furnace for tempering glass is generally air-cooled. In the glass deep processing industry, the tempering furnace is the main power-consuming equipment, which almost accounts for more than 70% of the factory's power consumption. Among them, the power of the fan is large, and its selection is right The deep processing industry has a great impact. For example, a company uses a 2.44*6 m forced convection tempering furnace. The furnace body heating power is 1920 kW, while the fan power is 315 kW. This power can only produce tempered glass with the thinnest thickness of 5 mm. For the thinnest 3 mm tempered glass, the fan power should be about 630 kW, close to 1/3 of the heating power. Only when the corresponding power configuration is met can the quenching and cooling tempering process of the fan blower be completed. To ensure the tempering stress and debris requirements of the international industry standards, sufficient fan power is required to ensure the quenching air pressure during glass tempering, and some equipment Manufacturers lack awareness of the influence of altitude on fan power and ignore its influence when providing equipment for high-altitude areas, causing the fan to fail to meet the design requirements.

Take a certain company as an example. The company has used the tempering furnace of Glaston, Finland. The tempering furnace manufacturer has taken full consideration in the production design. Requirements; and the 2.44*8 m tempering furnace purchased by a well-known enterprise in 2005, the fragments in the first two years just put into use can meet the requirements, but because a certain air volume margin was not considered when the equipment was invested, it was affected by fan function attenuation, dust blockage and other problems It is difficult to guarantee the fragments after two years, and the tempered fragments will continue to increase as time goes by, especially in summer, the fragments cannot meet the requirements. The thin plate 5 mm tempered glass can only be produced by other tempering furnaces, which seriously affects the production arrangement of the enterprise. and efficiency. The company purchased a 2.44*6 m tempering furnace from a tempering furnace manufacturer again in 2016. The fan power of this tempering furnace is 280 kW. After installation, the trial production of 5 mm fragments still failed to meet the requirements of the international industry standard. After communicating with the equipment manufacturer, we got It is known that the manufacturer of the tempering furnace did not consider the influence of the altitude of the area when configuring the fan, so the power could not meet the requirements, and then replaced the fan with a power of 315 kW, and the problem of tempered debris was solved.

In deep-processing production, with the increasing demand for safety glass and thermal insulation glass, the proportion of tempered glass directly shipped as products continues to decline, and tempered glass is more used as a substrate for further processing such as interlayer and hollow processes, becoming semi-finished products process. Therefore, whether the tempering quality meets the standard is very important. The most important quality index that directly affects subsequent products meets the requirements of the national standard. The most important index for evaluating the quality of tempered products is the number of fragments. The power of the fan is the root cause of the impact on the fragments. Choose a suitable fan To ensure that the fragments meet the requirements. At the same time, with the continuous increase of the service life of the tempering equipment, the air outlet of the air grille is blocked by dust, the performance of the fan is attenuated, and the position of the air grille is changed. These reasons may affect the air volume of the fan acting on the glass, thereby affecting the number of tempered fragments. These factors should be considered when installing the fan to ensure that the tempering furnace is always in a state capable of producing qualified products.

Figure 3 The equipment fans from automatic tempering glass machine 1

Figure 3 The equipment fans from automatic tempering glass machine 1

2.4 The use and influence of fans in laminated glass processing

Laminated glass involves the process of glass washing and drying. Like the above-mentioned edging and washing, it needs to be dried quickly with the help of a fan after the glass washing is completed to remove residual water droplets, ensure that there are no water droplets on the glass, and avoid moisture residues that cause laminated glass. Bubbles, degumming, and affecting service life and other issues. The whole process of the interlayer high pressure requires the fan to continuously deliver the air volume into the autoclave. The high pressure is usually completed at a temperature of 130°C>1,24 MPa. During heating and cooling, the fan is required to blow air to form heat convection, so that the inside of the autoclave temperature is in a uniform state to facilitate overall heating and cooling. If the fan is selected properly, production efficiency and product quality can be better ensured. If the fan power does not meet the requirements, the product quality and production efficiency will also be affected.

Figure 4 The equipment fans from automatic laminated glass machine 1

Figure 4 The equipment fans from automatic laminated glass machine 1

Figure 5 The equipment fans from automatic laminated glass machine 2

Figure 5 The equipment fans from automatic laminated glass machine 2

2.5 The use and influence of fans in insulating glass processing

Insulating glass processing, are producing by automatic insulating glass production line, also needs to wash and clean the glass and remove residual water droplets. If the residual water droplets are not dried after the insulating glass is washed, the water droplets will remain in the hollow glass cavity after assembly. The desiccant needs to absorb these water droplets, which directly reduces The service life of the desiccant, and the service life of the insulating glass mainly depends on the desiccant, which absorbs the moisture that continuously enters the cavity. Water vapor is formed under the change, causing the insulating glass to be blurred and lose the light transmission effect. It can be seen that the damage of the residual water droplets to the insulating glass is obvious. At the same time, the residual water droplets will form traces on the glass surface after drying. Once the traces are in the hollow cavity after being combined, they cannot be cleaned, which will affect the appearance quality of the glass. This trace is more obvious on the coated glass, resulting in unqualified appearance quality. When the power of the fan is insufficient, the film washing speed is also reduced to dry the water droplets, which will seriously affect production efficiency. In the deep processing enterprises mainly engaged in hollow glass, the reduction of the insulated efficiency will form a chain reaction, which will affect the production efficiency of almost all previous processes.

Figure 6 The equipment fans from automatic insulating glass machine 1

Figure 6 The equipment fans from automatic insulating glass machine 1

Almost every product of glass deep processing enterprises involves the use of fans. Choosing the right fan can not only save electricity costs but also avoid secondary investment costs caused by improper selection. At the same time, it also has a positive significance for improving production efficiency. Therefore, choosing the right fan is especially important for deep processing enterprises. But from reality, LIJIANG Glass has found that many glass deep-processing enterprises have encountered some cases of improper selection of fans in recent years, which has formed common problems in high-altitude areas. The main reason is that many equipment manufacturers have not considered the impact of altitude on Factors affecting fan power. Second, investors in some deep-processing enterprises do not understand the impact of altitude on fan selection, so problems such as customer equipment failing to meet requirements after being put into production and fan replacement not only affect the reputation of equipment manufacturers, It has also caused greater losses to glass processing enterprises and buried hidden dangers to product quality.

Figure 7 The equipment fans from automatic insulating glass machine 2

Figure 7 The equipment fans from automatic insulating glass machine 2

3. The selection considerations of equipment's fans

3.1 Factors to be considered in equipment's fan selection

Glass deep-processing enterprises should consider the local altitude as the basis to select equipment fans that meet the actual situation. How to choose fans? It is recommended to consider the following aspects: first, configure the fan with corresponding power according to the local altitude; second, what production speed requirements the fan power needs to meet; third, consider the appropriate margin; fourth, discuss the altitude with the equipment manufacturer. To communicate with height and related issues, equipment manufacturers are relatively more professional. Regarding the problem of margin configuration, it is recommended that enterprises pay attention to it. Fans will gradually age during use, and the power will also attenuate accordingly. Equipping with a suitable margin may increase power consumption and capital investment in the short term, but as the equipment is used With the continuous increase of the service life, the margin can offset the power lost by attenuation, and can still guarantee the use requirements of the equipment, which is an effective way to ensure the performance of the equipment. With the continuous improvement of people's expectations for output quality and the continuous strengthening of product quality supervision by relevant government departments, ensuring qualified product quality is to ensure the corporate reputation and customer loyalty. The product quality meets the requirements, and there will naturally be no problems in the supervision of relevant departments. Margin configuration is necessary.

3.2 The relationship between altitude and fans power

Air pressure, air temperature, and air density change with altitude, and the most important of the three attributes is air density. For example: when the altitude is 4000 m, the air density is only 2/3 of the standard air density (1.225 kg/M³). The thinness of the air density directly affects the output power of the fan. Therefore, choosing different fans for different altitudes is an effective means to ensure that the equipment meets the design requirements. In low-altitude areas, the fan power can be designed according to the requirements, and a certain margin can be left to offset the attenuation caused by the increasing service life. In high-altitude areas, fans with different powers can be selected for different altitudes. It can not only guarantee the equipment capacity, but also an effective way to reduce energy consumption.

3.3 The relationship between altitude and air atmospheric pressure and correction calculation

According to the empirical formula between atmospheric pressure and altitude:

Pa=101.3*(h0.0255*H/1000[6357/(6357+H/1000)]}5.256 (1)

In the formula: H: local average altitude, m; Pa: local average atmospheric pressure, kPa The ambient temperature of the fan does not change much in actual use, and the influence of ambient temperature can be ignored. The above formula simplifies the relationship between air density and altitude as formula (2).

P2=Pl* (1-H/44300)5.256 (2)

In the formula: H: local average altitude, m; Pl: standard atmospheric pressure 101,325, kPa; P2: local average atmospheric pressure, kPa.

According to the standard atmospheric pressure of 101325 P2 and standard air density of 1.225 kg/m3, the actual air volume and wind pressure correction value at the local altitude can be calculated according to the formula (1), to calculate the parameters such as the air volume and wind pressure of the fan that needs to be configured, and the corresponding parameters And the accompanying requirements are provided to the equipment manufacturer, and then the appropriate fan can be selected to meet the production requirements.

4. Epilogue

In the actual use of fans in the glass deep-processing industry, we encountered many problems in high-altitude areas such as the fan power not meeting the requirements. In the end, it was either time-consuming and laborious to replace, or it was not discovered at the time. After the problem was found, it risked reducing efficiency and quality defects. Reluctantly using them has brought many problems and hidden dangers to the production and operation of enterprises. Through the discussion, it can be seen that whether the fan selection meets the requirements is of great importance. To ensure that the fan configuration of the equipment meets the design requirements, ensure the product quality of the enterprise, and improve production efficiency, when the deep processing enterprises in high altitude areas configure the equipment, the equipment manufacturer and the enterprise must check the equipment. After the evaluation and correction of the altitude of the wind turbine, a choice that meets the needs is made to meet the purpose and requirements of the equipment, avoid unnecessary investment and losses, increase enterprise efficiency, and achieve sustainable development.

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