The application of the maze car tray dry spray room system in the vehicle coating workshop

The coating workshop is the main place where the whole vehicle manufacturing process produces "three wastes". Among them, the spray room over-painting fog separation system is an important part of the spray room, but also determines the "three waste" generation form and quantity. At present, the domestic and foreign vehicle coating production line mainly uses wet Wenqiuli paint fog treatment system and lime powder dry paint fog separation system to deal with the spray room over-spraying fog .
wet Venturi paint mist treatment system uses water and chemical agents as the capture medium, and uses the particle washing function of Venturi structure to capture the over-sprayed mist particles in the spray room exhaust into the water. The advantages of this technology are high washing efficiency, paint fog capture efficiency of 99.5%, mature technology, reliable performance. The disadvantages are that the system produces waste water, waste slag, easy to produce secondary pollution, the energy consumption of the whole system is high, the recycling wind needs to be dehumidification, the energy saving effect is not obvious.
the lime powder dry paint mist separation system uses lime powder as the paint mist capture medium, through the lime powder filtration unit paint mist is captured by lime powder, mixed to form a waste powder discharge system. The advantages of this technology are high paint fog capture efficiency, secondary plate filter, modular design. The disadvantages are the large quantity of lime powder waste, the high cost of treatment, easy to produce secondary pollution, and the initial investment cost of the system is high.
with China's attention to environmental pollution control and green production, energy conservation, intelligent overall industrial upgrading requirements, the traditional paint fog separation system has been unable to meet the domestic automobile production energy conservation and environmental protection needs. Labyrinth carton paint fog separation technology is currently the latest international paint fog separation technology, the system energy-saving, environmental protection, low cost, simple waste treatment, has attracted the attention of domestic and foreign automobile manufacturers, product market is broad.I. The current state of application technology development of the carton dry spray room
1.1 Labyrinth carton paint fog capture principle
Maze carton paint mist separation technology is the use of naturally regenerated flame retardant corrugated cardboard made of cube cartons instead of water or lime powder to capture paint mist particles. The inside of the paper tray forms a multi-folding channel through the edges and openings, expanding the adsorption surface for maximum adsorption. Labyrinth carton dry-spray system can effectively reduce procurement costs, and paint-foggy waste cartons can be treated harmlessly through low-cost incinerators, reducing environmental pollution. On the other hand, the exhaust of the labyrinth carton dry spray room is also suitable for recycling. Therefore, in energy conservation and emission reduction has a great advantage.
Figure 1 Carton and bag filter paint fog particle capture schematic
The basic working principle of the labyrinth carton is that the air containing the painted mist is drawn into the carton by the exhaust fan, the paint mist particles with the wind in the inside of the carton through a different path structure, the use of centrifugal force to make large particles fog droplets by the surface of the multi-folding channel adsorption. Since the paper tray is unable to fully capture all the paint mist particles, the carton filter is followed by a bag filter to further capture the paint mist particles in the exhaust, double filtration for the purpose of purifying the air, as shown in Figure 1.
1.2 Paper tray dry spray room technology development status
carton paint fog separation technology, due to its environmental protection, energy saving and low-cost advantages, has become the paint workshop over-spraying fog treatment of the popular application technology. At present, SAIC Engineering, Doyle and Esman have all introduced corresponding application technology solutions and have been partially brought to market (Figure 2).
Figure 2 Paper tray paint fog separation technology application
Due to the low production cost of filter cartons, so a number of enterprises are developing and launching their own carton form, and provide the corresponding carton performance parameters, but the authenticity and practicality of these performance parameters need to be verified. At present, there are four main types of domestic filter cartons (as shown in Figure 3):
(1)
Austrian
EDRIZZI company provides cartons, is the earliest introduction of carton technology
;
3 Types of filter trays
four carton process parameter pairs as shown in Table 1 (parameters provided by the carton supplier).
Table 1
II, Tray Performance Test
For the automotive production plants and equipment manufacturing units of the application body, the performance test data of maze cartons are urgently needed in order to correctly evaluate the actual application and promotion prospects of the technology in the vehicle coating line, and to prepare for subsequent development and application. To this end, we conduct a variety of performance tests on the cartons.
2.1 Performance Test Method
the entire test is divided into a single paper tray performance bench test and field spray line application test.The purpose of the
-rack test is to obtain the filter performance curve of the carton and provide basic data support for the design and use of the dry spray room of the carton in the future by detecting the pressure difference between the front and rear of the carton, the concentration of particulate matter, the efficiency of the paint mist and other parameters under different air volume, paint flow and paint type conditions (Figure 4).
4 Paper Tray Performance Test bench
Field test is designed to verify that the data tested by the bench is consistent with the actual application and to prepare for large-line engineering applications (as shown in Figure 5).
test objects are labyrinth cartons produced by EDRIZZI and Voku.
Figure 5 Spray Room Tray Test Schematic
2.2 Analysis of Test Results
The performance test focuses on the pressure difference of the maze tray, the content of the outlet particulate matter and the detection of capture efficiency, and the corresponding test work is done on the effect of water-based and solvent-based paint on capture efficiency (Figure 6).
Figure 6 Test Data Trend Analysis
Through bench testing and on-site spray room measurement of data and phenomenon comparative analysis, we can find:
(1) carton for large particle size of paint fog particles and high wind speed conditions, the capture efficiency is significantly improved.
(2) bench test carton capture efficiency is higher than the actual spray room application test results, because the bench test tray surface paint can not be accumulated, basically liquid, but in practice, the paper box surface is basically air-dried, although there is moisture but the degree is very low, paint residue will accumulate.
(3) labyrinth cartons are at the cost of consuming air pressure to achieve paint fog capture, so even the new carton wind resistance is also large (around 200Pa), which requires the carton in the installation process, the sealing requirements are higher, otherwise all filtration tasks by the secondary filter material to bear.
(4) From the field data, the filter efficiency of the carton should be around (85% to 95%), so the accuracy selection of the secondary filter should match the application cycle of the paper box as far as possible.
(5) water-based paint and solvent-based paint, carton capture efficiency is different, solvent-based paint capture efficiency is much worse, so solvent-based paint secondary filtration selection should be different from water-based paint.
(6) bench test capture efficiency data can only be used for trend analysis due to its limitations, but the paper tray outlet particle concentration measurement is consistent with the actual spray line test.
3, carton dry spray room system engineering design
maze carton dry spray room system is my company launched a set of independent intellectual property rights of the application of technology, the system through the standard modular carton filtration unit, after the channel simulation optimized exhaust structure, intelligent control system and circulating wind energy-saving technology, together constitute a reasonable structure, easy to install and maintain the spray room system.
3.1 Carton dry spray room system composition
In order to meet the spraying process and equipment production, installation, operation and maintenance needs, labyrinth carton dry spray room fully consider the overall modular and intelligent design of the spray room (figure 7), including:
(1) can be quickly replaced standard modular paper box filtering unit;
(2) automatic lifting mechanism that separates the filtration unit from the exhaust system or connects it;
(3) pneumatic valve that replaces the blades;
(4) modular paint chamber;
(5) the exhaust chamber at the bottom of the paint chamber optimized by the flow field simulation; and
(6) circulating air conditioning system (as shown in Figure 8).
Figure 7 Labyrinth Carton Dry SprayIng Room System Structure Map
Figure 8 Spray Room Design Flow Field Simulation
3.2 Tray Dry Spray Room Workflow
When the entire system is working, when the filter unit absorbs a certain amount of paint fog, the upper limit alarm is set by the pressure differential meter and differential switch to determine the blockage condition and replacement time of the filter. After the pressure differential alarm has been confirmed by the maintenance personnel, the paper tray filter unit is cut off and separated from the exhaust system by a set of automatic lifting mechanism and pneumatic air valve. Then pull out the mobile end of the tray filter unit to be replaced, and the spare filter unit mobile end of the new carton has been installed to connect with the exhaust system, complete the interface seal, open the pneumatic valve, restore exhaust and paint mist adsorption (Figure 9).
replacement filter unit mobile can be replaced and equipment cleaned in a dedicated area, and the updated filter unit mobile end can be used as a replacement spare part for the next cartridge filter unit. The entire replacement process can be carried out in the state of continuous production, and over time, the simulation found that the effect of replacing a filtration unit on the air balance in the paint room is negligible, as shown in Figure 8.
Figure 9 Maze Tray Dry Spray Room worksFourth, the comparative analysis of economic benefits
based on the standard spray room structure and configuration of the vehicle coating workshop and production and operation maintenance costs, the Wenchuli wet spray room, lime powder dry spray room and carton dry spray room in the one-time equipment investment, the operating time of the single-vehicle production energy consumption, single-vehicle production supplies costs and single-vehicle production waste disposal costs for comparative calculation, the results are shown in Figure 10.
Figure 10 Economic benefits of all types of spray houses compared to
(1) Investment costs:
compared to traditional wet spray houses to reduce one
-time investment costs by 24%, compared to lime powder dry spray houses by 60
%;
(3) Consumables Cost:
uses labyrinth cartons as a capture medium, and the cost of consumables increases compared to the amount of water and chemicals used in wet spray rooms and the consumption of lime powder in lime powder dry spray rooms.
(4) Waste disposal costs:
carton dry spray room generated a small amount of waste, so the treatment costs relative to wet spray room and lime powder dry spray room is much lower, and with the continuous improvement of national environmental standards, this gap will gradually increase.
(5) finally after a comprehensive calculation:
maze carton dry spray room of the single-vehicle production and maintenance costs than Venturi wet spray room 40% lower, 30% lower than the lime powder dry spray room.5. Conclusion
Labyrinth carton dry spray room as a new type of energy-saving and environmental protection-oriented technology, the maturity of its engineering application is not as high as Venturi wet spray room and lime powder dry spray room, still to be optimized and improved, and the paint mist of individual cartons Capture efficiency can not be compared with it, but its obvious economic and social benefits have made domestic automobile manufacturers and equipment suppliers to carry out active research and promotion, the main follow-up research includes:
0
1
carton structure optimization, in order to further improve its paint fog capture efficiency.
0
2
the overall design of the mechanical and electrical integration of the spray room, making the equipment more intelligent, easier to operate and maintain.
0
3
waste carton low-temperature carbonization and other harmless treatment technology development.
, the technology has begun to be rolled out and used in China (figure 11). I believe that in the near future, with the efforts of all parties, it will be popularized.
figure 11 Maze tray dry spray room