1. Powder coating line design | No | Name | Details |
| 1 | Workpiece | Gas cylinder |
| 2 | Workpiece material | Metal |
| 3 | Max. workpiece size | Φ300×H570(mm) |
| 4 | Workpiece weight | ≤30kg |
| 5 | Braced chain | QXT250/50Kg light common chain |
| 6 | Machine capacity | 2000pcs/12hours |
| 7 | Hanging type | One cylinder every two pitch, that means one cylinder per 500mm. |
| 8 | Linear speed | 2000pcs÷12h÷60min×0.5m/hang=1.4m/min |
| 9 | Heating source | Nature gas(LPG) |
| 10 | Location area | See layout drawing, beam bottom height 8.5 meters |
2. Process flow diagram
This line consists of powder coating chamber, booth, curing bake, suspend conveyor and electric control system.
| No | Name | Transit time | Working temperature | Operation |
| 1 | Loading | | RT | Manual |
| 2 | Powder coating | | RT | Auto+manual |
| 3 | baking | 17-18min | 180-190ºC | Heated air circle |
| 4 | cooling | 20min | | |
| 5 | unloading | | | Manual |
3. Curing bake
The drying tunnel consists of three parts: drying tunnel. Heating system and exhaust system.
3.1 Drying tunnel
| No | Name | Technical parameter |
| 1 | Overall structure | Bridge type |
| 2 | No of tunnels | 4 |
| 3 | Size of the inner tunnel | L14×W3.2×H2.1(m). Leg height 2.5meters |
| 4 | Thickness of the insulation | 150mm |
| 5 | Material of the insulation | High quality rock wool board |
| 6 | Unit weight of the insulation | 100Kg/m3 |
| 7 | Material of the inner plate | δ0.8 galvanized steel sheet |
| 8 | Metarial of the outer plate | δ0.8 color sheet |
| 9 | Structure of inner and outer plate | Assembly structure |
| 10 | Material of the inner angle plate | δ1 galvanized steel sheet |
| 11 | Material of the outer angle plate | δ3 hot-rolled sheet with paint |
| 12 | Supporter material of the tunnel | δ3 carbon steel sheet, edgefold with paint |
| 13 | Outer temperature of the tunnel | Lower than environment temperature 15ºC |
| 14 | Inner temperature of the tunnel | 180ºC |
| 15 | Drain cracking-off | Top of the tunnel |
3.2. heating system: consists of heating chamber, burner, heated air recycling fan, return airway and temperature control system.
(1)heating room: an access door is on the side of the heating chamber for future repairing.
| No | Name | Technical parameter |
| 1 | Position and number of heating room | Bottom of the bake tunnel, 1 set |
| 2 | Heating room configuration | 300000 calories, 1 set |
| 3 | Inner plate of the heating room | Galvanized steel, δ1 |
| 4 | Outer plate of the heating room | Cold-roll steel sheet, δ1.5 |
| 5 | Thickness of the insulation | 150mm |
| 6 | Material of the insulation | High quality rock wool board |
| 7 | Unit weight of the insulation | 100Kg/m3 |
| 8 | Material of the inner angle plate | δ1 galvanized steel sheet |
| 9 | Material of the outer angle plate | δ3 hot-rolled sheet with paint |
| 10 | Supporter material of the tunnel | δ3 carbon steel sheet, edgefold with paint |
| 11 | Structure of inner and outer plate | Assembly structure |
(2) burner
1 set, 300000 calories
Gas consumption: 10-15m3/h
Brand: Italian Riello RS34
(3)burning tank
Heat exchanger is used to transfer the heat to heating room, then hot-air blower will bring the heat to the tunnel. Adopts direct-fired heating, the burning tank is stainless steel with high temperature filter.
(4)Thermal cycling fan: adopts special air-cooled centrifugal fan
| No | Name | Parameter |
| 1 | Model | GCF-630C |
| 2 | Rotation speed | 1250r/min |
| 3 | Air flow volume | 13500m3/h |
| 4 | Total pressure | 900Pα |
| 5 | Motor power | 5.5KW |
| 6 | Fan structure | Impeller is in the heating room |
| 7 | Insulation thickness | 150mm |
| 9 | Impeller material | 16Mn |
| 10 | No. Of fans | 1 set |
| 11 | Fans supplier | Shanghai Shuyuan or Kewangda |
(5) Air delivery & returning duct
| No | Name | Parameter |
| 1 | Hot air recycling | Internal recycle, no outer tubes |
| 2 | Air delivery type | Under floor air delivery |
| 3 | Air returning type | Under floor air returning |
| 4 | Duct material | Galvanized steelδ1 |
| 5 | No of air regulation plate | 1 set |
| 6 | Material of air regulation plate | Galvanized steelδ1 |
(6) Temperature control system
Drying tunnel uses digital temperature controller to adjust the temperature automatically, it can display and control the drying tunnel temperature in real-time.
The temperature measurement uses platinum resistor temperature sensor.
The drying tunnel temperature can be adjusted continuously from normal temperature to 200°C.
3. Exhaust pipe
The entrance/exit of the drying tunnel on the top equips with exhaust pipe and butterfly valve, it is used for draining the exhaust gas of the drying tunnel.
The material of the exhaust pipe is δ1mm galvanized sheet.
4. Hang type conveyor
Hang type conveyor consist of driving device, tension device, variable-frequency governor, chain, straight conveyor, bend conveyor, temperature flexible conveyor, inspection conveyor and lubrication system etc.
Variable -frequency governor uses Mitsubishi. The speed is 1.4 m/min.
The lubrication system uses automatic oil drop device.
Hang type conveyor equips with 1 set driving device, 1 set weight-loaded type tension device, using frequency to adjust speed.
| No | Name | Technical specification |
| 1 | Driving device model | QXT-250 |
| 2 | Driving device quantity | 1 set |
| 3 | Overload protection for driving device | Adjustable safety clutch+travel switch |
| 4 | Driving device power | 3.0KW |
| 5 | Tension device type | Weight-loaded type |
| 6 | Tension device quantity | 1set |
| 7 | Turning radius of tension device | ≥R800(mm) |
| 8 | Frequency converter | Mitsubishi 1 set |
| 9 | Conveyor chain length | 125m |
| 10 | Conveyor chain pitch | 250mm |
| 11 | Hoisting weight of conveyor chain single point | 50Kg |
| 12 | Production speed | 1.4m/min |
| 13 | Production speed adjustable method | Frequency control(0.6-2.0m/min) |
| 14 | Column quantity,material | Complete set, steel section |
| 15 | Bottom plate quantity,material | Complete set, hot-rolled sheet steel |
| 16 | Beam quantity,material | Complete set, steel section |
| 17 | Diagonal bracing quantity,material | Complete set, steel section |
| 18 | lubrication system | Automatic oil drop device 1 set |
| 19 | "C" type jig and rotary rack | 250 pcs |
| 20 | Rotary rack | 1set |
5. Powder coating system
Using color-changed single grade filter core recycling powder room.
5.1. Technical parameter
| Machine type | Manual
|
Max. Hang range of the workpiece
| W310xH570 |
Conveyor speed
| About 1.4m/min
|
| Type of conveyor | Suspend conveyor
|
| Coating material |
Polyester powder and epoxy powder |
| Color | 2 kinds |
| Powder supplier |
Local |
| Type of coating chamber |
Filter type powder coating chamber |
| Type of powder coating systems |
Corona torch |
| No of powder coating systems |
6 sets auto, 1 set manual spraying torch |
| Type of hoister |
Reciprocating hoister |
| No of hoister | 1 set |
| No of the torch on the hoister | 2 sets on left, 2 sets on top, 2 sets on bottom |
| Suction capacity of coating chamber | 11000 m3/h |
| Required pressure for compressed air |
6 - 8 bar , + 0.1 bar |
| Remaining water in the compressed air |
Max. 1.3 g/N m3 |
| Remaining oil in the compressed air | Max. 0.1 mg/N m3 |
| Estimated air consumption for chamber |
120 N m3/h |
| Power supply | 220/380 VAC, 50Hz, 3L/N/PE, 3 phase 5 wires |
| Estimated power consumption for powder coating |
Approx. 10 KVA |
| Estimated power consumption for chamber |
15KVA -- powder coating chamber |
| Requirement for operation condition | Relative humidity<80%
Ambient temperature< 30ºC
Air speed near the chamber< 0.1 m/sec |
5.2. Configuration
(1) Powder coating room
The shell of powder coating room is made of high-quality stainless steel, the side sheet thickness is 1.5mm, the top gate thickness is 1.5mm, the bottom of powder coating room uses metal support structure. Powder coating room equips with the floodlight, luminance is 500 Lux.
The powder coating room equips with a manual spraying opening, it can be used for pre-spraying and repair spraying. The light color of powder coating room and the integration lighting guarantee the excellent working condition, the operators can enter into the powder coating room and clean the room by a extended air suction pipe.
(2)Filter cartridge recycling device
The back filter cartridge is used for splitting the micron powder from the air that is sent by the cyclone separator. In addition, the recycling fan guarantees the constant wind speed of the powder coating room. The material of filtration uses Toray. The air drained by fan can drain into the workshop. Airflow: 11000m3/h, motor power: 11KW, filter area: 165m2, compressed air consumption: 22 Nm3/h.
Filter control instrument is the intelligent control system using cartridge recycling reverse blowing device, it can not only control the pressure of the filter inside/outside automatically, once the pressure reaches the pre set point, the system will start the filter pulse blowback cleaning process automatically, but also has automatic optimize function, with the increase of working time, the filter control instrument will realize the filter pulse blowback according to the optimize process automatically. This system can save the consumption of compressed air greatly, extend the cartridge working life, reduce the manual cleaning number, lower the equipment noise at the same time.
Back filter cartridge recycling device incl.:
1. Back filter cartridge device equips with the shell.
2. Filter device equips with cartridge, fan impulse type filter
3. Filter
4. Clean air outlet equips with muffler
5. Residual powder collection box and vibrating screen
6. Air storage tank
(3)Spray gun
Total: 1 sets manual spray gun, 2 sets automatic spray gun, 4 sets fixed spray gun.
6. Isolating room
The room consists of δ50 rock wool color steel plate + A3 steel compound. The inner plate of rock wool color steel plate is Galvanized, shell plate is color steel plate. The aisle has windows for inspecting. Equip with workpiece in/out copying door and personnel in/out door. The room is equipped with lighting.
7. Electric control system
The powder coating line adopts scattered setting and centralized control.
In every important part of the line, there is emergency stop button, which is easy for worker to operate.
The temperature control of each part adopts digital auto controller. It will show the temperature of each heating point and auto control the temperature automatically at the same time.
The design, model, production and installation of the electric components all conforms with the national standards.
The electric control cabinet has the following features: neat surface, good appearance, reasonable panel layout, which is easy for observation and operation.
Adopts new series components with reliable performance and advanced technology.
There is lockset on the handle of the cabinet door.
The guide wire of the cabinet door is very tidy, the wire arrangement is standard, which is bundled into a bunch, horizontal and vertical emphasis.
If the wire needs go through corner, it will be arc-shaped.
The wires have good connection with each components. The insulation resistance between each wire > 1mge.
The connection between wire and components all have clear mark, and will not wear faded.
Every connector has the mark to show the connection secure.
The marks in the cabinet are uniform with the electric drawings, easy for check and repair.
All the components are from national standard factory or imported factory.
The ground resistance conforms with national standards.
8. Main components supplier
| No | Main components | Supplier |
| 1 | Fan | Shanghai Shuyuan or Kewangda |
| 2 | Conveyor chain | Shanghai Qingpu or Suzhou Youxin |
| 3 | Frequency converter | Mitsubishi |
| 4 | Digital temperature controller | Fuji or Omron |
| 5 | Contactor and button | Shanghai Schneider |
| 6 | Spraying torch | Domestic |
9. Power and nature gas consumption
| No | Name | Consumption |
| 1 | Electric | Hot-air blower | 5.5KW |
| Exhaust fan | 3.0KW |
| Powder coating chamber | 15KW |
| Conveyor | 3.0KW |
| Other | 3 KW |
| Total | 29.5KW |
| 2 | Compressed air | About 2-2.5m3/h |
| 3 | Nature gas | 10-15m3/h(5-7.5kg/h) |
