|HORIZONTAL ROLLER FLAT GLASS TEMPERING FURNACE MODEL NO. N- 1H30(4-19mm)|
1. Description of the Equipment
1.1 Brief Introduction
The furnace includes loading table, heating section, flat quench/cooling section (N-1H30), unloading table, blowing & cooling system and control system. It is used to manufacture flat and cylindrical tempered or heat strengthened glass for architectural, furniture, home appliance, solar panels usage, etc.
1.2 Loading Table
The loading table is composed of rubber-covered rollers. When the glass is put onto the rollers, the glass will be conveyed automatically to the entrance of the furnace where it will be in ready-to-enter-furnace position and the rollers stop moving. It will send the glass into the furnace once the computer control system gives enter instruction.
1.3 Heating Section
The structure of the heating section is of a double-layer box type covered with thermo-insulating material. Inside the section there is a conveyor system with high temperature resistant ceramic rollers, which are imported from well-known manufacturers, i.e. Vesuvius / France, Haldenwanger / Germany, etc. Heating elements and radiation plates are installed on the upper layer and lower layer of this section. The upper layer radiation plate is special heat resistant and anti-corrosion cast material. The heating element is of an integrated part with spiral type resistance erected on ceramic part, it's easy to replace. When the glass is going to enter the furnace, the front door of the heating section opens the rollers of the loading table and heating section move at the same time. When the glass is in the furnace, the front door will close and the glass on the rollers will be moved back and forth at the distance calculated by the controlling system automatically, so that the glass will be heated evenly. The upper section can be lifted up by remote control for maintenance. The heating elements are in matrix layout. The upper side has 35 heating elements, and lower side has 20 also. Each has one independent control loop. Radiant-plate matrix heating technology and intelligent PID power modulation make the heating very even and stable.
The heat transfer to the top and bottom surfaces of the glass is more balanced and even, which helps to reduce or eliminate white haze in the center of the glass, as well as breakage in the furnace.
1.3.1 Main driving system: Servo control system, adopting "8" type synchronous belt driving system, which reduces the phenomenon of the "white haze". It reduces the glass scratch damage between the rollers. The life of the ceramic rollers has been extended. No need to use encoder and soft rollers and reduce the damage chance. The no aperture has been adopted in the main driving system, easy to disassembly.
1.3.2 Ceramic rollers: Special roller ball bearing
1.3.3 Heat balancing system to meet the requirements of the changeable air supply system
1.4 Flat Quench/Cooling Section (N-1H30)
The quench nozzles are divided into upper and lower sections. The nozzles are made of aluminum alloy, and the upper and lower clearance can be adjusted according to the quenching demand for different kinds of glass. Between the quench nozzles, a roller-bed conveys the glass forward. When the glass comes out of the furnace, the quench rollers move synchronously with the rollers in the furnace, to transit the glass sheet into the quench section. Then, the glass sheets oscillate on the rollers. Simultaneously, the heavy-duty blower immediately blows high-pressure air on the surface of the glass through air ducts. The air pressure and flux is controlled by a butterfly valve at the inlet of blower, which in turn, is computer controlled. The cooling work is done in the same section which is controlled by computer. The rollers are covered with special heat-resistant material.
The unloading table is the same as the loading table. When the glass is transported to the end of the conveyor, the rollers will stop, and the glass can be taken away by hand, or by robot, if there is available at the customer's factory.
1.6. Control System
The control system includes the followings:
• Process parameters storage and re-call, such as glass thickness, size, color, glass type and maybe different sources of float glass and etc. Whenever you produce a new order for different thickness, size, color, type, source and etc., you just enter the process parameters, and the system will memorize these process data. Next time, when you have the re-order, or the same order, you can re-call the data, and the machine will automatically use the stored processing data to produce.
• Controller for roller driving system.
• Controller for the temperature control.
• Controller for quenching control.
• Controller for formation control
• The abnormity alarming system would warn while trouble happens to indicate how to solve this trouble.
• The main industrial control computer is installed with the terminals at the control desk. Display screen can provide users with analog process status: main screen, process parameter screen, operation and maintenance screen and system parameter screen. The system has reading and writing function for process parameters, automatic control, unit equipment operation and test as well as self-diagnosis, as well as display alarming function.
a) Main drive control system is accomplished by the inverter system which is controlled by computer. On-line of every part is controlled by computer.
b) The main screen is the page displayed on the monitor during normal production. The contents displayed directly in Russian are the statuses of glass in the furnace, driving system, temperature at each zone, time of heating, quench and cooling, actual pressure, set point of fans and length sum of pieces of glass in the furnace. This screen is for the operator's notice. The process parameter screen records the designed moving distance of loading table when the pedal switch is actuated by the operator, temperature set point of upper and lower furnace, pressure set point of fans, quench time and cooling time set point. These screens are frequently used for normal operation. Maintenance screen is used by maintenance people to test every part of the system. System parameter screen is used by the manufacturer, in order to test the machine, it is not for any other people using, otherwise the machine may be damaged. The system also has some supplementary screens, which will not be explained here.
1.7 SO2 gas feeding unit
The device of SO2 is composed with gas bottle (supplied by the Buyer), units of pressure reducing valve, flow meter and pipes (insider and outside), etc. By using this gas will form a thin film on the surface of the ceramic roller to reduce the friction between the surface of the glass and the ceramic roller. This will highly reduce or prevent the white haze phenomenon.
2. Technical Parts
2.1 Technical Specifications
2.1.1. Flat Glass
18.104.22.168 Glass thickness range: Tempering: 4-19 mm
22.214.171.124 Glass size:
Max glass size: 2'000 x 2'300 mm (at 4mm)
2'000 x 3'000 mm (at 5-19mm)
Note: Single glass sheet proposed at 4mm no more than 2 M2/each
Min glass size: 150 x 300 mm
126.96.36.199 Standard: EN12150-1:2000
188.8.131.52 Finish product rate: not less than 95%;
184.108.40.206 Productivity (based on clear float glass at 60%-65% loading table):
4 mm = 17 batches / hr
5 mm = 15 batches / hr
6 mm = 13 batches / hr
8 mm = 10 batches / hr
10 mm = 7 batches / hr
12 mm = 6 batches / hr
15 mm = 5 batches / hr
19 mm = 2.5 batches / hr
2.2.1 Installed power:
Heating: 490 kW
Drives : 20 KW
Flat Quenching : 250 KW
Total installed power: 782 kW x 80% ≈625 kW
Note: The power capacity may be different and should be referring to the actual designing power drawing which will be supplied after signing the contract.
2.2.2 Compressed air (an air tank should be supplied with 0.5M3 at least by the Buyer) :
Volume : 0.6 - 0.8 m3 /min
Pressure : > 0.7 MPa
2.2.3 Suitable glass sorts:
- Clear float glass
- Coated glasses (Including most kinds of hard coated glass which withstands about temperature 700 ℃)
- Patterned glass (so far as suitable for tempering)
- Tinted glass
2.3 Supply Scope
-- Loading table
-- Heating section
-- Flat Quenching/Cooling section (N-1H30)
-- Unloading table
-- Associated electrical and control equipment
-- Control terminal
-- UPS emergency driving system
-- SO2 gas feeding unit
-- Modem with long distance diagnosis system
-- Blower brackets
-- Blower inverters (250kW)
-- Transversal oscillating system of flat quench section
-- driving motors
-- blower motors
2.4 Controlling System
1) The whole control procedure, software of industrial computer and PLC are developed by shanghai Northglass Technology Co., Ltd.., the owner of all intelligence property right. shanghai Northglass Technology Co., Ltd. is responsible for the upgrading of the software system.
2) PLC is OMRON product.
3) Industrial computer is EVOC product.
4) Inverters are original Schneider products or equivalent ones.
5) Optical, Sensor Beam Switch is of OMRON product.
6) 17" LCD Monitor.