1. Raw materials dosing
Dosing section is storing, metering, conveying all raw materials of gypsum board, and finally those materials enter vertical mixer for next process. Powder raw materials mainly includes gypsum powder, accelerators, modified starch, other powdered additives, and glass fiber etc.
Dry Material Dosing
Due to a larger amount, gypsum powder conveyed by silo, bucket elevator, screw conveyors and other transportation equipment, continuously metered by high-precision closed-type rigid impeller feeder, high-precision electronic belt, finally enters double helix mixing conveyor. This system equips overflow material feeding of screw conveyor and return material of screw conveyor in order to ensure "constant" state of electronic scale feeding part, which greatly improves measuring precision of this system.
Due to a small amount, weight loss metering screw devices adopted for metering other powdered additives. The error is big if we adopt traditional method- continuous metering.Our design further improves metering precision. Those additives will also enter double helix mixing conveyor by metering screw after discharging from small hopper and silo bottom.
Glass fiber cut by special cutter, then enters double helix mixing conveyor after speed regulation and counting device.
Premixing of all powdered raw materials and cut glass fiber completed in double helix mixing conveyor, then them fed into vertical mixer through round tube type screw feeder.
Wet Material Dosing
Wet raw materials include pulp, foaming agent, liquid additives and water etc. Pulp system equips hydrabrusher. Waste paper and water mixed for getting a certain concentration of pulp. It pumped into tank by single screw metering pump with electromagnetic flow meter, finally fed into vertical mixer.
The foaming system is dynamic and static foaming system. Foaming agent, water and compressed air are metered and shown separately, then enter static foaming device and dynamic foaming pump for making bubble. Dynamic foaming system produces more stable, small and uniform bubble, which reduces gypsum board weight and increases strength of gypsum board.
Other liquid additives separately mixed with water in a certain percentage. It pumped into tank by prepared tank, then metering conveyor of single-screw pump and displaying on electromagnetic flow meter through , finally fed into vertical mixer.
2. mixer and forming section
Forming section mainly includes paper (upper and bottom paper) treatment systems and vertical mixer, forming platform, forming machine and other equipment.
Paper treatment system is mainly composed of automatic connecting device (hoist, uncoiling device, paper storage machine), stretching device, adjustable device, tension device, automatic alignment system, impressing device, ink jet printing device and other devices. After processing by above mentioned devices, the bottom paper enters into forming platform. The slurry discharged from vertical mixer evenly scattered on the bottom paper. The slurry covers bottom paper quickly with the help of four vibrating rollers of forming platform. It enters extrusion type forming machine through edges treatment devices. After processing by above mentioned devices (no impressing machine), 2 edges of upper paper coated with glue before entering the forming machine. The forming machine consists of the upper and lower extrusion plates. Upper paper coated two edges and bottom paper with treated edges start to glue together in forming machine. The evenly slurry fill with the middle part of 2 papers in order to form a qualified and wet gypsum board strip.
Wet gypsum board section
That is wet gypsum board setting and conveying section. Wet gypsum board strip will gradually harden in some certain on the 1 # and 2 # setting belt conveyor. 1 # setting belt equips with pneumatic device of pulling, This device is used to pull the head of gypsum board strip when plant starts to produce. Then case-hardened wet gypsum board strip is finished after a series of treatment such as spray, leveling, treating edges. Some moisture evaporated during setting. Some moisture starts to be evaporated from its 2 sides since it enters rollers conveyor. After initial setting, wet gypsum board strip enter into double-shaft rotary knife type cutter, then cut by knives roller with high precision. The upper & lower knives drived by double-servo motor independently controlled. After cutting, wet gypsum board will enter into 1 # horizontal conveyor by accelerating rollers. Wet gypsum board will be overturned in 1# horizontal conveyor, then 2 pieces of wet gypsum board will enter distributor of drying section together each time.
3. Drying section
This distributor is two belt conveyors type, which can reduce the degree of bend during transportation. This type also reduces rejection rate. Meanwhile, distributor also has "close" function of wet gypsum boards.
We adopt hot air as heat source of this dryer. Outside air is heated by directly burning burner equipped on the top of this dryer. The hot air will be blown into inside of dryer by circulating fan for heating the wet gypsum boards. The free water of wet gypsum boards will be evaporated continuously through heat conduction and heat convection. Finally we will get qualified dry gypsum boards with some certain humidity.
Feeding section of dryer has the function of "follow up", so that reduces the gap between neighbour gypsum boards as soon as possible, which ensures the drying quality of dryer.
We design "isolation of heat dissipating" structure on doors, roof and floor of dryer. At the same time the door seal with a special material, and install "stainless steel curtain" in inlet, outlet and the connecting parts of each zone. All of those design can reduce heat loss as soon as possible.
This dryer also has special "no overburn of gypsum board edges" structure. That is to say, some wet waste air blown into the part between curtains and doors which not only cools edges of gypsum board, but also increases humidity. This structure effectively avoid overburning of gypsum board edges. This dryer also has waste heat recovering system. The discharged waste hot air will heat fresh air from outside by heat exchanger. So that fresh air with higher temperature will enter dryer for further reducing heat loss.
4. Electrical control equipment
Power for main control cabinet is supplied by workshop power distribution cabinet or by the bus bar from the low-voltage switch cabinet of the substation (Buyer's responsibility).
Set up some sockets for maintenance in the proper place of the workshop (Buyer's responsibility).
Making board production line in electrical control first layer set up engineer workstation, engineer's station responsible for system maintenance and modification, production records (day and month), the second layer MODBUS network connection into site and equipment.
For the first layer, engineer workstation, main controller in the backbone network, the main controller using Siemens S7-300 series PLC, and communication can be easily extended. For the second layer using unshielded twisted pair, each branch station and long-distance I/O hang under the main controller. This structure of the controller, data exchange among workstations is fast, reliable, intuitive process, simple operation, easy maintenance, good expandability. The entire distribution system has the following features:
a. System uses advanced software programming and configuration software, can be run in WIN2000;
b. Electrical and meters inner system can be controlled by engineer workstation. Operating parameters can be changed at any time, advanced, streamlined, is good for stable production;
c. Configuration software using the latest industrial technology, integrated display screen. The main parameters and signals, graphics and other images in one scene, secondary parameters and local parameters then make a separate scene;
d. Engineers station with a UPS unbroken power supply, power-down protection of data.
Single computer control
The production process of higher real-time control, such as 1 # horizontal transportation, exit, 2 # horizontal transportation, plus single computer control to add human-machine interface, can be corrected real-time parameters at site. Single computer control adopts Siemens S7-300 series PLC, close to the scene using Siemens series of man-machine interface touch screen, in the 1# horizontal transportation by touch screen panel to easily adjust board cutting length, running time of taches, residence time and other parameters. In the 1# horizontal transportation stacking machine can control quantity of boards as needed. When 1# stacking machine reach the set value, touch screen by PLC sends compared data, then PLC send transfer command to output, the boards enter into 2# stacking machine, completes automatic stacking process. It is very easy to operate and maintain, low failure rate.
Configuration, PLC, touch screen control
Configuration software is based on the needs of industrial control of a newly developed to meet industrial production control, communication networks, logic operation, analog conversion, production real-time records, history records and required by industrial control computer software.
Touch screen is a new type of programmable control terminals, the new generation of high reliability and high-tech man-machine interface, programming is simple, easy maintenance, with configuration software and PLC greatly improves the entire production line automation control.
S7-300 series PLC are with high speed of operation, rich command, powerful communication, high reliability, easy operation, programming flexibility and good anti-interference ability. Configuration software, combined with touch screen PLC control frequency in the closed-loop system is a trend of automation, allowing operation in the industrial computer, touch screen set target directly through the PLC compared with the actual value of computing, directly to the inverter system to give directions, so as to control purpose inverter output frequency. And real-time monitoring system is charged with the actual value of the size and frequency converter with a number of parameters, the realization of the alarm, records and other functions.
Consumption of Raw Material for the Gypsum Board Production Line
(Take 9.5MM thickness board for example)
|Raw Material Designation