Abstract : Low-feed liquid levels are common and important in textile processes. This paper describes a spray disc type uniform low-feed liquid system where the entire electrical system utilizes Delta's electromechanical products, effectively meeting system requirements and offering strong cost-effectiveness. Furthermore, this paper introduces the equipment structure and working principle of the spray disc type uniform low-feed liquid system, as well as its control architecture and program.
Abstract : low wet pick-up in the textile process is very important. This article the Spray plate Uniform low wet pick-up system with a full set of Delta's electrical and electronic products, well positioned to meet the system requirements, the cost also has a strong competitive edge. In addition, this article also describes the structure and working principle of the device, and to achieve control structure and procedures.
Keywords: Low-fluid supply, textile, touch screen, PLC
Key Words : low wet pick-up Textile HMI PLC
1. Introduction to Equipment Structure and Working Principle
The spray disc type uniform low-pressure liquid application system is a technology that can apply various liquids to textiles. Its working principle is as follows: the liquid in the highly rotating spray disc is subjected to strong centrifugal force to form a water film, which is then cut into micron-sized water mist by centrifugal lines on the disc surface and sprayed at high speed, breaking through the fabric surface and uniformly penetrating the fabric fiber layer. This achieves the goals of rapid moisture regain, full hand feel, stable shrinkage, increased weight, and reduced energy consumption.
This equipment is widely used in processes requiring humidification, such as pre-shrinking machines, tenter frame machines, calendering machines, steaming machines, and steaming machines. It has the following characteristics:
1) Touchscreen setting and operation, PLC control;
2) The spray volume is automatically adjusted according to the vehicle speed, resulting in more uniform liquid distribution to the fabric;
3) The recycled spray water is filtered through multiple layers to ensure the dynamic balance of the spray disc and extend its service life.
4) Droplet size 30-70 μm.
The process is shown in Figure 3. Pump ① draws liquid or water from liquid tank ② and delivers it to various spray discs ④ on spray disc frame ⑤ through filter ③. When a fabric ⑥ running in a flat direction passes through, the liquid is sprayed onto it. The liquid that is not sprayed onto the fabric flows back to liquid tank through return pipe ⑦. Impurities in the return liquid are removed by pre-filter ⑧. Cleaning devices ⑨⑩⑾ ensure the cleaning of the liquid supply unit, and control unit ⑿ controls the entire device.
Figure 1. Full view of the spray disc type uniform low liquid supply system.
Figure 2. Main body of the spray disc type uniform low liquid supply system.
Figure 3. Process diagram of the spray disc type uniform low liquid supply system.
2. Electrical architecture diagram and selection instructions
Based on the compact size of the customer's equipment, we configured the following products for them:
PLC: DVP14SS11R2*1
Human-Machine Interface: DOP-B05S100
Inverter: VFD015M43A
Speed encoder
Other electrical accessories
Figure 4 Control Architecture Diagram
3. Equipment working principle and procedure description
3.1 Working Principle and HMI Screen
This device is mainly used to humidify woven fabric. It has two input signals: a main unit start signal and a main unit speed measuring wheel pulse signal. When the main unit starts, the spray disc motor runs, the valve opens, and the liquid supply pump initially operates at the set minimum frequency. As the main unit speeds up, the PLC calculates the actual linear velocity of the fabric in real time based on the pulse signal from the speed measuring wheel. Based on the actual linear velocity and the humidity setpoint, the PLC controls the operating frequency of the water supply pump, thereby controlling the humidity of the fabric surface. See Figure 5.
Figure 5 System Parameters
Parameter settings: Humidity settings are used to set the water supply volume. The system parameter screen also allows setting the minimum water supply frequency and other auxiliary actions. See Figure 6.
Figure 6 User Parameters
Monitoring screen: Monitors the current actual linear speed and humidity setting of the host. See Figure 7.
Figure 7 Monitoring screen
3.2 PLC Program Description
3.2.1 Speed Measurement Procedure :
The principle behind this part of the program is to use the PLC's built-in high-speed calculation function to calculate the number of pulses from the speed encoder per unit time, and then convert it into linear velocity based on relevant mechanical coefficients. This value is used as a coefficient to calculate the water supply pump frequency. Then, based on the humidity setting, the actual required water supply frequency is calculated. See Figure 8.
Figure 8 Speed Measurement Procedure
Another point to introduce is the high-speed counting function of SS PLC. As shown in Table 1, the ES/EX/SS series models support high-speed counters with a total bandwidth of 20kHz.
Table 1 SS PLC High-Speed Counting
Input points X0 and X1 can be configured as higher-speed counters, with a single-phase input reaching 20kHz. However, the sum of the counting frequencies of these two input points must still be less than or equal to the bandwidth limitation of 20kHz. If the counting input is a two-phase input signal, the counting frequency is approximately 4kHz. High-speed counters with input points X2 and X3 can reach 10kHz with a single-phase input.
3.2.2 Calculation of liquid supply frequency:
The liquid supply frequency (humidity control) calculation works as follows: When the machine starts, the water supply pump initially runs at the lowest frequency. As the machine speed increases, calculations show that the frequency exceeds the minimum operating frequency, and the pump outputs at the actual calculated frequency. When the machine stops, it resumes operation at the lowest frequency for a set delay before stopping. See Figure 9.
Figure 9. Calculation of liquid supply frequency
3.2.3 Communication Program:
Delta's SS PLC provides two communication ports. In this article, the SS PLC's COM1 port is already communicating with the touchscreen, so we utilize the SS PLC's COM2 communication port (this communication port interface is RS485), which supports MODBUS communication convenience commands. Programming communication programs is as simple as programming sequential logic programs, allowing even those unfamiliar with low-level communication to quickly get started. This enables rapid programming of MODBUS communication programs to control Delta's entire product line, including inverters, temperature controllers, and servo drives. See Figure 10.
Figure 10 Communication Program
4. Conclusion
The equipment has a simple electrical architecture and rich functionality, and has been ultimately approved by the customer.
