Application of Robin Kang frequency converter in textile dyeing vat
I. Introduction

After a long period of accumulation, the dyeing process has formed a relatively fixed process flow. However, with the different types of fabrics, dye types, and printing and dyeing requirements, the dyeing process is becoming more and more complex and refined. Simple manual processing is difficult to solve and low in efficiency. It can only rely solely on human experience. Dyeing vat is one of the main equipment for dyeing yarn and one of the main energy-consuming equipment. In today's situation of increasingly tight resources and increasingly fierce competition in the textile industry, reducing energy consumption means reducing enterprise production costs and increasing enterprise competitiveness. ; With the development of frequency conversion control technology, frequency conversion control of flow pressure difference has been widely used in the dyeing and finishing industry. The energy-saving transformation of dyeing vat with frequency conversion energy saving has also become the most effective way for dyeing and finishing industry to reduce the energy consumption cost of dyeing yarn and improve product competitiveness. Therefore, the application of AC frequency conversion speed control device on the dyeing vat is of great significance for reducing energy waste.


2. The basic principle of textile dyeing vat

The dyeing vat system is used to color the cloth, adjust the temperature, pressure, and pigment flow to form a certain process condition, and dye the cloth under relatively stable water level, pressure and temperature conditions.

Dyeing vat system structure diagram





3. Disadvantages of traditional dyeing vat

The yarn dyeing process is a process according to a predetermined periodic action, that is, the time control of the inflow and outflow to achieve the dyeing process. The internal and external flow is mainly realized by the commutator; the flow of the yarn is mainly realized by the main pump.

The first is hardware loss.

The main pump of the ordinary dyeing vat is started by the original Y-△ step-down voltage, and its starting torque and starting current are large, which accelerates the aging of the main pump and the accelerated wear of the commutator. Increased maintenance costs and energy waste.

The second is overflow loss.

As the yarn processing procedures are different, the temperature, flow, and pressure required for each procedure are different. For the main pump motor, the load of the dyeing vat during the dyeing process is in a changing state. The flow rate of the pump is designed according to the required maximum flow rate. The original main pump motor provides a pressure flow rate at a constant speed. When the flow rate required for each pump yarn is less than the maximum flow rate, the color material flows through every pound instead. Yarn, so that it is not added in the shortest time, this part of the energy is lost.

The third is throttling loss.

When the water flows through the reversing port of the commutator, there will be a certain flow and pressure, which increases the torque of the reversing solenoid valve. At the same time, due to the long-term full-speed circulation of water and the violent mechanical friction of the reversing device, the temperature of the sealing ring is too high. Excessive noise of the commutator and shortened mechanical life.

The fourth is the design margin loss.

Usually in the design, the commonality is generally considered, and the design is based on the maximum capacity. Therefore, the design capacity of the main pump motor of the dyeing vat is much higher than the actual need. There is a phenomenon of "big horse-drawn carts", resulting in a lot of waste of electric energy .


Four, Robin Kang inverter application energy saving principle

First, speed regulation and energy saving.

According to the process requirements of dyeing yarn, the original main tank injection tube is changed to a flow controller, which is converted into a 4-20mA current signal and then added to the PLC analog input terminal as the frequency given signal of the inverter, and the PLC will sample it in real time And through PID calculation processing, the frequency output to the inverter changes linearly with the analog signal of the flow controller; after the given pound size is calculated by the PLC, the pressure and flow rate will automatically adjust the motor speed, thereby reducing For the output power of the motor, a reversing in-position switch is installed at the reversing solenoid valve to ensure that the reversing solenoid valve is fully activated. When the internal and external flow is commutation, the speed will be automatically reduced according to the reversing switch action, and after the commutation is completed, it will automatically accelerate to the required frequency, so that the energy loss of the motor and the reversing valve in the entire load range is minimized.

Second, the cost is reduced and the operation is convenient.

Remove the original water level controller and magnet signal of the master tank and change it to an analog signal controller to control the water level. And install the man-machine interface to check the real-time water level of the main tank. No water running of the main tank has caused accidents. The water level controller of the material tank is removed, and the original analog signal controller is used to control the water level, which reduces the maintenance cost and production cost.

Third, improve power factor and save energy.

Reactive power not only increases line loss and heat generation of equipment, but more importantly, the reduction in power factor leads to a reduction in active power of the grid. It can be seen that the greater the power factor, the greater the active power. The COSφ value of the ordinary main pump is between 0.6-0.8, and after using the frequency conversion speed control device, due to the compensation effect of the filter capacitor in the frequency converter, the COSφ≈1, thereby reducing the reactive power loss and increasing the active power of the grid .

Fourth, soft start energy saving.

Since the original motor is a direct start or Y/△ start, the starting current is equal to (3-7) times the rated current, which will cause a serious impact on the electromechanical equipment and the power supply grid, and will also increase the grid capacity requirements, resulting in large Current and vibration are extremely detrimental to the service life of the equipment. After using the variable frequency energy-saving device, the use of the inverter’s soft start function will make the starting current start from zero, and the maximum value will be limited to the current limit level during acceleration set by the inverter, generally not exceeding 1.7 times the rated current, which reduces the The impact of the power grid and the requirements for power grid capacity have prolonged the service life of the equipment.

5. Routine maintenance and precautions of the inverter

1. This working environment is relatively humid and sultry. It is necessary to pay attention to the waterproof, anti-corrosion and overheat protection of the inverter;

2. Pay attention to the grounding of the motor during installation, and do not share the neutral wire with the ground wire;

3. The analog signal line and the main power line should be crossed to prevent interference.