Flow and pressure control of overflow dyeing machine
Jul 06, 2022
Flow and pressure are two important parameters of overflow dyeing machine, which are determined by the main circulating pump. The flow rate is necessary to ensure the dye exchange with the fabric, and it must be large enough. In a specific dyeing process, the change should be as small as possible. It is completely controlled by the main pump. For overflow jet dyeing machine, pressure refers to the pressure generated by the nozzle; For the package dyeing machine, it refers to the internal and external pressure difference of the package yarn, but the total pressure is still provided by the head of the main pump.
In the dyeing process, flow rate and pressure play a very important role. Different fabrics and processes have different effects on the flow rate and pressure (jet force or pressure difference) of dyeing solution. For example, compared with high count fabrics with large surface and rapid dyeing process, the flow rate is required to be large; For light and thin fabrics and fabrics with delicate surface, small spray force is required; For fabrics with large gram weight, it is required to have both sufficient flow and strong spray force. Therefore, the flow rate and pressure should vary according to different fabrics and processes.
In order to meet the changes of flow and pressure, the traditional overflow dyeing machine is controlled by the closure adjustment at the outlet of the main pump. Because this control method is affected by human factors, it is not accurate enough; At the same time, the main circulating pump does not work at the optimal operating point, and the efficiency is reduced. According to the characteristic curve of the main pump, within a certain speed adjustment range, the speed of the main pump is changed through AC frequency conversion to realize the change of flow and head, so as to meet the requirements of different dyeing processes, so as to ensure that the main pump always works at the optimal working point of the corresponding flow and curve, so as to save electric energy.
As for the specific determination of flow and pressure, flow or pressure detection can be set, and automatic control can be realized through PLC processing. Set in PLC, users only need to select the corresponding parameter menu according to the fabric they dyed.