Reconciling Multi Tube Dye Liquor Ratios across Mixed Capacity Jets
Reconciling liquor ratios across mixed-capacity jets demands adjusting total liquid for static piping dead volume to maintain absolute chemical concentrations.
Venturi Nozzle Throat
Acceleration Zone
Narrowest section of a hydrodynamic nozzle where the restriction of liquid flow causes a rapid increase in fluid velocity creates the primary driving force in jet dyeing machines. This constriction forces the dye liquor to accelerate, which generates the kinetic energy needed to propel the fabric rope through the transport tube. The dimensions of the venturi nozzle throat must be selected based on the thickness and weight of the fabric being processed.
Pressure Differential
Reduction in pressure within the restricted zone draws the fabric rope forward by suction and minimizes the mechanical stress on the textile fibres. In this zone, the venturi nozzle throat converts static pump pressure into dynamic kinetic energy, allowing for smooth fabric movement. If the throat diameter is too large for the fabric rope, the suction pressure drops, which can cause the fabric to stall and lead to localized dyeing defects.
Fabric Transport
Movement of delicate knitted fabrics requires precise matching of the throat size with the fabric rope diameter. When the rope passes through the venturi nozzle throat, it is fully saturated with the accelerated dye liquor, which ensures instantaneous and uniform chemical distribution. Choosing an incorrect nozzle size can cause excessive fabric tension or rope tangles inside the transport chamber.
This transport system is highly efficient compared to mechanical winches because the liquid itself is the driving medium, which reduces fabric friction and surface piling during the long dyeing cycles.
Velocity Control
Adjusting the pump flow rate regulates the fluid velocity through the nozzle to match the fabric transport requirements. This monitoring keeps the speed at the venturi nozzle throat within the optimal range for the fabric, ensuring uniform dye penetration.