9. Ratio of area exchange in aerodynamic jet dyeing machines
In an aerodynamic jet dyeing machine, the contact area of the fabric with the dye liquor is limited to the part of the vapor jet nozzle, and only the dye liquor contained in the fabric can contribute to the dyeing during the circulation, and the liquor contained in the fabric can be exchanged only when the fabric passes through the jet nozzle part.
In this mechanism, an extension of the effective area is impossible. The circulation of dye liquor is executed by the circulation of fabric and pump agitation for jetting of dye liquor at the nozzle part, and the exchange of dye liquor in the fabric is carried out when the dye liquor is momentarily jetted out from the nozzle.
The ratio of area exchange is expressed by equation (1'')
Ratio of area exchange in aerodynamic jet dyeing=Ratio of effective area×number of fabric circulation(times/min.) (1'')
The ratios of area exchange of low LR jet dyeing machines and aerodynamic jet dyeing machines are calculated and the results are shown in Table 3.
| Table 3 Ratios of area exchange of low LR and aerodynamic jet dyeing machines |
| Parameter |
Unit |
Aerodynamic
jet |
Aerodynamic
jet |
Aerodynamic
jet |
Low LR
jet |
Low LR
jet |
Low LR
jet |
| State of fabric |
|
Totally
vapor
phase |
Totally
vapor
phase |
Totally
vapor
phase |
partly
vapor
phase |
partly
vapor
phase |
partly
vapor
phase |
| LR |
|
１：３ |
１：４ |
１：６ |
１：６ |
１：８ |
１：10 |
| Weight of fabric |
kg |
100 |
100 |
100 |
100 |
100 |
100 |
| Length of fabric loop |
m |
400 |
400 |
400 |
400 |
400 |
400 |
| Total volume of liquor |
L |
300 |
400 |
600 |
600 |
800 |
1000 |
| Liquor volume of auxiliary part |
L |
200 |
200 |
400 |
250 |
250 |
300 |
| Liquor volume of effective part |
L |
0 |
0 |
0 |
250 |
450 |
700 |
| Liquor volume in vapor part |
L |
100 |
200 |
200 |
100 |
100 |
0 |
| Weight of material in vapor part |
kg |
100 |
100 |
100 |
50 |
50 |
0 |
| Speed of fabric |
m/min. |
400 |
400 |
400 |
400 |
400 |
400 |
| Capacity of pump |
L/min. |
2000 |
2000 |
2000 |
2000 |
2000 |
2000 |
| Flux |
L/kg/min. |
6.67 |
5 |
3.33 |
3.33 |
2.5 |
2 |
| Effective area |
|
|
|
|
|
|
|
| Liquid part |
L |
0 |
0 |
0 |
250 |
450 |
7 |
| Vapor part |
L |
100 |
200 |
200 |
100 |
100 |
0 |
| Ratio of effective area(Total) |
|
0.33 |
0.5 |
0.33 |
1.55 |
1.53 |
1.4 |
| Liquid part |
|
0 |
0 |
0 |
1.3875 |
1.4063 |
1.4 |
| Vapor part |
|
0.33 |
0.5 |
0.33 |
0.1667 |
0.125 |
0 |
| Number of liquor circulations |
times/min. |
6.67 |
5 |
3.33 |
3.33 |
2.5 |
2 |
| Number of fabric circulations |
times/min. |
1 |
1 |
1 |
1 |
1 |
1 |
| Ratio of area exchange |
times/min. |
0.33 |
0.5 |
0.33 |
1.55 |
1.53 |
1.4 |
|
From the results shown in Table 3, it is obvious that low LR jet dyeing machines with partly vapor phase have a high ratio of area exchange giving level dyeing, but aerodynamic jet dyeing machines have a lower ratio of area exchange like a conventional jet dyeing machine, which is not effective in respect of area exchange.
However, level dyeing can be obtained practically with an aerodynamic jet dyeing machine so that another consideration should be made together with the ratio of area exchange.
| Figure 4 Example of low LR aerodynamic jet dyeing machine |
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