|
|
| Spirax Marshall >> Industry Specific Solutions >> Textile Industry - Frequently Asked Questions |
• What is the disadvantage of using Thermodynamic Steam Traps for draining drying cylinders?
The Thermodynamic Steam Traps are specifically designed for draining steam headers and steam lines, they have low capacities and intermittent discharge characteristics. Also there is no air venting or steam lock release facilities. All these disadvantages lead to water logging of system space and inefficient heating resulting in increased process timing and excess steam consumption. In this situation, a Ball Float Steam Trap System Unit would be the most suitable solution.
• What is the best type of steam trap on the JET and I-box dyeing machines? Why?
The Ball Float Steam Trap is the only best trap to be installed on Jet and I-box dyeing machines. The Thermodynamic and Inverted Bucket steam traps have disadvantages explained above.
• What is the recommended steam pressure for vertical and horizontal drying range?
2.5 bar g to 3.5 bar g depending on the cloth being processed. A Pressure Reducing Station should be installed to reduce the boiler pressure to the equipment pressure.
• What is the disadvantage of group trapping of drying ranges?
Group trapping can work only, if the pressure in each drying range is exactly equal. Even if the using applications are supplied with the same pressure, the steam pressure at each steam trap can never be exactly the same, because of different heat transfer rates. Due to this there is varied condensate and pressure changes. This different pressure leads back to improper removal of condensate when group trapped.
The end result is uneven drying of clothes and poor quality of dye fixing.
• Is it worthwhile to use larger size Inverted Bucket traps or Float traps instead of individual traps on dying cylinders?
No, individual trapping takes care of condensate of each drying cylinder and ensures efficient removal of condensate and air/incondensible gases from that individual cylinder.
• What all are the advantages of using system units on the drying cylinders?
A System unit is a product specifically designed for draining condensate from drying cylinders. It comprises of a ball float trap, air vent assembly, strainer and a sight glass as a whole assembly. This unit ensures that all the air in drying cylinders is completely vented and that the heat transfer is most efficient.
• Is it recommended to lift the condensate from the drying cylinder traps?
No, because waterlogging may occur in the steam space and drying cylinders due to low differential pressure.This leads to a higher process time, higher steam consumption and lower heat transfer rates.
• What is correct steam pressure at inlet of Jiggers?
The correct pressure is 0.8 to 1.2 barg.
• Why it is necessary to install individual Pressure Reducing Valves at inlet of each steam consuming equipment in a textile processing unit?
First, the boiler steam pressure should be reduced to department level pressure through Pressure Reducing Stations and then department level pressure is reduced to equipment level pressure through individual Pressure Reducing Valves. This is efficient and correct steam distribution practice.
• How can the control of steam flow optimize the Jigger's heating efficiency?
Temperature of water baths should not rise above 110 oC and fall below 70 oC. Thus, self-actuating temperature control and regulator and Steam Injectors (IN)should be installed on individual Jigger & Winch which will ensure the supply of optimum steam flow to the process and efficient heating. No operators intervention is required to control or operate the steam valves.
• Can flash steam be used in Jiggers or Winches?
Yes, flash steam can be thermo compressed to desired pressure level and then it can be fully re-used.
• How can hot effluent from Jiggers be used for heat recovery?
By using Spirax Textile Waste Heat Recovery System. This is a special system and needs thorough study of exsting plant system Please email us at spx@forbesmarshall.com or call our nearest representative for customized help.
• What is the importance of Vacuum Breakers on steam lines to Jiggers, Winch and J-boxes etc.?
When steam supply is cut off by closing the isolating valve, the steam in line space beyond the closing valves condenses and a partial vacuum is created. Due to this, effluent for machines may enter the steam line or steam system. To avoid this, Vacuum Breaker should be provided on the steam supply line.
• What is the best engineering practice to recover condensate form dyeing machines, hot air stentors and dyeing ranges? Which are the different steam pressures?
All the above mentioned equipment operate at different pressures. To avoid back pressure on low pressure vessels, steam trap modules of proper sizes should be installed. All the module outlet lines should then be taken to a Flash Vessel and Pressure Powered Package Unit for flash steam generation and condensate lifting (pumping).
Click over for additional pointers in :
Steam Generation Steam Distribution Steam Utilization Condensate Recovery
|
