Separation of wastewater discharges in dyeing department
The goal of the innovation was to separate wastewater discharges in a textile manufacturing company. Relatively clean water could be reused in the technological process, polluted water is transported through a heat exchanger to utilise its heat.The innovation has been generated and implemented at a textile manufacturing company performing all operations from thread preparation to fabric finishing processes. The operations include preparation for dyeing and printing with washing and strengthening, giving shape and exterior to fabrics.
The fabric finishing process consumes the largest amount of energy, water, steam and chemicals, hence, the environment is affected most of all as compared to other departments. However, it is impossible to avoid wastewater from the dyeing department.
To address this problem, a technology for separation of wastewater discharges was introduced: relatively clean water is reused in technological processes, polluted water is transported through the heat exchanger to use its heat.
Two systems were installed to facilitate wastewater separation:
- the first system: after washing operation, relatively clean wastewater is transported to the tanks and reused in the technological process by means of a pump;
- the second system: after dyeing operation, polluted wastewater is collected in a wastewater tank. A submerged pump transports waste water through two heat exchangers for soft water heating.
Barriers and drivers
A possibility to reduce the use of water and to minimise steam consumption
Annual savings due to this innovation total LTL 600 000 (EUR 173772). Total costs are LTL 600 000 (EUR 173772). The project repaid within 1 year.
Separate discharges in the dyeing department allow saving approximately 90 000 m3/year of soft water.
Heat recovery from wastewater after dyeing operations allows minimizing consumption by 3 400 Gcal/year.