Heat recovery applications in textile industry

Heat recovery by using waste water or effuent is a very important issue where the first investment amortise itself in a considerable short time.

Especially in textile industry , it is very important to be more competitive against the competition and saving energy is the key stone about how to be so,by lowering the costs in plant .The outlet waste water stream is a substantial source of energy to recover and give back to the process.The clean cold process water can be easyly heated to desired temperatures while waste stream acts as a heating medium .For example , the cold clean process water at 15 C with a rate of 25-30 m3/hr , can be easyly heated up to 40-45 C .That energy recovery lowers the operation costs by 300,000-600,000 DM annually ,depending the type and volume of the process.And the break even point in such an investment is about 3-5 months.

Waste water is transfered to large gapped plate heat exchanger after a simple filtering process .The cold clean process water coming into the primeary side of plate heat exchanger , is heated up to desired temperatures by using the warmer medium, the waste process water .Then the cooled waste water is transfered to purification section of plant ,while its energy recovered to the system again.

The feasibility of a sample heat recovery project - according to fuel oil consumption
	Sample 1	Sample 2	Sample 3

Waste water flow rate	m³/saat	50	30	20
Waste water inter temperature	°C	55	60	60
Waste water outlet temperature	°C	25	25	25
Clean water inlet temperature	°C	18	18	18
Clean water outlet temperature	°C	48	53	53
Clean water flow rate	m³/saat	50	30	20
Recovered heat	Kcal/saat	1,500,000	1,050,000	700,000
Fuel oil type specific heat	Kcal/kg	9,600	9,600	9,600
Fuel oil type 6 unit price	TL/kg	121,287	121,287	121,287
Saved fuel oil	Kg/saat	191	133	89
Daily saved fuel oil	Kg	4,573	3,201	2,134
Daily saved operational cost	Milyon TL/Gün	555	388	259
Annual saving day	DM/Gün	1,733	1,213	809
Annual saving	DM/Yıl	520,000	364,000	242,666
Annuel elecrticity consumption	kWh	216,000	158,400	108,000
Electric unit price	TL/kWh	51,071	51,072	51,072
Annual electric energy consumption	Milyon TL/Yıl	11,031	8,090	5,516
Yıllık elektrik enerjisi sarfı karşılığı DM	DM/Yıl	34,473	25,281	17,237
Service ,maintaince and other expenses	DM/Yıl	8,000	7,000	6,000
Net amount saved by heat recovery	DM/Yıl	477,527	331,719	219,430
2 pieces of will be run in operation	Kw	15	11	7.5

The currency is taken as 1 dm=320 000 TL


The risk of intermixing of waste water and clean water is out of consideration because of the structure of heat exchanger.

It is very easy to autpmize the system.there is no need additional stuff to run the system.maximum heat recovery can be achieved by minimum operational costs.

In the system ,gea ecoflex large ga pped plate heat exchangers of Arasta Company are used .The plate materials used in the system is AISI316 . Additionaly ,all kinds of spare parts are kept in our stock while in general they are needed even in long terms.

Prior the heat recovery by heat exchanger, it is necessary to install a filter system where fouling inscreasing materials are hold and prevented to enter the heat exchanger.However, the heat exchanger is periodicly cleaned by back washing operation to avoid any heat transfer decrease.The type of heat exchangers are specially designed for textile industry and everyone of them proves how gea heat exchangers are suitable for such purposes.

When the level of waste water decreases in tank or pool, the pump stops automaticly and continues to run when the level get a certain level again.clean water exiting from heat exchanger, is directed to hot water tank in the process.

Arasta Company designs,projects and erects above mentioned heat recovery systems in 5-6 weeks on turn-key basis.

Your sicerely.....