Letter 35032

DM water plant  

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We are having DM plant with capacity of 400 lph which is running 24 hours a day. This plant is filling water into tank with 1000 litre capacity. We are maintaining water conductivity below 0.3 micro Siemens. If at the end of the day the concductivity increase to 1 micro Siemens what should be the plant capacity to bring it below 0.3 micro Siemens. In our system we are using copper, SS and breaded PVC pipes. The 7.5 HP pump is used for circulating the water from storage tank. The pump capacity is 480 lpm. The small pumps with 400 lph capacity are used for re-circulating water through mix bed units. The stoarge tank is air-tight. We are not using nitrogen filling. The temperature is around 35-40 degrees calcius during the operation as the DM water is used for cooling copper heatsinks.

I want to know when I should recharge the mix bed unit. What is the formula for recharging the mix bed unit with respect to conductivity of the water.

Ahmed Syed
Engineer - Gandhinagar, Gujarat, INDIA

Your problem is not clearly explained. When you say recharge, do you mean you have an exchange tanks as DI mixed beds? Where is the 480 lpm pump recirculting water to from the storag etank to the copper sinks? Why is 1 microsiemen not good enough? The application should not require much better purity. Your materials and no nitrogen balnket will allow CO2 from the air to mix with the water, eventhough the tank is air tight as you say.
If CO2 is the contaminant, to go from 0.3 microsiemens to 1 microsiemens will take approximately 100M3 of recirculated water per liter of mixed bed resin.
I hope this helps.

Juzer Jangbarwala
- Brea, CA, USA

We are using this DM water plant for water cooled heatsink. The total system is like this. A multi secondary transformer is supplying AC power to the 80 units. Each unit is connected in series. Each unit is converting 940 VAC in to 100 to 1000 VDC(variable). All secondary of the transformer is isolated from one another and from ground. The first unit is at 1000 VDC from earth, Second unit is at 2000 VDC from earth and so on. The Electronics parts are mounted on the heatsinks in each of the 80 modules. All the modules cooling water is supplied from one plant, which gets short circuited after some distance. The flow is from storage tank to one supply header with 80 branches and back to return header and to storage tank. To avoid electrical short circuit between two modules we require very low conductivity water. We are using water because it is excellent coolent. We are using stored water in the tank at 480 lpm to circulate in this main loop.

The water purification loop is from storage tank to mix bed unit and back to storage tank at 400 lph rate. For this system we require to know the capacity of the mix bed plant to achieve 0.3 micro siemense conductivty with 37 to 40 degree ambient temperature.

I mean recharging of mix bed unit. When should I recharge resins of mix bed unit with acid and caustic? What is the formula after whcih time one should recharge the unit?

Ahmed Syed
- Gandhinagar, Gujarat, INDIA

Want technical know-how on dm water plant.

Jasbir Singh
new enterprenuer - Delhi, India

Hello Jasbir. Sorry, but it isn't really clear what you want people to do. Do you want us to recommend a few books about DM, or do you want a DM Water consultant to offer his retainer terms, or do you want vendors to send a flyer? If the latter, please give some clues about what general type of DM system you are looking into -- what is the water used for, what is the source of the water, what is the flow rate? Thanks.

Ted Mooney, P.E.  finishing.com Brick, New Jersey

Please We wants to know, that how can we check DM Water by simple method.
We purchase DM Water for our paint line.

Dilip Gupta
shock absorber mfgr. - Indore, Madhya Pradesh, India

Dear Sir,

Does the quality of DM water deteriorates upon storage (with caustic breather at vent and water jaketing of overflow) for more than some specified period? If yes, what is that period?

S. Banerjee
- Jamshedpur

WHAT IS THE CHEMICAL NAME OF D.M.PLANT CATION & ANION RESIEN
PRAMOD MISHRA
DELHI
INDIA

PRAMOD MISHRA
PLANT OPERATOR - DELHI INDIA