Mixed Bed Exchangers
A mixed bed exchanger has both cation and anion resin mixed together in a single vessel. As water flows through the resin bed, the ion exchange process is repeated many times, "polishing" the water to a very high purity. During regeneration, the resin is separated into distinct cation and anion fractions as shown in Figure 8-12. The resin is separated by backwashing, with the lighter anion resin settling on top of the cation resin. Regenerant acid is introduced through the bottom distributor, and caustic is introduced through distributors above the resin bed. The regenerant streams meet at the boundary between the cation and anion resin and discharge through a collector located at the resin interface. Following regenerant introduction and displacement rinse, air and water are used to mix the resins. Then the resins are rinsed, and the unit is ready for service.
Counterflow and mixed bed systems produce a purer water than conventional cation-anion demineralizers, but require more sophisticated equipment and have a higher initial cost. The more complicated regeneration sequences require closer operator attention than standard systems. This is especially true for a mixed bed unit.


There are four distinct stages in the operation of Deionizers:

•	Service
•	Backwashing
•	Regeneration
•	Rinse/remix
1.	Service: In the Service cycle the water enters the vessel and passes through the Resin bed of the respective exchanger.

2.	Backwashing: After the resins are exhausted, the bed is backwash. Backwashing is carried out by a uniform upward flow of water through the resin bed. The backwash step expands the resin bed releasing any entrapped particulate matter & removes the channeling in the resin column if occurred during the service cycle. 
3.	Regeneration: When the ion exchange resins lose all the exchangeable ions, they require regeneration to restore them back to hydrogen or hydroxyl form depending upon whether they are cation or anion resins. To achieve this 4 - 5% concentrated solution of Hydrochloric acid is used for cation resin and a 4% - 5% concentrated solution of caustic soda for anion resin. Sulphuric acid can also be used for Cation Regeneration but the concentration of acid during injection must be kept at a minimum, such as to prevent calcium sulphate precipitation on the resin.

4.	Rinse: The final stage of regeneration is to rinse the resins of excess regenerate

DELIVERY SCHEDULE 
Delivery Period will start from date of receipt of Technically & Commercially clear Purchase Order 
Drawings will be provided for approval within a week after receipt of request from you and you will Provide drawing approval within 1 week. 
In case you have any comments/observations or any change required on Drawing submitted for approval, please get back to us within 7 days else we will presume that drawings are in order and shall be released for production. Any delay in approval of drawings by you beyond one week or any time taken to redo the drawings after approval until re¬-approval, the delivery will be extended accordingly. 
Delivery starting on Ex¬ works basis 	: 	8-10 weeks	

Rs. 5000/Head/ Day (8 hours) will be charged for supervision for Erection & Commission and all accommodation (Lodging & Boarding) will be extra or  in client scope
 Though erection and commissioning is performed by client and client request from us to be present in time commissioning. is payable.
STANDARD TERMS AND CONDITIONS
SPECIFICATIONS 
Specifications, dimensions, design, description, shades of paint etc are not binding on us in minute details and are subject to reasonable alteration / change without notice. 
INSPECTION 
If necessary, the goods will be offered for inspection at our works/our supplier’s works. The date of inspection will be intimated about one week in advance. If inspection is not carried out on the date mentioned, we shall be free to dispatch the equipment as per the terms of delivery. 
If payment is not made within 15 days from the date of Performa Invoice, we reserve the right to divert the ordered material. We will give fresh delivery period and new price at the time of diversion which will be binding on the purchaser and contract cannot be rendered void on this account.  If the goods are not diverted, charges for storage, insurance and interest at 1% of the Invoice value each week/part thereof commencing 15 days from the date of Proforma Invoice will be charged. Warehousing charges are subject to a maximum of 5% of the Invoice value.
WARRANTY
The equipment supplied by us shell be warranted for 12 months from the date of installation and commissioning or 18 months from the date of supply for any manufacture defect, however defect arise due to miss handling, incorrect operation wear and tear shell be entertained with reasonable charges. The warranty of all instruments and pump and motor and other equipment except prefabricated items will be covered under actual manufacturer’s warranty conditions. 
HANDOVER 
Unless and otherwise specified in the order and accepted, handing over of the equipment and / or installation would be considered as completed and a formal completion certificate shall be issued by the purchaser / user. 
The equipment/system, to be supplied by us, shall be site erected and commissioned at purchaser’s site. 
This equipment/system shall be legally transferred to the buyer only after realization of full and final payment. 
MODE OF DELIVERY 
The goods may be dispatched in one or more lots at our option. If we are required to dispatch the goods on behalf of customer, we can arrange to do so on freight to pay basis on the understanding that no liability is attached to us. In such case, Freight charges contracted by us on behalf of the purchaser shall be final and binding on the purchaser. 
CANCELLATION 
Order received and acknowledged by us shall not be subject to cancellation, either wholly or partly for any reason whatsoever without our written consent. 
FORCE MAJEURE 
The order from the purchaser is subject to force majeure by which it means, such as war, invasion, civil disobedience, govt. orders or restrains, strike, lockout, riots, fire, epidemics, sabotages, trade embargoes, earthquakes, floods, accidents, breakdown of machines, delay or inability to obtain labour, raw material, wagons, shipping space or any other process, which is beyond our and our supplier’s control. 

JURISDICTION 
All contracts between purchaser and ourselves are deemed to have entered into in DELHI and are therefore subject to the Jurisdiction of Courts in DELHI. 

Excluded

Extra as per actual

Design Criteria 

Input Conductivity - 22 µS

Out Put Conductivity - 0.25µS

Thickness of MS Plate of Shell/Dish end shall be 6/8mm.
Thickness of Rubber Lined of Shell/Dish end shall be 3mm.
The frontal Pipelines shall be MSRL
Earthling/electrical/civil or not included in specification, shall be in client/customers scope