UV disinfection water filtration system Ultraviolet germicidal irradiation

UV Disinfection

Principle of Operation
Ultraviolet disinfection systems typically utilize thin cylindrical bulbs capable of generating narrow band wavelength UV light in the 254 nm range, placed in close proximity to high-purity glass tubes through which the water flows. The unit must be sized to provide adequate dosage at the specified flowrate. The water to be treated must be sufficiently free of turbidity (sediment), iron, manganese and any colorant that could affect transmission of the 254 nm UV light. Manufacturers' specifications should be consulted.


UV units for water treatment

Special low-pressure mercury vapor lamps produce ultraviolet radiation at 254 nm, the optimal wavelength for disinfection and ozone destruction. The UV lamp never contacts the water; it is either housed in a quartz glass sleeve inside the water chamber or mounted external to the water which flows through UV transparent Teflon tubes. Some ultrapure water systems use 185 nm UV units for reducing TOC (total organic carbon).


Technical parameters:

model	Processing capacity (Ton/Hour)	power (W)	inlet and outlet (inch)	working pressure (Kg/cm 2 )	malfunction alert for UV lamp	reactor dimension (cm) L×W×H	dimension of panel(cm)	anchor bolt  (cm)	overall weight (Kg)
YLCn-005	0.3	16	1/2"	6	matched	30×6×11			5
YLCn-008	1	25	1/2"	6	matched	47×6.3×11			10
YLCn-050	2	40	1"	6	matched	100×9×20	Φ8.9×25 (diameter×length)	69×4×Φ1	25
YLCn-150	6	80	1+1/4"	6	matched	100×11×23		69×4×Φ1	30
YLCn-200	8	120	1+1/2"	6	matched	100×15.9×30	Φ8.9×45 (diameter×length)	69×7×Φ1	35
YLCn-300	12	160	2"	6	matched	100×15.9×32		69×7×Φ1	40
YLC-050	2	40	DN25/1"	6	matched	100×8.9×30	25×30×12 (L×H×w)	60×4×Φ1	45
YLC-150	6	80	DN32/1 1/4 "	6	matched	100×10.8×30		60×4×Φ1	50
YLC-200	8	120	DN40/1 1/2 "	6	matched	100×15.9×40		60×7×Φ1	60
YLC-300	12	160	DN50/2"	6	matched	100×15.9×40		60×7×Φ1	70
YLC-360	15	200	DN65/2 1/2"	6	matched	100×15.9×40	50×78×25 (L×H×W)	60×7×Φ1	120
YLC-500	20	240	DN65/2 1/2"	6	matched	100×21.9×50		60×11×Φ1.2	130
YLC-600	25	280	DN80/3"	6	matched	100×21.9×50		60×11×Φ1.2	140
YLC-700	30	320	DN100/4"	6	matched	100×21.9×50		60×11×Φ1.2	150
YLC-1000	40	360	DN100/4"	6	matched	100×21.9×50		60×11×Φ1.2	160
YLC-1200	50	400	DN125/5"	6	matched	100×21.9×50		60×11×Φ1.2	180
YLC-1500	60	420	DN150/6"	6	matched	170×27.3×57		120×16×Φ1.4	210
YLC-2000	80	560	DN150/6"	6	matched	170×27.3×57		120×16×Φ1.4	220
YLC-2500	100	700	DN150/6"	6	matched	170×27.3×57	60×128×30 (W×H×T)	120×16×Φ1.4	275
YLC-3000	125	840	DN150/6"	6	matched	173×27.3×57		120×16×Φ1.4	300
YLC-4000	150	1120	DN200/8"	6	matched	173×32.5×65		120×20×Φ1.6	325
YLC-5000	200	1400	DN200/8"	6	matched	173×37.7×72		120×22×Φ1.6	350
YLC-7000	300	2100	DN250/10"	6	matched	175×42.6×80		120×24×Φ2.0	400
YLC-10K	400	2520	DN250/10"	6	matched	176×52.9×95	60×150×40 (W×H×T)	120×28×Φ2.2	475
YLC-15K	600	3080	DN300/12"	6	matched	176×78×110		120×32×Φ2.4	600
YLC-20K	800	3920	DN350/14"	6	matched	confirmed	confirmed	confirmed	confirmed
YLC-25K	1000	4760	DN350/14"	6	matched	confirmed		confirmed	confirmed

Maintenance requirements for UV units

Lamp Replacement
UV lamps do not burn out as normal florescent lamps do. Instead, the UV lamps will solarize, reducing their intensity to about 60% of a new lamp after about one year of continuous use. When lamps are new, they will generate a dosage level near 60,000 µW-s/cm2 . When the dosage drops to 30,000 µW-s/cm2 (the minimum dosage needed to effectively kill bacteria) lamps should be replaced. Lamp life will be shortened significantly if the lamp is turned on and off more frequently than once every eight hours.

Monitoring Performance
Water should be sampled and tested for bacteria counts regularly. Sample before and after the UV unit to test its performance. Water should also be sampled in the animal rooms since bacteria regrowth can occur downstream of the UV unit.

Cleaning
As water passes through the UV unit, minerals, debris and other material in the water will deposit out and onto the quartz or Teflon sleeve. This will limit the penetration of UV rays through the sleeve and into the water. To maintain high clarity, the glass around the lamp must be cleaned regularly. Cleaning frequency depends on the water quality and will be minimal with RO, distilled, or deionized water.

Monitoring UV Dosage
UV light intensity meters are available which indicate the penetration of UV light through the glass sleeve and the water. Low intensity means the UV dose is too low to provide adequate disinfection. This meter will indicate when cleaning or lamp replacement is needed


FAQ:

Q. Does the water have to sit in the UV sterilizer to be disinfected? 
A. No. If the system is sized correctly, the water is disinfected as it flows through. 
 
Q. What if the water flows faster than is allowed through the system? 
A. If the flow rate exceeds the design flow rate of the UV sterilizer, then there is a possibility that the water will not be properly disinfected. It is important to use a flow restrictor so that the flow rate cannot be exceeded. 
 
Q. How long does the lamp last? 
A. The lamps last approximately 10,000 hours. That is why we recommend replacement approximately every 12 - 14 months of continuous operation. After this period, the lamp itself becomes solarized and blocks the rays form entering the water. 
 
Q. Are these systems bigger energy users? 
A. No. The 12 gallon per minute model, for instance uses only 39 watts, about half the amount an ordinary light bulb uses.
 
Q. My water is sometimes cloudy. Is that a problem? 
A. Yes. The water that enters the ultraviolet sterilizer must be absolutely clear and have a turbidity of less than 1 NTU. If your water is cloudy, then it must be pretreated.