1. OdoNash Odor Control System shall be provided to reduce dramatically or eleminate odor and Hydrogen Sulphide (H2S) released by Vent Air from odor producing wells of Sewage Treatment Plant (STP) or in Sewage Lift Wells.Wells/Tanks to be treated are limited to odor/H2S producing wells/tanks only. Water Treatment and other non odor non H2S producing tanks are not considered in this scope of work.

2. Vent Air releassed from odor/H2S producing tanks shall be confined within the tanks. To achieve this, well/tank top shall be covered as part of construction of the tanks by civil contractor or others

3. Vent Air from odor/H2S producing wells shall be extracted from free board or air column over liquid/sludge level. Extracted air shall be ducted to odor removal equipment called for in this specification. The extraction shall provide negative air pressure in the free board space. This shall prevent migration of H2S and odor bearing Vent Air from wet wells into the plant room. Air shall always infilterate into the wet well from plant room and never vice versa. This shall keep the STP Plant Room free of odor and H2S. Fan necessary to provide this air movement shall be factory built in the equipment.

4. System Deliverable: Based on air displacement at 5 complete air changes per hour of volume of air column over liquid/sludge in the wet wells, and H2S concentration at 10 PPM in Vent Air, H2S at exit from contact chamber measured at radius 4 Ft (1.2 M) from point of discharge shall not be greater than 1 PPM. H2S measured at fence line of plant room at length 20 Ft (6 M) or greater from point of discharge shall be less than 1 PPM.

5. H2S Monitor/Controller with digital display of H2S concentration in PPM shall be provided in the air exhausted to atmosphere. H2S Monitor/Controller shall meet specification given in later paragraph of this text.

6. Ozone Monitor with digital display of ozone concentration in PPB shall be provided in the air exhausted to atmosphere. This shall automatically deactivate the ozone producing cells in the event concentration of ozone in the air exit to atmosphere reaches regulatory specified maximum or user set concentration. The Ozone Monitor shall meet specifications given in later paragraph of this specification.

7. The Odor Removal Equipment shall comprise Ozone Generation Compartment, Fan Compartment, Mixing Air Chamber, and Electrical and Instrumentation Enclosure.

8. Ozone Generation Compartment shall comprise team of multi plate, double sided corona discharge plates operating at high voltage, to produe adequate quantity of ozone at medium concentration. The system shall not require any consumable and maintenance shall be minimum. Feed air shall be plant room air. Use of annular tube type corona with air as feed gas is not permissible, so as to prevent deposition of nitrogen oxides on the corona surface. To minimize maintenance and operational consumable, use of oxygen feed system is not permissible.

9. Mixing Air Chamber shall facilitate entry of H2S laden air from wet wells into Odor Control System. It shall also allow entry of ozonized air from Ozone Generation Chamber. Air movement into the Fan Chamber and the Mixing Chamber shall be designed to prevent ozonized air and H2S laden air to come in contact with any other part or component of the equipment.

10. Air intake grille with opposed blade volume control dampe, filter track with filter housed in filter frame, shall be provided for intake of plant room air into the fan compartment. The filter shall provide 80 % arrestance in conformity to 7.4 of ARI Standard 850-93. The filter media shall confirm to UL Class 2, and tested to Std 900.

11. SS Collar shall be provided to connect H2S laden intake air ducts from wet wells complete with opposed blade volume control damper fabricated out of Stainless Steel, and fitted with filter housed in filter frame. Filter shall confirm to specifications mentioned in above clause.

12. The Fan Chamber shall comprise centrifugal fan sized to extract required flow of Vent Air from wet wells. Static Pressure of the fan shall be adequate to overcome pressure drop in Contact Chamber and discharge the Vent Air to atmosphere with adequate air vilocity at point of discharge. As H2S and ozone are corrosive gases and as H2S has low flash point temperature, all parts and materials of the fan including casing, volute chamber, and impeller shall be Non Metallic Food Grade Polypropylene, non sparking, and non flamable. Shaft shall be Stainless Steel. Contact of H2S and ozone laden air shall be restricted to fan components only. To enable this, the fan shall be bifurcated type, Motor shall remain outside the Vent Air Stream and shall never come in contact with Vent Air or ozone laden air. Considering safety, performance and longetivity, these requirements cannot be waived.

13. The Electrical Compartment shall house all electrical components, controls, monitors, and instruments. This shall be isolated totally from all other compartments. The Electrical Compartment shall comprise sufficient number of electrical induction type transformers to drive ozone geenrator heads.

a. The Transformer shall be electrical induction type. Solid-state voltage converter shall not be acceptable. The Transformer shall be Cross Ferro Magnetic Type. Secondary windings shall not burn, generate smoke, or elevate greater than 90ºF (32ºC), even if the high voltage secondary output is short-circuited for extended period of time, in full load conditions. Upon removal of the short circuit, the transformer shall revert to normal operation without any damage or loss of efficiency, or reduced insulation capacity, or blow out of fuse, or trip of circuit breaker.

i The transformer shall be fully encapsulated. The encapsulation is to ensure the transformer windings and core are fully impregnated with epoxy rated for use in electrical equipment. The epoxy shall penetrate into various layers of primary and secondary windings, and into the various sections of the core. This is to ensure electrical spark, if any, shall be contained and isolated within the specific spot of occurrence in the windings, and temperature elevation if any shall be contained and isolated within the specific spot of occurrence of the winding or in the layers of the core. The epoxy for encapsulation shall be fire rated to UL94V0. The electrical properties of the epoxy for this encapsulation shall be;

a Dielectric strength at 23ºC not less than 425 volt/mil
b Voltage receptivity at 23ºC not less than 2 x 1015 Ohm Cm

ii The encapsulation of the transformer shall be done in a one piece die cast metallic enclosure 18 G CRS. The top cover shall be riveted. The enclosure shall be filled with fire rated epoxy to UL 94V0. This shall ensure the transformer is completely fire rated and non flammable.

iii The metallic enclosure and encapsulation shall also render the transformer totally safe to operate even if there is settlement and deposition of moisture or water on the transformer.

iv Primary of Transformer shall be rated for input voltage varying from 0 to 110V, or 220V, 50/60 Hz.

v Transformer shall be tested to CSA or UL recognized.

b. Passage of high voltage conductor from transformer secondary terminal, across the metallic enclosure, to Generator Enclosure, shall be through Liquid Tight Strain Relief Connector rated for cables. One connector shall be used for each cable. Connection shall be of ozone resistant material such as Polyamide. Neoprene seal shall be used to ensure total air tightness up to 70 psi (5 Bar) and to NEMA 6 P (IP 68). It shall be ROHS Compliant, UL and CSA Listed.
c. High voltage electrical wire from the transformer secondary terminal to Corona contact plates shall be single length cable without joints or connectors, rated for 25 KV, 250ºC, certified to be ozone and corona resistant, have high flexibility, and shall be silicone insulated. Wire diameter shall not be less than 18 AWG. The wire shall be rated to UL3257. These shall be stamped on each wire. This is essential and cannot be waived from safety standpoint, as this wire carries high voltage.

d. The Ozone Generator Compartment shall not have any trace of H2S while it starts and operates. This care is essential to ensure no spark or ignition occurs. Necessary Electrical System Relay compliant to ROHS and UL shall be provided to ensure this.

e. Auto/Manual Change Over Switch.

f. Manual Regulator to modulate production of ozone 0 to 100 %.

g. Mushroom Top Emergency one push shut down switch mounted on the outer surface of the enclosure for instant shut down of the odor control unit, in the event of emergency.

h. Hour Meter, UL Listed or Recognized housed in NEMA4 enclosure, to enable timely maintenance.

i. Two # Air Pressure Monometer rated to read negative air pressure in quantifiable units, one to balance air flow from plant room to Ozone Compartment, and second from STP Wells/Tanks to Mixing Chamber.

j. DPST Main On/Off Switch, DPST Fan On/Off Switch, Indicating Lamps, circulating fan to cool the Electrical Compartment, and Terminal Block.

14. Contact Switch shall be provided on the door of Generator Compartment and Fan Compartment to ensure the unit automatically shuts down completely if the doors are opened during operation of the unit.

15. All parts and components shall be factory installed complete with electrical and control wiring in one neat 18 G all Stainless Steel Enclosure. Stainless Steel Collar shall be factory provided in the unit to facilitate field ducting to contact chamber. No fieldwork shall be necessary except interconnect ducts, contact chamber, and electrical connections.

16. The equipment shall be installed on a 6” (150 mm) or higher foundation pad and grouted firmly to the foundation. Installation shall be in indoor ventilated plant room.

17. Based on contact time required to achieve effective removal of H2S and odor as called for in this specification, Manufacturer shall provide volume and design of contact chamber.

18. Contact Chamber, all interconnect ducts, electrical connection, and control cables to BMS shall be provided by others.

19. At client’s request, pre shipment inspection and testing of equipment shall be provided at the manufacturer’s facility. Besides normal tests, following tests are mandatory;

a. Air Flow through a duct shall be modulated to provide the actual design air flow or air flow to simulated conditions. H2S gas shall be injected into the duct to the design concentration or to simulated conditions. With use of contact chamber to actual design volume or simulated contact volume, concentration of H2S at exit of contact chamber shall be recorded to demonstrate ability of system performance. H2S Monitor shall be installed to prove H2S concentration before and after treatment. If conditions are simulated, calculations shall be presented to prove the results extrapolated from simulated conditions meet deliverables called for in this specification.

b. Transformer secondary output, under full voltage and load will be subject to short circuit continuously for minimum of 24 hours. The primary and secondary windings shall not burn nor elevate in temperature greater than 90ºF (32ºC).

c. Upon release of the short circuit, the transformer shall revert to normal operation without any change or modification or repair, or fuse blow out, or trip of circuit breaker.

d. Demonstrate safe and undamaged operation of the transformer at full secondary voltage and load, with transformer fully immersed in a pail of water.

e. At inspectors instructions, cut open a transformer through the windings and core to demonstrate the penetration of the encapsulation epoxy into various layers of primary and secondary windings, and into the core.

f. Demonstrate that high voltage wire is stamped with ratings of voltage to 25 KV, temperature to 250ºC, and UL rating 3257.

20. H2S Monitoring and Control System shall be provided. It shall be shipped loose for field installation at outlet of treated vent air at exit from contact chamber. The Monitor shall display concentration of H2S on LED Screen in PPM. It shall comprise a Relay with one NO and one NC potential free Dry Contact rated for 250 V, 10 Amps AC/DC. The LCD shall also display Alarm Condition and activation of Relay. It shall provide 0-10 VDC Analog Signal for interface to BAS/BMS. 0-10 VDC Analog Signal shall also be available for input to Auto Controller.

21. As optional item, if called for in the BOM, H2S Controller shall be provided in the Electrical Enclosure. Based on Analog 0 – 10 VDC input signal from H2S Sensor/Monitor, it shall modulate output voltage to primary of transformer from 0 to 110 V (or 0 to 220 V), for automatic modulation of ozone generator in response to level of H2S at exit of air from Contact Chamber to environment. The Controller shall be Listed to UL 916.

22. Ozone Monitor shall be provided. It shall be shipped loose for field installation at outlet of treated air at exit from contact chamber. The Monitor shall display concentration of ozone in PPB. It shall comprise Relay with one NO and NC potential free Dry Contact rated for 250V, 10 Amps AC/DC. The LCD shall also display Alarm Condition and activation of Relay. It shall provide 0-10 VDC Analog Signal for interface to BAS/BMS. In the event ozone concentration at exit of treated vent air reaches regulatory mandated maximum or user set concentration, it shall deactivate the ozone generator cells. Sensor shall be factory housed in 18 G CRS Powder Coated Enclosure.

23. The system shall be rated for operation on 220 V, 3 Ph , 60 Hz or 220 V, 1 Ph, 50 Hz. Operating Temperature and RH shall be 32ºF to 115ºF (0ºC to 46ºC) and RH 0 to 100 % Non Condensing.

24. All individual parts and components of the odor control system shall be UL Listed or Recognized.

25. The equipment shall be CE Certified.

26. The equipment shall be;
Odor Control System: Ruks OdoNash
H2S Sensor: CZ10
Auto Controller: CZ6-C- H2S
Ozone Monitor: CZ12
Make Ruks Engineering Ltd or equivalent
Country of Manufacture: Canada