SECTION 11395
DIRECT DRIVE SUBMERSIBLE MIXERS
PART 1 GENERAL
1.1 SECTION INCLUDES
A. WAS Holding Tank Mixer No. 2: M-7-2-5.
B. Major Components For Each Mixer:
1. Submersible mixers.
2. Mounting system.
1.2 SYSTEM DESCRIPTION
A. The mixer will be used to mix the contents of WAS Holding Tank No. 2, as shown on the Drawings (Group 80).
1.3 DESIGN REQUIREMENT
A. General Requirements:
1. Tank Dimensions:
a. Length, ft: 72.0.
b. Width, ft: 40.0.
c. Side wall height, ft: 19.5.
d. Side water depth, ft: 15.0.
2. Tank volume, gal: 323,100.
3. Tank contents: Thickened waste activated sludge.
4. Solids concentration: 1.25– 3.5%.
B. Performance Requirements:
1. Maintain uniformly mixed tank contents.
1.4 SUBMITTALS
A. Shop Drawings: Submit under provisions of Division 1, including the following.
1. Complete assembly and installation drawings.
2. Descriptive information on material and equipment furnished.
3. Electric motor data.
4. Performance data including:
a. Flow.
b. Total power requirements in Kw.
B. Submit operations and maintenance manual under the provisions of Division 1.
C. Submit certificates of proper installation and operator training under the provisions of Division 1.
1.5 DELIVERY, STORAGE AND HANDLING
A. Deliver, store and handle the equipment under the provisions of Division 1.
PART 2 PRODUCTS
2.1 ACCEPTABLE MANUFACTURERS
A. Xylem Flygt, Pewaukee, WI.
B. Or approved equal. (See Schedule A in bid form for engineer’s designated alternate.)
2.2 GENERAL
A. Mixers shall be direct drive submersible type. All components capable of continuous submerged operation to a depth of 130 feet and continuous operation in air completely unsubmerged for two (2) hours.
B. Provide each mixer with a mast.
2.3 STEEL FABRICATION
A. Metal parts as described herein conforming to Section 05500.
B. Plates and Structural Members: Type 316 stainless steel.
C. Anchor bolts, bolts, hex nuts and washers: Type 316 stainless steel.
2.4 MIXER
A. Motors:
1. Motor nameplate horsepower: 20 HP
2. Type drive: Constant Speed.
3. 460 VAC, three phase, 60 Hz.
4. Moisture resistant Class H insulation.
5. Continuous duty, 30 starts per hour.
6. Enclosure: Submersible.
7. Motor shall be inverter duty rated and meet NEMA MG1, Part 31.
8. The motor shall have NEMA B starting torque and low starting current. The motor shall not be overloaded beyond the nameplate rating under any normal conditions encountered.
9. Temperature sensors embedded in motor windings.
10. The motor shall have moisture sensors located within the stator chamber.
B. Electrical Power and Signal Cable:
1. Type: Water proof.
2. Power cord entry to mixer: Protected with a compression fitting followed by sealed terminal board with permanently affixed binding posts.
3. Length (each): See Design Requirements. Contractor shall coordinate power and signal cable length.
C. Mixer Construction:
1. Mixer, case:
a. Mixer motor housing: Gray cast iron ASTM A-48, Class 30 inner stator base with outer 316 stainless steel jacket.
b. Seals: External mating parts machined and sealed with a nitril rubber O- ring on a beveled edge.
c. Exposed fasteners: 316 series stainless steel.
2. Mixer shaft: 420 series stainless steel.
3. Bearings: Roller and angular contact bearings with a rated minimum B10 life of 100,000 hours.
4. Mechanical seal:
a. Number of seals: Two.
b. Type: Mechanical with tungsten carbide rotating seal faces and tungsten carbide stationary seal faces.
c. Mounting: Tandem with an oil chamber between seals.
d. Lubrication: Oil bath.
5. Propeller:
a. Construction material: 316 stainless steel.
b. Type: Three-vane, dynamically balanced, non-clogging backward curve design.
c. Jet Ring:
1) Construction: 316 stainless steel
2) Provide an extended jet ring that surrounds the motor from the propeller to within 6” of the sliding bracket
6. Mixer connection to mast: 316 stainless steel.
7. Lifting and support cable: Stainless steel.
8. Mounting brackets: 316 stainless steel, minimum 3 required.
9. Sliding brackets: 316 stainless steel.
2.5 MAST
A. The mast will be used to mount mixer during operation and guide mixer during installation and removal.
1. Materials of construction: 316 stainless steel, with a minimum mast size of 4" X 4" square.
2. Mast shall be adjustable in horizontal and vertical plane with positive lock.
3. Include all mounting hardware, including upper, lower and intermediate guide brackets and anchor bolts. Include 316 stainless steel spacer piece between mixer mounting brackets and wall of tank.
4. Include cable holder for mixer electrical cable.
5. Mast shall be non-sparking.
2.6 FINISHING
A. Shop and Field Painting: Conform to Section 09900, and the following requirements:
1. Verify compatibility of shop prime and field paint.
2. Finish all non-stainless steel and reinforced fiberglass surfaces as follows:
a. Submerged Surfaces: Conform to Section 09900, System No. 2.
b. Non-Submerged Surfaces: Conform to Section 09900, System No. 5.
2.7 INSTRUMENTATION AND CONTROL
A. Mixer Control Sensors:
1. Moisture Detectors: Provide in motor stator chamber.
a. Upon the moisture sensors sensing moisture in the stator chamber, the controls shall shut down the pump, indicate pump fail alarm, and activate the remote common fail.
2. Temperature Sensors: Provide thermal switches for each phase in pump motor.
a. Upon the temperature sensors sensing a high temperature in the motor stator, the controls shall shut down the pump, indicate pump fail alarm, and actuate the remote common fail. Automatically reset when temperature returns to normal.
3. Provide moisture and motor high temperature protection relay(s) to provide separate moisture and high temperature signals for each pump. Supervision relays shall be mounted in respective MCC.
a. Relay power supply to be 120 VAC.
PART 3 EXECUTION
3.1 INSTALLATION
A. In accordance with Drawings, shop drawings and manufacturer's instructions.
3.2 MANUFACTURER'S SERVICES
A. Provide manufacturer's services under the provisions of Division 1.
B. Minimum service requirements:
1. Installation: As required for proper installation.
2. Start-up and field testing: One half day on site.
3. Operator training: One half day on site.
C. Service to Repair Defective Work: Provide during one-year warranty period under the provisions of the General Conditions.
END OF SECTION
No comments:
Post a Comment