VORTEX GRIT CHAMBER EQUIPMENT

This specification was used recently on a project in Colorado. It is based around John Meunier, but also name Ovivo, Wetech, and WasteTech.

VORTEX GRIT CHAMBER EQUIPMENT

PART 1          GENERAL

1.01       REFERENCES

A.     The following is a list of standards which may be referenced in this section:

1.      Hydraulic Institute Standards (HIS).
2.      National Electrical Manufacturers’ Association (NEMA): MG 1, Motors and Generators.
3.      Underwriters Laboratory (UL): 674, Electric Motors and Generators for use in Division 1 Hazardous
         (Classified) Locations.

1.02       SYSTEM DESCRIPTION

A.     Performance Requirements: Remove 95 percent of the grit greater than 50 mesh in size, 85 percent of
         the grit greater than 70 mesh but less than 50 mesh in size and 65 percent of the grit greater than 100
         mesh and less than 70 mesh in size, at the wastewater flow rate of 30 mgd (peak hydraulic flow) and
         grit characteristics specified.

1.03       SUBMITTALS

A.     Action Submittals:

1.      Shop Drawings:
         a.      Make, model, weight, and horsepower of each equipment assembly.
         b.      Manufacturer’s catalog information, descriptive literature, specifications, and identification of
                  materials of construction.
         c.      Detailed structural, mechanical, and electrical drawings showing the equipment fabrications and
                  interface with other items. Include dimensions, size, and locations of connections to other work,                      
                  and weights of associated equipment.
         d.      External utility requirements such as air, water, power, drain, etc., for each component.
         e.      Power and control wiring diagrams, including terminals and numbers.
         f.       Shop and Field Painting Systems Proposed: Include Manufacturer’s descriptive technical catalog
                  literature and specifications.
         g.      Anchorage and bracing drawings and cut sheets, as required by Section XXXXX, Anchorage
                  and Bracing.

B.     Informational Submittals:

1.      Manufacturer’s reference listing of previous installations as specified herein.
2.      Anchorage and bracing calculations as required by Section XXXXXX, Anchorage and Bracing.
3.      Manufacturer’s Certificate of Compliance.
4.      Certification that the factory-applied coating system(s) is identical to the requirements specified.
5.      Special shipping, storage and protection, and handling instructions.
6.      Manufacturer’s written/printed installation instructions.
7.      Routine maintenance requirements prior to plant startup.
8.      Performance test procedures and sample test log.
9.      Manufacturer’s Certificate of Proper Installation in accordance with Section XXXX, Manufacturers’
         Field Services.
10.    Operation and Maintenance Data: As specified in Section XXXXXX, Operation and Maintenance
         Data.

1.04       QUALIFICATIONS

A.     Manufacturer shall have provided similar systems for a period of not less than 5 years. Provide
         references for at least five installations as specified herein confirming such experience.

1.05       FACILITY DESIGN BASIS

A.     The structure and appurtenant facilities have been designed around the Mectan Grit Chamber by John
         Meunier, Inc. Equipment by other named manufacturers may require adjustments to the facility design
         and configuration to accommodate their system. Subcontractor shall be responsible for clearly identify
         such changes to Engineer in the Submittals for this section.

1.06       EXTRA MATERIALS

A.     Furnish, tag, and box for shipment and storage one complete set of special tools if required to maintain
         or dismantle unit.

B.     Delivery: In accordance with Section 01 61 00, Common Product Requirements.

PART 2          PRODUCTS

2.01       MANUFACTURERS

A.     Materials, equipment, and accessories specified in this section shall be products of:

1.      John Meunier.
2.      Ovivo, Jones & Attwood Products.
3.      Westech.
4.      WasteTech.

2.02       SUPPLEMENTS

A.     See supplements to this section for additional product information.

2.03       SERVICE CONDITIONS

A.     Total Wastewater Flow per Unit:
1.      Minimum (Startup): 3.5 mgd.
2.      Average Daily Flow: 12 mgd.
3.      Maximum 30-Day Flow: 14 mgd.
4.      Peak Hydraulic Capacity Required: 30 mgd.

B.     Grit Characteristics:
1.      Type: Typical municipal wastewater grit characteristics and quantities.

2.04       EQUIPMENT DESCRIPTION

A.     Grit Collection Mechanism:
1.      Consisting of a vortex type, nonaerated, grit removal mechanism; each complete with drive unit,
         mechanical gear head, paddle drive tube, and items necessary for a complete grit removal assembly.
2.      Capable of removing grit from raw wastewater and suitable for installation in a circular concrete basin
         as shown on Drawings.
3.      Mechanism shall have no moving parts below the water surface which require lubrication or which will
         be subject to wear or blockage.
4.      Drives, bearings, and support equipment for grit mechanism shall be supported by and readily
         accessible from a concrete walkway above the water surface as shown on Drawings.

B.     Grit chamber hydraulics shall incorporate a toroidal flow path enhanced by a slow vortex. Grit
         chambers incorporating the gravity principle are not acceptable.

C.     Grit Paddle Mechanism:
1.      Designed to promote removal of grit and assist in sweeping grit to a circular grit wetwell located within
         center of the basin.
2.      Grit moving across the bottom of the grit chamber shall be hydraulically scoured as the propeller
         blades pass over the moving grit and cause hydraulic currents to maintain the organics in suspension.

D.     Equipment below Top Slab: Removable through access hatch provided in basin cover as shown on
         Drawings.

E.      Grit Removal Mechanism:
1.      Axial flow pitch propeller driven by drive tube powered through a helical gear motor.
2.      Helical Gear Motor: Oil lubricated.
         a.      Output Speed: 13 rpm maximum.
3.      Spur-Tooth Bull Gear:
         a.      Enclosed in grease-packed heavy cast iron gear case.
         b.      Forged steel with minimum Brinell hardness of 200. Pinion: Cut from high strength normalized
                  steel.
         c.      Mounted on minimum 21-inch diameter turntable bearing.
4.      Bearing Life:
         a.      All Bearings of Drive Unit: B-10 bearing life of 50,000 hours.
         b.      Turntable Bearing Supporting Propeller Assembly: B-10 life of 20 years.
5.      Pinion and Bull Gear Service Factor: Five or greater.
6.      Gear Box: Sealed. Furnish air bell around bottom opening of drive tube to prevent water from entering
         gear box.

2.05       WELDING

A.     Welded connections subjected to submerged conditions shall be seal welded.

2.06       ACCESSORIES

A.     Lifting Lugs: Provide suitably attached for equipment assemblies and components weighing over 100
         pounds.

B.     Equipment Identification Plates: Provide 16-gauge Type 316 stainless steel identification plate securely
         mounted on each separate equipment component and control panel in a readily visible location. Plate
         shall bear 3/8-inch high engraved block type black enamel filled equipment identification numbers and
         letters.

C.     Anchor Bolts: Type 316 stainless steel, sized by equipment manufacturer, 5/8-inch minimum diameter,
         and as specified in Section XXXXX, Metal Fabrications. Coat in accordance with Section 09 90 00,
         Painting.

2.07       CONTROLS

A.     In accordance with general control requirements specified in Section XXXXXX, Package Control
         Systems.

B.     Grit system remote control and alarm monitoring provided by plant control system, furnished by others.

2.08       PAINTING

A.     Factory prepare, prime, and field finish coat with the following systems, as specified in Section 09 90
         00, Painting.
1.      System No. 2 for all submerged metal surfaces.
2.      System No. 4 for exposed metal surfaces with maximum operating temperatures not exceeding 200
         degrees F.

PART 3          EXECUTION

3.01       INSTALLATION

A.     In accordance with manufacturer’s written instructions.

B.     Anchor Bolts: Accurately place using templates furnished by vortex grit equipment manufacturer and as
        specified in Section 05 50 00, Metal Fabrications.

3.02       FIELD QUALITY CONTROL

A.     Functional Tests: Conduct on each unit.

1.      Alignment: Prior to facility startup, test complete assemblies for correct rotation, proper alignment and
         connection.
2.      Operate for a continuous 3-hour period without malfunction.

3.03       MANUFACTURER’S SERVICES

A.     Manufacturer’s Representative: Present at Site or classroom designated by Owner, for minimum
         person-days listed below, travel time excluded:
1.      One trip for 2 person-days for installation assistance and inspection.
2.      One trip for 2 person-days for functional testing, completion of Manufacturer’s Certificate of Proper
         Installation, and prestartup classroom or Site training. Training shall not commence until an accepted
         detailed lesson plan for each training activity has been reviewed and accepted by Owner.
3.      One trip for 2 person-days for facility startup, and post-startup training of Owner’s personnel. Training
         shall not commence until an accepted detailed lesson plan for each training activity has been reviewed
         and accepted by Owner.

B.     See Section 01 43 33, Manufacturers’ Field Services, and Section 01 91 14, Equipment Testing and
         Facility Startup.