 Key Features
- Adjustable Operational Parameters for Key Equipment
The control panel has been designed for simplicity. With this in mind we have provided external facilities for manual adjustment to operational times for the flocculant screw feeder and agitator. This enables an operator to easily vary the flocculant's strength by adjusting the run time length of the screw feeder in any batch cycle. As some flocculants requires slightly different agitation duration, agitation time of a solution can be varied as well by adjusting a similar timer adjacent to the screw feeder's.
For testing and calibrating the screw feeder's capacity for specific types of flocculant, a facility exists for an operator to run the screw feeder without the requirement of running other equipment or a batch cycle
- Fail Safe method Against Solution Contamination
The logic of the system ensures that solution in the mixing tank does not contaminate aged solution in the storage tank should a system fault or power loss occur. Following such an event, the interrupted batch cycle can not automatically re-commence if the operational mode still remains in 'auto'. The system shall remain idle until the mixing tank registers a low level when the contaminated solution is manually dumped.
Should the interrupted batch cycle still be required, manual override facilities exist within the system enabling continuation of the cycle, or dumping of the solution into the storage tank.
- Internal Tank Treatment
Our standard systems are provided with a single primer coat, two pack internal paint lining for the mixing and storage tanks for prolonged protection against rust contamination into the flocculant solution.
- Easy Loading of Bulka Bags into Bag Breaker Storage Hopper
As an integral part of the flocculant system the bag breaker hopper is supported from the main flocculant storage tank and platform, with the feeding system supported from the hopper.
The hopper is positioned such that a standard 25 kg flocculant bulka bag can be easily and safely lifted manually onto the storage tank access platform allowing an operator to simply lower a bulka bag onto the bag breaker assembly opening and emptying the bag into the hopper.
A meshed screen exists underneath the bag breaker assembly at the top of the hopper ensuring no bag or plastic pieces enter the hopper and flocculant feed system following the bag being broken.
- Ease of Lifting, Transport and Installation/Commissioning
The standard Polymix systems are built on a compact skid frame that is designed with RHS feet for fork lift handling rather than using cranes.
The system's compact design enables ease of transport and takes minimal room on site. It therefore also reduces site requirements for extensive installation and commissioning as the system is factory pre-assembled, wired and tested prior to shipment.
- Dosing Pump Package
As an optional extra to the standard system, various dosing pump packages can be included with the system that can range from:
- Supply of dosing pump only.
- Supply of dosing pump and stand alone VVVF drive unit for installation into a site MCC.
- Supply of dosing pump dry run protection probe for the storage tank.
- Complete dosing pump package including an integrated pump control panel local to the flocculant system housing a VVVF drive unit and dry run protection with power and signal references looped through the main flocculant system control panel.
- Pneumatic Feeding System and Venturi Heated Flocculant Feeding Cone
The flocculant powder is conveyed into the mixing tank through a simple, low pressure lean phase pneumatic transfer system through steel piping. The flocculant is metered from the storage hopper through a small centreless auger at a fixed rate and presented to the lean phase air stream through a small feed cone. The feed cone has a heated internal skin ensuring no condensation forms on the flocculant as it enters the air stream.
As the flocculant powder enters the air stream, at the throat of the heated feed cone, it is drawn in by the venturi assembly attached to the heated cone throat. At this stage the flocculant powder is conveyed pneumatically up into the mixing tank for agitation with water into solution form.
- Simple Process, Power and Reference Signal Connection
The standard fully automatic Polymix systems are supplied to site with only three process connections required. Three phase power supply and external signal referencing is connected to the main control panel, which provides the dosing pump control package if required as well. Process water is connected to one terminal point on the system's water supply piping on the mixing tank.
This makes site installation to power and water a simple and easy process.
- Control Flexibility
Our standard systems are provided as full relay or PLC automated systems with the ability for site DCS referencing and monitoring. However we have custom designed systems to suit requirements for external control by simply marshalling associated instrumentation and power for the system to a common point for external control to be achieved.
- Flocculant Powder Wetting Head Assembly
Prior to entering the mixing tank, the flocculant requires being wetted to ensure thorough dilution into the process water during agitation. The 'Wetting Head' assembly achieves this by simply spraying process water within a clear plastic tube at pressure in a annular ring around the flocculant powder being introduced into the middle. The flocculant and water therefore mix in this chamber, pre-wetting the powder sufficiently for effective dissolution into the agitated solution.
The Polymix systems utilise the wetting head as the sole source of process water supply into the mixing tank.
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In Brief
- The combination of Transmin's bulk material handling expertise and the technical knowledge of some of the worlds largest manufacturers of polyacrylamide flocculants, has resulted in the development of a range of fully automated 'Polymix' flocculant preparation systems.
- The Polymix range exists of four standardised systems designed to cater for the most commonly required capacities. These are the Polymix 1000, 2000, 4000 and 8000 systems, relating to their prepared flocculant solution output capacity in litres per hour. Each system has identical standardised control and mechanical design philosophies with tank and equipment sizes and capacities.
- This high degree of standardisation reduces delivery lead times and allows high spares inventory support.
- Units are fully modularised on a single integral base for ease of movement. Each system consists of the mixing tank mounted on top of the larger storage aging tank as well as the dry flocculant powder loading, storage and pneumatic feeding system. All pneumatic and process water piping, fittings and instruments exist as an integral part of the modular system package.
- Various optional flocculant dosing pumps and control packages are available as part of this system if required.
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Bags of dry polymer (25kg) are manually emptied into the modular feed hopper on the bottom of which is a tubular screw feeder. This withdraws the polymer and delivers it to the heated eductor feed cone where it is pneumatically conveyed by a dilute phase blowing system to the wetting head located above the mixing tank.
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The wetting head has a set of full cone sprays, which wet the individual polymer particles as they are discharged from the blower tube. The resulting solution, free falls into the mixing tank where it is agitated for a minimum of 30 minutes to prevent agglomeration of the polymer and to enhance uncoiling.
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On completion of the mixing cycle, the solution is discharged into the storage tank via a dump valve where it is retained for further aging whilst another batch is mixed.
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When the second batch is complete this also is emptied into the storage tank which has been designed to minimize the mixing of fully aged and partly aged polymers.
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A third batch is then mixed and on completion is also dumped, however with little capacity remaining in the storage tank, most of the solution remains in the mixing tank. At this point the first batch of polymer is fully activated and the dosing pump can be started. As the solution is withdrawn from the storage tank, the level in the mixing tank drops until the level sensor detects an empty tank, the dump valve is then closed and a new batch of polymer started.
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An optional low level detection is available in the storage tank above the pump suction nozzle to assist against the dosing pump running dry.
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Larger systems can be supplied for specific projects utilising similar control, process and design philosophies as the Polymix systems.
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In conjunction with SNF (Australia) P/L Transmin can also supplier a range of FLODOSE automatic sampling systems to monitor flocculant mix being produced by the Polymix unit - click here to download a data sheet.
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Benefits in using Transmin Polymix systems:
Simple modular construction and efficient design ensures easy maintenance, fault finding, parts replacement and reliable operation.
Automated control with minimal operational involvement other than loading bulka bags into the storage hopper at pre-set frequencies.
Remote monitoring of system is easily connected.
Safe and easy hopper loading bag breaker with bag loading bay and access ladder to the hopper inlet.
Sensible layout and design results in minimal splashing of slippery and potentially dangerous flocculant solution, with platform layouts enabling an easy and safe wash down for tank surfaces. Efficient spatial design of system ensures minimal plant room is taken up.
All mechanical equipment is sufficiently rated for external operation, and is sufficiently shrouded from flocculant wash down.
Optional sized flocculant dosing pumps and control packages with dry run protection if required.
Main control box exists on the flocculant access platform as an integral part of the modularised package, providing easy access and observation of system control.
Simple external operator adjustments for required equipment control exist on the main control panel as well as a fail-safe emergency stop facility.
Installation via single power, instrument and point process water inlet.
Blower ducting is joined by simple couplings for flexibility of installation and easy pipe removal for maintenance.
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