Turbine Distributor
The water turbine distributor is positively driven by the weight of water collected in the turbine and eliminates the use of syphon chambers and the difficulties associated with syphon domes. The equipment is therefore most suitable for small rural treatment works since frequent attendance and maintenance is not required.
Given that adequate hydraulic head is available the machine can be installed on conventional circular distributor beds.
The distributor comprises a central bearing housing fixed to a concrete or brick support structure. A turntable with a vertical shaft is retained within the housing; comprising bottom ball thrust bearing and a top ball journal bearing.
The distributor is mounted on the turntable with the arms true and level.
The central turbine shaft is supported within the basin by a large ball thrust bearing, having nylon housings. At the top a nylon spherical journal assembly locates the turbine in its tilted elevation and is fixed by means of a bracket and retaining rod supported from the overhead feed pipe.
The top inlet feed chamber rotates with the machine basin and the outlet from this chamber is maintained in the same relationship with the offset turbine thrust housing, always discharging water into an elevated turbine compartment.
The filling of these turbine compartments with water provide the out of balance loading onto the eccentric positioned bearing housing. This can best be described as a walking stick type drive to rotate the basin.
Two open trough arms are provided with v-notch overflow weirs, spaced along each arm, staggered to evenly distribute the liquor over the filter bed media. The arms are supported by solid rods that will maintain level arms at all times. The arms cannot be choked, as with conventional arms. The open trough arms obviate the need for cleaning on a frequent basis to maintain performance of the distributing machine.
Waterwheel Distributor
The waterwheel driven distributor has been developed to help limit the time consuming visits by operative staff to small rural works and to eliminate the difficulties often caused by syphonic controlled dosing chambers.
Given that adequate hydraulic head is available the machine can be installed on conventional circular distributor beds.
The distributor comprises a centre column, supported on a duckfoot or equivalent under bed pipework arrangement with a basin surrounding the column and suspended via four rods from a top fulcrum bearing.
The basin has a short central inner tube, which is sufficiently tall as to prevent any central leakage of effluent. The outer wall of the basin is much higher and surrounds the drive wheels.
From the upper rim of the basin is fixed G.R.P. quadrant covers to prevent snow or other substances from causing problems in the basin.
The two waterwheels are pivoted from a bracket fitted to the central column. On the end of the wheel is a knurled aluminium wheel and this rotates on the rubber drive support ring which is retained by an angle fixed to the inner wall of the basin.
Effluent is discharged onto each waterwheel by discharge arms bolted to the side of the central column.
On the underside of the basin are three wind pressure pads to centralise the basin and to steady the basin in rotation.
From the basin two open trough or tubular arms are fixed spanning the diameter of the filter bed to evenly distribute settled liquor over the surface of the filter bed media. The arm level is adjusted after installation to give practical equal distribution of flow over the bed. Galvanised vertical and horizontal wire ropes support the arms.
The design principles are:
- That flow can be fed to the distributor at the rate at which it enters the works under gravity conditions or pumped flow. The feed arms at the central column discharge water to the two waterwheels via a two or three-stage overflow weir configuration. The low flow weir and the intermediate weir drive the waterwheels. The third weir (not applicable to the 100 dia. machine), overflows directly into the basin and therefore provides a restricted maximum flow discharge to the waterwheel, hence providing a controlled maximum speed of rotation for the machine.
- The arms cannot be choked, as with conventional arms. The large weir box openings obviate the need for cleaning on a frequent basis to maintain performance of the distributing machine.
- To reduce as far as possible on site mechanical maintenance. Waterwheel units are designed as hand removable 'Pods' so that replacement and maintenance can be made easy or undertaken in workshop conditions.
Syphonic Distributor
The syphonic filter distributor is suitable for use on new and existing circular filter beds. Flow to the machine is via a feed pipe from under the filter bed, into the central support column. Transfer of the influent from the stationary to the moving part of the machinery is through syphons fitted to the centre column referred to as ‘pending arms' and as such, no water seals or glands are required.
This machine utilizes a number of wind pressure pads fitted to the basin, which act as a steady bearing. They can be adjusted and locked into position.
The central basin, into which flow has been transferred, is supported by rods from the oil-filled top fulcrum bearing, designed for a low resistance to rotation and capable of correctly aligning itself to the out-of balance loads which occur during operation.
From the central basin are connected four distributing arms in a cruciform layout, supported by steel ropes taken back to the upper part of the centre column and stabilised laterally with steel wires from the adjacent arm.
The flow within the arms is distributed onto the filter bed through plastic 'venturi' shaped nozzles which are spaced along the tube providing equal distribution per unit area of the filter bed. The discharge from the nozzles also provides the driving force on 'jet reaction' machines.
The weir plates set within the central distributing basin divide the arms into two groups; 'high-flow' and 'low-flow' thus, on low flows only two arms will be discharging. As and when the volume of flow increases, the high-flow arms will discharge. It has been demonstrated that this method provides better distribution under low-flow conditions and hence an improvement in treatment standards.
The main components of the machine are manufactured in cast iron with steel central basin. The design of the machine is simple in concept, producing a robust, well-engineered machine, manufactured and protected to give a long and functional life.
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