Low Head Cloth Washing Machine
The low head Cloth Washing Machine will be designed to operate under the following conditions:
- Spray Pressure: 40 – 70 Bar
- Longitudinal Traverse Speed: Variable
- Washer Traverse Speed: Variable
The washing machine will be manufactured as a robust mild steel fabrication construction from rolled steel sections and flat plate. The carriage will be designed to run in conjunction with the linked plate separation system.
Twin hydraulically driven screws, locating each plate gap by means of proximity switches, will achieve the longitudinal traverse. The Wash Traverse will be driven from a hydraulic motor coupled to a 12 mm pitch lead screw. The carriage will be attached to a phosphor bronze nut to pick up the lead screw drive.
The raising and lowering of the spray arm is a mechanical function using a system of levers with a cam follower and guide. Such that the traverse of the spray carriage across the press will mechanically locate the spray arm in its correct position for washing.
The spray arm will be manufactured in 304-grade stainless steel and will be fitted with Delavan Nozzles Type LD5-40. The water supply will be connected to the spray arm using a high-pressure swivel coupling and suitably rated flexible 1” nom bore wire braided hose.
All switches are of the inductive type. Proximity switches fully encapsulated to IP67. The switches will only sense metals and will ignore water droplets. Each switch will be fully wired to a junction box mounted on the machine.
CLOTH WASH FEED PUMP
The water pump set has been designed specifically for use on a filter press unit. It incorporates a 3/2 way co-axial valve, which can be remotely operated so as to stop the flow of water to the filter press and return it upstream of the pump suction line under no pressure, thus reducing power consumption of the pump set, whilst flow and pressure to the filter press is not required.
Due to the cyclic discharge of a positive displacement pump, a discharge dampener is also fitted in the discharge line to reduce peak pressures to the filter press. When maintained at the correct “charge pressure”, these dampeners are very effective. A loss in “charge pressure” may result in excessive vibration in the discharge line.
System pressure is obtained by correct sizing of the discharge nozzles, excessive wear of these nozzles will result in a loss of pressure in the system. To protect the system from over pressure, a pressure regulating and a relief valve are fitted to the pump discharge head.
The pressure regulator is used to accurately control discharge pressure, which may otherwise increase if too small a nozzle was used. The discharge of excess flow from this valve may be piped back to the header tank depending on the backpressure imposed on the valve. The relief valve is purely an over pressure safety device and must only be piped to drain.
The pump system is rated at 70 bar maximum working pressure and will generate 360 L.P.M. To ensure no cavitations a water supply of 1.5 times discharge flow is required, i.e. around 500 lpm at positive pressure, ideally around 1 bar which enables the electric motor to start under no load conditions. The hydraulic control valves are operated by solenoids that are in turn controlled by proximity switches. A drain plug is provided for draining the hydraulic oil tank during an oil change. A suction strainer is provided to protect the hydraulic oil pump against debris. Full flow oil filtration is provided which features a visual condition indicator. The first fill of hydraulic oil is included.