Rotajet Fron Loading Spray Washers

Rotajet manufacturers the D series of front loading spray washers, the machine can be supplied as single stage spray washers, two stage spray washers for washing and rinsing or three stage washing, rinsing and final rinsing for metal treatment or NDT applications.

There are 8 machines is the Rotajet “D series” range, ranging from the smallest D24 spray washing machine typically used for cleaning small components to the D108 used for washing large diesel engines etc….

Specifications:

Material of construction:

Rotajet can manufacture the “D series” of Rotajet front loading spray washing machines from mild steel.
Mild steel is typically chosen for single stage alkaline cleaning applications.

Method of cleaning:

Dirty Components are placed in a workbasket forming part of an integral wheeled frame that may be located on a trolley or fixed platform fitted with rails designed to align with rails located within the Rotajet spray washing machine.  The loaded basket is then manually wheeled into the wash cabinet and the machine door is closed.  The washing cycle will commence on pressing the green start button.  Washing is achieved by direct and indirect (ricochet) impingement of a high volume of solvent or hot (70-80° C) inhibited aqueous detergent solution delivered at a nominal 5 to 6 bar* pressure from all sides, below and by means of reciprocating spray arms containing jetting with a V pattern, set in line such that the sprays merge to provide all round coverage of the wash area. On completion of the wash stage of the process cycle the cleaning solution is recirculated to source via removable (for cleaning) perforated metal filter basket by means of a pneumatically actuated, pivoting shed plate located in the liquid return passage.  After the pre-set drain period has timed out, the shed plate bias changes to the rinse side and on proving, the rinse pump is activated. At the process cycle end the extraction fan is automatically energised to create a negative atmosphere within the wash cabinet to assist natural thermal draught to clear it of steam. After a pre-set timed drain and extract period, interlocks are negated allowing the door to be opened. Components may then be removed from the machine to flash dry.

Machine Construction:

Cabinet & Liquor Tanks

The Rotajet “D series” spray washing machines are robustly fabricated from either heavy gauge mild steel plate,  to form the wash area located above two heated liquor sumps. Cleaning solution is drawn from the sumps by separate close-coupled centrifugal type pumps feeding common internal pipework as required by the control circuit. After impinging upon the components, each solution is returned to source via removable perforated metal filter baskets by the use of sloping and pivoting shed plates. Blanked off water infill tapping’s are provided in each sump to facilitate plumbing in. Fitted to each sump are a 1" bsp gate type drain valves and a large hinged door that together with the sloping bottom construction facilitates clean out.

Insulation

Where practical, the outer surfaces of the Rotajet spray washing machine are insulated with 30mm thick mineral wool lagging, held in position and protected by an outer skin of steel sheeting.

Effluent Discharge Pump (optional)

Where it is necessary or desirable to containerise spent cleaning solutions, a built in sump emptying pump complete with its own ancillary sump, valving and pipework is available, on multi-stage machines this facility can be used for transferring solutions between sumps in addition to emptying.  Controls for this unit are located the control panel and interlocked to prevent use when the main pump is running.

Heating Electric ( optional, used for water based systems.)

Multiple 6 kW. stainless steel electric immersion type heaters are fitted to the sumps with a general adjustable thermostat control for each sump. (For rating see schedule) Where the Rotajet spray washing machine is to be employed on short cycle continuous processing of heavy masses of cold metal, extra heaters may be fitted to compensate for the extra heat losses that will occur.

Low Water Heater Element Protection (optional, used for water based systems.)

Low water level safety devices are incorporated into the control circuit of the Rotajet spray washing to prevent damage to the heating elements, an indicator light located in the panel door will illuminate on low water condition. If low water condition is reached during cycle, the machine will stop.

Door Pneumatic

The Rotajet spray washing machine is fitted with a pneumatically actuated vertical sliding door located at the front as standard. Interlocks are provided to prevent the door from being opened during the machine operating cycle and to prevent the pumps from operating when the door is in the open position. Operation of the door is by a spring to centre 5-port lever valve so that release of the control lever immediately stops the door movement, retaining it in its achieved position. A second press button valve is inserted in the exhaust line to the lever valve so that two-handed operation is required to operate the door. The door is fully insulated in a similar manner to the cabinet to prevent heat loss during cycle.  Optionally, two pneumatic doors may be fitted to facilitate through, in line production or shuttle operation.

Pumps and Jetting

Close-coupled centrifugal type pumps are fitted to all  Rotajet front loading spray washing machines, (rated as shown in the table on the schedule page.) pumping into mild steel pipework to feed the rotating spray arms inside the cabinet. The rotating spray arms are fitted with removable spray jets to give a working pressure of approximately 5.0 to 6.0 bar*. The jets have a Vee spray pattern, set in line so that the sprays converge to achieve maximum coverage of the wash area when the spray arms rotate. The whole of the rotating pipework is easily removed for maintenance

Lower Spinner Assembly Reciprocating

An externally mounted rack and pinion assembly, actuated by a pneumatic cylinder to give reciprocating rotational drive is fitted. Controls are designed to park the spray arms in a clearance position at the cycle end so that the workbasket traverse path is not obstructed.  The benefits to be gained by this arrangement are:

1) Positive control of the spray arm rotation speed ensures maximum possible cleaning efficiency.

2) Alternating directional motion eliminates shading that can occur with single directional rotation when cleaning components of certain configurations.

3) 1 + 2 = Efficient cleaning results achieve in shorter cycle times

Extraction Fan

A bifurcated steam extraction fan is fitted to the top of the Rotajet front loading spray washing machine cabinet, fully wired into cycle during the machine manufacture to give the correct sequence of operation to assist natural thermal draught to clear the cabinet of steam when the door is open and to minimise heat losses during cycle.  The fan is actuated at the commencement of the drain time out period and will run continuously until the next cycle start unless deliberately stopped.

Filtration (Option to fit fine particulate filtration to the delivery side of the wash pump)

All Rotajet front loading spray washing machines are fitted with coarse filtration baskets on the fluid return side, filtration on this side is necessarily coarse since fine mesh filters can quickly blind up causing pump starvation. Optionally, in line fine particulate filtration may be fitted to the delivery side of the pump consisting of a free standing upright cylindrical vessel measuring 380mm. dia. x 1066mm. high containing three 762mm. long x 100mm. dia. perforated metal sleeves into which washable /renewable, graded polypropylene sock type filter elements are fitted.  Washable element grading’s range from 800 micron down to 100 micron.  Renewal felt elements will filter down to 10 microns. Fitting of in line filtration ensures that particulate is not recirculated to block spray jets and/or, re-deposit on the components, ensuring maximum cleaning efficiency is maintained at all times. The filter also prevents abrasive substances from entering the spinner arm bearings which are pressure lubricated by the cleaning solution, thus ensuring maximum life for these items and generally keeping maintenance requirements to a minimum.

Controls & Gauges

A fully wired control panel is provided housed in an IP66 electrical enclosure containing all fuses, contactors, relays timers etc. The panel is mounted on the left hand side of the Rotajet front loading spray washing machine near the front as standard; any other preferred position should be clearly notified with order. A suitably rated electric isolator is provided, interlocked with the control panel door.  The machine control buttons and sequence indicator lights are all mounted on the control panel door. Gauges to indicate the working spray pressures and temperature in the sump are provided, mounted to the front of the machine.

We can either, Allen Bradley, Mitsubishi or Siemens PLC 

You can find some applications in which the Rotajet Spray Washers are used below: