SPECIFICATION
Name of Product: OFFLINE AIR cooled Hydraulic oil cooling unit with Filtration Technical data :
1) Oil circulating Pump Flow : 40 Ipm
2) Maximum system pressure : 10 Bar
3) Radiator cooling capacity : 4000 Kcal/hr
4) Return line filter capacity : 630 Ipm
5) Return line filtration : 10 micron
6) Cooled Oil outlet temperature : Between 40 to 45° C
Electricals :
1) Oil circulating Pump Motor : 1.5 HP Three Phase
2) Radiator fan Motor : 0.2 HP Three Phase
General :
1) Overall.dimensions ( L x B x H ) mt. : 0.85 x 0.65 x 0.63
Note :
1) Unit can be used with any Hydraulically operated machine requiring oil cooling system.
2) Return line filter is fitted with Clogging indicator to indicate / give alarm in case filter gets clogged.
3) In the system OIL preheating attachment can be fitted. When ambient temperature is below 25° C ( Settable ), heater will be ON, along with oil circulation pump. When oil temperature reaches above 30° C ( settable ), then after main machine can be started . This is as an OPTIONAL.
4) If main machine is not equipped with PLC, independent control unit is required for operation of this OFFLINE cooling unit. This can be supplied as an OPTIONAL.

COMPLETE SPECIFICATIONS
TITLE : OFF LINE AIR COOLED HYDRAULIC OIL COOLING UNIT WITH FILTRATION
FIELD OF INVENTION :
This invention relates to improvement in hydraulic ONLINE oil cooling and filtration system presently used in Plastics Injection Moulding machine. Its design concepts permits use with any type of Hydraulically driven machinery requiring Oil cooling system.
BACK GROUND :
In the Hydraulic Driven Machine, oil is used as a circulating media. When pressurized oil is
circulated through Valves, Pipes and Actuators, because of inefficiencies caused by the
internal leakages in various elements, throttling effect and friction, heat is generated.
In hydraulic system heat load is equal to the total power lost (PL) through inefficiencies and can be expressed as:
PL total = PL pump + PL valves + PL plumbing + PL actuators
Inefficiencies result in losses of input power, which gets converted to heat and increases temperature of oil. The rate of increase in temperature depends upon the Hydraulic circuit design, Selection of Hydraulic elements, System operating pressure, Pump type, Pump flow, Grade of oil used and Type of oil cooling system used.
If the total input power lost to heat is greater than the heat dissipated, the hydraulic system will eventually overheat. This has to be avoided to ensure smooth and efficient running of Hydraulically Driven machine

Depending upon type and grade of Hydraulic fluid used in the system, its optimal operating temperature range, filtration class and viscosity is recommended by supplier. Similarly for Sealing components used in the Hydraulic elements, Actuators etc. maximum operating oil temperature is recommended by seals manufacturer. Ideally it is
* Recommended temp, range 30° C to 50° C
* Max. Operating temp. 65° C
* Oil filtration Class NAS 6
So operation of any hydraulic system at temperatures around 65° C should be avoided as above this temperature most of sealing compounds gets damage and accelerate degradation of the oil.
Viscosity falls below the optimum value there by increases internal leakages in Hydraulic elements increasing inefficiency of system.
General trend is to use ONLINE water cooled heat exchanger, in which water is used as Heat transfer media. Depending upon the water quality, scaling problem occurs, which works as bad conductor. This results reduction in cooling efficiency thereby increasing oil temperature, which in turn deteriorate the quality of the oil. End result of all these deterioration in machine performance.
Secondly over a period of time Scaling can erode Copper tubes, there by puncturing the same allowing Oil and Water to get mixed up.
Thirdly high temperature can also damage Brazing done in the construction of water oil cooler, which can result into Oil and Water mixed up.
Above calls for immediate descaling of the copper tubes in the oil cooler and sometimes replacement of the oil if its viscosity has increase, oil and water has mixed up.
End result is long period of machine maintenance and financial burden if oil and seals are to be replaced.

As present system is ONLINE, Firstly the oil cooling and Filtration will be effective only when the machine is in running condition. Secondly oil flow through the oil cooler is not constant and varies depending upon setting / cycle time of machine. This hampers the cooling efficiency of oil cooler. Thirdly when ambient temperature is very low ( Less than 25° C, oil is thick hence viscosity is high which is not recommended by oil manufacturer ) it may be necessary to preheat the oil. With ONLINE system it is difficult as one need high capacity of heaters to be used.
Alternatively one can think of using OFFLINE water cooled heat exchanger. In this case oil cooling and Filtration can be in operation irrespective of machine in running, oil heating system can be easily provided BUT most importantly problems related to water SCALING still exists.
OBJECTIVES OF INVENTIONS:
To achieve stable fluid temperature a hydraulic system's capacity to dissipate heat must exceed its inherent heat load. There are only two ways to solve overheating problems in hydraulic systems:
1. Decrease heat load; or
2. Increase heat dissipation.
Decreasing heat load is preferred option because doing so increases the efficiency of the hydraulic system. However this purely depends on the machine design and selection of hydraulic elements.
Alternatively increasing heat dissipation system is preferred option for a given design of machine.
I have invented OFFLINE Air cooled Hydraulic oil cooling Unit with filtration.

BRIEF DESCRIPTION OF THE INVENTION :
The single line diagram ( Drawing no. OLOCFU - 001 ) along with its general Assembly (drawing no. OLOCFU - 002 ) is attached herewith. As shown in general Assembly drawing the OFFL|NE AIR cooled Hydraulic oil cooling UNIT with filtration, is assembled on a steel structure frame (11) which can either be fitted inside the machine base or can be kept outside the machine base.
It has got one Suction ( Inlet) and one Return ( Outlet) connection. Using hose pipes ( 6a and 6b) unit is connected with the main oil tank of the machine (10) Electric connections are terminated on one common socket which is to be plugged with main machine control panel.
As soon as circulating pump (1) driven by Electric motor (2) is started (irrespective of the main machine running) the oil gets sucked through hose pipe ( 6 a) from the machine oil tank and passes through oil cooling radiator having fins tube (7), 10 micron return line oil filter (4) and return back through hose pipe (6 b) to oil tank.
On the radiator cooling fan ( 9) is fitted which is driven by electric motor (8). When oil temperature in the machine exceed say 45°C (settable value) the radiator fan will start throwing forced air over the fins tubes, there by cooling the circulating oil through tubes. The cooling fan continues to run till circulating oil temperature drops to the temperature of say 40°C (settable value).
The return line filter has got almost 5 times more capacity than required design capacity, hence almost NO chance of its clogging. However still filter is fitted with Clogging indicator ( 5) to indicate/give alarm in case filter gets clogged.

When ambient temperature is below 25° C ( Settable ) oil is recommended to pre heat. I have selected heater for preheating. Along with oil circulation pump, heater also gets ON. When temperature reaches above 30° C ( settable ), then after main machine can be started. This OIL preheating attachment can be fitted as an OPTION.
All these functions are set through PLC and operation is automatic. By using this system oil temperature is maintained within the specified operating range thereby increasing its life and gives optimum performance of the machine.
In case main machine is not having PLC control, separate control box can be supplied which can be plugged with Main machine control panel. This is an OPTIONAL attachment.
As this cooling system is air cooled, the disadvantage of water scaling is totally eliminated thereby its maintenance related problem is avoided, secondly replacement cost of OIL is reduce.

I claim:
1. With the use of this unit the oil temperature in the Hydraulically operated machine is maintained within its optimal operating temperature range which in turn increases its working life and gives consistent performance of the machine.
2. As unit is capable of maintaining optimal oil temperature range and provides good quality Filtration, life of all Hydraulic elements and Actuators increase. End result reduction in maintenance efforts and down time of machine.
3. As NO water is used problems of Scaling and Copper cooling pipes getting punchered associated with water is totally eliminated. This reduces maintenance efforts, down time of machine and Oil replacement cost.
4. Depending on the weather condition the ON -OFF cycle for the air cooling, Oil Pre heating ( Optional) can be set to achieve optimum oil temperature.
5. The system can be operative irrespective of Main machine running.
6. The unit can be kept at any convenient place near the machine and easy to hook up with main machine.
7. As there is NO water requirement for Air cooling system, total water requirement for main machine operation is reduce.