HO Series Oil-Free Air Compressor

History of scroll compressor
The principle of scroll compressor had been mentioned in Italian patent literature as early as 1886. French engineer Creux officially presented the principle and structure of scroll compressor in 1905 and applied for United States Patents.
Scroll compressor is a kind of positive displacement compressor with features of tight structure, high efficiency, strong reliability and low noise etc., which is especially applicable to frequency conversion control. However, as there is no numerical control machining technique and lack of proper solution for axial force balance, scroll compressor cannot be put into production for a long time. In 70s, A.D.L Company achieved fruitful researches, firstly settled the sealing technique for wearing compensation on scroll plate ends and cooperated with Switzerland to develop types of scroll compressor samples.
Large scale production of scroll compressor started from Japan. In 1981, SANDEN Company started to produce the scroll compressors for automobile air-conditioners. In 1983, Hitachi Company started to produce 2~5Hp scroll compressors for room air-conditioners. Besides, since Copeland Company built scroll compressor production lines in 1987 and started to produce scroll compressors in United States, Carrier, Trane, Tecumseh and other companies started to built factories to produce high-quality scroll compressors. By now, oil-free scroll compressor has been extensively applied in all high-end application fields due to its excellent performances, energy conservation and environmental protection and has been the development trend of total oil-free air compressor.
Operating principle
TOTAL OIL-FREE SCROLL—A BREAKTHROUGH IN COMPRESSION TECHNOLOGY

Bright spirals are for fixed plate and gray spirals are for movable plate. Red represents intake chamber, blue and green represent the crescent compression chamber covered by two spirals, and the yellow in the middle represents the compression exhaust chamber covered by two spirals. The red intake chamber will enlarge with the compression, while the blue and green compression chambers are shrinking, and the area of yellow compression exhaust chamber is becoming small as well. Gas is compressed from sides to center and finally discharged from the exhaust hole on fixed plate.Internal Structure Diagram
Simpler and tighter space design, convenient for maintenance.

Above figure shows the structure diagram of HO-0025 2.5/7 (4×5.5KW)
Operation Flowchart

Internal Structure and Flowchart
When the oil-free scroll air compressor (hereinafter referred to as compressor) runs, the air is sucked by the compressor and then exhausted after compression. Except for volume contraction and pressure rise, the air temperature rises as well. Therefore, the air will be discharged to air collecting buffering pipe after cooling by compressed air radiator and then flow to external air cylinder for air supply.
True total oil-free air compressor
As there is no metal contact between compression scrolls, no grease lubrication is needed in compression chamber. Consequently, the operating principle of the scroll compressor ensures high-quality oil-free compressed air. The head of the scroll compressor is driven by couplings, and thus, gearbox is not required any more. Thus, Hipower HO series compressor will be oil-free air compressors forever, and the pipelines of the air compressor are made of stainless steel materials. 
New industrial standards
Your crucial technological processes need oil-free compressed air. The compressed air standard ISO 8573-1 was altered in 2001. A new stricter grade was added based on original five grades: ISO 8573-1 CLASS 0. Meanwhile, much comprehensive and stricter test ways were determined.

Grade	Existing Form of Oil (Oil Mist, Oil Drop, Oil Steam) mg/m3
0	Specified by users or suppliers, stricter than Class 1
1	＜0.01
2	＜0.1
3	＜1
4	＜1

Strictest air purity grade
1. Oil mist
Slight oil drops suspending in the flow
2. Oil drop
Liquid oil extending along pipe walls
3. Oils steam
Gaseous cloud-shaped oil
Most manufacturers prefer to “partial flow” test method which only tests the central part of the flow. Hipower HO series oil-free scroll compressors use stricter “full flow” test method that tests the oil mist, oil drop and oil steam within the whole flow range. Although such strict test has been made, no oils are found at the outlets of the compressor.
Advanced monitoring and control system
All HO series oil-free air compressors are equipped with advanced monitoring and control systems which could enable to compressor to adapt to user’s air consumption requirements to the largest extent when air consumption changes. It’s able to implement automatic control over the start and shutdown of each scroll compressor head via the controller to extremely accurately meet your demands for compressed air. The algorithm of the controller ensures the exhaust pressure within a narrow range, forces the compressor to keep highest efficiency and guarantees steady system pressure. Moreover, the monitoring and control system also provides digital display setting and control parameters to display the operating state of the compressor. Such parameters could be adjusted on the panel directly as system requirements. Simple operation interface, multifunctional fault self-diagnosis and record will greatly reduce the costs for air compressor system management.
Humanized operation panel
Concept of forced frequency conversion
Concept of forced frequency conversion, automatic head switching, reduction of energy consumption, prolonging of service life
The range of HO series oil-free scroll compressors could extend to 55KW. It’s able to maximize the advantages and flexibilities of modular design after integrating 2 to 9 scroll compressor heads on a soundproof hood. Hipower HO series multi-head controllers could continuously monitor and control the start and shutdown of each scroll compressor head; therefore, they could make sure that the compressed air displacement matches with user’s air demand.
Ø Realize optimal running and energy conservation via multi-level control.
Ø Multi-level control has the energy-saving performance better than frequency conversion control.
Ø Restrain power consumption greatly and have perfect energy-saving effect.
Take HO-0036 3.6/7 (6×5.5KW) as an example:
When the air consumption is small, 1-6 compressor heads will run in an energy-saving manner automatically.
When the air consumption is large, the 6 compressor heads will run in full power automatically.
Low energy consumption
HW series oil-free air compressors are high-efficiency. As simple start/stop control is adopted, there is no loss from unloading power. The machine type higher than hW-1.2/7 uses variable flow control technology which could match the compressor displacement with the air demand.
Total oil-free scroll air compressors are well-known air compressors with highest EER. Electric charge is the largest cost for air compressor running.The scroll air compressor has higher efficiency than piston, screw, sliding vane and other traditional air compressors due to its principle advantages.
Unique muting and site type concept
Total oil-free scroll air compressors have broken the common awareness of compressor and are named as the fourth-generation air compressor in the world, which will create clean, quiet and comfortable environment for you.
Ultra-strong muting, no vibration sense
The characteristics of scroll compressor determine that HO series oil-free air compressor has unique muting.
Ø There is no contact between the dynamic and static scroll plates, the whole compressor contains no wearing parts, and the vibration produced is slight.
Ø Scroll air compressor contains few main engine parts, that is, 1/8 of the quantity piston compressor. The great reduction of parts quantity is a crucial factor for reliability promotion.
Ø The turning radius is small and the linear speed is only 2m/s. Therefore, the compressor owns small wear, high mechanical efficiency and small vibration.
Ø As the compressor contains no inlet valve, exhaust valve and complicated running mechanism, the knock from the valve plate and blasting of flow are avoided, due to which the noise reduces sharply.
Ø The air inlet and outlet are steady and 6000r/min, which causes slight flow pulsation.
Ø One 20HP scroll air compressor could only produce 63dBA noise, owing to which it could be installed at any place, save a large amount of installation cost and meet environmental protection requirements much.
Ø The scroll compressor head is directly driven by coupling, due to which it’s much quieter than belt connection.
Ø The whole system with scientific control could ensure the promotion of stability.
Unique muting (as quiet as automobile and library)
Small vibration. The coins standing on the top cover could maintain standing state during operation.
Site type concept, nearby air supply
HO series could be laid in any production sites to offer the compressed air solution with the best efficiency and help you to save energy and cost.
HO series compressors produce the noise lower than any other compressors, could be laid in the production workshop, produce less disturbances to workers and omit the special room for the air compressor. They could be laid at any convenient places due to the low noise feature, and it’s needless to lay the air compressor at the site far from the building in order to isolate noises. In this way, not only the building costs and long-distance air pipe installation costs are saved, but also the disturbance to neighbors and the company is avoided. Moreover, it’s able to increase the compressed air supply arbitrarily and conveniently with company development. (Definitely, the compressor shall be far away from heat source and dusts etc.)
Realize onsite directly air supply
oil-free air compressor
Muting site type, save pipelines, realize nearby air supply
Traditional air supply environment
Extremely low maintenance cost
Lowest maintenance cost, fewer main engine parts, fewer wearing parts, great reduction of parts replacement possibility. Long parts replacement cycle, convenient for operation, few maintenance amounts.
Ø As no lubricating oil has to be filled, the exhausted gas contains no oil, which eliminates the bad effect on production process caused by oily gas, avoids the pollution to user’s final products and could meet special requirements from food industry, pharmaceutical industry and other special fields.
Ø As the compressor uses no lubricating oil, no bad effect caused by lubricating oil solidification will occur during low-temperature engineering.
Ø As the gas contains no oil, the possibility that the oil stains will deposit on the pipe wall of heat exchanger is reduced and eliminated, which improves the heat transfer efficiency and reduces gas resistance loss.
Ø It’s able to cancel the lubricator, oil separator and other equipments, and it’s even needless to install degreasing filter on the main pipeline. Therefore, the system resistance is greatly reduced, and the operating efficiency improves greatly. Due to the reduction of equipment, the processing costs reduce compared with the scroll compressor with lubricating oil.
Ø It’s able to save a large number of lubricating oils. One high-pressure circulator could save 3600kg lubricating oil every year, and thus, it could save more resources and is much environment-friendly. Besides, under current circumstance that the price of petroleum resources is rising, such compressor could reduce operating costs and promote the economical efficiency of the oil-free scroll compressor.
Ø As the stuffing box made of self-lubricating materials with sealing elements are used, the heavy scraping to original metal stuffing box could be avoided basically. Moreover, the overhaul work amount reduces greatly and the labor intensity lowers down as well.
Ø Ideal oil-free lubricating compressor. As the friction coefficient of the sealing friction pieces is low, the service life prolongs.
Ø The medium to be compressed in the oil-free lubricating scroll compressor will not oil-gas mixture any more. The analytic target in thermal process is pure gas. It’s able to suppose the medium to be compressed as ideal gas, and thus, the operating efficiency of the compressor improves.
As the scroll air compressor contains no wearing parts and has excellent unit performance and reliable automatic control, what has to be done by users is to sweep the filter screens at two sides, replace the filter elements and add lubricating oil to bearing as provisions, after which you could use the scroll compressor without worry. It’s unnecessary to pay extra costs (such cost will be a large amount after a long time) for the replacement of wearing parts like other air compressors, and on the other hand, it’s able to avoid the economic loss caused by production stagnation due to fault shutdown.
Standby concept, continuous air supply for ever
In case faults occur, the multiple compressor bodies equipped in the crate will start backup running, based on which you do not have to worry about the air supply stop.
Performance parameters
Ø There is no grease in the compression chamber in the main engine; thus, the compressed gas will be clean, pollution-free and oil-free truly.
Ø The energy efficiency of a single compressor head is higher than 90%, saving higher 15% energies compared with other machine types with the same power.
Ø Multi-head forced frequency conversion, automatic head switching, prolonged service life.
Ø Standby concept, continuous air supply for ever.
Ø Low noise, available for nearby direct air supply, save the costs for pipeline layout, reduce energy loss during transfer.
Ø Extremely low maintenance costs, only normal maintenance and cleaning to compressor filter needed.
Ø Box-type structure, volume smaller than 1/3 overseas same type products.