ESV+-TMA Two-Stage PM VSD Screw Air Compressors

Two-stage compression is nothing new, but turning it into a complete series that runs from the low twenties of kW all the way past three hundred kW, while holding steady efficiency and reliability, tests a manufacturer's airend design capability and manufacturing process. For the user, a product where "one series covers multiple power steps" makes selection, spare parts and O&M easier to standardise.

The ESSENCE ESV+-TMA two-stage high-efficiency PM VSD screw air compressor is just such a wide-span model. Its power range is 22–355kW, air delivery 1.16–73.00m³/min and working pressure 0.7–1.25MPa, with air outlets available in flange DN80 and flange DN100. ESSENCE is a wholly owned subsidiary of Fusheng Group, and its products are backed by the group's technical depth and service system, with efficiency and energy performance as the focus. The units use PM VSD starting, with voltage/frequency coverage of 220/380/415/440V and 50/60Hz to suit different regional power grids.

The Efficiency Logic of Two-Stage Compression

Air heats up as it is compressed; the hotter it gets, the harder it is to compress further and the more energy it takes. Two-stage compression introduces cooling between the two stages, so the air enters the second stage at a lower temperature and smaller volume, reducing overall compression work. This logic pays off most clearly at higher pressures and higher power — which explains why higher-power models tend toward a two-stage structure.

From 22kW to 355kW: One Series for Multiple Steps

The most visible feature of ESV+-TMA is its span. It covers continuously from 22kW to 355kW, with air delivery extending from 1.16m³/min to 73.00m³/min. For companies with multiple production lines and workshops, choosing different power steps as needed within the same series keeps control logic, maintenance practice and spare parts types consistent, and lowers the cost of training O&M staff. Of course, a wide span also means that frame sizes and port sizes differ between power steps in the same series, so selection still needs to follow the parameters of the specific model rather than the series range in general terms.

PM VSD and Coupling Drive

The units use PM VSD starting, with speed adjusted continuously to air demand — as much air as is used, so much power is consumed — avoiding the no-load waste of load/unload cycling on fixed-speed machines; the soft-start characteristic also reduces the impact on the grid. The drive is coupling drive, with a direct power transmission path and few routine maintenance items. Aftercooler outlet temperature is held within ambient + 15°C, easing the load on downstream drying and filtration equipment. For a company running continuously, these details add up to the stability and maintenance cost of the equipment over the long run.

Specifications at a Glance

Two points in the table stand out: one is the 355kW power ceiling, enough to cover the centralised air supply needs of a large compressor station; the other is the 1.25MPa pressure ceiling, giving a wider range of application than the common 0.7–0.8MPa models. Bear in mind that within the same series pressure and air delivery trade off against each other — the higher the pressure, the smaller the available air delivery usually is — so the usual pressure should be fixed first. In addition, air outlets come in flange DN80 and flange DN100, making it easy to connect to plant piping networks of different scales and reducing piping adaptation work during retrofits.

Who It Suits

• Large compressor stations and centralised air supply: the high power ceiling can replace several smaller units running in parallel;
• Manufacturers with multiple production lines and workshops: one series covers several power steps, simplifying unified management;
• Processes needing higher pressure: the 1.25MPa ceiling covers a wider process range;
• Companies sensitive to electricity costs and running continuously: PM VSD and two-stage compression together lower running energy consumption.

Selection Advice

1. Confirm total air demand and pressure first: for a large station, calculate from actual working conditions rather than estimating;
2. Give priority to centralised air supply: one large unit with VSD is usually easier to control than several small units;
3. Leave room to expand: when lines expand, adding a unit within the same series is less trouble than switching brands;
4. Plan compressed air treatment alongside: configure drying and filtration to process requirements and cost them together with the main unit.

Conclusion

A wide span and a high ceiling are the two most visible labels on ESV+-TMA. From a selection standpoint, a series with a wide power span has a hidden benefit too: as a company expands capacity and air demand rises, a higher-power model can be found within the same brand and series, without having to adapt to a new set of control logic and maintenance standards. For large air-demand scenarios that run over the long term, choosing a series that covers everything from small to large within one system is itself a way to lower long-term cost.