Dual Phase and 2-Phase Soil Vapor Extraction Systems

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The Wintek soil vapor extraction system WSVE utilizes vacuum for groundwater remediation and can remove volatile organic chemicals (VOC's) from contaminated sites. It differs from other forms of soil vapor extraction in that it employs a liquid ring pump to pull a deep vacuum (15"HgV - 29"HgV) on groundwater remediation wells utilizing Wintek's LVP (Low Vapor Pressure) Liquid ring vacuum package.

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Groundwater remediation

Why Deep Vacuum for Groundwater Remediation?

There are several benefits that can be derived from using deep vacuum for remediation. Some of these benefits and the efficiencies that can be gained are listed below.

Why Liquid Ring Vacuum Pumps?

While there are many vacuum pumps that can achieve deep vacuum, the liquid ring pump is particularly well suited for soil vapor extraction. First, it can pull deep vacuum so that the benefits described above can be attained.

In addition, liquid ring pumps can handle the slugs of water, soil particles, contaminants and dissolved organics that are likely to be pulled into the pump in this application. Internally lubricated pumps, like rotary vane and rotary screw pumps, are designed for clean service and simply can not be expected to operate for any length of time in this type of environment. While the risk of pulling something into an internally lubricated pump can be reduced by employing a knock-out pot and using a series of filters, it can not be eliminated.

Lastly, liquid ring pumps are exceptionally quiet. They operate at less than 85 DbA and are not creating a noise disturbance to the surrounding area.

When most people think of liquid ring they think of a pump sealed with water. One of the biggest criticisms of liquid ring pumps is that they require vast amounts of cool water in order to pull and maintain deep vacuum. This is because water has a fairly high vapor pressure. If water is used as a seal fluid, capacity drops as the water temperature rises because the sealant vaporizes, reducing the potential capacity of the pump.

Another problem with using water as a seal fluid is that the vacuum system's reliability is limited by the quality of the water used. Typical of groundwater remediation sites, is that the only available water is hard in minerals. Hard water leads to mineral plating inside the pump which both hampers performance and requires frequent maintenance. If you use water high in minerals, you should expect the liquid ring vacuum pump to have problems and frequent shut-downs (after a year of operation with a competitor's water sealed system, Xerox typically saw 50% up-time, or in other words 50% of the time it was not running).

Humidity is also a problem in this application because high humidity in the discharge gas stream reduces the effectiveness of carbon adsorption and incineration equipment. By using a water sealed vacuum system, you actually add to humidity in the discharge stream, typically approaching 100% RH.

Wintek's design has been used with many of the patented Xerox 2-phase process installations. The WSVE package can be used in conjunction with other remediation technology such as standard SVE, Dual Phase, sparging, steam injection or composting.

Increases Groundwater / VOC Yield from the Well:
When compared to traditional pumping methods, wells under deep vacuum have shown dramatic increases in the rate of groundwater remediation, up to a 10-fold increase. The radius in influence has been measured up to 40 feet from the well.

Strips VOC's from Groundwater into a Vapor Form:
This allows for easier and less expensive treatment of organics. So not only is more water extracted from the site but also the concentration of contaminants in the water removed is reduced.

Allows Operation in Tight Soil Formation:
This typically is the most difficult, and where Wintek's WSVE has been most successful. Our system has been used successfully in clay soils w/ permeability as low as 10-5 to 10-8 cm/sec.

In summary, your existing downstream equipment becomes more effective, your timetable for remediation is shortened significantly, your water treatment costs are reduced and you are ensured operation across a broader range of soil types.

Wintek Corporation

Wintek's LVP (Low Vapor Pressure) liquid ring packages do not use water as a seal fluid, but use low vapor pressure oil as the seal fluid and use ambient air as a cooling source. This takes advantage of the strengths of the liquid ring pump and eliminates the problems of both water sealed and lubricated type vacuum pumps.

The primary benefit of using our sealant is that it allows deep vacuum operation over a broad range of temperatures. Wintek's LVP systems can pull deep vacuum at ambient temperatures up to 110oF (43oC).

By eliminating water as the sealant, you no longer contribute to the humidity of the discharge gas; maintenance and downtime are reduced. In addition, we can incorporate a humidity control option on the system to provide cool (100o-120o), dry (<40% RH) effluent to the carbon beds.

Volatilizes VOCs with Less Air:
This makes for a more concentrated stream of contaminants. Which, in turn, optimizes carbon adsorption equipment by allowing the carbon to pick up a higher ratio of organic contaminants. It also makes incineration equipment more cost effective as the more concentrated stream of contaminants can be handled by a smaller and less expensive incinerator.

For additional information, Call: (973) 252-8200, Fax: (973) 252-8233, or Email Sales at Wintek-Corp.com