pdblowers, Inc. custom built this 125 HP Soil Vapor Extraction system to meet the customers exacting specifications. The system features include:
- Gardner-Denver 9CDL18 Helical Lobe Positive Displacement Blower
- 125 HP Explosion Proof Motor
- Inlet Air/Water Separator
- Extraction Pump with level control
- Inlet Air Dilution Valve
- Inline Filter – Stainless Steel
- Discharge Silencer – Stainless Steel
- Inlet Flame Arrester
- Instrument Panel
- System integration with all components mounted
- Acoustical Enclosure with hinged or removable panels
This system was installed at a chemical facility in Iowa and was to be installed indoors. Noise control was an important factor as well as the ability to maintain the equipment.
The enclosure featured a welded skeleton construction with either removable or hinged and removable panels. The hinged and removable panels were personnel entry ways to allow easy access to critical maintenance components. Removable roof panels were also provided to allow access to major components from above.
A decoupled acoustical material with a quilted mylar layer was mechanically fastened via welded pins to the interior surfaces to prevent sagging of the material.
The enclosure was provided with an exhaust fan mounted in a top panel to allow the customer to connect duct work. The enclosure exhaust fan was sized for a minimum of six air changes a minute for the enclosure volume to insure adequate cooling. This required a 0.75 HP motor.
The enclosure provided a 12 dBA noise reduction to the overall sound level of the equipment when measured from three feet. The photograph above shows the configuration used for noise testing. A butterfly valve was used to simulate the vacuum level and absorptive type silencers were used to simulate what the noise level may have been in the connecting process pipe.
The actual operating conditions of the blower were:
|Inlet Volume (ACFM)||2009|
|Inlet Volume (SCFM)||1000|
|Barometric Pressure (“HgA)||29.5|
|Inlet Pressure (“HgA)||15.6|
|Inlet Temperature (°F)||70|
|Differential Pressure (“Hg)||16.1|
|Blower Brake Horsepower (BHP)||77.1|
|Blower Speed (RPM)||2010|
The vacuum pump was driven through a v-belt drive arrangement with the inlet piping arranged below the vacuum pump. The vacuum pump was isolated from the extraction field with a flame arrester to protect the field should any spark occur inside the vacuum pump. A inlet air/water separator and inline filter were utilized to remove the water and any particulates pulled from the field.
The equipment was rated for a Class 1 Division 1 Group D area. A Nema 7 enclosure was provided for the starter and controls and was mounted on the exterior of the enclosure. The entire system was assembled and tested to confirm proper operation and then dismounted for shipment. A soft start was used for the 125 HP motor and relay logic was utilized for control.
The system was instrumented with temperature and pressure transmitters as well as analog gauges. The vacuum pump was protected via differential temperature monitoring to insure that it was not over it maximum allowable temperature. Differential temperature monitoring provides the best electronic protection when inlet and discharge pressures can vary based on process conditions.
PDF’s of the system drawings are provided below as a reference as well as AutoCad files of the Process & Instrument Diagram as well as the Motor Control Panel. These may be used as a good starting point for similar concepts or designs.