Vacuum Tanks
Many different liquids are handled with vacuum tanks, including water, sewage, oil and molten metals. Applications such as: septic system maintenance, molten steel refineries, industrial liquids, construction sites, campgrounds, grease trap services, portable toilet service, and agricultural processes like manure spreading and vegetable harvesting all use pressure tanks to move and contain liquids. Vacuum tanks are typically measured in gallons and can range greatly in size depending on their applications. The interior walls need to be smooth without grooves or imperfections, as they need to be thoroughly cleaned in between storing or processing. These tanks must be very corrosion resistant, and are either made of steel, stainless steel or aluminum. For added strength, many high pressure vessels are constructed of a double wall, and undergo further strength and resistance building in secondary processing operations.
Pumps are used with process tanks in order to create the pressure required to create a vacuum. Some pumps are small enough to be powered by a vehicle engine, while others require a larger, separately powered pump. In choosing the construction design and material choice for a vacuum tank, the water-tightness of the vessel is a priority. Depending on the size of the tank, there may be a need for braces (interior or exterior) to ensure the tank itself does not collapse due to the pressure of so much liquid. Many tank walls are galvanized and dipped into molten zinc to form a strength-enhancing film on the metal's surface. Manufacturers are able to custom finish tanks, especially those which are attached to trucks or large vehicles for substance clearing purposes. There are three main types of vacuum systems that require the use of vacuum tanks for storage and reservoirs. The first is an older system, called the eductor vacuum. It's used on small diameter, thin wall tubing and a centrifugal pump transfers water under pressure through a venture eductor, this water creates a vacuum. The second is called direct vacuum. These systems are for heavy wall tubing and large profiles. It sucks air and liquid directly through a vacuum pump. Finally, the centrifugal blower vacuum system operates on a closed loop and is designed for tight tolerances. The blower in this system operates in reverse, creating a vacuum inside the reservoir. A tubing system connects the reservoir to the upper tank, which pulls the air and liquid in.
