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DOT units for working with wet (hazardous) substances in industry

DOT units for WET hazardous substances

Red KOKS USA EcoVac DOT vacuum truck for wet substances

A vacuum truck which is mounted upon a vacuum tank is called a wet substances DOT unit. By means of a vacuum pump a negative pressure is applied to this tank. This pressure creates a pressure difference between the atmosphere and its contents. This results in a suction effect: air (gas) is discharged into the atmosphere via the vacuum pump. Due to this wet substances units are also called pressure/vacuum trucks (or DOT units).

What are industrial DOT units?

KOKS industrial DOT units, also called industrial vacuum loaders have a long history and solid reputation in the field world wide. An industrial vacuum loader is powerful and efficient; they recover, contain, and carry liquids, dry bulk powders, solids, slurries, and thick sludge from hard to reach areas. KOKS industrial DOT units are designed from the ground up, customized to our customers requirements to tackle the most demanding dry or wet industrial cleaning applications. To ensure the best fit for the industrial cleaning applications, various models, options and off-loading solutions are available.  

What do industrial DOT units do?

KOKS industrial DOT units clean up a full spectrum of materials and recover and recycle valuable raw materials, including liquids, dry bulk powders, solids, slurries, drilling mud and thick sludge. These KOKS DOT units are built to endure. They are simple to operate and easy to maintain, giving you rugged performance whenever and wherever you need it. Our vacuum trucks function even in extreme conditions. KOKS industrial DOT units are reliable and durable.    



How a wet substances DOT unit works

When using a wet substances DOT unit, the product, as a result of this negative pressure, is captured in the sludge tank. The product can be both liquid and/or sludge. Only the vapours (gases) and particles go in the vacuum pump or the service water thank, not the vacuumed product itself. When the tank is full, the shut-off valve/ball float on the intake of the vacuum pump comes into operation. In the event excess vapours (gases) are going to be released. Before they are released in the atmosphere, a KOKS scrubber can be connected to clean them.   

how works wet substances dot vacuum truck ecovac koks usa
brief description working wet substances dot vacuum truck ecovac koks usa min

Brief description of how a wet substances DOT units works

Brief description of how a wet substances DOT unit works:

  1. Vacuum transport
    The pressure difference results in the movement of the product.
  2. Volume increase
    The liquid seperates from the air flow, as the material makes the transistion from the suction pipe connection (6”) to the tank (which is bigger than 6”).
  3. Filtration
    Liquids/vapours are removed from the air flow in the service water tank.
  4. Venting
    A vent pipe discharges the remaining air flow.

Safety provisions for wet substances DOT units

Wet substances DOT units with DOT 407/412, ASME and/or ATEX (ex) certification are further equipped with various safety equipment. This makes them suitable for the transportation of hazardous substances on public roads. These include, for example, tank locking, nitrogen connection, impact/roll bars, etc.

safety provisions wet substances ecovac dot vacuum truck koks usa min
main components controlbox wet substances dot vacuum truck ecovac koks usa

Main components of a wet substances DOT unit

  • Pressure/vacuum tank (clean water tank, sludge tank and service water tank)
  • Pumps and drive (high-pressure pump, vacuum pump and compressor)
  • Various control and operating systems (hydraulic, electrical and pneumatic)
  • Various safety devices (clamp protection, nitrogen connection, rear cover safety, rupture disk, etc.)

One of the unique components: liquid ring vacuum pump

This type of pump features a liquid ring, just as the name liquid ring vacuum pump suggests. There is no mechanical contact between the moving parts of the pump. In much as the same way as a traditional piston pump, the liquid acts as small pistons. Resulting in the pump developing very little heat and making it possible to achieve a deep vacuum.

When the pump starts, the liquid ring rotates at the same speed as the rotor. The liquid ring features an array of small cells and the rotor is slightly offset from the centre. In the uppermost position the small cells are completely filled with water. As the cells turn, a pocket of air is created at the rotor hub.   

As the liquid moves away from the rotor hub to create a suction effect, it acts as a piston. The liquid begins pressing in towards the rotor hub, as the cells pass the bottom of the chamber. This forces the air out of the cells, filling it with liquid ready for the next suction cycle.  

The ends of the casing are fitted with a flow plates and pump housing, so the suction and compression parts of the pump are seperated. Some pump types feature connections at both ends. Other pump types (monoblock pumps) have only one connection at the end of the liquid ring.

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applications use wet substances dot vacuum equipment koks usa plant min

Applications for use of wet substances in vacuum equipment

  • Technical chemical cleaning
  • Oil separation
  • Petro-chemical activities
  • Silo cleaning
  • Vacuum cleaning work
  • Offshore activities
  • Onshore activities
  • Emergency clean-up
  • Industrial cleaning
  • Sewer cleaning
  • Shutdown cleaning work
  • Grease pit cleaning
  • Well cleaning
  • Collection of waste oil
  • Oven cleaning
  • Ship cleaning
  • Water surface cleaning
  • Septic tank cleaning
  • Pressuring liquids
  • Municipal cleaning
  • Transport work
  • Soil boring

KOKS United States Corporation is part of the Dutch KOKS Group an international manufacturer and supplier of vacuum trucks (DOT 407/412) and heavy industrial cleaning equipment. Founded in 1989 and has since grown into a dynamic company that operates globally and consists of seven specialised subsidiaries in the USA, The Netherlands, the Czech Republic, Saudi Arabia and participations in rental organizations that operate in The Netherlands and the United Kingdom. As a growing, innovative, healthy and reliable company, KOKS Group has gained an excellent reputation in the (petro)chemical sector and other industries as a vacuum truck (DOT 407/412) builder. 

KOKS Group DOT vacuum truck builder factory in Alkmaar

More information?

Do you have questions about the KOKS EcoVac wet DOT unit (407/412). Just get in touch with our customer service desk. We are ready to help you, 24/7. Feel free to contact us! 

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