Vacuum truck

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Vacuum truck Vacuum tanker for pit emptying.jpg
Vacuum truck

A vacuum truck, vacuum tanker, vactor truck, vactor, vac-con truck, vac-con is a tank truck that has a pump and a tank. The pump is designed to pneumatically suck liquids, sludges, slurries, or the like from a location (often underground) into the tank of the truck. The objective is to enable transport of the liquid material via road to another location. Vacuum trucks transport the collected material to a treatment or disposal site, for example a sewage treatment plant.

Contents

A common material to be transported is septage (or more broadly: fecal sludge) which is human excreta mixed with water, e.g. from septic tanks and pit latrines. They also transport sewage sludge, industrial liquids, or slurries from animal waste from livestock facilities with pens. Vacuum trucks can also be used to prepare a site for installation or to access underground utilities. These trucks may use compressed air or water to break up the ground safely, without risk of damage, before installation may begin.

Vacuum trucks can be equipped with a high pressure pump if they are used to clean out sand from sewers.

Other names used

Vacuum tanker used to collect sewage at Tatton Park flower show, July 2009, England Aa sewagetanker tattonflowershow2009.jpg
Vacuum tanker used to collect sewage at Tatton Park flower show, July 2009, England
Fleet of vacuum trucks used for desludging services by Manila Water in Manila, Philippines Desludging fleet Manila Water.jpg
Fleet of vacuum trucks used for desludging services by Manila Water in Manila, Philippines

Other names used for vacuum trucks: vacuum tanker, "Sucker truck" or vac-trucks (in Australia) or "Sewer Sucker", "Hydro-vac", or "vac-trucks" (in Canada) or "Exhauster truck" (in Rwanda, Malawi). Slang terms include: "honey truck", "honey sucker" (in India and South Africa), and "honeywagon", all (probably) derived from honey bucket.[ citation needed ]

When a vacuum truck is used to transport fecal sludge then it can also be called "fecal sludge truck".

Design and configurations

Commercial vacuum trucks which collect fecal sludge usually have a volume of 10–55 cubic metres (350–1,940 cu ft). [1] However various smaller versions for specialized applications or low-resource settings can be found with tanks as small as 500 litres (110 imp gal; 130 US gal). [2]

Pumps

They generally use a low-volume sliding vane pump or a liquid ring pump to create a negative air pressure. [1] The use of diaphragm mud pumps is less common, but with the advantage of a simpler design and usually lower overall costs. [3] The disadvantage is that mechanical parts come into contact with the sludge, which is not the case for the more common vacuum pumps.

The truck can be configured to be a direct belt drive, or a hydraulic drive system.

There are two different ways to mount the pump: either directly on the truck with the vacuum drive powered by the truck motor, or on the trailer with an independent motor. The second option with the independent motor is more complicated and not commonly used. It has the advantage of potentially having the pump closer to the septic tank. It is also able to use the negative pressure suction side of the pump as well as the positive pressure side to pump sludge over longer distances or lift it higher into the tank.

Suction hoses

The suction hoses are typically 2" - 4" (or 50mm to 100mm) in diameter with 3" (or 75mm) being the norm. The possible length depends on various factors mainly related to the lift and other pressure losses. It is usually impossible to extend it beyond 50 metres (160 ft).

An inherent suction limitation of all suction pumps is that they can only lift a liquid through utilizing atmospheric pressure. For pure water the theoretical maximum lift is approximately 10.3 metres (34 ft). [4] However, due to the viscosity of fecal sludge it is possible to mix air into it either by sucking close from the surface or by adding air with a compressor through a separate hose. Through this process, the overall density of the sludge/air mixture can be reduced below that of pure water and thus a higher lift (10–15 metres (33–49 ft)) can be reached under optimal conditions. Other factors affecting the possible lift and total length of the suction hose are that single stage vacuum pumps only reach an 85-90% partial vacuum, and that small air leakages, pipe friction losses, and the viscosity of the liquid further reduce the possible lift.[ citation needed ]

Emptying the tanker

Normally a tanker is emptied by gravity. It is possible to pressurize the vacuum tank to "pressure out" the liquid quicker (or against a small difference in elevation). This procedure is detrimental for the equipment, hence is used in special situations.

The regular discharge time for a tanker of 8–9 cubic metres (280–320 cu ft) is about 15 minutes (or 7–10 minutes to unload a tanker of 4,000 litres (880 imp gal; 1,100 US gal)). The outlet is typically 4 to 6 inches (10 to 15 cm) in diameter. The discharge time depends on the thickness of the sludge, the size of the outlet valve and hose, the amount of garbage in the fecal sludge, and the frequency of driver cleaning the dump screen.[ citation needed ]

Uses

Vacuum trucks are used by town and municipal governments, as well as commercial entities around the world. [5]

Human excreta

Several types of non-centralized sanitation systems are served by vacuum trucks. They are used to empty septage from cesspits, septic tanks, pit latrines, and communal latrines, for street cleanup, for sewer clean out, and for individual septic systems. [6] The trucks are used in the cleaning of sanitary sewer pumping stations. Vacuum trucks are used to empty portable toilets. In commercial aviation, vacuum trucks are used to collect waste from airplane toilets.

Vacuum trucks discharge these wastes to the sewer network, to a wastewater treatment plant, or—usually illegally, for example in many developing countries— directly into the environment. The latter practice, called "institutionalised open defecation", is dangerous since it constitutes a public health and environmental hazard.

Industrial liquids

Vacuum trucks are used in the petroleum industry, for cleaning of storage tanks and spills. They are also an important part of drilling oil and natural gas wells, as they are located at the drilling site. Vacuum trucks are used to remove drilling mud, drilling cuttings, cement, spills, and for removal of brine water from production tanks. They dispose of this in sump pits, treatment plants or if within safe levels may be spread in farm fields.

Others

Vacuum trucks are also used for exposing underground utilities. Before installing many pieces of underground equipment, the ground must be excavated far enough down to create a solid foundation for the structure to be placed on. Underground utilities can include lamp poles, traffic lights, road signs, and even commercial grade trees for landscaping. [7]

To prepare the ground for installation it is jetted with water, and the vacuum truck sucks up the muddy product. This exposes the buried utility without the possibility of damage, as would be possible if a digging machine were used (i.e. tractor backhoe, tracked or wheeled excavator, ditch witches).

Vacuum trucks can also be used for cleanup of contaminated soil. For some instances, air excavation may be used in place of hydro excavation. Air excavation, also known as soft dig, uses compressed air to break up the ground and then vacuums up the soil into the debris tank. Air excavation is often used for locating underground electrical cables and gas lines. [8]

See also

Related Research Articles

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<span class="mw-page-title-main">Sewerage</span> Infrastructure that conveys sewage or surface runoff using sewers

Sewerage is the infrastructure that conveys sewage or surface runoff using sewers. It encompasses components such as receiving drains, manholes, pumping stations, storm overflows, and screening chambers of the combined sewer or sanitary sewer. Sewerage ends at the entry to a sewage treatment plant or at the point of discharge into the environment. It is the system of pipes, chambers, manholes or inspection chamber, etc. that conveys the sewage or storm water.

<span class="mw-page-title-main">Septic tank</span> Method for basic wastewater treatment (on-site)

A septic tank is an underground chamber made of concrete, fiberglass, or plastic through which domestic wastewater (sewage) flows for basic sewage treatment. Settling and anaerobic digestion processes reduce solids and organics, but the treatment efficiency is only moderate. Septic tank systems are a type of simple onsite sewage facility. They can be used in areas that are not connected to a sewerage system, such as rural areas. The treated liquid effluent is commonly disposed in a septic drain field, which provides further treatment. Nonetheless, groundwater pollution may occur and is a problem.

<span class="mw-page-title-main">Sanitary sewer</span> Underground pipe for transporting sewage

A sanitary sewer is an underground pipe or tunnel system for transporting sewage from houses and commercial buildings to a sewage treatment plant or disposal.

A vacuum ejector, or simply ejector is a type of vacuum pump, which produces vacuum by means of the Venturi effect.

<span class="mw-page-title-main">Cesspit</span> Underground holding tank or soak pit

Cesspit, cesspool and soak pit in some contexts are terms with various meanings: they are used to describe either an underground holding tank or a soak pit. A cesspit can be used for the temporary collection and storage of feces, excreta, or fecal sludge as part of an on-site sanitation system and has some similarities with septic tanks or with soak pits. Traditionally, it was a deep cylindrical chamber dug into the ground, having approximate dimensions of 1 metre (3') diameter and 2–3 metres depth. Its appearance was similar to that of a hand-dug water well.

<span class="mw-page-title-main">Pit latrine</span> Toilet that collects human waste in a hole in the ground

A pit latrine, also known as pit toilet, is a type of toilet that collects human waste in a hole in the ground. Urine and feces enter the pit through a drop hole in the floor, which might be connected to a toilet seat or squatting pan for user comfort. Pit latrines can be built to function without water or they can have a water seal. When properly built and maintained, pit latrines can decrease the spread of disease by reducing the amount of human feces in the environment from open defecation. This decreases the transfer of pathogens between feces and food by flies. These pathogens are major causes of infectious diarrhea and intestinal worm infections. Infectious diarrhea resulted in about 700,000 deaths in children under five years old in 2011 and 250 million lost school days. Pit latrines are a low-cost method of separating feces from people.

<span class="mw-page-title-main">Draft (water)</span>

A draft is the use of suction to move a liquid such as water from a vessel or body of water below the intake of a suction pump. A rural fire department or farmer might draft water from a pond as the first step in moving the water elsewhere. A suction pump creates a partial vacuum and the atmospheric pressure on the water's surface forces the water into the pump, usually via a rigid pipe or a semi-rigid hard suction hose.

This is a glossary of firefighting equipment.

<span class="mw-page-title-main">Tank truck</span> Motor vehicle designed to carry liquefied loads, dry bulk cargo or gases on roads

A tank truck, gas truck, fuel truck, or tanker truck or tanker is a motor vehicle designed to carry liquids or gases on roads. The largest such vehicles are similar to railroad tank cars, which are also designed to carry liquid loads. Many variants exist due to the wide variety of liquids that can be transported. Tank trucks tend to be large; they may be insulated or non-insulated; pressurized or non-pressurized; and designed for single or multiple loads. Some are semi-trailer trucks. They are difficult to drive and highly susceptible to rollover due to their high center of gravity, and potentially the free surface effect of liquids sloshing in a partially filled tank.

<span class="mw-page-title-main">Space toilet</span> Toilet used in weightless environments

A space toilet or zero-gravity toilet is a toilet that can be used in a weightless environment. In the absence of weight, the collection and retention of liquid and solid waste is directed by use of airflow. Since the air used to direct the waste is returned to the cabin, it is filtered beforehand to control odor and cleanse bacteria. In older systems, wastewater is vented into space, and any solids are compressed and stored for removal upon landing. More modern systems expose solid waste to vacuum pressures to kill bacteria, which prevents odor problems and kills pathogens.

<span class="mw-page-title-main">Gully emptier</span>

A gully emptier is a type of specialized tank truck with suction gear which can suck wastewater and mud and sludge out of hollows such as the hollows below drain grids in street gutters and carry it to a suitable disposal point. It needs to be able to suck out and pump through into its tank any road grit and miscellaneous solids that have entered the hollow.

<span class="mw-page-title-main">Hard suction hose</span> Drafting fire hose made to withstand vacuum

Flexible suction hose, not to be confused with hard suction hose in U.S., is a specific type of fire hose used in drafting operations, when a fire engine uses a vacuum to draw water from a portable water tank, pool, or other static water source. It is built to withstand vacuum, rather than pressure, abrasion, and heat. Conversely, hard suction is capable of withstanding up to 200 PSIG, as well as vacuum. In the United States, it is standard equipment according to the National Fire Protection Association standards for fire engines. It is used in both structural and wildland firefighting throughout the world, and is made in various diameters and connection types.

<span class="mw-page-title-main">Sanitation worker</span> Person who is responsible for the cleaning and maintaining of a sanitation technology

A sanitation worker is a person responsible for cleaning, maintaining, operating, or emptying the equipment or technology at any step of the sanitation chain. This is the definition used in the narrower sense within the WASH sector. More broadly speaking, sanitation workers may also be involved in cleaning streets, parks, public spaces, sewers, storm

A rotodynamic pump is a kinetic machine in which energy is continuously imparted to the pumped fluid by means of a rotating impeller, propeller, or rotor, in contrast to a positive-displacement pump in which a fluid is moved by trapping a fixed amount of fluid and forcing the trapped volume into the pump's discharge. Examples of rotodynamic pumps include adding kinetic energy to a fluid such as by using a centrifugal pump to increase fluid velocity or pressure.

<span class="mw-page-title-main">Suction excavator</span> Soft excavation technique applied in loosen soils and uncompacted sediments

A suction excavator, or vacuum excavator, is a construction vehicle that removes heavy debris or other materials from a hole on land using vacuuming. Suction excavators are meant to be more non-destructive than regular excavators. The suction excavator uses suction fans for the airflow to suck up the material that is then transported into the holding tank.

<span class="mw-page-title-main">Effluent sewer</span>

Effluent sewer systems, also called septic tank effluent gravity (STEG), solids-free sewer (SFS), or septic tank effluent drainage (STED) systems, have septic tanks that collect sewage from residences and businesses, and the liquid fraction of sewage that comes out of the tank is conveyed to a downstream receiving body such as either a centralized sewage treatment plant or a distributed treatment system for further treatment or disposal away from the community generating the sewage. Most of the solids are removed by the interceptor tanks, so the treatment plant can be much smaller than a typical plant and any pumping for the supernatant can be simpler without grinders.

<span class="mw-page-title-main">Omni processor</span> Group of physical, biological or chemical treatments to process fecal sludge

Omni processor is a term coined in 2012 by staff of the Water, Sanitation, Hygiene Program of the Bill & Melinda Gates Foundation to describe a range of physical, biological or chemical treatments to remove pathogens from human-generated fecal sludge, while simultaneously creating commercially valuable byproducts. Air from feces are separated from common air, then these collected air from feces are compressed like (LPG) and used as fuel. An omni processor mitigates unsafe methods in developing countries of capturing and treating human waste, which annually result in the spread of disease and the deaths of more than 1.5 million children.

<span class="mw-page-title-main">Fecal sludge management</span> Collection, transport, and treatment of fecal sludge from onsite sanitation systems

Fecal sludge management (FSM) is the storage, collection, transport, treatment and safe end use or disposal of fecal sludge. Together, the collection, transport, treatment and end use of fecal sludge constitute the "value chain" or "service chain" of fecal sludge management. Fecal sludge is defined very broadly as what accumulates in onsite sanitation systems and specifically is not transported through a sewer. It is composed of human excreta, but also anything else that may go into an onsite containment technology, such as flushwater, cleansing materials, menstrual hygiene products, grey water, and solid waste. Fecal sludge that is removed from septic tanks is called septage.

A bayakou is a sanitation worker who works to empty the fecal sludge out of pit latrines in Haiti, especially in larger cities, such as Port-au-Prince. The word bayakou comes from Haitian Creole. Bayakou are subjected to social stigma for their work in manually emptying septic tanks and pit latrines.

References

  1. 1 2 Strande, L., Ronteltap, M., Brdjanovic, D. (eds.) (2014). Faecal Sludge Management (FSM) book – Systems Approach for Implementation and Operation Archived 2017-10-14 at the Wayback Machine . p. 81. IWA Publishing, UK ( ISBN   978-1780404738)
  2. O’Riordan, Mark (April 2009). Investigation into Methods of Pit Latrine Emptying (PDF). WRC PROJECT 1745 Management of sludge accumulation in VIP latrines. pp. 15pp. Retrieved 18 January 2017.
  3. Wastecorp Pumps. "Mud sucker diaphragm pumps" (PDF). Wastecorp. Retrieved 18 January 2017.
  4. "Hydrostatics". Composed by J.B. Calvert. 5 January 2007. Retrieved 18 January 2017.
  5. Strande, L., Ronteltap, M., Brdjanovic, D. (eds.) (2014). Faecal Sludge Management (FSM) book - Systems Approach for Implementation and Operation Archived 2017-10-14 at the Wayback Machine . IWA Publishing, UK ( ISBN   9781780404738)
  6. Lloyd Kahn, John Hulls, Peter Aschwanden, The Septic System Owner's Manual Shelter Publications, Inc., 2007 ISBN   0-936070-40-4 p. 49
  7. "CAN HYDRO EXCAVATION WORK FOR YOUR INDUSTRY?". Adler Industrial Services. Retrieved 8 December 2021.
  8. "Low Impact Air Excavation". Adler Industrial Services. Retrieved 8 December 2021.