29 September 2023

Lifting station: what it is, what it is for and how to choose it

The lifting station, also known as recovery station, is a component of water purification plants, fundamental in all situations where gravity alone is not sufficient to relaunch the wastewater, for example because the collection basin is positioned at a lower rate than the final delivery. It is usually a pump, or a set of submersible or centrifugal pumps, that make the water flow from closed tanks along the discharge pipes to the retention tank.

Operation is simple: when the wastewater reaches the retention tank, the float rises to a preset level. This activates the regulation and control system that drives the pump (or pumps, depending on a mono- or double pump system), and pushes the water towards the desired point of discharge. The design of the lifting station and the power of the pump must therefore be appropriate to the water flow to be discharged.

 

Components of a lifting station

The lifting stations for black water or clear water Di Camillo are composed of a corrugated container for the stop, an internal pump, an inlet and outlet pipe, a float with anti-reflective valve, an inspection cap and a breather fitting. The use of polyethylene, for the realization of the tanks, is advantageous because it allows to obtain robust tanks in a single section, and at the same time light, to increase the safety and ease of movement and installation. The polyethylene lifting stations are also non-toxic, ideal for the containment and relaunching of clear water, and withstand the high temperature changes, from -20°C to +80 °C. The polyethylene surfaces are then resistant to common fluids and reagents, including disinfection, and polyethylene prevents the development of algae, as it is additived with anti UV agents.

The pump, or pumps in the case of high and variable flow rates, is connected to the electrical panel and powered by single-phase current (230V, for domestic environments) or three-phase (400V, for industrial environments). The start control can then be manual, or automatic, activated by the floats inside the tank, and the lifting station can be equipped with light and acoustic alarms to signal failures even in the absence of electricity. In dual pump models, moreover, the electric panel allows you to activate both pumps in alternating or simultaneous mode.

Choose the pump according to the type of water: the grain size

A lifting station can provide different types of pumps, also depending on the type of water, and therefore the size of the waste water to be treated.

• • Clear or white water lifting station: clear water (for example, rainwater) and non-cloudy water to be treated are usually found at the exit of a treatment or purification system such as a sand filter, or a microstation. The residues suspended in the wastewater have a very small particle size, from 5 to 20 mm, so Di Camillo proposes, in these cases, multi-channel impeller pumps.

 

• Black water and grey water lifting station: this is the most frequent case of use of lifting stations to discharge domestic or industrial waste water into the public sewer.
  • Greywaters are lightly charged waters, which may contain small, low concentration substances in suspension. It is often water at the exit of a septic tank or a pretreatment plant, so the backward impeller pump at low head, of average particle size from 20 to 50 mm, serves to revive the water to the sand filter, or to the spreading.
  • Sewage or sewage, on the other hand, contains solids directly from household waste before the water is sent to the collective sewage treatment plant or to the septic tank. The grain size of the pumps must therefore be large, greater than 50 mm. To avoid packaging problems in the sewage lifting station, the pumps should also be equipped with a shredder impeller, a kind of “wheel” that destroys the solid materials that pass through it, before conveying the flow to the waste pipes. In this case, we are also talking about “lifting station with shredder”.

For all your purification needs, discover Di Camillo Serbatoi polyethylene water lifting stations. Contact us for more information on accessories, available capabilities, and for personalized advice on the best products according to your needs. You will have all the experience of our technicians, who for over 60 years have designed and manufactured systems for the recovery and treatment of wastewater and rainwater.