Supply of DAF Floats for oil refinery waste water plant

Characteristics of discharges to be treated

The effluents to be treated are defined by the following parameters: 

High load spills

Oily spills

SIGMADAF guarantees that the treated effluents comply with the following parameters, provided they are operated correctly and with the corresponding chemical treatments:

• SS content ≤ 20 mg/l
• Oils and fats content ≤ 10 mg/l

Description of supply

The Mexican firm specializing in wastewater treatment and reuse: AMBBIO supplied the oil company PEMEX with a wastewater treatment system for its refinery located in Dos Bocas (Mexico), in order to comply with local discharge regulations and minimize environmental impact. Among the treatments to be carried out, SIGMADAF supplied two DAF flotation systems for the so-called cargo and oily discharges.                                                           

The solution provided consists of the DAF flotation system model FPHF, which is designed to treat large flows and various pollutant loads.

The DAF SIGMA FPHF flotation equipment is a pressurized air clarification system that represents an improvement over lamella plate technology thanks to a combination of cross-flow and counter-current flow.

The inlet zone of the lamella packs is divided into equal parts to ensure uniform distribution of the entire lamella surface within the system. In practice, very low hydraulic loading ratios are achieved compared to conventional plate separators.         

The system works by means of a single separator movement that rotates against the hydraulic current to minimize the distance that the floated sludge travels and eliminating solids entrainment in the effluent. The separated sludge achieves dry solids contents 3 to 4 times higher than a conventional system; thus optimizing costs and subsequent treatment results. The heavy sludge is concentrated at the bottom of the system, where it is retained for concentration and partial dewatering by the shaftless conveyor system, thus controlling the concentration of the sludge and reducing its accumulation. The discharge process has a self-cleaning effect that removes any particles adhering to the walls along with the rest of the waste.

Each system includes a saturator-manifold, a recirculation pump and a control panel that controls the air supply to the aeration module and the sediment discharge valve; contact coils for the flocculation and in-line pH adjustment processes are also supplied. 

The SIGMA FPHF-1000 dissolved air flotation equipment supplied has the following basic characteristics:

Basic characteristics of the SIGMA FPHF-1000 devices

• Unitary free area: 28^m2 -
• Unit projected area: 175^m2
• Installed power: 39 kW -
• Air consumption: 180 l/min
• Dimensions: 12,000 x 4,131 x 3700 (L x W x H)                          
• Boiler material: Carbon steel with two-component epoxy resin protection.

On line Flocculator, model = PFL700 for Q = 600 - 720 ^m3/h, in PVC DN400/400

The results obtained with these assemblies are significantly better than those obtained by other conventional processes, which benefits the rest of the wastewater treatment plant facilities.