Submerged diffuser

alternatives are available for submerged discharge (Palermo 1994) and are

described in the following paragraphs.

Submerged diffuser

A submerged diffuser (Figures 8 and 9) can be used to provide addi-

tional control for submerged pipeline discharge. The diffuser consists of

conical and radial sections joined to form the diffuser assembly, which is

mounted to the end of the discharge pipeline. A small discharge barge is

required to position the diffuser and pipeline vertically in the water column.

By positioning the diffuser several feet above the bottom, the discharge is

isolated from the upper water column. The diffuser design allows mate-

rial to be radially discharged parallel to the bottom and with a reduced

velocity. Movement of the discharge barge can serve to spread the dis-

charge to cap larger areas. The diffuser can also be used with any hydrau-

lic pipeline operation including hydraulic pipeline dredges, pump-out

from hopper dredges, and reslurried pump-out from barges.

Figure 8. Submerged diffuser system, including diffuser and discharge barge

A design for a submerged diffuser system was developed by JBF Corpo-

ration as a part of the USACE Dredged Material Research Program

(DMRP) (Barnard 1978; Neal, Henry, and Greene 1978). This design con-

sists of a funnel-shaped diffuser oriented vertically at the end of a sub-

merged pipeline section that discharges the slurry radially. The diffuser

and pipe section are attached to a pivot boom system on a discharge barge.

Chapter 5 Equipment and Placement Techniques