Leading the Way in Deep Bed Nutshell Filtration

BLACKWALL PROCESS, with its experience, has designed, engineered and developed the most advanced deep bed nutshell filter for use in treating oilfield produced water. The filter is critical as the final barrier for reducing finely dispersed oil droplets and solid particles to minimum ppm after undergoing multiple upstream separation stages. We supply a nutshell filter that has been demonstrated up to 99% efficient in reducing TSS of under 50 ppm at inlet to less than 5 ppm upon leaving the filter.

Why Is Ours Better?

BLACKWELL PROCESS deep bed nutshell filters incorporate unique features that aid operating results and improve your bottom line.  Among them are:

•   Uniform graded and pre-washed black walnut shells assure even distribution of oil and suspended solids as they pass through the filter, making it easier and more efficient to filter and backwash. 

•   Internal mixer attached to a top-mounted, right-angle gear box motor allows rapid fluidizing of the media during backwash to typically less than 10 seconds.  Our tank design and attention to detail improve the filter flux rate compared to other nut shell filter designs

•   Special design of bottom wedge wire screen provides full support of the media while promoting efficient clean water discharge and greatly reducing the weight of the vessel

•   Rotating stainless steel wedge wire scrubber screen attached to the mixing impeller shaft increases the efficiency of the backwashing process and reduces settling time to under 30 seconds

learn why we have the right filter solution

Benefits to You

The BLACKWALL PROCESS deep bed nutshell offers users numerous benefits and cost savings in both capex and operating expenses.

• Compact configuration – the BLACKWALL PROCESS vertical nutshell filter is packaged fully equipped with automation and motor assembly on a single skid.  Pump driven filters require additional space and additional installation. The space savings are even more pronounced with horizontal configurations.

• Long-lasting media – Black walnut is the most durable media available, allowing it to be backwashed and regenerated consistently with near zero attrition. Alternative sand, anthracite, or mixed media, after initial backwash, can need continual replenishment.

• Reduced installation costs – Innovative wedge wire bottom screen materials and design dramatically reduce weight for the vessel since it requires no grout or concrete base.  This feature, and the single skid configuration, simplify installation time, reduce foundation complexity, and lower transportation costs to the field site.

• Lower operating costs – With the internal mixer design, uptime reliability is exceptional.  Total backwash and recovery time is less than 10 minutes during scheduled daily cleaning. With external pump filters, this interval can extend to one hour or more.

• Less water consumption – Backwash water volume in our vertical tank is far less than with pump filters. The BLACKWALL PROCESS normally filters at 100 gpm and only consumes 700 gallons of water during backwash. That is approximately .4% of throughput.  Pump filters consume at least 10 times that amount.

• Lower power consumption – The BLACKWALL PROCESS filter mixer motor uses 5 – 60 hp depending on vessel size.  External pump units consume 4 times that amount.

• Less maintenance – The BLACKWALL PROCESS filter design is self-contained with no manual intervention needed for component maintenance. Screens are stainless steel, and graded nutshell media needs minimal replacement over time.

What Is Filtered Out?

Suspended solids, oily residues, hydrocarbons, ash and metallic hydroxides

Industries We Help

BLACKWALL PROCESS deep bed nutshell filters are used extensively in produced water applications.  They are essential in steam and water flood use and in Steam-Assisted Gravity Drainage (SAGD) or heavy crude applications where steam generators need clean water for their operation.  Our outlet ppm is generally clean enough that cartridge filters are not required.

Nutshell filters have application in industrial use and have had excellent results for generation in steel mills, aluminum smelters, and similar wastewater.  They are also capable for use in refinery pretreatment at sour water stripper service.

How it Works

The BLACKWALL PROCESS-designed nutshell filter uses a downward flow of oil and suspended solids in water through the filter inlet from the upstream filtration train.  The flow carries the liquid through the black walnut filter media where the oil droplets and particles are uniformly captured and clean water is discharged. 

When the backwash cycle begins, the agitator impeller uniformly fluidizes the nutshell media with attached suspended solids and oil. This agitation pushes the particulates to the rotating wedge wire screen where the solids are filtered and discharged with the backwash water.

After the backwash discharge valve is closed, the cleaned media settles to its original position atop the bottom wedge wire support screen to start the filtration process again.

Why Blackwall Process?

BLACKWALL PROCESS technology is the result of more than 60 years combined experience in industrial filtration equipment development.  We innovate, design, engineer and supply the necessary equipment for all phases of oil and solids removal. We work closely with our clients to understand their operating parameters and identify potential problems that can impede equipment and add costs. Our designs not are ‘off the shelf’, but rather incorporate new and improved features to time-tested equipment.

Now is the perfect time to talk to us about nutshell filters.