How to cope with by-products and waste?

Marel has always opted for fluming feathers in water, pressing them dry and then returning water to the feather flume for re-use. This method has proven itself over many decades as environmentally friendly and sustainable, because process wastewater is re-used for transporting the feathers to the pump.

Marel has made three improvements to the system, which make it even more robust, efficient and reliable. The feather pit has been deepened by 300mm to promote the better mixing of feathers and water, ensuring a continuous flow of the correct mix to the feather pump.

Dividing feathers

A second stand-by recirculation pump has been added for higher volume plants. Should there be a problem with the original pump, the stand-by pump can be brought into action by flicking a switch. Any downtime is therefore minimal.

In those processing plants where two dry feather containers can be accommodated at the same time, dividing feathers equally between the two containers could sometimes be problematical, necessitating the intervention of an operator. Improvements in the design of the system will ensure that filling the containers is done more evenly to make the best possible use of available space.

Evisceration debris

Evisceration room waste consists of all internal organs and debris unfit for human consumption. Intestines and gall bladder removed by the Marel PGI machine and taken away by the PGI’s integral vacuum transport system account for most of this. Besides that, crops, glandular tissue and the outer skin of the gizzard removed in an automatic gizzard harvesting system must also be dealt with. As is the case with the PGI, residual lungs and other cavity debris removed in the FIM final inspection machine are taken away by vacuum.

Soft offal screen

Marel has now introduced a soft offal screen, installed in a pit in the flume at the end of the evisceration department. This replaces individual screens under evisceration line machines such as the NIC neck inside cleaning machine. The new screen will not only catch all solids from all machines but also any solids in the washdown water. In the old situation, flumes were often covered in grids to prevent this happening. Advantages of using the new screen are savings in water usage and vacuum connection points. The screen also reduces turbulence resulting in less damage to solid residue and less contamination of the water used to transport it.

Single vacuum connection

The new soft offal screen will handle the evisceration room waste from up to 15,000 bph and can be used as a back-up for the vacuum system on the PGI. In higher volume plants, solids will be conveyed away by vacuum with just a single connection to the vacuum transport system. In the past, each machine equipped with a screen had its own connection to the system. The new screen saves vacuum transport piping and simplifies the system itself. An additional benefit is that the risk of solids smaller than 5 mm ending up in the sewer is lower.

Less contaminated water

In plants handling up to 6,000 bph, the new screen can replace the combination of offal pump and rotary screen. This has several advantages. Rotary screens need a continuous feed of water and blockages are a common experience. Offal pumps also damage waste, raising BOD levels*.

The new screen will remove all particles larger than 5mm and handles them more gently. This means that water that comes free is less contaminated, reducing the amount of work that the water treatment plant has to do. This improves payback on such systems. Solids proceed to containers such as dolavs and are removed from the evisceration department.

No time to waste for waste

Improvements to feather handling and the handling of evisceration room waste make these systems ever more robust and reliable. Today’s highest throughput plants operate at 15,000 bph virtually round the clock and even outside production times they don’t have any spare time left to deal with offal. Downtime due to the inability to remove waste from the process should ideally not happen at all. Quick remedies should be available on the very rare occasions it does. With its latest improvements, Marel has addressed this vital issue.

* Biological Oxygen Demand, the amount of oxygen required to remove waste organic matter from water in the process of decomposition by aerobic bacteria.