21/03/2024 – Operating CV lines responsibly

By-product separator

Byproduct formation during the continuous vulcanizing process has been primarily a cable quality issue, but in this day and age is has equally become an environmental one.


Typical quality issues on the outer cable surface due to byproducts. © Maillefer


The schema of the BPS loop in a CV process. © Maillefer

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Maillefer offers a modern “Byproduct Separation” (BPS) system that couples to extrusion lines seamlessly. Here is an optimal system for extracting byproduct in a responsible fashion.

Byproduct extraction improved
Medium voltage, high voltage and extra high voltage cables are largely XLPE insulated and produced on CV lines. The crosslinking method employed on horizontal (HVC), vertical (VCV) or catenary (CCV) CV lines is peroxide based. Unwanted byproducts result from this process. If insufficiently extracted, they will cause cable quality issues. It is best to handle byproduct removal carefully and in a systematic manner.

Improved byproduct separation and collection during the CV-process has multiple benefits directly on the product and also on the neighbouring environment:
Maintaining optimal production conditions
– Stable cooling and heating capacity
– Cleaner cooling water and cooling gas
– Less quality issues with produced cables and scrapped cables

Reduced maintenance work
– Less curing tube and heat exchanger cleaning needed
– Vulcanizing equipment and instruments increased reliability in operation
– Decreased maintenance costs

Environment and Sustainability
– Cleaner exhaust nitrogen gas from CV line to atmosphere
– Less waste water
– Better controlled by-product collection.

The entire BPS loop
Maillefer has continuously developed the byproduct removal process as an integral part of CV-line development. Nowadays, we offer several individual components for byproduct removal as a part of an overall approach. The goal is to secure and maximize customer’s production potential and to minimize the scrap cable produced.

 The BPS with the Gas ReHeater (GRH) component are the most effective and the most essential parts of a byproduct extraction system. The BPS separates the decomposed crosslinking byproducts by condensing associated particles found in the nitrogen flow. The condensate is collected at the bottom of the unit. The BPS is equipped with a time controlled valve, which purges the liquid waste collected towards holding tanks.

BPS functionality and construction
The GRH continues by increasing temperature of the gas returning from the BPS. It is located in the same gas circulation loop as the BPS. The heated gas is injected into the second to last curing tube, at the same temperature as the nitrogen within the curing tube.

Gas Re-heater
Both BPS and GRH are available as upgrades, ready to integrate into any existing CV line, whether a Maillefer line or other. Three main upgrade types for existing CV-lines in order to improve byproduct extraction are provided.

Complete byproduct removal system
If the CV-line is not equipped with a byproduct removal system, a complete BPS system with GRH is proposed. A holistic approach is used by studying the byproduct removal process for the CV in place, and a full system is engineered accordingly.

Partial byproduct removal system
If the line is already equipped with BPS but without a GRH, it is possible to improve byproduct separation system by integrating the new component into the existing circulation loop and BPS.

Selective byproduct removal system replacement
If the existing CV-line is already equipped with a byproduct removal system that gives undesired results, selected elements are replaced accordingly, which may include Maillefer's BPS and GRH.

High cable value to consider
CV cables are high added value products. Sacrificing cable quality due to insufficient byproduct removal directly effects the bottom line, not to mention product image. Do not hesitate further to extract your crosslinking byproducts effectively and responsibly. We stand ready to offer a solution that is tailor-made for your specific conditions.

wire 2024, hall 10 booth C 22

Maillefer SA
Avenue du Tir-Fédéral 44
1024 Ecublens/Switzerland
Contact person is Roger Möller
Tel.: +41 21 694-4111