Case Study · Thermal Oil System Maintenance

JY-N95 Centrifuge Eliminates Carbon Deposits
and Restores Boiler Efficiency — Pakistan Manufacturing

JY-N95 fully automatic centrifuge — large industrial manufacturing facility, Pakistan (thermal oil loop purification)

Project Overview

1. The Challenge: Managing Thermal Oil Degradation at High Temperature

Heat transfer oil systems operating at 250–300°C undergo continuous thermal degradation that progressively contaminates the oil with solid byproducts. Four interconnected problems were undermining the Pakistani facility’s boiler system performance and safety.

Carbon deposit (coking) formation

At sustained operating temperatures above 250°C, thermal oil molecules undergo cracking — breaking down into lower-molecular-weight hydrocarbons and leaving behind solid carbon residues (coke). These fine, sticky carbon particles have high surface energy and readily adhere to pipe walls, forming an insulating coke layer that progressively increases thermal resistance across the heat exchanger surface. As the coke layer thickens, energy consumption rises to maintain the same process temperature — directly increasing fuel costs.

Pipeline blockage and pump wear from solid particulates

Solid contaminants — carbon particles, metal wear debris from pump impellers, and oxidised oil solids — accumulate in system dead zones and narrow pipe sections. This progressive accumulation reduces circulation flow rate, creates localised hot spots in the system, and accelerates mechanical wear on pump seals and valve components, leading to unplanned maintenance requirements.

High-temperature filtration — an unsolved problem with conventional filters

Conventional filter cartridges — paper, glass fibre, or polymer media — cannot withstand sustained exposure to 250–300°C thermal oil. At these temperatures, filter media carbonise, binders fail, and structural integrity collapses. Even high-temperature rated cartridges require frequent replacement under the heavy contamination load of a degrading thermal oil system, with each change requiring partial system shutdown and exposure of maintenance personnel to hot oil hazards.

Tube burnout fire risk from hot spots

Heavy coke deposition on furnace tube inner walls creates localised thermal barriers — “hot spots” where tube metal temperature exceeds design limits while the process-side oil temperature remains below the thermocouple set point. In severe cases, tube metal reaches its yield point and fails — a catastrophic event in a thermal oil system carrying hot oil at positive pressure, creating immediate fire risk. This is the most serious safety consequence of unmanaged thermal oil contamination.

2. The Solution: JY-N95 Fully Automatic Centrifuge — No Filters Required

Jingyuan deployed the JY-N95 centrifuge in bypass mode on the facility’s thermal oil circulation loop. The centrifugal separation principle is inherently compatible with high-temperature, high-contamination thermal oil applications where filter-based technologies fail.

High-speed centrifugal separation

The JY-N95 rotates its separation drum at thousands of revolutions per minute, generating centrifugal forces many times greater than gravity. Solid particles — carbon coke, metal debris, and oxidised solids — are denser than the thermal oil carrier fluid and are thrown outward to the drum wall by centrifugal force, leaving clarified oil at the centre axis for return to the system. The separation efficiency is determined by particle density and size, not by filter media performance — making it immune to the temperature and contamination limitations that prevent filter-based separation.

Zero filter consumables

The centrifuge requires no filter media of any kind. This fundamentally eliminates the procurement, logistics, and maintenance challenges associated with high-temperature filter cartridge replacement — challenges that are particularly acute in Pakistan’s industrial supply environment where specialist high-temperature filtration consumables may not be locally available.

Automated solid discharge

The JY-N95’s fully automatic discharge system periodically expels the accumulated solid cake from the separation drum on a timed cycle, without requiring operator intervention or system shutdown. The automated discharge eliminates the need for maintenance personnel to manually handle high-temperature oil or hot carbon sludge — significantly improving workplace safety in this application.

Continuous bypass purification without boiler shutdown

The bypass installation draws a side-stream from the thermal oil circulation loop, passes it through the centrifuge, and returns clarified oil to the system — continuously and simultaneously with normal boiler operation. There is no interruption to production during the purification process. Over time, the continuous bypass “dialysis” progressively reduces the total contamination load in the system, restoring oil clarity and system heat transfer performance.

3. Results

4. Customer Statement

“In our Pakistan facility, the thermal oil system is our lifeline. We struggled with carbon build-up for years, which increased our energy bills and risk. The Jingyuan JY-N95 Centrifuge is a brilliant solution — it spins out the coke and sludge without needing a single filter. It has made our boiler operations safer and much more efficient.”

— Plant Engineering Manager, Industrial Manufacturing Facility, Pakistan

5. Technical Notes: Why Centrifugal Separation for Thermal Oil

Why conventional filters cannot handle thermal oil contamination

Thermal oil filtration presents two simultaneous challenges that defeat conventional filter media: (1) operating temperature of 250–300°C exceeds the thermal stability limit of glass-fibre binders (~200°C) and most polymer filter media; (2) the contamination is predominantly carbonaceous — fine, sticky coke particles that rapidly blind filter media and require very frequent replacement. Centrifugal separation is temperature-independent (the separation drum is steel) and regenerates automatically, making it inherently suited to this application.

How to detect thermal oil coking before it causes equipment damage

Early warning indicators of thermal oil coking include: rising supply-to-return ΔT at constant process load (indicating increasing thermal resistance); darkening oil colour (visual inspection); rising acid number in oil analysis (oxidation byproducts); and increasing differential pressure across heat exchanger circuits. Regular oil sampling — quarterly in normal operation, monthly in high-temperature systems — provides the earliest warning of contamination buildup. The JY-N95 is most effective when deployed proactively, before coke accumulation has reached the stage of measurable efficiency loss.

Applicability across heat-intensive industries

The thermal oil coking challenge is universal across all industries using indirect heat transfer systems: textile dyeing and finishing, chemical process heating, food processing (frying, drying), rubber and plastics vulcanisation, bitumen and asphalt processing, and solar thermal power generation. Any facility with a thermal oil boiler operating above 200°C and a service life exceeding 3–5 years is a candidate for JY-N95 bypass purification.

Shenyang Jingyuan Membrane Systems Co., Ltd.  |  filtration-system.com/contact  |  info@jingyuan.hk  |  +86 138 8931 0698