Begin an energy retrofit with operating and energy records to locate losses, then select lining, sealing, heating, combustion, control or heat-recovery measures. Check changes to workpieces and output before comparing production, holding and stopped states. Without corresponding evidence, do not attribute increased use to one component.
Suneng high-temperature trolley-furnace documents distinguish furnace-wall fibre modules, a local fibre blanket at the heating-strip connection, load-bearing trolley bricks and hearth plates. First locate the suspected loss or damage, then check the materials, joints and seals at that position. If a quotation gives only a refractory grade, ask where it will be used, what area is covered and how the work will be checked. A material name cannot prove lower whole-furnace heat loss or energy consumption.
1. Lining and insulation
Assess refractory and insulation damage, heat loss, material suitability and the existing layered structure. Select materials and thickness for the furnace geometry, working temperature and process. Thicker insulation is not always the best solution: it must remain compatible with the equipment structure, usable space and thermal duty.
2. Doors, openings and seals
Investigate heat leakage at doors, observation openings, trolley interfaces, lids and other joints. Check alignment, compression and the mechanism as well as the sealing material. Soft, sand or water seals are applicable only where the furnace design and operating conditions support them. Reducing uncontrolled leakage requires a suitable complete arrangement.
3. Temperature controls and records
A programmable controller, operator interface, zoned temperature control, stored curves, alarms, interlocks and operating records can support more consistent operation. Sensors, control logic and actuators must work together. Reducing overshoot or unnecessary holding requires process-compatible settings and verification, not merely new hardware.
4. Electric heating or combustion
For electric furnaces, assess heating elements, circuits, power distribution and power control. For fuel-fired furnaces, review burners, air-to-fuel control, pressure, exhaust, ignition and safety functions. Converting between electricity and gas requires a separate assessment of tariffs, supply capacity, utilities, safety and economics. A change in energy source is not inherently an energy saving.
5. Fans, drives and heat circulation
Review circulation paths, airflow, fans and conveying systems against process requirements and the load. Variable-speed control may be suitable for certain operating phases, but reducing speed indiscriminately can affect heat transfer and uniformity. Identify restrictions, wear and loading effects before selecting a change.
6. Flue-gas heat recovery
Possible uses include preheating combustion air or workpieces and supplying another suitable heat demand. Assess flue-gas temperature and flow, operating hours, fuel, available space, fouling and the usable heat sink. Recovery equipment must fit the furnace and production schedule.
For heat-recovery equipment within China’s special-equipment catalogue, identify the applicable requirements by equipment category and activity. Design, manufacture, installation, modification or repair that legally requires a licence must be undertaken by a provider holding the relevant licence. They must not be included casually as ordinary furnace components.
7. Production and operating practice
Low loading, prolonged empty holding, incompatible mixed recipes, excessive door opening, poor loading layouts, inappropriate parameter changes and inadequate maintenance can increase unit-product energy. Review scheduling, loading and maintenance together with hardware measures. Preserve the required product quality and safety conditions.
8. When should other options be compared?
If the structure is badly deteriorated, the process no longer suits the furnace, energy-price changes undermine the economics, or implementation cannot fit the site and shutdown window, compare overhaul or replacement with the proposed retrofit. There is no universal investment-return period. Make assumptions, exclusions and constraints explicit.
9. How to set priorities
First collect equipment, workpiece, process, energy, output, fault and site information. Diagnose the dominant causes of loss, define mandatory repairs and optional improvements, estimate costs and benefits under comparable conditions, and agree implementation and acceptance. Verify the result using energy per unit of product and representative operating records rather than unmatched bills.
10. Suneng's service scope
Jiangsu Suneng Industrial Furnace Co., Ltd., established in 2006 in Jiangyan District, Taizhou, holds National High-Tech Enterprise certificate GR202432008987 and ISO 9001 certificate 03824Q60289R3S, valid until 11 January 2027, and has multiple Chinese patents. Its services include energy retrofits, overhauls, relining, controls, heating-system work and relocation/restart assessments.
Suneng can assess its own equipment and some furnaces from other manufacturers, subject to documents, component availability and site condition. Related service information and the three-line 1,250 mm stainless-steel retrofit provide project context. Final scope and results must be assessed for the particular furnace and operating conditions.
11. Common questions
What can an energy retrofit include?
Lining, seals, controls, heating or combustion, circulation and drives, heat recovery and operating improvements, as justified by diagnosis.
Where should high electricity consumption be investigated first?
Compare consumption with conforming output, load, temperature, cycle and operating hours, then examine the relevant heat losses and system behaviour.
Can relining solve the problem?
It can address insulation losses, but other causes may remain and require coordinated work.
Does a control upgrade save energy?
It may improve the execution of the process and reduce avoidable losses when sensing, logic and actuators are suitable. The actual effect requires verification.
How much energy will be saved?
That depends on the existing furnace, scope, process and operation. A fixed percentage without a baseline is not a reliable project estimate.
Should the old furnace be retrofitted or replaced?
Compare structure, process suitability, total investment, interruption, operating costs and future maintenance under the same requirements.
This article provides general guidance, not a project-specific performance guarantee. Agree the final technical scope and acceptance requirements for the actual equipment.
Related Pages and Sources
- Furnace Retrofit and Overhaul Services (Chinese)
- Three 1,250 mm Stainless-steel Lines: Energy Retrofit
Related public sources: Industrial furnace energy balance and efficiency calculations. Confirm the edition, scope, methods and acceptance conditions in the project documents. Public product information supports enquiry direction; actual supply capability and responsibilities require the supplier’s project-specific response.