For each minor improvement and innovation and effort made for tackling difficult technical problems at the site, cost reduction lies in all measures for improvement; Efficiency improvements are achieved through bold thinking and actions. Fuhai Packaging is moving forward ever more solidly on the road of “cost reduction, quality improvement, and efficiency enhancement”.

While Seeking Solutions, Try to Keep a Meticulous Account of “Carbon” 

As the plant's major energy consumer, the power workshop stands as the main battlefield in the tough battle of "energy saving and consumption reduction." Most of the efforts for reducing material consumption and carbon emissions lie in operating conditions that are easily overlooked. During an inspection, Mr. Yang (an engineer) keenly identified an abnormal case: after the wastewater from various units is mixed, its COD value falls below the lower limit for anaerobic tank influent. He immediately gathered the workshop's key staff, reviewing designs and checking references, and sorted through the issues one by one—finding that to keep the system running normally, 1 ton of carbon source needed to be added daily to raise the COD value. The daily consumption seems insignificant, but will become great when accumulated over time.

▲The Power Workshop discusses the PEIC anaerobic revamp program.

While discussing the above case, Mr. Yang proposed to cut the PEIC anaerobic reactor out of the main process. However, everyone present hesitated. For once it was cut out, the original wastewater treatment path would need to be restructured. Besides, to maintain the current operating conditions requires making up carbon source every day. Having reviewed the drawings and through careful deliberation, a consensus was finally reached—they could try a revamp. Based upon the original design and actual operating conditions, the workshop team provided an additional nipple to the outlet of the PEIC anaerobic lifting pump, so that the wastewater from the distribution well could be directly transmitted to tank A via the lifting pump to isolate the anaerobic tank. Thus, the wastewater was bypassed to allow the anaerobic tank to switch to a "live" state and no longer bear the full load for treatment. After the revamp, only 0.15 tons of carbon source needed to be added daily to satisfy the operating conditions.

Following the example of the Power Workshop, other workshops were unwilling to lag behind and rushed to benchmark against it. As a result, more than one energy-saving programs were being carried out, such as those for optimization of make-up water parameters for bleaching and improvement for chilled water consumption etc.  Everyone knew clearly that to reduce costs and increase efficiency, they must go to the site, examine carefully, and investigate thoroughly. A valve, a pipeline and a parameter adjustment—any of these could yield extra benefits.

Investigate Thoroughly to Address Blockage

Surficial problems are easily to be identified visually for solution, while some need to be investigated thoroughly for their root cause before they are finally addressed.

"It's blocked again!" At the site for sludge disposal, the screw press was found shut-down once more. This is the key equipment for sludge treatment—once it failed, the normal operation of the entire process will be affected. The supplier has come to the site several times for troubleshooting and maintenance, but has failed to solve the problem thoroughly. Mr. Bi (an engineer) from the Equipment Operation and Maintenance Dept. squatted beside the equipment, looking at the thick accumulated sludge, and said firmly: "Relying only on disassembly of the machine doesn’t work at all. Though the supplier is still working on it, we can't wait any more. We must crack the nut ourselves."

▲The task force conducted an on-site investigation of the screw press. 

What are the reasons behind the problem? The Equipment Operation and Maintenance Dept. set up a task force to sort out the reasons one by one, investigated thoroughly and tested repeatedly. Detailed data for each set of tests was recorded carefully in the notebook beside the equipment.

Increasing the rotational speed—no obvious improvement was found;

Reducing the sludge feed rate—the situation eased slightly;

Optimizing the flocculant ratio and reducing the sludge-water viscosity—The results were still unsatisfactory.

After a series of attempts, the problem still remained. Despite the dilemma they were in, someone boldly proposed: "Can we adjust the compression ratio of the screw press and modify the screw?" The idea immediately caught everyone's attention, and they considered it feasible. However, the team did not rush to start work; instead, they first conducted technical exchanges with several equipment manufacturers to verify the viability of the plan. Yet when the plan was improved and became mature, the supplier held that the risk was too high and recommended against directly modifying the screw as a whole. The progress of the plan was temporarily suspended, but the team did not give up. Having considered fully the supplier's advice, they immediately adjusted their test approach: "Let's first try adjusting the key taper." As a response, the supplier urgently machined a test screw cone as required.

On the day the new cone was installed, everyone gathered around the equipment, focusing on the discharge outlet. the root cause for equipment trouble was finally identified: there was a design deviation between the pitch of the original screw and the taper of the cone in the screw press. Although the deviation was small, it caused abnormal sludge dewatering, making the material prone to adhering and accumulating on the screw, ultimately leading to clogging. After replacing the new cone, the clogging was addressed completely. Once the root cause was identified, a remedy could be made, i.e., the supplier, as required, re-optimized and modified the taper of the screw cone. The modified screw press has been running smoothly and achieved long-term stable operation.

Cost awareness, energy saving and consumption reduction, innovative improvement, exploratory thinking are becoming the simplest yet most powerful consensus and action among all of the employees in Fuhai.