The innovative practice of multi-bag filters in filtration applications in the food industry
Customer Challenge
A fresh juice production enterprise still encountered problems with fine fruit pulp fibers and pigment sedimentation after the coarse filtration process. Even though they had adopted 25μm filter bags for filtration, there were still visible suspended substances in the finished product, which failed to meet the strict requirements of the high-end supermarket channels for product clarity - the impurity particle size needed to be strictly controlled within 15μm. Additionally, the customer needed to achieve a stable processing volume of 220m³ per hour, while the maximum processing capacity of a traditional single-filter bag unit was only 80m³/h. Therefore, they had to use three units operating in parallel. This solution not only occupied up to 12㎡ of space but also caused fluctuations in filtration effect due to uneven flow distribution, affecting product consistency.
The original equipment also has obvious shortcomings in terms of operation and maintenance: It adopts a flange-type open cover structure, and each time the filter bag needs to be replaced, 12 bolts need to be disassembled. The single operation takes as long as 40 minutes. Frequent shutdowns not only affect production efficiency but also increase the risk of material deterioration during the retention period. At the same time, the polishing accuracy of the inner wall of the equipment is insufficient, there are cleaning dead corners, and it is difficult to meet the strict hygiene requirements of food production.
Professional demand analysis
Freshly squeezed juice is slightly acidic and rich in natural sugars. This requires higher standards for the corrosion resistance and anti-contamination properties of the equipment materials. Additionally, the filter elements must meet food-grade standards to prevent the release of impurities that could affect the natural flavor and quality safety of the juice.
Customized solution
Based on the flow characteristics of multi-bag filters in the food industry, we recommended a 6-bag filtration system for our customers, combined with food-grade polypropylene (PP) filter bags. This system can achieve a maximum processing capacity of 240 m³/h when handling low-viscosity fruit juices, fully meeting the customer's peak production capacity requirement of 220 m³/h.
The main body of the equipment is made of food-grade 304 stainless steel. The inner wall is polished to a mirror finish (surface roughness Ra ≤ 0.8 μm), effectively preventing residue and bacterial growth. The core filter element uses 15 μm food-grade PP filter bags, which have been certified by a third-party authoritative institution. There is no release of any unpleasant odors. The filtration efficiency is as high as 99.9%. While effectively intercepting fine impurities, it also preserves the natural flavor substances of the juice intact.
Efficiency and cost optimization results
The system adopts a quick-opening ring structure instead of the traditional flange design, combined with special lifting tools, significantly reducing the filter bag replacement time from the original 40 minutes to 15 minutes. As a result, the daily downtime for maintenance is reduced by 1.2 hours, and the annual cumulative effective production time increases by approximately 360 hours, significantly enhancing the ability for continuous production and rapid response. Additionally, the filter bags support cleaning and regeneration with warm water and weak alkaline solutions, demonstrating excellent reusability performance. This not only ensures the filtration effect but also significantly reduces the cost of consumables.
Summary
By introducing an efficient multi-bag filtration system, this juice production enterprise not only successfully solved the core problems of filtration accuracy and processing capacity, but also achieved a comprehensive improvement in equipment operation efficiency, hygiene safety standards, and overall operating costs. As a result, it has been continuously providing high-quality products with stable quality and pure flavor for the high-end market.