Single Filter Housing
Single Bag Filter Housing System
Single bag filter housings are compact, economical pressure vessels designed to hold one replaceable filter bag for effective solids removal from liquids. Fluid enters the housing, passes through the bag (capturing particles inside the media or on its surface), and exits as clarified filtrate. These housings are widely used when flow rates are low to moderate, quick bag changes are desired, and cost-effective filtration is a priority. Common applications include chemicals, paints & coatings, food & beverage, water treatment, pharmaceuticals, and various industrial process streams.
System Design & Key Components
Single bag filter housings feature a cylindrical pressure vessel equipped with a perforated stainless steel support basket. This basket holds and stabilizes the filter bag during operation. Operators insert the bag and seal it at the top with a snap-band, O-ring, or flange ring before securing the lid. Liquid typically enters above the bag, flows downward through the media, and exits via a bottom or side outlet. Housings are constructed from stainless steel, carbon steel, or high-grade plastic and use quick-access closures such as V-clamps, swing bolts, or eye-bolt designs for easy maintenance.
Filtration & Maintenance Process
Users generally follow this sequence to operate and maintain a single bag filter housing:
- Initial Setup — Clean the housing interior, insert a fresh filter bag, close the lid securely, and vent trapped air.
- Normal Operation — Pump liquid into the housing under pressure (typically 2–10 bar); solids accumulate inside the bag while filtrate exits.
- Performance Monitoring — Observe the differential pressure gauge. When ΔP reaches 1–2 bar — or visual inspection shows heavy loading — pause the flow.
- Bag Replacement — Depressurize the system, open the lid, remove the used bag (often using the built-in handle or ring), dispose of it or clean if reusable, and install a new bag.
- Restart — Secure the lid, vent air, and resume flow. The entire change-out usually takes only 5–10 minutes.
Comparisons
| Feature | Single Bag Housing | Multi-Bag Housing |
|---|---|---|
| Flow Capacity | Low to moderate (5–50 m³/h typical) | High (50–500+ m³/h depending on number of bags) |
| Footprint & Space | Very compact | Larger (multiple bags in one vessel) |
| Change-Out Time | Very fast (5–10 minutes) | Moderate (10–20 minutes) |
| Cost (Housing + Bags) | Lowest initial cost | Higher initial cost, but lower per-flow cost |
| Best Suited For | Small systems, pilot plants, batch processes | High-flow continuous processes |
| Maintenance Frequency | More frequent bag changes | Less frequent per bag due to higher total capacity |
| Feature | Single Bag Housing | Cartridge Filter Housing |
|---|---|---|
| Filtration Mechanism | Depth filtration (solids trapped inside bag) | Surface or depth (pleated or wound cartridges) |
| Solids Holding Capacity | High (large internal volume) | Moderate to high (especially pleated designs) |
| Change-Out Time | Very fast (5–10 minutes) | Moderate (10–20 minutes for multi-cartridge) |
| Cost per Change-Out | Low (bags are inexpensive) | Higher (cartridges cost more) |
| Best Suited For | Moderate to high solids, coarse-to-medium filtration | Fine filtration, polishing, low-solids streams |
| Typical Micron Rating | 1–200 μm | 0.2–100 μm |
Typical Operating Parameters
| Parameter | Typical Range | Notes |
|---|---|---|
| Micron Rating | 1–200 μm (nominal) | Depends on bag material and construction |
| Operating Pressure | 2–10 bar (30–150 psi) | Maximum recommended ΔP usually 1.5–2.5 bar |
| Flow Rate | 5–50 m³/h | Varies by bag size (#1 or #2 most common) |
| Recommended Change-Out ΔP | 0.8–2 bar | Follow manufacturer guidelines |
| Temperature Range | 0–150 °C | Limited by bag material (polypropylene, polyester, nylon, PTFE, etc.) |
Common Applications & Advantages
| Industry / Application | Typical Fluid | Primary Goal |
|---|---|---|
| Chemicals & Coatings | Resins, solvents, paints, inks | Particle removal, product clarity |
| Food & Beverage | Syrups, juices, edible oils, beverages | Clarification, solids control |
| Water Treatment | Process water, cooling water, rinse water | Equipment protection, fluid reuse |
| Pharmaceuticals | Intermediates, buffers, process liquids | Pre-filtration before finer stages |
| Laboratory & Pilot | Test fluids, small batches | Quick setup, flexible filtration |
Key Advantages of Single Bag Filter Housings
- Extremely compact design — ideal for limited space
- Very fast bag replacement (5–10 minutes typical)
- Lowest initial capital cost
- Economical consumables (bags are inexpensive)
- Easy integration into existing piping systems
- Reliable performance for low-to-moderate solids loading
Also check out, "Bag Filtration"