Pure Air & Water Engineers

13/04/2026

🔷 What is a Positive Pressure Dust Collector System?
A positive pressure system means:
Clean, filtered air is pushed INTO a room or enclosure
Internal pressure is higher than outside
Air leaks flow outward, preventing dust from entering
👉 In simple words:
Instead of sucking dust out, you block dust from coming in

23/03/2026

Opportunity
Pure Air & Water Engineers
Pls contact
Pinsara 071577 6779
Amila 0772355990

21/03/2026

Mechanical Ventilation System

21/03/2026

Roof Mounted Powered Ventilators
Less Power, More Efficient, Less Maintenance

06/03/2026

Not only for QS and Who prepare the BOQ never Give Pre Budgets without Site Visit or Detailed Planning.

🪤 **QS ලා අහුවෙන දරුණුම උගුල:**
**“මල්ලි, නිකන් Rough එකක් කියන්නකෝ!”** 😂🤦‍♂️

ලෝකේ ඉන්න **අහිංසකම ජාතියක්** තමයි අපි QS ලා.

කවුරුහරි Client කෙනෙක් හරි Boss කෙනෙක් හරි මෙහෙම කිව්වොත්…
අපිත් පව් කියලා උදව් කරන්න යනවා.

🗣️ **Client / Boss: **

“මල්ලි මට මේකේ Detailed BOQ ඕන නෑ.
ඔයා Area එක බලලා නිකන් Rough Estimate එකක් කියන්නකෝ…
Idea එකක් ගන්න විතරයි.”

ඔන්න ඉතින්… 😌

👷‍♂️ **අපි (QS): **

Drawing දෙක තුනක් බලලා…
ඇඟිලි වලින් Rough calculation දෙකක් දාලා…
Confidence එකෙන් කියනවා:

💰 **“සර්, roughly ලක්ෂ 10ක් වගේ යයි.” **

⏳ **මාස 2කට පස්සේ…**

Detailed Drawings ඔක්කොම ඇවිත්
Proper Take-off කරලා
Current Market Rates දාලා
හරියට BOQ එක හදලා බැලුවම…

💸 **Final Cost – ලක්ෂ 15යි!**

😡 **Client / Boss: **

“මල්ලි… එදා ලක්ෂ 10යි කිව්වේනේ!
දැන් කොහොමද මේක 15 වුණේ?”

එතනින් පස්සේ තමයි
**QS කෙනෙක්ගේ ජීවිතේ explaining session එක පටන් ගන්නේ!** 😂

📌 **Moral of the Story: **

QS කෙනෙක්ගෙන් **“නිකන් Rough Estimate එකක්”** අහන එක
ඇත්තටම **Dangerous Sport එකක්!**

Drawing නෑ ❌
Details නෑ ❌
Market Rates unstable ❌

එතකොට Rough Estimate එක
**Guessing Game එකක් වගේ තමයි!** 😅

👇
**QS ලා… මේ “Rough Estimate” උගුලේ වැටිලා තියෙනවද?**
Comment එකක් දාලා බලමු! 👷‍♂️

04/03/2026

Positive Pressure Dust Collector


A **positive pressure dust collector bag system** (also called a *pressure-type baghouse*) is a dust collection system where the **fan is located before the filter unit**, pushing dusty air **into** the bag filter housing under positive pressure.

Since you're working in **dust extraction systems**, I’ll explain this from a practical design and application perspective.

---

# # 🔹 1. Basic Working Principle

In a **positive pressure baghouse**:

1. The **blower/fan** pulls dusty air from the process.
2. The fan **pushes air into the bag filter housing**.
3. Dust-laden air enters the bag chamber.
4. Dust particles are trapped on the **outside surface of filter bags**.
5. Clean air exits from the clean air plenum to atmosphere or duct.

```
Process → Fan → Bag Filter → Clean Air Outlet
```

System inside the baghouse is under **positive pressure**.

---

# # 🔹 2. Main Components

* Centrifugal blower (placed before baghouse)
* Bag filter housing (mild steel / SS / FRP)
* Filter bags (Polyester / PP / Nomex depending on temperature)
* Bag cages
* Dust hopper
* Rotary airlock valve
* Pulse jet cleaning system (if pulse type)
* Pressure gauge / DP gauge

---

# # 🔹 3. Types of Positive Pressure Bag Filters

* Pulse jet bag filter
* Shaker type bag filter
* Reverse air baghouse

(Pulse jet is most common in industrial applications.)

---

# # 🔹 4. Advantages

✔ Suitable for small & medium systems
✔ Lower initial duct static pressure
✔ Good for non-hazardous dust
✔ Fan handles clean-side balancing easily

---

# # 🔹 5. Disadvantages

⚠ Leakage risk — because casing is under pressure
⚠ Not ideal for toxic or explosive dust
⚠ Maintenance access must be well sealed
⚠ Higher casing fabrication quality required

If leakage happens, dust escapes outside instead of air entering inside (which happens in negative systems).

---

# # 🔹 6. Positive vs Negative Pressure Baghouse

| Feature | Positive Pressure | Negative Pressure |
| ---------------- | ----------------- | ----------------------- |
| Fan Location | Before baghouse | After baghouse |
| Housing Pressure | Positive | Negative |
| Leakage Effect | Dust leaks out | Air leaks in |
| Safety | Lower | Higher |
| Common Usage | Small plants | Large industrial plants |

Most modern industrial plants prefer **negative pressure systems** for safety.

---

# # 🔹 7. When to Use Positive Pressure System

You can consider positive pressure when:

* Dust is non-toxic
* System is small (< 10,000 CMH approx.)
* Budget limitation
* No explosion risk
* Workshop-type application

Avoid for:

* Pharmaceutical plants
* Chemical plants
* Fine combustible dust
* High-temperature processes

---

# # 🔹 8. Design Considerations (Important for You)

Since you're a design engineer, key calculations:

* Air volume (CMH)
* Air-to-cloth ratio (1–1.5 m/min typical for pulse jet)
* Bag diameter & length selection
* Static pressure

22/02/2026

Mechanical Ventilation

18/02/2026

Service Inspection maintenance

18/02/2026

Site Inspection Maintenance

02/01/2026

31/12/2025

Happy New Year 2026!
From Pure Air & Water Engineers,
we wish our valued clients and partners a year filled with pure success, fresh opportunities, and crystal-clear progress, as we continue delivering innovative solutions for cleaner air making every breath count in the new year!.

2026