Back pressure flap ProFlapII and ProFlapPlusII for ... · PDF fileBack pressure flap ProFlapII and ProFlapPlusII for explosion decoupling Numerous processes can create ex- ... ProFlapII_200

ProFlapII and ProFlapPlusII

Back pressure flap ProFlapII and ProFlapPlusIIfor explosion decoupling

Numerous processes can create ex-plosive dust/air mixtures inside in-dustrial systems (eg., dust collectors, mixing machines, fluid bed granula-tor, mills, etc.). If ignition sources cannot be prevented due to process conditions, these systems are often equipped with constructive explosion preventive measures such as pres-sure relief or pressure suppression. In this regard, connected ductworks are

decoupled from containers to be pro-tected so that no flames and explo-sion pressure can be transferred into other areas.

Sample application of an exhaust system that is equipped with explo-sion pressure relief:

Keller Lufttechnik developed the back pressure flap series ProFlap for an ef-fective explosion decoupling for near-ly all industrial sectors. The ProFlap is certified as a protective system according to EU Guideline 94/9/EG (ATEX 95) and is approved for decoupling of dust explosions of organic and mineral dusts.

The Task

The Solution

ProFlapPlusII

mounting distance

back pressure flapcapturing

separator

explosion pressure relief

fan

2

Operation

During operation, the downstream mounted back pressure flap is kept open by means of the air flow. When fully stopped, the flap closes by its own weight. When the system starts up, the opening of the flap is restrained by a damping element

Normal operation

During an explosion inside a protect-ed system, the flap is closed by the pressure surge inside the ductwork. The explosion flame and the pressure cannot strike back the ductwork. Per-sonnel working at capturing points or downstream system parts are pro-tected against the explosion effects. The flap damping element prevents the flap from opening following an explosion because of decreased pres-sure.

In the event of an explosion

The downstream mounted back pressure flap is kept open by means of the air flow

To increase inspection intervals, the optional monitoring device “ProFlapPlus” is available (patented). An integrated wear sensor and a sen-sor to monitor the flap position con-trol the wear of the flap and the clos-ing operation.

The sensors are completely wired inside a control cabinet which is mounted at the return valve. An anal-ysis of the signals is carried out at the electrical cabinet which is provided by the customer. Alternatively, it is possible to purchase a separate electrical cabinet (see „accessories“).

Monitoring function of ProFlapPlus (optional)

Accumulation sensorWear sensor

ProFlapPlusII

On an explosion within a protected system the flap closes due to the pressure front spreading within the ductwork

3

downstream explosion decoupling of dry dust separators• when grinding fiberglass reinforced

components• for chemical and pharmaceutical

industries• for timber industry

• for varnish dusts etc.• for blasting plants

Explosion decoupling for dryers, air separators, mills, silos, fluid bed granu-lators, etc. Applications also possible for dust concentrations exceeding the lower explosion limits.

Scope of applications

• certified according to the latest test standard CEN/TC 305/WG 3 N457 (Stand: 05/2012)

• applicable for organic and mineral dusts

• passive system, no triggering sensors required

• inexpensive in comparison to other decoupling systems

• modular monitoring package for

system control and greater inspection intervals

• easy access using fasteners, without loose components

• ease of access for inspection with swiveling flap

• integrated consoles for easy assembly

• variable mounting distances (for suction ducts, the referenced

distances are minimum dimen-sions)

• application feasible for dust concentrations beyond the lower explosion limits (specified distances must be strictly adhered to)

Advantages

When developing the monitoring sen-sors, up-to-date air flow simulation systems were used in order to deter-mine ideal positioning of the sensors.

Simulation systems

flow advancing from belowdirectly advancing flow

laterally advancing flowadvancing flow from above

CFD Proflap NS315simulation parameters:velocity of oncoming flow : 20 m/sparticle mass flow (silica): 5,7 g/sparticle size distibution (silica): 10µm up to 500µm

Effect of impacting particles on sheet metal (indication of abra-sion):blue: no abrasionred: increased abrasion

4

Sizes, technical data

Type Nominal width

Length L Width B Height H Height S Weight Pressure loss on 20 m/s

Max. ope-ning angle of the flap

Possible dust explosion category

Max. KST-value

Max. reduced excess pressure (pred, max) in the con -tainer filter)*

Pressure surge resist-ance of back pressure flap

Min. installa-tion distance at St1


Max. installa-tion distance at St1


NW mm mm mm mm kg Pa bar x m/s bar bar m m m m

ProFlapII_140 140 420 380 430 390 27 380 20° St1 and St2 300 0,7 1,5 2,6 3,6 6,6 7

ProFlapII_160 160 490 455 462 420 31 approx. 400 20° St1 and St2 300 0,7 0,95 2 3,5 7 7,5


ProFlapII_250 250 590 540 530 480 46 320 20° St1 and St2 300 0,7 0,95 2 3,5 7 7,5



ProFlapII_355 355 750 610 642 590 82 360 30° St1 200 0,5 0,6 2,6 Not allowed 6,6 Not allowed




ProFlapII_560 560 930 840 846 820 152 approx. 450 30° St1 200 0,5 0,6 2,6 Not allowed 6,6 Not allowed

ProFlapII_630 630 1090 1050 970 880 220 approx. 500 30° St1 200 0,5 0,6 3 Not allowed 7 Not allowed





Scale drawing ProFlapII

Mounting position: horizontal, on the suction side (fan behind ProFlapII)Air flow velocity: 15 – 30 m/sTemperatures: -10 to + 60°CMaterials: housing: S235JRG2, flap: stainless steelPaint finish: RAL 3000 “blazing red”

5

Type Nominal width

Length L Width B Height H Height S Weight Pressure loss on 20 m/s

Max. ope-ning angle of the flap

Possible dust explosion category

Max. KST-value

Max. reduced excess pressure (pred, max) in the con -tainer filter)*

Pressure surge resist-ance of back pressure flap





NW mm mm mm mm kg Pa bar x m/s bar bar m m m m

ProFlapII_140 140 420 380 430 390 27 380 20° St1 and St2 300 0,7 1,5 2,6 3,6 6,6 7










ProFlapII_560 560 930 840 846 820 152 approx. 450 30° St1 200 0,5 0,6 2,6 Not allowed 6,6 Not allowed






Subject to modifications.* The ductwork between ProFlapII and explosion protected housing/filter shall have the same

max. reduced Pred, max (normally at least 2 mm sheet thickness, welded).

6

Accessories and guidelines

A separate electrical control cabinet is available with integrated switch amplifier for the wear sensor.

Back pressure flaps are subject to a design check according to EU Guide-line 94/9/EC (ATEX 95), latest stand-ard applicable. Quality assurance is audited according to 94/9/EC (ATEX 95) and is regularly controlled. It is

therefore permissible to return the back pressure flaps into circulation as independent protection systems.

Accessories

Guidelines and Standards

Reference installations – examples

7

© K

elle

r Luf

ttech

nik

- all

right

s re

serv

ed.

Sub

ject

to m

odifi

catio

ns.

11/2

012

ProFlapII and ProFlapPlusII

Keller USA, Inc.2168 Carolina Place Drive FORT MILL, SC 29708Phone: +1 8033962000Fax: +1 8033962905 [email protected]

Documents

Back pressure flap ProFlapII and ProFlapPlusII for ... · PDF fileBack pressure flap ProFlapII and ProFlapPlusII for explosion decoupling Numerous processes can create ex- ... ProFlapII_200