All filter elements from production are checked for leaks and loss of pressure prior to shipment

Different versions of sintered filter elements

Fan housing, the main purpose of which is to dampen the noise of outflows.

Clean air recirculation is the recirculation to the working space of the air which has been removed by vacuum extraction and cleaned in separators (clean air). (Source: http://www.weka.de/Explosionsschutz/BGR-121-Arbeitsplatzlueftung---Lufttechnische)

The ratio of volumetric flow to filter surface area

Filter element of the ALPHA filter series for maximum operating temperatures of 450°C

Filter series for maximum operating temperatures of 450° C

Surface design for discharging electrostatic charges

Directives concerned with the fireproof and explosion-proof design of machinery and plants

A backup filter is downstream of another filter and serves a safety function.
This is necessary in case the upstream filter no longer carries out its filtration function correctly because of damage.

What is known in the industry as a filter rupture, with resultant escape of dust to the clean gas side, is a problem associated with conventional filter media such as fabric filters (textile) or cartridge filters (paper).

The Herding sinter-plate filter, being an inherently rigid filter medium with classic surface filtration, is not affected by this.

A second filter stage in the form of a backup filter is not necessary for Herding sinter-plate filters.

The baffle plate/deflector plate in the Herding filter unit serves as a pre-separator for large particles which are brought into the filter unit with the air current. In addition, the baffle plate/deflector plate is also used for setting the air flow in the filter unit so that there is a homogeneous distribution of dust.

See: Top Mounting Filter or Silo Filter

Part of the cleaning system that directs the cleaning pressure pulse into the filter element

PE sintered element of HSL design for maximum temperatures of 100°C

Dust-type inert solid for inertisation and precoating

This is the concentration of dust relative to volumetric flow on the clean gas side of the filter unit and is normally expressed in mg/m³.

Synonymus with clean gas values and residual dust content.

Space in the Herding filter unit is bordered by the slotted plate on which the Herding sinter-plate filters are installed and the housing cover or the acoustic hood. The cleaning unit is in the clean gas compartment.

Dislodging of the cake of filtered dust from the surface of the filter element

All the filter elements of the filter unit are cleaned once during a cleaning cycle

Pressure of the cleaning gas in the pressure tank for the filter cleaning system

See: Cleaning Unit

System for cleaning the filter elements, generally comprised of: pressure tank, diaphragm valves and blow pipes

Surface coating of components or filter elements

Component in the filter unit for guiding the base strips of the Herding sinter-plate filters

Gas compressed to a specific pressure level

Electrical or mechanical control of the function of the dedusting plant.

Component used for sealing an empty installation point for a filter element in the slotted plate of the filter

Cleaning runs on the basis of a pre-set cycle. One cycle means that each quick-opening valve is actuated once. The number of cycles and pause times can be set separately for each job.

Integrated manual plate flap on the acoustic hood for adjusting the volumetric flows within certain limits

Design of the PE sintered filter element with a filter area of 3.75 m²/element

Filter series with a round housing for the installation of DELTA filter elements

Design of the PE sintered filter element with a filter area of 4.75 m²/element

Compact filter series with a rectangular housing and DELTA / DELTA² filter elements mounted horizontally

Modular filter series with a rectangular housing and DELTA / DELTA² filter elements mounted vertically

Modular filter series with a rectangular housing and DELTA / DELTA² filter elements mounted horizontally

The filter elements are cleaned on the basis of the differential pressure

Pressure loss across the entire surface area of the installed filter

Electromechanical switching component which switches the in accordanced with the applied differential pressure

Airtight device for connecting the dust collecting bin to the filter unit hopper

Filter elements with a double filter-active surface coating

Distribution and prevential flow direction of the raw gas in the raw gas chamber of the filter, which in this case is primarily from the top down and can therefore help the process of dust sedimentation during cleaning

Sinter-plate, cartridge, hose, pocket and cassette filters with manual or fully automatic pressure pulse cleaning, plus the respective discharge system required for each. (Source http://www.bioairtec.de/abluftreinigung.htm)

Filter element seal with a foam-filled seal body

Mounting and locking device for the dust bin

Occurs when the dust on the raw gas side uncontrolled breaks through the filter medium to the clean gas side

This is available as an option for getting the cleaned dust from the filter elements out of the filter plant. The dust collecting bin is located below a hopper and is an intermittent discharge system. The dust collecting bin can only be emptied when the filter plant is switched off. If a shut-off mechanism is incorporated between the hopper and the dust collecting bin, the dust collecting bin can also be changed during operation as well.

Operating mode in which the filter's clean gas is transferred to the environment outside the operating areas

Equipment for explosion suppression

This is the term for system components made of stainless steel which come into direct contact with the dust in the raw gas

The resistance loss of the gas flow outside the filter (on the suction side upstream from the filter unit and on the outlet side downstream from the fan) which at least must be overcome by the fan

Part of the extinguishing system for extinguishing fires.
It is comprised of an extinguishing agent tank, pipe line and extinguishing nozzles.

The extinguishing agent in the extinguishing agent tank is specifically suited to the dust to be extinguished (extinguishing powder or extinguishing gas).
The pipe line is aerodynamic in design and construction.

The geometry of the extinguishing nozzles is specifically designed for the requirements of the extinguishing agent and special feeding of the extinguishing agent and the nozzles are fitted in an ideal position on the filter unit.

System for protecting the filter unit; for fire detection, fire alarm and fire extinguishing.
Detectors with VdS approval are used for fire detection purposes and these communicate with a VdS-approved control system.
Fire extinguishing with powder or gas specifically suited for the type of dust to be extinguished.

Average flow velocity over the entire filter surface in m/min

Dust-type material which is inert in respect of filtration and which is metered into the raw gas flow on either a continuous or intermittent basis in order to protect the filter medium

Installed filter surface area

Filter element body. Provides the filter-active surface

Layer of filtered dust on the filter element

Similar to loading per unit of filter area. This describes the ratio of volumetric gas flow to filter area

Control unit of the filter unit, which is mainly for actuating the cleaning process

Self-explanatory

Mounting and fixture device for the filter elements

Support structure for filter elements installed horizontally to reduce the load torque at the element clamping point

Top part of the filter element with the mounts for fastening and for the seal

Filter unit comprised of a slotted plate, filter elements, cleaning system and clean gas housing

Filter-active surface of a filter element

In this context synonymous with the filter element

Equipment for suppressing the spread of flames

Series type

Flexing means the forming of materials by mechanical processes such as kneading, pressing or drawing. (Source http://de.wikipedia.org/wiki/Walken). In the case of filter elements made of fabric, this often leads to high wear. Sinter-plate filters from Herding are not exposed to flexing, because they are rigid bodies.

In this case through air injection of solid particles floating in the air, via a suitable air distribution system

For operating the filter unit without the dust-generating machine.
Follow-up control is used for processes involving short interruption times on the dust-generating machine or where an air flow run-on is required on the machine in the ductwork and/or in the filter unit.

Pressure requirement which is available on the intake port of the Herding filter unit. This must be sufficient for the raw gas pipeline and the dust-generating machine.

This refers to the type of coating used for the surface of the filter

Gas-tight version of a filter unit for pressure and vacuum applications within certain limits

High Efficiency Penetration Air Filter. High-performance filter insert of classes H13 and H14 in storage filter design

HEPA filter (High Efficiency Particulate Airfilter), ULPA filter (Ultra Low Penetration Air) and SULPA filter (Super ULPA) are terms for filters of a particular particle filter class. Filters in this class are used for the filtration of viruses, respirable types of dust, mite eggs and excretions, pollen, smoke particles, asbestos, bacteria, diverse toxic dusts and aerosols from the air. (Source http://de.wikipedia.org/wiki/Schwebstofffilter).

Herding® sinter-plate filter = Depressurized, sintered polyethylene filter element with different filter-active surface coatings

Filter element seal, made of extruded rubber material in the shape of a hollow body

Special filter unit series for maximum operating temperatures of 450°C

Generally the housing of a filter unit

The top cover plate on the filter housing

Herding sinter-plate filter element and series type of Herding

Type HSL filter element exclusively for vertical installation

Series type for installation of HSL filter elements

Series type for installation of HSL filter elements for maximum operating temperatures of 100°C

Compact filter unit with HSL filter elements in tested, explosion-proof design

Series type for installation of HSL filter elements

See: Face velocity

See interval time

Conversion of a reactive dust into an inert dust (solid or gas inertization of combustible, potentially explosive dusts, or inertization for binding adhesive substances. See: precoating

Component with certain material characteristics that help it to retain its geometric shape under the influence of external forces

Application of precoat material on the installed filter elements prior to start-up

When the dust is discharged from the Herding filter unit, the separated dust is discharged by the compressed air flowing into the injector at high velocity and the vacuum effect that is generated

Separate or attached housing part of the filter apparatus for the raw gas inlet

Pause between the opening intervals of the valves on the cleaning unit for the Herding sinter-plate filters

For cleaning the Herding sinter-plate filters with compressed gas

Geometry of the Herding sinter-plate filters. Apart from an optimum inflow the lamella shape also provides for a large surface area and a sturdy structure.

The length of time that a technical object can be used before it has to be replaced or completely fails.

Given the classic surface filtration process on a non-pliable rigid body, this is normally many years for Herding sinter-plate filters, if they are used as intended.
For example, 15 years in the cement industry in 3-shift operations, or more than 10 years in the chemicals industry.

Separate equipment for receiving the dust from the filter unit hopper

Vacuum extraction of an object such as a machine (dust-generating machine) in order to clear the machine of dust as it collects and to prevent the operating personnel getting covered in dust as well. This requires the use of a local filter (see local filter)

Filter unit with connected raw and clean gas pipelines and fan on the raw gas side for vacuum extraction of an object such as a machine (dust-generating machine). The purpose of the local filter is to remove the dust collecting in the machine so that the machine does not suffer any damage from the dust, and to prevent the hazardous dust coming into contact with the operating personnel - see local exhaust.

For the opposite to this, see process filter.

Component made of powder-coated metal in the filter unit for guiding the base strips of the Herding sinter-plate filters

Dust discharge with least possible contamination/soiling of the environment surrounding the filter unit, and therefore for the protection of objects and persons, when the dust is removed from the filter unit

Herding filter plants and filter elements require very little maintenance, because of their rugged design.

A version of surface coating for the Herding sinter-plate filter. M-coating is a mineral coating with high pH resistance.

A series of Herding filter units comprised of modular units (see modular unit).

A version of Herding filter units.
For applications involving larger volumes of air, the required filter surface area is achieved with a modular sequence of several filter housings.

Filter control system developed in-house for Herding filter units.
Processor unit for controlling and monitoring the cleaning of Herding sinter-plate filters, the vacuum generators such as fans or by-pass blowers, the discharge systems and other field devices on the filter unit.

Equipment developed in-house for the automatic running of the precoating process. Either a precoat material is used here which is different to the dust separated in the filter unit or dry dust is used which is similar to the dust separated.

A version of the Herding sinter-plate filter. The uncoated filter elements are comprised of a microporous filter element without coating and act as deep-bed filters. The separation of oil mist or more generally of liquid droplets (mist) from the process gas is possible.

A version of the Herding sinter-plate filter.
The pore structure of these filter elements prevents the filter element from becoming charged by the inflow of dust particles with the process gas or during cleaning and therefore the keeps the dust particles separate from the filter elements.

Surface coatings which contain no halogenated substances (above all free of fluoride compounds)

Grille on the clean gas outlet of the filter to prevent access

The base body of the Herding sinter-plate filter is made of sintered polyethylene (PE) material. It is this material, in combination with the saw-tooth geometry of the filter surface, that makes the filter element so stable and non-pliant. In combination with the surface coating, the Herding sinter-plate filter acts as a classic surface filter and is very long lasting if used as intended.

A Herding filter unit that is suitable for potentially explosive dusts without constructional protection against explosion. Explosion volume limitation measures allow organic dust of dust explosion class St2 (up to K(St) = 300 barm/s) to be handled, as well as an explosion pressure of 10 bar and minimum ignition energy of greater than and less than 3 mJ.

Emptying of the hopper by means of pressure or vacuum

Pneumatic quick-opening valves can be actuated by pilot valves or by a pneumatic controller. A pneumatic controller controls a maximum of 20 filter pulse valves and replaces the solenoid control unit. The pulse valves are connected to the pressure chamber of the controller by small bore airlines (max. 2m long). The wiper arm assembly of the controller is operated by a pneumatic ratchet drive. It pauses between valve connections for a preset time which is adjustable by the user. The switching time is also user adjustable by means of a throttle valve accessed after removal of the bottom casing. During the switching time the wiper arm passes beneath a valve connection port and vents the pilot. The valve open and remains open until the wiper arm moves on to the next position. The pilot air is vented through the port underneath the manual override knob, which is marked to show the exact position of the wiper arm. (Source http://www.buschjost.de/pdf/D82870.pdf)

Equipment developed in-house for the manual running of the precoating process. A precoat material can be used here which is either different to or the same as the dust separated in the filter unit.

The addition of an inert solid (see inertization, see calcium carbonate) will bind a dust which has adhesive characteristics. The result is an inert, non-adhesive mixture of substances that can be safely separated and cleaned in the Herding sinter-plate filter. Stable extraction from the dust generating-machine is possible.

The equipment is able to withstand a specific pressure surge

Pressure shock resistant design of the apparatus in accordance with the required pulse of compressed air

Volume of the pressure accumulator for the cleaning system

Pressure-resistant design of the apparatus in accordance with the required pressure level 

Filter unit with connected raw and clean gas pipelines and fan on the raw gas side for vacuum extraction of a machine which is directly upstream. The process filter is for separating the solids from the air current and is used for the production of bulk material products suitable for further processing.
For the converse of this, see local filter.

A series of Herding filter units comprised of welded steel structures. Available in stainless steel and normal steel versions.

The dust separated in the Herding filter unit and discharged at the hopper can be fed on to a further working and treatment process. The converse of product recovery is the disposal of the dust as waste.

A version of surface coating for the Herding sinter-plate filter. The PTFE coating is a microporous coating which is bonded fast to the surface of the base body. This coating on the inherently stable and saw-tooth shaped base body made of polyethylene (see PE substrate) is what is responsible for the functional principles of the Herding sinter-plate filter as a classic surface filter (see surface filtration).

Equipment developed in-house for the automatic running of the precoating process. The separated, transformable dust is used here as a precoating material.

Opening time of a valve on the cleaning unit for the Herding sinter-plate filters

Valve on the cleaning unit for the Herding sinter-plate filters.
This is actuated by electromagnetic actuators, and the special geometry of the valve enables it to open quickly and therefore send a shock-like pulse for cleaning the dust off the surface of the Herding sinter-plate filter.

A series of Herding filter units comprised of pipe sections connected to each other with clamping rings. The Herding sinter-plate filter and the cleaning unit are mounted on the slotted plate. This slotted plate with mounted components is also clamped between two pipe sections with a clamping ring.

This is the concentration of dust relative to volumetric flow on the raw gas side of the filter unit and is normally expressed in g/m³

Dust side (=the system components that come into contact with dust in normal operation).

In circulating air mode there is no air fed in from outside (saving of saving), the air being recirculated instead (Extraction point -> Filter plant -> Extraction point (or building))

Operation used for recoating used Herding sinter-plate filters.

Re-use of the treated and recoated base body of used Herding sinter-plate filters.

Herding sinter-plate filters are designed as rigid bodies. Hence our filter elements do not develop any signs of wear caused by flexing.

Rotary air locks are devices used for dosing, feeding or discharging fine-grained and dust-type products or granulates from the bottom section of a hopper. Rotary air locks are installed below filters and cyclones to enable bulk solid material to be discharged from air conveying systems with minimum possible loss of pressure.  (Source http://de.wikipedia.org/wiki/Zellenradschleuse)

Filter unit with a cylindrical design. Typical round filters include, e.g. pressure shock resistant filter plants

For cleaning the Herding sinter-plate filters without process gas and dust flowing through the filter unit.

Safe (low contamination) change of dust collecting bins or other system components. As a rule this is normally carried out with a sack board with two grooves and two O-rings. Also referred to as BIBO (bag in and bag out).

Partition wall between the clean gas compartment of the filter and the compressed air tank for the filter cleaning system

With a SelfCoater, part of the cleaned dust is discharged back to the raw gas pipeline again. This circulating dust then serves as a filter additive.

The percentage relationship between the difference between the raw and clean gas dust concentration relative to the raw gas concentration

The service lives of Herding filter plants often exceeds 10 years. We provide a 24 month warranty for the filter plant/elements as standard, subject to a maximum of 15,000 hours of operation. You are also welcome to extend the warranty period for the filter elements to a maximum of 5 years or 25,000 hours of operation by concluding a service contract with us. The service is carried out once a year and gives you enhanced operational reliability.

High-molecular polydimethylsiloxanes (PDMS, or known simply as "silicones"), and sloughage from synthetic materials (e.g. polyethylene, polytetrafluorethylene) and high-molecular polyglycols can cause severe surface deterioration even with the least contamination of our products when these are used in paint shops. Cross-linked silicones (e.g. silicon rubber) are by themselves harmless. But most silicon rubber products contain enriched high-molecular silicon oils as softeners. Such substances are highly incompatible with varnishes and they cause surface deterioration (sinkholes) in the varnish coating. (Source http://www.purplan.com/information/silikonfreiheit.html). Silicon-free means not using any materials and products in production that contain silicon. An additional cleaning process is often required to ensure that this is the case.

See: Top Mounting Filter and Bin Vent

A filter which is mounted on top of a large storage tank and which allows the displaced air without dust to escape from the tank after filtering during filling.

Synonymous to bunker top filter.

Porous, seamless sintered PE plates.

We guarantee that our sinter-plate technology delivers clean gas values of < 1 mg/m³, even for types of dust with D50 < 1µm. The base body is made of sintered PE. An additional PTFE coating is embedded in the pores of the PE base body and forms a microporous, non-stick surface. This combination of materials is resistant to chemicals to the greatest possible extent. Herding® sinter-plate filters are exceptionally stable, non-pliable and water-proof and require only minimal maintenance. They can last for longer than 10 years.

Herding® sinter-plate filters offer top rates of separation and excellent environmental compatibility. The filters can be recycled without any problems, and there is no hazardous waste to be disposed of from the materials used for the elements.

The siphon is a trap in a hopper used with oil mist devices. It is based on the principle of an S-shaped pipe, the lower bend of which is permanently filled with oil and therefore prevents gases from getting through. At the same time, however, the siphon does not prevent liquids from flowing through it. (Source http://de.wikipedia.org/wiki/Siphon_%28Geruchsverschluss%29)

The separation level between raw gas (dust side) and clean gas (clean side), on which the filter elements are secured.

A quick-opening valve which is mounted on a pressurized tank. The opening of the valve generates a cleaning pulse which dislodges the dust from the filter elements.

Multipurpose, low-cost valve controller. In combination with the MP12 suitable for use as master and slave. The MP12 filter control center can only be used as a master whereas the SP16 valve controller can be used as both a master or slave. This provides maximum flexibility at the hardware level.

Assembly component for restricting the filter element seal pressure during installation

Device for extinguishing sparks brought in from outside

The Herding sinter-plate filter has a coating on/in its surface (not a membrane). This microporous coating permits classic surface infiltration of the dust particles on the stable and non-pliable base bodies of theHerding sinter-plate filters when the process gas flows through.

In surface filtration the dust particles are held back on the surface of the filter medium. The dust particles form a filter cake which is responsible for the actual filtration function. The thicker the filter cake layer becomes, the greater the dust separation. This leads to an increase in differential pressure and reduction in volumetric flow. The cleaning of the filter elements counteracts the increase in pressure and reduction in volumetric flow. In classic surface filtration on the Herding sinter-plate filter, continuous cleaning ensures that suction ratios are maintained at a constant level.

Surface resistance is the electrical resistance measured on the surface of an object.
It is measured between two parallel electrodes of minimal width and both with lengths of 100 mm, positioned 10 mm apart and in contact with the surface to be measured. The surface resistance is expressed in Ω

Stabilization rail on the foot of a filter element

Generally filter units used for the direct venting of silo systems. See also silo filter bunker filter and bin vent

Total separators are used for separating large volumes of dust held in the feed air. Since the feeding process requires high levels of pressure, the plants are designed as round filters. The raw gas inflow is often tangential because of the high product loads involved.

Stabilization on the filter elements' head

The vacuum feeder is a discharge device which is installed at the lower end of a hopper. The negative pressure in the filter unit keeps the vacuum feeder closed. When the separated product (dust) or a cleaning pulse exerts a high enough load, the vacuum feeder will open and the product (dust) will be discharged. As soon as the negative pressure and the load return to a state of equilibrium, the vacuum feeder will close again.

In the Herding Flex series the valve compartment is integrated in the area of the clean gas compartment. This can be supplied with a sealing wall in such a way that access to the valves from the outside is possible during operation. In addition, the sealing wall can also seal the valve compartment in such a way that the valves are not exposed to the volumetric flow of clean gas.

Herding Filter Technology uses an MP12 or SP16 for the control unit for the valves as standard. This enables a wide range of cleaning programs to be used.

It is advisable to install a valve heater for filter plants installed outdoors. This prevents condensation water from freezing in the cleaning unit when temperatures fall below zero, thereby preventing malfunctions on the quick-opening valves.

Self-explanatory

A washable filter element can be washed

Herding filter plants can be supplied with a first-rinse system or with a WIP system. With the first-rinse the elements are rinsed with a rinsing fluid prior to removal, thereby enabling the hazardous dust, if present, to be bonded so that no dust is raised when the filter elements are removed. With a WIP system the element is rinsed in such a way that only a minimal amount of dust is left over.

Herding sinter-plate filters can be used as an ATEX zone barrier for dust explosions. The clean gas side can be declared as zone-free if there is an ATEX Zone 20/21 or 22 in the raw gas section and Herding sinter-plate filters are used.