food, chemical & pharmaceutical powder recovery · advanced cyclone systems (acs) ... (see...

Hurricane & ReCyclone® Systems

Food, Chemical & PharmaceuticalPowder Recovery

2 www.advancedcyclonesystems.pt

Advanced Cyclone Systems (ACS)Towards total particle capture with optimized cyclone systems

ACS is a company exclusively dedicated to the development and supply of the most efficient cyclone systems worldwide.

ACS SystemNestléAçores

ACS FocusWe focus on particulate matter (PM) emission control (EC) in boilers, furnaces and dryers.We also work on enhancing powder recovery (PR) in pharmaceutical, food and chemical processes.

ACS Mission Achieving particle capture exclusively with cyclones by continuously researching and innovating, freeing the client from the costs and problems of Electrostatic Precipitators (ESPs) and Bag filters (BF).

ACS Approach We work in close cooperation with our clients, designing customized cyclones that solve their filtration problems. Unlike most cyclone providers, we give strict guarantees of emissions and efficiency.That’s why ACS has been the chosen company for over 200 projects in 36 countries all over the world.

unique provider of high performance gas/solid separation at a much lower total cost of ownership

ACS Cyclones

ACS cyclone systems contradict the general thinking that cyclones are inefficient powder collectors. Hurricane cyclone geometries, with the possibility of recirculation (ReCyclone Systems) have proven to be an alternative to ESPs and BFs in numerous plants all over the world to comply with strict limits, reaching emissions as low as 30mg/Nm3.

Why are our cyclones better?We have a specialized scientific knowledge in particle ag-glomeration modeling (PACyc) and numerical optimization in partnership with the Engineering Faculty of Porto (FEUP) where we run a pilot system for R&D.

The revolutionary concept of particle agglomeration is essen-tial to explain how cyclones really work and, consequently, to optimise them. The outcome of our research is not an univer-sal solution, but a set of very different cyclone families and systems serving particular client needs and customizable for each given application.

Total cost of ownership (maintenance & operation)

0

Multicyclones& other

cyclones

www.advancedcyclonesystems.pt 3

The problem with powder collection

The recovery of Active Pharmaceutical Ingredients (APIs), chemical substances and food powders after drying applica-tions, such as spray and fluid bed drying, is frequently inefficient. Powder losses also occur in milling, micronization and tablet pressing applications. To recover these sensitive products, cy-clone collectors are frequently mandatory, as they allow for a direct powder capture, avoiding product holdup of filters. That means no contamination with filter fibers, no product cross con-tamination and no product degradation with temperature. However, cyclones’ low efficiency results in economic losses due the high value of the powder or due to the large processed quantities per year. Frequently, cyclones have to be followed by expensive “food grade” bag filters to increase yield or to avoid emissions to the atmosphere.

Separation processes after drying, milling and micronization are frequently inefficient

Spray drying is a technology used for the most varied types of powders, including milk, whey, coffee, APIs, proteins, coatings, ceramics, among many others. Usual spray drying arrangements (single point, two point and closed cycle) include a high efficiency cyclone and a bag filter, whenever emission limits are stringent. Indeed, for fine powders with a median volume diameter (MVD) of less than 5 μm, losses/emissions due to low cyclone efficiency can rise to more than 25%. In pharmaceutical powders and in many food ingredients, the fraction of product escaping to the bag filter is not considered as 1st grade product, but as loss. In other applications where powder collected in CIP type bag filters is usable, clogging problems are frequent and filter washing times cause high production downtime.

The industry needs a cyclone system which dramatically increases powder yield and is efficient enough to comply with dust emission limits, thus avoiding the use of bag filters.

In tablet pressing, cyclones are an effective way to collect powder originated inside the machine and which is extracted into a cartridge filter. Product can be either put back in the process without cross contamination or contamination with filter fibers or to account for losses of the tablet pressing machine, following API regulation. Also, it serves the purpose of reducing blockage of cartridge filters.

Pharmaceutical ingredients

Chemicals

Food ingredients

Fuel oil combustion

Nanoparticles

Mineral processing

Calcination processes

Fertilizers

Milling & drying processes

Application Fields

ExamplE CasE 1 Typical spray drying arrangement

ExamplE CasE 2 Typical tablet pressing machines arrangememt arrangement

Single point discharge spray drying arrangement

Tablet pressing machine arrangement

hurricane system

tablet press

cent

ral a

spira

tion

syst

em

deduster


ACS numerically optimized cyclones

What is ACS solution?The 200 projects implemented over the past 7 yearshave allowed ACS to develop a complete line of very different hurricane cyclone families that take into consideration the way inter-particle agglomeration / clustering affects efficiency. From coarse particle separation provided by compact and low pressure drop cyclones, such as the SD and DX lines, to fine particulate capture with high-end geometries such as the EX and MK, ACS provides solutions for a wide range of industrial cases, being able to reach emissions as low as scrubbers or even WESPs (down to less than 30mg/Nm3).

Particle Agglomeration and Numerical OptimizationACS research team has been investigating this phenomenon since its foundation. Several related technical and scientific articles were published, among which the “Impact of particle agglomeration in cyclones” (Chemical Engineering Journal 162 (2010) 861–876)”. This knowledge has helped ACS build very accurate models of efficiency prediction, capable of explaining why sub-micrometer particles are often captured with much higher efficiency than expected. Indeed, particles tend to form bigger agglomerates (clusters) much easier to collect than the original particles. Agglomeration increases in the presence of wide particle size distributions, long residence times in the cyclone and high inlet particle concentrations. This knowledge has been incorporated in ACS numerical simulation tool, combining a sophisticated stochastic algorithm with a classical numerical model to predict cyclone performance: the PACyc (Particle Agglomeration in Cyclones) model.

Creating multiple cyclones for multiple needsThanks to the PACyc Model, and considering several economic and operational constraints (such as size and pressure loss), it is possible with numerical optimization to simulate millions of virtual prototypes within an affordable period. Considering this approach as the best path to obtain truly optimized cyclones, sound theories of cyclone collection and pressure loss were chosen for each process application. These numerical optimization problems have resulted in several families of cyclones, some of those patented. Indeed, different industrial cases have different needs. The optimization functions to incorporate in the PACyc model may be as complex as minimizing cost or space, subject to a minimum efficiency result. The following cyclone families, always subject to further customization, are the result of very different client demands ACS has come across so far.

How can cyclones be improved?Since the early 1900’s, cyclones have been mostly designed and improved by empirical means, due to the difficulty of building a good prediction method that handles with the modeling complexity related with multiphase and highly turbulent flows. Computerized Flow Dynamics (CFD) can be used for partial cyclone optimization but it is still incomplete for full cyclone optimization, due to the very large computational burden associated with highly vorticial, assimetrical and multiphase flows with polidispersity. Sub-optimization of cyclones, and notably low collection efficiency result from the fact that particle agglomeration in cyclones has been disregarded until present days.

ACS high efficient cyclones: fine powder capture (process & end stage) increasing yield & compliance

with emission limits

ACS high end agglomerator cyclones: very fine powder capture (process & end stage). Maximizing yield & compliance with very strict emission limits

RE EX MK

About Hurricane cyclones

ACS compact process cyclones: coarse powder collection at low pressure drop and space.


Cyclones needed (ø2900mm): System size: Objectives / Applications:

Designing cyclones to increase yield & reduce emissions: The food ingredients processing industry is facing both an environmental and a plant efficiency challenge. In some cases ACS has come across, such as Nestlé Açores, where target was to reduce emissions, high effi-ciency cyclones were placed downstream of the process cyclones in order to achieve results under 50mg/Nm3. Alternatively, in cases such as Arla Foods, where the main driver was to enhance yield (see page. 9), we replaced the orig-inal Spray Dyer process cyclones by HR cyclones. The more efficient the solution is the larger the number of cyclones needed to increase residence time and promote particle ag-glomeration with impact on space and cost. ACS will always search for the most cost-efficient solution. Please compare the performance of several products below.

Global Efficiency (%): Emissions (mg/Nm3):

TX 72% 42

RX 87% 21

HR 81% 29

92% 13

95% 9

96%

RE

EX

MK 7

Operating Conditions:Spray Drying of Demineralized Powder

powder Demineralized Whey* median volume based particle size 20µminlet concentration 154mg/Nm3

gas temperature 90ºCflow rate 100 000m3/hmoisture content in flue gases 7%(v/v)

*Escaping the process cyclones of the spray dryer

RE Final stage cyclones with agglomeration for strict emission limits

TX Good efficiency process cyclones to increase powder yield

HR High efficiency cyclones for process and end stage applications

RX Very high efficiency cyclones for process and end stage applications.

EX Ultra high efficiency with agglomeration to compete with Bag Filters.

MK The agglomerator cyclone – Maximum agglomeration. Most efficient cyclones

Mod

erat

ly s

tric

tPM

Em

issi

ons

Com

plia

nce

Stric

t PM

Em

issi

ons

Com

plia

nce

100%

65%

53%

33%

23%

15%

Alternative Cyclone Solutions | Real Case Analysis: Spray Drying of Demineralized Powder


Recyclone Systems®

Mechanical and Electrostatic Recirculation

Mechanical ReCyclone® (MH)ACS holds a patent for a recirculation system to increase the efficiency of cyclones. A mechanical ReCyclone® (ReCyclone® MH) is made up of a high efficiency Hurricane and a particle separator, placed downstream, called the “mechanical recirculator” (please see figure). In 2016, ACS introduced more compact recirculators that can be placed on top of cyclones, exempting the need for additional footprint.The main purpose of the recirculators is to reintroduce the uncaptured particles into the cyclones after they have been driven to the outer walls of the recirculators by centrifugal forces. While this gas is enriched in particles, the axial gas stream exhaust to the stack

is clean of particles. Recirculation flow requires an additional fan.Since the recirculation system only serves the purpose of dust separation (and not collection), the particles are exclusively collected in the cyclones and the need of rapping mechanisms is avoided. Systems are arranged in groups of cyclones and recirculators.

Efficiency increaseEfficiency increases due to recirculation and agglomeration of very small particles with larger ones coming directly from the process. A ReCyclone® MH decreases emissions of Hurricane cyclones alone by 30 to 60%. Finally recirculation control has the benefit of handling variable process flow rates very well.

R E C Y C L O N E ® M H F E AT U R E S

Very high efficiencies: decreases emissions of any ACS cyclone by [30-60]%.

Very low emissions: < 30mg/Nm3 is achievable for multiple applications

Pressure drop: [150-230] mm w. g.

No temperature restrictions with an appropriate alloy steel or refractory selection

Recirculation assures a reasonable velocity in the cyclones

Robust construction with no moving parts (no rapping mechanisms)

Near zero maintenance and downtime costs

Low investment costs

APPLICATIONEFFECTIVE FLOW RATE

(m3/h)

TEMP.(ºC)

MEDIAN PARTICLE SIZE

(µm)

CYCLONES DIAMETER

(mm)

PRESSURE DROP

(mm w. g.)

INLET CONCENTRATION

(g/Nm3)

EFFICIENCY (%)

EMISSIONS (mg/Nm3)

Portugal - Drying of API 90 89 1.54 150 290 0.42 >94 25

Spain - Drying of organic fertilizer 50 400 40 13-17 1.000 190 1.58 >97 <47

Brazil - Drying of glucose 60 000 94 80 900 230 25 99.4 <15

E X A M P L E S O F F I N I S H E D A N D O N G O I N G P R O J E C T S

A ReCyclone® MH is the most efficient purely mechanical collector in the market, as it enhances efficiency of any given cyclone geometry.

R E C Y C L O N E ® M H S C H E M EPatented

clean air

air and particlesfrom the process

collectedparticles

mechanical recirculator

numerically optimized HIGH EFFICIENCY Hurricane cyclone TX HR RX RE EX MK FAMILIES

venturi/fan


numerically optimized HIGH EFFICIENCY Hurricane cyclone TX HR RX RE EX MK FAMILIES

Electrostatic ReCyclone® (EH) Recent adoption of electrostatic recirculation in the cyclone system has successfully proved to further reduce particle emissions, even in the [1;5] μm particle size range, assuring future regulation compliance, particularly where legal limits are very strict. A high voltage direct curent is applied to the recirculator, al-lowing the recirculation of very fine nanometric particles, more resistant to centrifugal forces, to the cyclone collec-tor. After having been separated in the recirculator and con-centrated in the recirculation flow, electrically charged fine

R E C Y C L O N E ® (E H) S C H E M E R E C Y C L O N E ® (E H) F E AT U R E S

Very high efficiencies: decreases emissions of a ReCyclone MH by [40-70]%

“Bag Filter comparable” emissions: <20mg/Nm3 is achievable for many multiple applications

Pressure drop: [120-170] mm w. g.

Operates up to 400ºC

Not sensitive to variable flow rates

Robust construction with no moving parts (no rapping mechanisms)

Low maintenance and downtime costs

Reasonable investment costs

particles are attracted by the cyclone walls, while agglomerat-ing with larger particles entering the system – both promoting their easier capture.Since particles are not captured on the walls of the recircula-tor, contrary to ESPs, ReCyclone® systems avoid the prob-lem of dust accumulation and condensation.Additionally, ReCyclone® EH systems have low sensitivity to either low or high dust electrical resistivity while the high volt-age required power is only 10 to 15 % of that used in ESPs.

APPLICATIONEFFECTIVE FLOW RATE

(m3/h)

TEMP.(ºC)

MEDIAN PARTICLE SIZE

(µm)

CYCLONES DIAMETER

(mm)

PRESSURE DROP

(mm w. g.)

INLET CONCENTRATION

(g/Nm3)

EFFICIENCY (%)

EMISSIONS (mg/Nm3)

Portugal - Drying of API 260 Amb. 1.3 280 240 5 >97.6 120

France - Drying of organic fertilizer 17 725 31 30 1400 1,7 1.8 >97 47

USA - Drying of glucose 62 100 0.023 80 0,1 26.7 >59 5 544

E X A M P L E S O F F I N I S H E D A N D O N G O I N G P R O J E C T S

cleaned air

air and particlesfrom the process

collectedparticles

electrostatic recirculator

venturi/fan


Performance of different equipments for the collection of Demineralized Whey Powder. Median Particle Size in Volume (MVD) = 20µm, r (kg/m3) = 1000 | Inlet concentration: 154mg/Nm3

Residual emissions (mg/Nm3) at the stack from page 5. Example: Spray Drying of demineralized whey powder

Comparison of fine powder secondary collectors (placed after process cyclones in spray dryers)

Wet Venturi Scrubbers

“CIPable” Bag Filter

CompetitorHight

EfficiencyCyclone

Hurricanecyclones:

HR, RX, RE, EX, MK

ReCyclone® MH systems

ReCyclone® EH systems

Efficiency (%) 85 to 95 99+ 60 to 70 81 to 96 88 to 96 93 to 97 Maximize Efficiency& ReduceEmissions: (depending on system configuration) 10 to 25 <10 45 to 60 9 to 25 7 to 18 4 to 11

Quality of separated product Waste Second grade First grade First grade First grade Waste, if organic

Improve Powder QualityContamination risk (sanitary conditions) Very high Considerable Minimal Minimal Minimal Minimal

Cleaning perfection with CIP Bad Reasonable Very Good Very Good Good Good

Investment costs Low Very high Low Low / Reasonable Reasonable High Minimize Total Cost of OwnershipMaintenance and operating costs High High Low Low Low Low

Technology comparisonHurricane cyclones | ReCyclone MH | Recyclone EH | Other technologies

T E C H N O L O G Y C O M PA R I S O N B E T W E E N A C S A N D O T H E R P R O D U C T S

R E S I D U A L E M I S S I O N S C O M PA R I S O N B E T W E E N A C S P R O D U T C S

Approach to any new projectWhenever it’s possible to achieve a requested emission limit or powder collection objective with a given optimized cyclone geometry, ACS will avoid recirculation in order to reduce investment and operating costs (mainly power consumption of fans) and to improve the system cleanability. For the recovery of very fine products, such as nanoparticles, or when emissions need to be minimal, as in API collection before HEPA filters, electrostatic recirculation may be mandatory. Any hurricane family can be coupled with mechanical or electrostatic recirculation to increase efficiency. Residual emissions comparison between ACS products - Operating conditions in page 5

recyclone MH

recyclone EH

hurricane

5

6Hurricane

Recyclone MH

Recy. EH

Hurricane

Recyclone MH

Recyclone EH

3

Hurricane

Recyclone MH

Recy. EH

Hurricane

Recyclone MH

Recyclone EH

Hurricane

Recyclone MH

Recyclone EH

8

7

3

13

10

5

21

15

13

10 20 20 40

29

21

13

hot air

existingcyclones

IDFan

productproduct

Clean air

spraydryer

WetScrubber

watertank

water +particles

2nd stage dryer

Stack


Case Study Hurricane HR cyclones to maximize recovery of milk proteins from a spray dryer

The client Arla Foods is a global dairy company and a co-operative owned by dairy farmers. The existing cyclones installed on the MSD Spray Dryer 3 (SD3) provided a 96.9% capture efficiency (emissions of about 500mg/Nm3). The remaining product (emissions from existing cyclones) was being lost, captured in a wet scrubber installed downstream.

The problem and solution ACS confirmed that the separation efficiency could be increased with two new numerically optimized cyclones (hurricanes). An estimated global collection efficiency of 98.9-99.27% was predicted for the hurricane for the same operating conditions and pressure drop. The improved separation efficiency of the hurricanes provided a reduction of product losses of about 70% resulting in considerable savings for the company. The success verified in this installation led to another supply of 2 Hurricane cyclones (HR ø2800mm designed for 57 878m3 /h at 75ºC) for another spray dryer at the same production facility.

Design Conditions:Powder milk proteinsMedian particle size 15µmInlet dust concentration (after multicyclone) 15g/Nm3

Temperature 65ºCEffective flow rate 92 140m3/h

Output/Performance:Efficiency 98.9 - 99.27%Pressure drop 1.9kPaACS system 2HR2800

The client Hovione is a Portuguese multinational pharmaceutical company. It provides high technology products (ex: API’s) and innovative services to the pharmaceutical industry. In this particular case, the goal was to increase the recovery of very fine and valuable powder (produced in a small-scale Spray Dryer).

The problem and solution Considering a design flow rate of 82 kg/h, a median particle size of 1.6 µm and a true particle density of 1.61g/ml, ACS designed and supplied a high efficiency Hurricane HR cyclone with ø130mm. Powder losses were reduced to one fourth of what was achieved by the previous cyclone.

Case Study Hurricane HR to increase the yield of powder capture after a pharma spray dryer

Design Conditions:Powder Inhalable APIMedian particle size 1.6µmTemperature 70ºCEffective flow rate 112kg/h

Output/Performance:Efficiency 78.3–83.1%Pressure drop 1.9kPaACS system 2HR2800

feed

cyclone

product

outletair

inletair

pre-filterheater fan

disposable product

spraydryer


Case Study Hurricane HR cyclones to reduce PM emissions from a drying tower of powder milk

The client Nestlé a global food company, has close to 500 production plants spread across 85 countries. ACS’s system was installed in the production plant of Azores, in the beautiful Portuguese island of S. Miguel. ACS was contacted to help bring down particulate matter emissions to under 75mg/Nm3 from a Drying Tower of Powder Milk.

The problem and solution The existing cyclones installed after the Spray Dryer at Nestlé’s plant had emissions around 170mg/Nm3 besides being above the emissions limits this valuable product was being lost to the atmosphere. ACS designed a Hurricane system comprising 8 Hurricane HR numerically optimized cyclones with ø850 mm, disposed in 2 batteries, operating in parallel. The system is capable of guaranteeing emissions under 75mg/Nm3 at a pressure drop of 1.7 kPa.

Case Study Hurricane HR to capture pharmaceutical waste particles (deduster & tablet press machine)

The client Teva is the leading generics company in North America. 1 out of 7 generic prescriptions in the US and 1 out of 6 generic prescriptions in Canada is filled with a Teva product. Teva is committed to the development and production of high-quality, affordable generic medicines for doctors, pharmacists, and most importantly, patients.

The problem and solution Having a cyclone system in each room allows Teva to isolate the waste powder of each tablet press and dedusting set individually, making it possible to determine the waste of each machine separately. ACS originally provided an HR275 system and went on to supply Teva with 7 similar ones and another 3 larger HR400 systems for the same purpose.

Resumed Design Conditions:Powder Waste particles from a pharma tablet press and a dedusterMedian particle size 1100μmTemperature AmbientEffective flow rate 45m3/h

Output/Performance:Efficiency 98,4% Pressure drop 1.8kPaACS system HR_TMø275

Resumed Design Conditions:Powder MiIlk powderMedian particle size 1,5μmTemperature 70-80Effective flow rate 31 100m3/h

Output/Performance:Efficiency 90,7%Pressure drop 1.7kPaACS system 8HRø850Measured emissions in 2017 <25mg/Nm3

cent

ral a

spira

tion

syst

emdeduster

Hurricane syste m

tablet press

existingcyclones

Hurricanesystem

IDFan

spraydryer

Stack2nd stage dryer


Case Study ReCyclone EH to recover ZnO Nanoparticles

Resumed Design Conditions:Powder GasMedian particle size 1.3μmTemperature AmbientEffective flow rate 260m3/h

Output/Performance:Efficiency >95%ACS system HR_EHø280

The client Innovnano is a Portuguese manufacturer of micro and nanoparticles of metal oxides. Innovnano is a subsidiary of Bondalti, the largest Portuguese chemical group, with production facilities in Portugal and Spain.

The problem and solution The goal was to reduce losses of the wet scrubber, treating 260m3/h of gas and placed downstream of the reactor. The objective was to recover all particles on a dry basis. ACS provided a fully insulated and heat traced Electrostatic ReCyclone®. The equipment is composed by one Hurricane cyclone and one electrostatic recirculator. The Median Volume Diameter (MVD) of the particles is 1.3μm and efficiency was expected to be higher than 95%.

Case Study Recyclone MH to capture chemical powder (Sulphanilic Acid)

Resumed Design Conditions:Powder Sulphanilic acidMedian particle size 20μmTemperature 115Effective flow rate 6 700 - 12 000m3/h

Output/Performance:Efficiency >99%Pressure drop 1.9kPaACS system 6MK_ø900

The client Bondalti is the biggest Portuguese producer in the chemical sector, having finished a project, in 2010, to double its production capacity in Estarreja, for both the production of organic chemicals - aniline and derivatives – and of inorganic chemicals - chlor-alkali products.

The problem and solution The goal was to replace a cyclone & bag filter arrangement with a mechanical system to capture chemical powder. A Recyclone® MH was installed after a fluidized bed dryer aiming to recover the fine fraction of sulphanilic acid (MVD = 17‐20μm, 6% submicrometer) in a 14 000m3/h gas flow rate and inlet concentration of 30g/m3.

product

ReCyclone EH

UNDISCLOSEDPROCESS

Stack

BRO_

RP_E

N_2

0190

517

ACS around the worldNumber of installations per country

4

2

7

5

1

3

25

4

2

23

4

2 1

4

1

2

11

3

14

1

1

3 1

66

3

9

1

4

4

5 1

11

1

1

ACS Development, Commercialization and Installation of Industrial Filtering Systems | Tel: +351 226 003 268Rua de Vilar, 235 3 Esq. | Ed. Scala | 4050-626 Porto, Portugal | [email protected] | www.advancedcyclonesystems.com

North America

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food, chemical & pharmaceutical powder recovery · advanced cyclone systems (acs) ... (see...

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