PARAMETERS AFFECTING THE FINE GRINDING OF AQUAFEEDS USING A HAMMERMILL VICTAM – Utrecht – May 2007 Olivier Rousseaux STOLZ ASIA SALES MANAGER
INTRODUCTION A] Raw Materials B] Main Mechanical parameters we can change for better result C] Global solution CONCLUSION VICTAM – Utrecht – May 2007 PARAMETERS AFFECTING FINE GRINDING CONTENT
VICTAM – Utrecht – May 2007 INTRODUCTION: GRINDING COST: HAMERMILL VS. PULVERIZER Pulverizer : Needs a lot of aspiration High aspiration means high moisture losses High power consumption Hammermill : Need aspiration Reasonable power consumption Reasonable Moisture losses Cost : Electrical cost: easy to evaluate Wearing parts cost: easy to evaluate Moisture losses: difficult to evaluate
No.ParameterHM StolzPulverizer 1Actual Cap (T/H) Electric Consumption - in kWH/Ton Electric Cost (US$/Ton) 1,4 1,7 3Spare Parts - Hammer / Beater (US$/Pcs) 2,6 50 Number of Hammers Total Hammer Cost/mch Hammer Lifetime (Tons) Hammer Cost (US$/Tons) (assump T/month) 0,1 1,0 - Screener / Liner (US$/Pcs) Number of Screen/liners 2 2 Total Screener / Liner Cost / mch Screener/Liner Lifetime (Tons) Screener Cost (US$/Tons) (assump T/month) 0,1 - - Counterbeater & Liner: in H26/Tons 0, Turbo sifter Screener: in US$/Tons 0,09 - 4TOTAL COST (IN US$/TON) DIFFERENCE US$ 0.95 SAVING / MONTH (IN US$/MONTH) US$ VICTAM – Utrecht – May 2007 GRINDING COST: HAMERMILL VS. PULVERIZER HUGE SAVING
In terms of fineness Still pulverizer is better than Hammermill But this has a cost Compromise: Hammermill + Pneumatic System + TurboSifter VICTAM – Utrecht – May 2007 INTRODUCTION: GRINDING COST: HAMERMILL VS. PULVERIZER
Which raw materials: Corn, Soya, cassava… Wheat bran, rice bran… Fish meal, feather meal… Grinding design Either pre-grinding or post grinding system Either 1 or 2 step(s) grinding VICTAM – Utrecht – May 2007 PARAMETERS AFFECTING FINE GRINDING A1] RAW MATERIALS
VICTAM – Utrecht – May 2007 PARAMETERS AFFECTING FINE GRINDING A2] RAW MATERIALS a)Physical aspects Initial size of the particles initial size, capacity b) Biological aspects a)Moisture content Moisture content, capacity b)Fat content fat content, capacity c)Hardness hardness, capacity BASICALLY, RAW MATERIALS have to be used as what they are
VICTAM – Utrecht – May 2007 Generally : 1500 rpm hammermills rotors are of about mm diameter 3000 rpm hammermills rotors are of 650 to 700 mm diameter Disadvantages of a 1500 rpm hammer mill vs. a 3000 rpm : The size Screen changing more difficult Needs more important screen surface Disadvantages of a 3000 rpm hammer mill vs. a 1500 rpm : Noise Fan makes more noise than hammermills, what ever its size B1] Rotor Speed: 1500 or 3000 RPM PARAMETERS AFFECTING FINE GRINDING B] Main Mechanical parameters you can change for better result
VICTAM – Utrecht – May 2007 B2] Rotor Speed How can the rotor speed affect the granulometry? Speed variation of the rotor, using an inverter Speed Screen Table giving medium size of particles in function of Screen size and rotor speed. The mathematical model was made by TECALIMAN French Technical Centre. PARAMETERS AFFECTING FINE GRINDING B] Main Mechanical parameters you can change for better result ROTOR SPEED, PARTICLES SIZE
VICTAM – Utrecht – May 2007 How can you control the best quality? A: no steel heat treatment or bad treatment B: correct steel heat treatment + C Addition 1: new beater 2: one side worn 3: both sides worn A: no steel heat treatment or bad treatment concave wearing B: correct steel heat treatment : convex wearing A: no steel heat treatment or bad treatment Round shape wear B: correct steel heat treatment : Spoon shape wear PARAMETERS AFFECTING FINE GRINDING B] Main Mechanical parameters you can change for better result B3] Beaters : Steel treatment and Wearing
VICTAM – Utrecht – May 2007 PARAMETERS AFFECTING FINE GRINDING B] Main Mechanical parameters you can change for better result B4] Counters Beaters C ounters beaters increase Flow rate and fineness C ounters beaters
VICTAM – Utrecht – May 2007 Useful Screen Size, capacity Screen perforation, Particles size Screen Opening (%), capacity Screen Thickness, Particles size Opening% = D² * / EA² EA D PARAMETERS AFFECTING FINE GRINDING B] Main Mechanical parameters you can change for better result B5] Screen : Dimensions and design
VICTAM – Utrecht – May 2007 WORN: while rebounding, the grain is taken again by the hammers NEW: while rebounding, the grain is returned outside rebounding Product Worn screen New screen rebounding Screen wearing effect PARAMETERS AFFECTING FINE GRINDING B] Main Mechanical parameters you can change for better result B6] Screen: Wearing Lifetime of the screen depends also of the cleanliness of the raw materials
VICTAM – Utrecht – May 2007 For Coarse Grinding (Screens 2 mm and more): Air Flow of about 8500 m3/h for 1 m² Air Pressure is of about 300 to 500 mm water column on the screen For Fine Grinding (screen 1.5 mm and less): Air Flow of about 5500 m3/h for 1 m² Air Pressure of about 700 to 1000 mm water column on the screen Air flow is made 2 main parameters: Air flow : m 3 /h, … Pressure: WC, bar PARAMETERS AFFECTING FINE GRINDING B] Main Mechanical parameters you can change for better result B7] Air Flow
VICTAM – Utrecht – May 2007 AIR SPEED : Air speeds: m/s through the destoner 4-6 m/s through the grid 2.5 to 3 m/s through the filtering media AIR FLOW ACTIONS: Generally little effect on the particle size Depending of the hammermill feeder design: Better heavy materials removal. Will help reducing the T° increase of the ground product, avoiding down stream condensation Enables product passing through the screen AIR FLOW REGULATION : Allows a constant flow rate, whatever may be the pressure loss From where, a better de stoning Avoids any overload of the filtering media Allows a progressive air flow increase, avoiding inopportunely emptying of the stone box PARAMETERS AFFECTING FINE GRINDING B] Main Mechanical parameters you can change for better result B8] Air Flow through hammermill and air jet filter
VICTAM – Utrecht – May 2007 PARAMETERS AFFECTING FINE GRINDING B] Main Mechanical parameters you can change for better result a) Mechanical handlingb) Pneumatical handling B9] GRINLING LINE DESIGN
FeederHammermill VICTAM – Utrecht – May 2007 PARAMETERS AFFECTING FINE GRINDING C] GLOBAL SOLUTION C1] HAMMERMILL
The Feeder Dimension same as the grinding room Pneumatic Magnet Heavy particle remover Unique Very advanced System The Grinder Liner Screen Beaters Counters beaters But also for safety reasons Temperature control Auto greasing Screen sliding VICTAM – Utrecht – May 2007 C2] HAMMERMILL: Feeder + Grinder PARAMETERS AFFECTING FINE GRINDING C] GLOBAL SOLUTION
Magnet Air Inlet with a djustable flaps Feeder with global regulation Pocket feeder with frequency inverter Automated Air flow adjustment Heavy particle remover Stainless steel Stone Sand Any high density particle VICTAM – Utrecht – May 2007 C3] Feeder : Very unique PARAMETERS AFFECTING FINE GRINDING C] GLOBAL SOLUTION
Material to be ground Raw materials Air flap Feeder Magnet Heavy particles separator Air Air inlet VICTAM – Utrecht – May 2007 C4] How works the feeder PARAMETERS AFFECTING FINE GRINDING C] GLOBAL SOLUTION
Thanks to the design of the feeder: Removal of any heavy particles ( Stone or not) Adjustment of the air flow through the feeder Not the least, the feeding of the hammermill is: Regular Continuous Done homogenously on all the length of the hammermill All the conditions are gathered for a good grinding: VICTAM – Utrecht – May 2007 PARAMETERS AFFECTING FINE GRINDING C] GLOBAL SOLUTION C5] Feeder : Its benefits
Crushing plate or liner Rotor made of 8 axes Beaters VICTAM – Utrecht – May 2007 Counters Beaters PARAMETERS AFFECTING FINE GRINDING C] GLOBAL SOLUTION C6] Hammermill : Its design
Locking plate to release or tighten the screen Air cylinders to pull in or push out the screen No doors to open to replace a screen safety VICTAM – Utrecht – May 2007 PARAMETERS AFFECTING FINE GRINDING C] GLOBAL SOLUTION C7] Screen fixations
Step 1: Stop of feeder Step 2: Unlocking Step 3: Pushing out Step 4: Change of screen Step 5: Pulling in Step 6: Locking Step 7: Start of feeder Time = Maximum 3 MINUTES VICTAM – Utrecht – May 2007 PARAMETERS AFFECTING FINE GRINDING C] GLOBAL SOLUTION C8] Screen replacement SAVE POWER AND TIME
Rotor specially designed High speed Clock rotation Sieving drum rotates Low speed Clock rotation Sequenced rotation Compressed 7bars When sieving drum rotates Sequenced air pulsing Cross contamination less Main features VICTAM – Utrecht – May 2007 PARAMETERS AFFECTING FINE GRINDING C] GLOBAL SOLUTION C9] Turbosifter
Screw inlet Design of the rotor Paddles arrangement Sieves Small gap between sieves and paddles VICTAM – Utrecht – May 2007 PARAMETERS AFFECTING FINE GRINDING C] GLOBAL SOLUTION C10] Turbosifter: Rotor
Adjustable Air Pressure Nozzles lines VICTAM – Utrecht – May 2007 PARAMETERS AFFECTING FINE GRINDING C] GLOBAL SOLUTION C11] Compressed air system
VICTAM – Utrecht – May 2007 PARAMETERS AFFECTING FINE GRINDING C] GLOBAL SOLUTION C12] Grinding line for shrimps feeds or fish feeds
VICTAM – Utrecht – May 2007