Ravensdown – Christchurch, New Zealand

Summary

Plant Commissioning. From Left: Peter Hay, Vaughan Chaffey, Scott Grimwis (Of Sackett), and Paul Ratford.

Ravensdown Fertilser Co-operative was founded in 1978 to stave off the fallout from the merger of the two primary suppliers of superphosphate in New Zealand. Rising prices and falling quality drove members to found a co-operative that was owned by farmers, and worked for farmers.

The company’s goal was to modernize an existing facility and provide the best quality fertilizer available to their members and customers. Ravensdown needed: efficient raw material prep through conditioning and screening, availability of a large number of ingredients for each blend, system flexibility, high precision weighing, ability to add micronutrients, high quality blending, and a significant increase in system speed.

The result was:

  • Ability to keep input materials separated in 2 lines, to prevent contamination or reactions
  • Dual conditioning and transfer systems to feed the tower
  • Dual screening lines
  • 14 holding hoppers, with a total capacity of approximately 200 metric tons
  • A 4-ton High Intensity Mixer (HIM) and dual weigh hopper system
  • Capacity to blend 250 metric tons per hour (MTPH)

Ravensdown now has a highly accurate system that incorporates the most efficient mixer in the industry with a dosing system that provides the speed and accuracy to meet their production schedule and stringent quality controls.

At Left: One of the systems 275+ MTPH reclaim and conditioning systems, At Right: A view of the plant’s two screeners (one per reclaim).

Challenge: Quality, speed, and efficiency.

A view of Ravensdown’s new Precision fertilizer Blending® Tower

Sackett was tasked with engineering a system capable of blending 250 mtph, while keeping some of the primary ingredients separate and providing conditioning and screening prior to the blend operation.

Raw materials produced at the site would be reclaimed from storage bins, conditioned, screened and fed to the overhead storage hoppers. Other various blend ingredients would be fed in through the same systems as well. Provisions would be made to include 6 micronutrient bins in addition to the main hopper’s 8 ingredients (at 200 mtons).

Additionally, the system would need to be fit into an existing space in the center of the plant – which would be razed for the new construction.

Sackett’s Precision Fertilizer Blending® Technology was of primary interest, given the complexity of the blends and the speed at which material was to be dispatched. Sackett’s PFB System would allow for a high volume of precisely formulated fertilizers to be accurately blended and dispatched – at three times the speed of the existing system.

The tower allows for faster processing due to its intricate and significant storage capacity, while the High Intensity Mixer utilizes its twin counter-rotating shafts and overlapping paddles to gently and thoroughly mix all ingredients, both dry and liquid trace elements.

 has a highly accurate system that incorporates the most efficient mixer in the industry with a dosing system that provides the speed and accuracy to meet their production schedule and stringent quality controls.

At Left: A view of the tower’s weighing system. Materials are dosed from 3 hopper clusters. At Right: The heart of the Precision Fertilizer Blending® System, The H.I.M. 2500 Mixer.