01Urea and Nitrogen Fertilizer Coating
Surface coating of urea and nitrogen granules to reduce dust and caking during storage. The additive rate is set according to the product and climate conditions.
Fertilizer PlantsCoating Drum – Rotary Coating System for Granular Products
PRO MAKINA · Rotary Coating Drum
- Task
- Applying additives to granule surfaces
- Additive
- Liquid coating oil or powder
- Metering
- Ratio control to product rate
- Scope
- Drum, nozzle line and metering unit
Overview
Controlled, Even Additive Application on the Granule Surface
A coating drum is rotary process equipment in which granular product is turned continuously while a liquid coating agent or powder additive is applied to its surface. The aim is not to change granule size but to cover the surface as evenly as possible.
Coating distribution is determined by the number and position of nozzles, spray angle, metering of the additive in proportion to product rate, drum speed and the rolling behaviour of the product. Viscosity and temperature of liquids, and flowability of powders, are part of the design.
Coating is usually carried out after cooling and screening and before packing. The drum is engineered together with the additive preparation and metering unit, product feeding and the packing line.
01Process Flow
Coating Line Process Flow
The diagram shows the typical position of the coating drum after cooling and screening, and the additive metering line.
Scroll horizontally to view the full diagram.
Product line
- 1
Screened product inlet: Cooled and screened granules are fed steadily to the drum.
- 2
Additive application: Nozzles apply liquid additive, or a feeder applies powder, onto the bed.
- 3
Even distribution: Granules rolling with the drum spread the additive over their surface.
- 4
Coated product discharge: Product is sent to packing or storage.
Additive metering line
- A
Additive preparation: Liquid additive is kept at the required temperature in a tank; powder waits in a hopper.
- B
Ratio metering: A pump or feeder delivers the additive in proportion to the product rate.
Screening before coating reduces the amount of coating agent consumed by fines and limits lump formation.
02Applications
Coating Drum Applications
01
02Surface Treatment after Cooling
Coating nitrate and compound granules after cooling. Since product temperature affects how well the coating agent adheres, the coater is assessed together with the cooler.
Rotary Cooler
03Phosphate and Chemical Granule Coating
Applying powder or liquid additives to DAP and similar phosphate granules and to chemical granules. Internal surface and cleaning access suited to the additive are part of the design.
Chemical Process Industry03Design & Manufacturing
Custom Coating Drum Design and Manufacturing
PRO MAKINA engineers coating drums around product rate, granule size, additive type and application rate. The drum shell, internal surface, nozzle line, additive preparation and metering unit are designed together so that they match the product flow in the line.
- Nozzle layout and spray zone
- Additive metering in ratio to product
- Cleaning and service access
- Anti-build-up internal surfaces
Process Design Data
- 01
Product Data
Granule type, size range, bulk density and product temperature.
- 02
Additive Data
Liquid or powder, viscosity, preparation temperature and application rate.
- 03
Capacity
Hourly product rate and operating regime.
- 04
Line Integration
Connections to cooling, screening, packing and the additive tank.
The application temperature and rate recommended by the additive supplier are the basis for selecting the metering unit and nozzles.
04FAQ
Coating Drum FAQ
Which additives can a coating drum apply?
Liquid coating agents (e.g. coating oils) are applied through nozzles and powder additives through a feeder. The additive type determines the metering unit and internal surface.
Does a coating drum change granule size?
The purpose of a coating drum is not to grow granules but to apply an additive to the existing granule surface. Granule formation takes place in the drum granulator.
What determines how evenly the coating is distributed?
Nozzle layout, spray angle, metering in proportion to product rate, drum speed, filling level and the rolling behaviour of the product all act together.
Why is coating done after cooling?
Product temperature affects how the coating agent adheres and behaves. Coating is therefore usually carried out after the product has been cooled and screened.
What information is needed for a quotation?
Product type and rate, granule size, additive type and the application rate recommended by its supplier, product temperature and the existing line connections.
05Resources
Related Machines and Plants
Rotary CoolerDrum for controlled cooling of hot product with ambient air.Rotary Drum GranulatorDrum in which powder feed is formed into granules with a liquid binder.Rotary DryerRotary drum that reduces the moisture of granules or bulk solids with hot gas.Reactors & Process TanksTanks for liquid preparation, mixing and storage.
Technical Quotation
Request a technical quotation for a coating drum
Share your product, additive type and application rate, and we will define the coating drum, nozzle line and metering unit together with you.
Information Needed for a Technical Quotation
- Product type and granule size
- Hourly product rate (t/h)
- Additive type (liquid / powder)
- Recommended application rate
- Product temperature before coating
- Existing line and packing connections