Infinite Grinder (Hammer Mill)

Description

The biomass pulveriser shall be a conventional hammer mill with an integrated material classifier and handling system.

The Pulveriser would consist of the following sub-systems :

Hammer Mill
The Hammer mill consists of grinding chamber in which the dry biomass is pulverised by a set of swinging multi edged hammers, a sieve classifier and electrical driving mechanism.

The size reduction is achieved by the shattering of the dry biomass by impact from high velocity multi edge hammers. The hammers are swivel mounted on a sturdy shaft which runs on heavy duty bearings. The Sieve classifier is placed at the bottom of the grinding chamber.

The hammer mill shaft is driven by electric motor through a multi groove V belt pulley drive.

Pneumatic Conveyor
The pulverized material is sucked through the bottom sieve by the pneumatic conveying system and transported to the vicinity of either biomass storage space or the feed screw as per the plant layout requirements.

The conveying blower is also mounted on the same shaft as the Hammer mill and hence the space and electric motor requirements are reduced.

Cyclone Dust collector
The separation of the conveying air and the pulverised material is achieved in the high efficiency cyclone dust collector.

The material collected at the cyclone bottom hopper would be removed by a rotary air lock valve. This would eliminate the dust pollution at the bottom of the cyclone where the dried material would be discharged.

Bag Filter Dust collectors
Due to the nature of impact pulverisation, the prevention of generation of fine dust in the grinding chamber is not possible. Hence a bag filter type dust collector is provided to trap the fines which are not collected by the cyclone.

Electricals
All electrical motors for be controlled ( on-off control only ) from the main panel. The panel would also include Indicating Ammeters and Voltmeters. The main drive electric motor would be provided with Star Delta starters and the smaller motor for the RAV shall be connected through a DOL starter.

Supports
All supports for the Pneumatic conveyor, cyclone separator and bag filters would be from the ground. The foundation for all supports shall be provided by the client. The pulveriser with motor would be mounted on a separate concrete foundations which shall be provided by the client.

Specifications of Biomass Grinder

Pulveriser Model   HM 600 HM 1000
Material Output (nominal rating) kg/h 500-1000 1000-1500
Operating Speed RPM 2880 2880
Connected Load Hp 40 60
No. of Hammers   24/36 48
Weight Kg 400 700
Size of pulverised Material Mm 4-6 4-6
Dust content in exit of bag filter mg/nm3 < 100 < 100


Hammer Mill Model List  HM Series HM 150 HM 300 HM 750 HM 1000 HM 1500
Material output kg/h 125 - 225 250 - 400 550 - 850 850 - 1250 1350 - 1850
Connected Load* hp 15 20 40 60 75
Speed RPM 2500 - 3000 2500 - 3000 2000- 2200 1400 - 2000 1400 - 2000 
Feed Material Size mm <  25
Bulk Density of Feed material
(Material to be pulverized)
Kg/m3 300 - 800
Moisture content of material at inlet % < 15
O/P Size of pulverized Material mm < 6
 Hammers Nos 24/36/48*

Parameters

Design Parameters

Pulveriser Model   HM 600 HM 1000
Material Output (nominal rating) kg/h 500-1000 1000-1500
Material to be pulverised Size   Biomass granular / fibrous less than 25 mm
Moisture content of material at inlet of the pulveriser % < 15 < 15
Size of pulverised Material Mm 4-6 4-6
Dust content in exit of bag filter mg/nm3 < 100 < 100


Performance Parameters

Model   HM 600 HM 1000
Pulverised Material Output* kg/h 600-1000 1000-1500
Power consumption kW 26-30 40-48
Life of Hammers Hours >200 >200
Dust content in exhaust gas mg/nm3 < 100 < 100

The output indicated is a nominal rating only and the actual output is likely to be depend on Biomass feed size & Bulk Denisty of Biomass . The actual output is very sensitive to the moisture content of the input biomass and the nature ( fibre content) in the biomass.