|
ITEM
|
ROTARY
PRESS
|
THE
PLATE AND FRAME PRESS
|
| 1. |
Continuous
operation |
Cyclical
batch-type operation |
| |
Constant
low pressure sludge feed. (10 à 50 kPa). |
Variable
high pressure sludge feed. (Up to 1500 kPa) |
| |
Constant
cake production. |
Batch
type. |
| |
Stable
cake dryness. |
Cake
dryness may vary a great deal from one batch to the next. Important quantities
of badly dewatered cake are produced when the operating cycle is interrupted. |
| |
|
|
| 2. |
Simple,
reliable, very few ancillary equipment, screens with long life. |
Complex
systems, many ancillary equipment. Filter cloth requires frequent replacement.
|
| |
|
|
| 3. |
The
wash cycle consists of an internal flush cycle lasting approximately 5 minutes
per day. |
The
wash cycle may last for two (2) hours and may generate dangerous airborne
contamination. |
| |
|
|
| 4. |
Totally
enclosed process. |
The
exposed process may require an important odor treatment system. |
| |
Manpower
is not exposed to the sludge and/or cake. |
From
time-to-time, the process may generate high pressure sprays from hoses,
plates, diaphragms, etc.Manpower is exposed to sludge/cake/filtrate. |
| |
|
|
| 5. |
Little
manpower is required. |
Manual
discharge of complete cake is usually the norm. |
| |
Automation
is very simple. |
Automation
is next to impossible. |
| |
Simple
start-up and shut down procedure. |
Complex
operational cycle. |
| |
|
|
| 6. |
Low
maintenance and operation cost. |
High
maintenance and operation cost.Sludge feed pump wear can be very costly. |
| |
|
|
| 7. |
Low
overall capital cost. |
Large
overall capital cost. |
| |
|
|
| 8. |
Small
space. |
Large
space (as much as 4 times). |
| |
|
|
| 9. |
Low
overall energy consumption.20 kW-hr/dry ton (includes pumping). |
High
overall energy consumption. |
| |
|
|
| 10. |
Low
installed HP. |
High
installed HP with the ancillary equipment. |
| |
|
|
| 11. |
Low
noise |
Noise
operation during several parts of the operating cycle. |
| |
|
|
| 12. |
For
the multi-channel machine, one or more channel(s) may be removed for maintenance
purposes, while the machine with the remaining channel(s) may still be operated. |
The
whole machine is in operation or is shut down. |
