7. CONSUMPTION OF FUEL, ELECTRIC POWER AND WATER


7.1 Fuel Oil Consumption
7.2 Electric Power Consumption
7.3 Water Consumption


The following figures for fuel, electric power and water consumption of fishmeal plants are based on data from existing plants with indirect steam drying. The figures are to be considered, as only indicative since they may vary with many factors such as temperature and oil content of the raw fish, the seawater temperature, the number of stages in evaporation plants and several other plant design features.

7.1 Fuel Oil Consumption

The usual type of fishmeal plant with indirect drying requires fuel only for steam production in the boiler. The price of fuel oil varies greatly over the world. Reasonable quotations may, however, often be obtained as fishmeal plants are usually situated near sea ports, and expensive land transportation costs will not be incurred.

The high energy prices ruling during the last decade have inspired most factories to check carefully the opportunities which are present for reducing fuel consumption by improving boiler efficiency, insulation of hot surfaces, recuperation of heat in condensates as well as increasing the number of stages in concentration plants.

A new range of equipment has been developed for utilizing the heat in the vapours from drying and evaporating activities. These vapours are characterized by high calorific values but at rather low temperatures, and their application to heating raw fish and to preconcentrating stickwater has therefore demanded the design of special types of cookers and evaporators. A considerable number of items of such equipment for waste heat recovery are today working satisfactorily in Scandinavian factories. (For details see IAFMM Processing Bulletin No.1. July 1983).

Table 3 gives rough estimates of fuel oil consumed when presscake meal and whole meal are produced.

Table 3 Consumption of fuel oil

Size of plant: raw material (ton/24 h)

Fuel oil consumption per ton of raw material (kg)

Presscake meal

Whole meal

Without evaporation plant

With evaporation plant

With additional waste recovery heat

10-60

35

55

-

100-200

34

50

44

250-500

33

48

41

More than 500

30

45

38

7.2 Electric Power Consumption

Fair sized fishmeal plants usually receive their power supply as high voltage current from a municipal power works and have power substations of their own.

Table 4 provides rough estimates of the power consumption per ton of processed raw fish.

Table 4 Electric power consumption

Size of plant: raw material (ton/24 h)

kWh consumption per ton of raw material

Without evaporation plant

With evaporation plant

10- 60

30

35

100- 200

28

33

250- 500

26

31

More than 500

25

30

7.3 Water Consumption

Fishmeal plants require water for the following purposes:

  1. as feed water for the boiler;
  2. for operation of the sludge separators;
  3. to clean machinery and tanks;
  4. to clean floors, raw fish pits, etc.;
  5. for condenser of concentration unit;
  6. for cooling and deodorizing;
  7. for staff bathroom and canteen.

For purposes (a), (b), (c) and (g) - water has to be fresh.

For purposes (d), (e) and (f) - water could be sea water.

Table 5 gives rough estimates of water consumption.

Table 5 Water consumption

Size of plant: raw material (ton/24 h)

For purpose:

a-d m3/t

e m3/t

f m3/t

10-60

0.50

9

22

100-200

0.40

7

15

250-500

0.35

7-5

12

More than 500

0.30

5

11