A fermentation broth contains 15 wt.% of dead mass and rest liquid, the latter needs to be recovered fully. The annual production of the broth is 20,000 kg. The liquid can be sold at a profit of Rs. 100/kg. If a simple filter is used the solids retain 10 wt.% of the liquid, while if a centrifuge is used the solids retain only 2 wt.% of the liquid. Cost of a filter is Rs. 2,00,000 while the cost of a centrifuge is Rs. 2,50,000. The annual maintenance plus operating costs of the filter is Rs. 50,000 and that of the centrifuge is Rs. 80,000 per annum. If you assume that the life of both the equipment is 4 years and there is no resale value for them, suggest the correct filtration equipment with reason. Assume all other factors are the same. The discount factor for the money is 10%. Assume that the equipment will be purchased at the beginning of year 0, and the profit on sales will be received in the beginning of year 1, 2, 3 and 4.

Also assume that all the operating costs will be accrued in the beginning of year 1, 2, 3 and 4.