The invention relates to a plant for dehydrogenating C3-C5 paraffin hydrocarbons to produce corresponding olefin hydrocarbons. The plant includes a reactor and a regenerator with a fluidized bed of afinely dispersed chromia-alumina catalyst, pipes for circulating equilibrium catalyst from the reactor to the regenerator and vice versa, pipes for supplying feedstock to the reactor and for supplyingair to the reactor, pipes for removing contact gas and regeneration gas, which are connected to cyclones disposed in the upper part of the reactor and the regenerator, shell and tube heat exchangersmounted on said pipes in order to recover the heat of the contact gas and of the regeneration gas as these gases are supplied to the tube side of the heat exchangers, and devices for the wet and dry scrubbing of entrained catalyst dust from the contact gas and the regeneration gas. The plant is characterized in that it has a system for supplying equilibrium catalyst from the reactor-regenerator system to the inlet to the tube side of the heat exchangers, devices for entrapping catalyst at the contact gas and/or regeneration gas outlet from the tube side of the shell and tube heat exchangers and for returning the entrapped catalyst to the upper part of the fluidized bed of the reactor and/or the regenerator. The claimed plant stabilizes the working of the dehydrogenation units, and increases olefin hydrocarbon production capacity by reducing clogging of the heat exchangers for recovering the heat of the contact gas and regeneration gas by catalyst dust.