Dryer Air Preheater

Dryer Air Preheater (APH) is fabricated equipment designed to heat air before enter in another process (for example, combustion in a boiler) with the primary objective of increasing the thermal efficiency of the process.

The purpose of the air preheater is to recover the heat from the Dryer Flue Gas which increases the thermal efficiency of the Dryer by reducing the useful heat lost in the flue gas, thereby improve the exhaust heat value and utilization As a consequence, the flue gases are also conveyed to the flue gas stack (or chimney) at a lower temperature, allowing simplified design of the conveyance system and the flue gas stack. It also allows control over the temperature of gases leaving the stack (to meet emissions regulations, for example).

Construction features

Tubular preheaters consist of straight tube bundles which pass through the outlet ducting of the Dryer and open at each end outside of the ducting. Inside the ducting, the hot gases pass around the preheater tubes, transferring heat from the exhaust gas to the air inside the preheater. Ambient air is forced by a fan through ducting at one end of the preheater tubes and at other end the heated air from inside of the tubes emerges into another set of ducting, which carries it to the boiler furnace for combustion.

Dryer Air Heaters for Carbon Black Plants are custom built to match specific Dryer requirement.

Working principle: The high speed Rotor of the Pelletizer intermixes the dry powder feed with atomizing spray of water and / or a liquid binder mixture and coats individual powder particles with the binder, that pelletizes the particles into spherical granules or pellets. The powder enters at one end of the Shell , feeded at a fixed rate( by a screw or rotary feeder ) dropped through a top hopper or opening at one end and is whipped by the pins as it moves from the inlet to the bottom outlet at other end, . The Pelletizer speed can be varied from 100 to 750 RPM., using High HP Motors. The gap between the Rotating Rotor and casing can also be varied from 3mm to 6mm. Accordingly the pellets size dia will be determined. Powder Particle size , Chemistry & parameters such as Temperature Density/Moisture need to be synchronized to achive desired pellets.

Oil Preheater (OPH)

Oil Preheater (OPH) is a fabricated equipment designed to heat Oil ( Carbon Black Feed Stock) before it enters the Soft or Hard Black Reactor, with the primary objective of increasing the thermal efficiency of the process.

Carbon Black is produced by partial combustion of oils and pyrolysis in the reactor. Predetermined quantities of process air from a process air header system, fuel natural gas and Carbon Black feedstock are introduced into the reactor, which has been brought up to the desired temperature level. Effluents from the reactors are essentially carbon-laden flue gases containing some combustibles. These gases are at a temperature between 800°C and 1000°C. This heat is first utilised in preheating incoming process air in an air preheater. The heat is then further utilized in Oil Preheater where oil (carbon black feed stock) is heated from 60°C to 250°C in the coil side while the carbon black smoke flows through the shell side.

Construction features

This heat transfer equipment consists of Shell & Tube / Coil Bundle Assembly.

Coil bundle consist of coil pipe, coil inlet and outlet flanges, return bend and top cover flange welded with coil pipe, Coils supports such as coil guide rings, flat bars etc

Shells complete with all nozzles/flanges .Skirt /saddle support for shell.