Heat Transfer Capacity
The rate of heat transfer within a reactor can be determined from the following relationship:
qx = U.A.
Where qx = the heat liberated or absorbed by the process (W)
U = the heat transfer coefficient of the heat exchanger (W.m-2.K-1)
A = the heat transfer area (m2)
Tp = process temperature (K)
Tj = jacket temperature (K)
From a reactor design perspective, heat transfer capacity is heavily influenced by channel size since this determines the heat transfer area per unit volume. Channel size can be categorised in various ways however in broadest terms, the categories are as follows:
Industrial batch reactors : 1 – 10 m2/m3 (depending on reactor capacity)
Laboratory batch reactors : 10 – 100 m2/m3 (depending on reactor capacity)
Continuous reactors (non micro) : 100 - 5,000 m2/m3 (depending on channel size)
Micro reactors : 5,000 - 50,000 m2/m3 (depending on channel size)
Small diameter channels have the advantage of high heat transfer capacity. Against this however they have lower flow capacity, higher pressure drop and an increased tendency to block. In many cases, the physical structure and fabrication techniques for micro reactors make cleaning and unblocking very difficult to achieve.
Read more about this topic: Continuous Reactor
Famous quotes containing the words heat, transfer and/or capacity:
“Coal is a portable climate. It carries the heat of the tropics to Labrador and the polar circle; and it is the means of transporting itself whithersoever it is wanted. Watt and Stephenson whispered in the ear of mankind their secret, that a half-ounce of coal will draw two tons a mile, and coal carries coal, by rail and by boat, to make Canada as warm as Calcutta, and with its comfort brings its industrial power.”
—Ralph Waldo Emerson (1803–1882)
“If it had not been for storytelling, the black family would not have survived. It was the responsibility of the Uncle Remus types to transfer philosophies, attitudes, values, and advice, by way of storytelling using creatures in the woods as symbols.”
—Jackie Torrence (b. 1944)
“Modern man’s capacity for destruction is quixotic evidence of humanity’s capacity for reconstruction. The powerful technological agents we have unleashed against the environment include many of the agents we require for its reconstruction.”
—George F. Will (b. 1941)