Showing posts with label furnaces. Show all posts
Showing posts with label furnaces. Show all posts

Hotfoil-EHS Heat Treatment Equipment

EHS engineers, designs, and manufactures proven heat treatment systems to effectively complete any project more efficiently than competitive systems, while staying within any budget. Years of application experience and successful installations have produced thousands of happy customers. A focus on customer service second to none.

Custom Fabricated Gas Trains and Nozzles Capable of 10 Million BTU Output

Gas Trains designed with safety in mind. All gas trains have dual valves on the pilot line and main, low gas pressure switch, high gas pressure switch, and proof of closure.
Fully automatic units are supplied with a 4-20 mA controlled actuator that regulates gas. The control system includes a power-on switch, power-on light, master controller with 4-20mA slave controller, air-on light, gas-on light, ignition-firing light, burner-on light, high-fire light and high-fire switch. Should the limit switch fail system come with a dump button and procedure for clearing the gas out of the lines. Construction is 1.5 inch powered coated tubing.

Other features include:
  • 15HP blower motor than can move up to 2200 cubic feet/minute 
  • Damper with a handle wheel for adjustment 
  • Blower is powder coated for longevity 
  • Starter box incorporates a lockable disconnect 
  • Supplementary circuit breaker 
  • Starter contactor 
  • 750VA transformer 480/120 for power to the train. 
Burners are 316 stainless steel. Three standard sizes: 6-10 million BTU; 3-6 million BTU burner; 1 million BTU burner.

For more information. contact:
Hotfoil-EHS, Inc.
2960 East State Street Ext.
Hamilton, NJ 08619
Phone # 609.588.0900
Fax # 609.588.8333

Heat Transfer - The Basics

Hopper Heaters
Industrial hopper heaters are
example of conductive heat transfer.
Heat transfer is the movement of heat from one body or substance to another by radiation, conduction, convection, or a combination of these processes.

When heating a pan of water over a gas flame for example, all three forms a heat transfer are taking place. Heat from the flame radiates in all directions. Conduction takes place with the transfer of heat from the burner to the metal pan. This heat transfer is also responsible for making the handle hot after a period of time. Water is heated by the process up convection which is a circular movement caused by heated water rising and cold water falling.

The process of heat transfer also occurs when an object cools. If a mug of hot coffee is left standing on a cold kitchen countertop, its temperature will gradually decrease as heat is lost. The heat energy dissipates by conduction through the mug to the table top by convection as the liquid rises, cools and sinks, and by the radiation of heat into the surrounding air.

One way to conserve the heat a liquid and prevent heat transfer is to place it in a thermos. The use a vacuum chamber with silvered surfaces, along with low conductive materials, can greatly improve the amount of heat or cold that is lost to the surrounding environment. In between the silvered glass walls up a thermos lies a vacuum. In the case of a hot liquid heat transfer by convection through the vacuum is greatly restricted due to the absence have air molecules necessary to facilitate the transfer of heat. The lack of physical contact between the inside and outside walls of the thermos due to this airless space also greatly inhibits the movement of heat by conduction. Heat loss by radiation is prevented by the silvered walls reflecting radiant energy back into the thermos. Some conduction of heat through the stopper in glass can be expected but this too is limited because they are made of materials with very low conductivity. Thus the temperatures are both hot and cold liquids can be maintained by a properly designed thermos that limits the transfer energy through radiation convection and conduction.

Heat capacity is the amount of heat required to change the temperature of an object or substance by one degree Celsius. The heat capacity of water varies depending on its phase. As solid ice, the heat capacity of water is .5 calories per gram for every one degree Celsius, which means it takes half a calorie to raise the temperature of one gram of ice one degree Celsius.

As a liquid, water heat capacity is one calorie per gram for every one degree Celsius, so it takes one calorie of heat energy to raise one gram of water one degree Celsius.

The processes of phase change between solid, liquid, and gas also require a specific amount of heat energy. The amount of energy required to change a liquid into a solid, or a solid into a liquid, is known as heat of fusion. The amount of heat required to change one gram of ice to water is 80 calories. Similarly the heat vaporization is the energy required to transform a liquid into a gas. It requires 540 calories to change one gram of liquid water into a gas. With these values its easy to calculate exactly how many calories of heat energy are required to transform one gram a ice at absolute zero to steam.

To warm 1 gram of ice from -273 degrees Celsius to 0 degrees celsius would be 273 times .5 gram per calorie or about 140 calories. The phase-change of one gram a ice to liquid water requires 80 calories. Then to heat the water from zero degrees Celsius to 100 degrees Celsius with the heat capacity at one calorie per gram, would require 100 calories. The final phase change it one gram a boiling water to steam would require an additional 540 calories. Adding all of these values together yields 860 calories, the amount of heat energy it takes to transform one gram gram of ice at absolute zero to steam.

Watch this video for an illustration of the above: