TORCH FURNACE CO.,LIMITED

Booklet of MoSi2 Heating Element Description：

This bulletin provides useful information on the handing, storage, installation, operation, and maintenance of Torch Furnace heating elements.

 It will help you achieve maximum performance and service from your Torch Furnace heating elements, thereby reducing your operating costs.  The information, recommendations, and opinions set forth herein are offered solely for your consideration, inqury, and verification, and are not, in part of total, to be construed as constituting a warranty or representation for which we assume legal responsibility. Nothing contained herein is to be interpreted as authorization to practice a patented invention without a license.

Handling

Torch furnace mosi2 heating elements have high compressive strength. They are relatively low in tensile strength, however, and are sensitive to mechanical shock.

To avoid breakage, handle elements carefully at all times—even when the elements are still packed in their shipping cartons. Remember, an element can be broken merely by dropping or bumping the carton.

Never pick up an element by one end—handle with both ends.

 Unpacking and Inspecting

 Shipments should be unpacked and inspected as soon as received. Packaging is designed to protect elements in transit. Dropping or bumping a carton may break the element inside without damaging the exterior of the carton.

Here’s how to unpack and inspect:

Lay shipping carton on a flat surface.

Cut tapes and carefully open top of the shipping carton—not the ends.

Remove individual boxes with both hands. Don’t pry them out.

Place element box on a flat surface, cut the tapes, and carefully open the cover.

Turn box on its side and gently ease out the wrapped element.

Carefully roll the elemnt out of its packing.

Don’t rip the wrapping off the element.

Don’t open the end of the carton and try to pull the element out.

Don’t hold the element by one hand and pull or lift it out of its box.

Never inspect an element by merely pressing on the wrapped element, or by lifting one end up off the fiat surface.

Storage

To reduce the possibility of accidental breakage, Torch Furnace heating elements should be stored horizontally and fully supported on a flat surface in the original wrappings and boxes.℃

After inspecting, roll elements back into the packing, as received, and place them back in their boxes.

Store elements horizontally in a special warm, dry storage area. Be sure the elements will not be accidentally bumped and broken. Do not stand them on end.

 Place boxes in stock, on by one, on a firm, flat shelf that is long enough to support the entire length of the boxes. Avoid excessive stacking.

Installation

1. Vertically Hanging

 Under normal temperature, MoSi2 element is very brittle while under high temperature it is of plasticity. So the better way of installation is to hang it vertically to the furnace top through the support clamping chuck. The aim is to avoid putting the mechanical stress directly to the element heat-generating end , or the element will easily be broken.

2. Element Holder

 The element holder supports the whole weight of the element and the position of the element is also determined by it. Therefore, it must be installed carefully to assure that the element is vertically hung. In order to prevent the element from being over heated locally, the cone part of the element lower end must be put into the furnace chamber.

3. Connection Strap  ã€€

 The connection strap is made of aluminum braided strap or multilayer aluminum foil. The outside clamp isn't used for electrical conduction. For Diameter6/12 element, single loop type is used and for Diameter9/18 element, double loops type is used. The length of the lead wire should be a little longer than the linear distance between the element and bus.

When install the element, don't twist the screw too tight at one time and it can be tightened when the element rises to high temperature because the element is plastic and isn't easily broken under high temperature. The temperature of the wire clip generally shouldn't be higher than 200℃. Therefor, the contact voltage between the clip wire and element should be lowered to 0.1V. In order to avoid that the radiation heat is conducted to the clip, the distance between the lower end of the clip and upper surface of the through brick should not less then 50mm. Generally for Diameter6/12 element, 170A should not be used for a long time and for Diameter9/18 element, 300A shouldn't be used for a long time.

Operation

1. Drying of the Furnace

  The new built furnace or the furnace that haven't been used for a long time should be dried before use. The drying temperature generally is 100-200℃. As for the MoSi2 heating element, if it  has been used for a long period under low temperature, low-temperature oxidation will be caused. For the small-sized furnace, as its drying time is short, several hours will affect the element little. But for the large-sized one, as its drying time is long, it should be dried carefully. You'd better open the furnace gate to make it ventilated. The gate can be half-opened with the rising of temperature and fully closed when the temperature rises above 1000℃.

2. Starting of the Furnace

   If the furnace has been dried or needn't to be dried, it can be started to raise temperature. In order to avoid that it is impacted by over current and the electric device is overloaded, the following steps should be adapted:

 

If it is found that one element is damaged during operating, firstly you should determine where it is and at the same time prepare a made up one. Then loosen the thread which links the lead wire of the damaged element and the bus, clear out the ceramic cotton and pull out the through-brick. Afterward, insert the new element from the furnace top, link the lead wire, block the gap with ceramic cotton and start raising temperature.

Key Factors Affecting Element Life

• Operating Temperature 
• Surface Loading 
• Atmospheres in the furnace and Materials to be Processed 
• Energizing Method 
• Electrical Connection 
• Installation Method of Heating Elements

Words of Wisdom

Handle Torch Furnace heating elements carefully at all times.

Inspect Torch Furnace heating elements immediately upon receipt.

Store Torch Furnace heating elements in a dry and protected storage area where they cannot be accidentally bumped and broken.

All elements in the furnace must be operative.

Replace any elements that have failed and be sure that groups of elements are balanced.

Don’t forget to turn off and lock out the power before replacing elements.

Install elements carefully and be sure they are free to expand and contract at all times-when the furnace is hot, as well as when it is cold.

Be sure the heating section is centered in the chamber and not back in the wall.

On startup, with new elements, bring elements up to temperature slowly on lower voltage taps, and adjust the voltage upward as the furnace heats up.

Don’t subject the elements to unnecessary thermal or mechanical shock.

Don’t blow air into the chamber for rapid cooling.

Thing to Check to Avoid Trouble or to Solve a Problem

Are the correct-size Torch Furnace heating elements being used?

Are there any inoperative elements in the furnace?

Are the terminal holes straight and in alignment so the element doesn’t blind?

Are the elements free to move in the furnace?

Are the heating sections centered in the chamber and not back in the wall?

Are any elements sticking in the terminal holes from foreign material condensing in the holes?

Are elements overheating?

Are the transformer taps set correctly to permit all elements to operate at recommended watt loadings?

Are any terminal straps too snug, thus putting a stress on the elements?

Are any terminal clamps too close to the furnace wall, thus preventing expansion and contraction?

Are all the electrical connections tight, so power is being applied to the elements?

Is the temperature-control equipment working correctly?

Are the elements being attacked by any chemicals burned out of the charge?

Has the composition of the atmosphere been changed?

Has the moisture involved increased and become detrimental?

Is anything dripping onto the elements?

Is the material being heated too close to the elements?

Are elements being hit when the furnace is being loaded or unloaded?

Are elements being subjected to vibration or floor shocks?

Have any new operators or maintenance personnel read this booklet?

 Are elements being handled properly and carefully at all times?