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Log Mean Temperature Difference (LMTD) Method with Examples

Logarithmic Mean temperature Difference is used to measure the Heat transfer rate in double pipe heat exchanger. The rate of heat transfer is got from the formula - Q = U.A.LMTD . U= Heat Transfer Co-efficient A= Heat Transfer Surface Area LMTD= Mean Temperature Difference LMTD is the logarithmic temperature difference between the hot and cold fluids passing through the each ends of heat

Stress Strain Graph for Mild Steel explained

Stress: When any object of certain material is subjected to tensile or compressive or shear force, there may be a chance that its dimension will be affected. If the dimension of a material is changed due to application of forces we can say that the material is under stress or experiencing the state of stress. Stress is defined as the Force per unit cross section area. Stress = F/A Stress is

A Low-Cost EggPlotter

Features Plots on spheres and eggs, similar to the EggBot Uses low-cost components (total cost around 25 €) Software is written as an Arduino sketch But: NOT as accurate as the original EggBot Introduction I have admired the idea of the EggBot for quite some time. The original device is an art project of Bruce Shapiro, apparently conceived in 1990. Read about the history of it

Plastic Extrusion Process Principles

Extrusion Process Principles Extrusion process is very common in the plastic industry. It is used for high volume plastic production. In extrusion process the color pigments along with other performance enhancing additives are combined with resin which is then pushed through the rotating screws. The heat and pressure generated within the barrels of screw is dispersed and melts the plastic

Different Types of Plastics- Advantages and Disadvantages

Plastics can be classifies into two broad categories - Thermosets and Thermoplasctics. A brief description of these two classes will be discussed here. Thermosets are the kind of plastics which are not recyclable. They undergo a kind of chemical change at the time of heating. As a result they can be shaped once because of this permanent chemical change. This process is known as heat hardening.

Diferent Parts of Sand Mold- Features

Cope and drag in Sand Mold : Cope and Drag are the two parts of the casting flask. Cope is the upper part and drag is the lower part. Even if the casting process is flaskless , the same terms are used for the upper ans lower parts. Generally the flask is made of wood or metal. It contains molding sand. When metal is poured into the mold cavity the flask supports the mold. Gating system:

Lost Wax or Investment Casting Method Steps

Investment or lost-wax castings: The Lost-wax method, sometimes, also called simply as precision-investment casting has been used for many years by jewelers and dentists. Since world-war-II, the method has been adapted to the production of small and precise, industrial fasting. Basically, the method involves the use of expendable (heat disposable) pattern unrounded with a shell of refractory

WiFiRGB - A WiFi-enabled RGB high-power LED

Features Simple hardware, using pre-fabricated modules Controls an RGB LED via any recent browser, any operating system WiFi credentials can be configured via browser Software is written as an Arduino sketch Introduction Some time ago I read about the cheap and easy to use ESP8266 WiFi modules and I had to have a couple of them. So I ordered two ESP-01 modules. At the time I had no idea

Die Casting Principles

Die casting process is very different from sand casting as the mould used here is permanent. The mould is not expandable and need not to be broken after the cooling and solidification. Here the mould is called the die. Please Read : Comparison of different casting process A complete Guide to casting process Gravity die casting: When the molten is metal is poured under a gravity

Sand Casting Process with Diagram

Sand casting: In sand casting which is also known as sand molded casting, an object is produced by sand mold. The process involves pouring of the molten metal in to the mold cavity. The molten metal is then cooled to the room temperature. The metal is solidified. After cooling, the metal object is separated from the mold. Sand casting process has its advantages and disadvantages. So care

A Complete Guide to Steps Involved in Casting Process

We know that casting is the process of pouring molten metal in a desired shaped cavity and allowing it to solidify. After the solidification we get the desired shaped object. Please read : Comparison of different casting processes. What is casting ? Main application of castings Basic Steps of Sand casting Basic Operation of the casting process First we have to make a pattern Then the

Different Types of Pattern Allowances in Casting

Pattern allowances: There are some allowances which are responsible for the difference in the dimensions of the casting and the pattern. These allowances are considered when a pattern is designed for casting. In this article we will discuss those allowances - 1. Shrinkage allowance: After solidification of the metal from further cooling (room

What is Brazing-Principles

Discovering Brazing (Braze Welding) Brazing is a gas welding process in which you join metals by using heat that surpasses the 800 degree Fahrenheit mark and a nonferrous (iron-free) filler rod with a melting temperature below that of the base materials. The most important point about brazing is that you can use it to join dissimilar metals — cast iron to steel, brass to steel, or copper to

Electrical Discharge Machining (EDM) Principles

EDM is a non-conventional machining technique uniquely used for cutting metals which are not possible to cut with traditional methods. EDM only works with materials which are electrically conductive. Delicate cavities and intricate contours which are difficult to produce with a grinder or other machines can be done with Electrical Discharge Machining or EDM. The cutting tool for EDM may be made

Electrochemical Machining (ECM) Principles

Electrochemical Machining (ECM) is based upon Faraday's law of electrolysis. Faraday's law states that the the mass of a metal altered by the electrode is proportional to the quantity of electrical charges transferred to that electrode. In ECM the removal of metal is controlled by the anodic dissolution in the electrolyte. In ECM - The workpiece acts as the anode The tool act as cathode.

Match Plate Pattern - Used in Casting (With diagram)

What is Match - Plate Pattern The match plate pattern is almost similar to the mounted pattern but it can have part of the casting in the cope and part in the drag like split piece pattern. These parts are generally attached to the plate / board in opposite sides in the perfect positions. When the plate is removed and mold is in close position the cavities in the cop and drag match perfectly.

Ultrasonic Machining (USM) Working Principles

In this process the material of the workpiece is removed by the repetitive impact actions of abrasive particles. The erosion takes place by the abrasive particles which are carried by a liquid medium in the from of a slurry . A shaped vibrating tool is used to produce the impact. The term shaped is used to explain that the process is capable enough to create 3D profiles in correspondence to the

Water Jet Machining (WJM) Advantages and Disadvantages

In Water jet Machining no abrasive is used. Water jet alone is used for cutting. In WJM, materials like concrete, asbestos, wood, rocks, coal, textiles and leather can be cut. The material is removed by means of erosion. These days hydraulic coal mining as well as tunneling, descaling and cleaning is also done by this process. Water Jet Machining (WJM) Principles As

ADVANTAGES AND DISADVANTAGES OF WELDING

Like all joining processes (in fact, like all processes!), welding offers several advantages but has some disadvantages as well. The most significant advantage of welding is undoubtedly that it provides exceptional structural integrity, producing joints with very high efficiencies. The strength of joints that are welded continuously (i.e.,full length, without intentional skipped areas) can easily

A MythTV Remote Control without LIRC - Power Switch Addon

Overview This is a little add-on for my MythTV remote control. It adds a hardware power switch feature. This means that you can switch the PC on even if it is completely shut down. There is just one condition, which is that the remote control receiver must have power, supplied through the USB port. On most modern mainboards, this is an option in the BIOS settings. The additional hardware is