How coffee works

Because I learned Agile Software Development and used it as an example of coffee maker in the book, I found this article to better understand it.

How coffee works

Author: Marshall brain

 

This article includes: 1. Introduction 2. Learn more 3. Read all Household AppliancesClass Article Introduction

Most people who love caffeine cannot leave an old friend for breakfast-this is a coffee maker! Every morning, you scoop coffee in the coffee maker, add water, and turn on the switch. Have you ever thought about what is going on? How does water flow out from the sub-tank-the place where you pour water to the top of the coffee maker?

In this article, we will take a closer look at the Typical drip coffee machine, so that you can know what is happening when you cook your own coffee. We will also discuss some potential problems that may cause your coffee machine to malfunction. After reading the full text, you may have a new understanding of your old friends!

The modern drip coffee machine is an extremely simple device. Manufacturers have been constantly improving their design over the past 25 years, so once you turn on these coffee machines, you will find them very intuitive. This is the coffee machine discussed in this article:

Front View of drip coffee maker

Bottom View

Heating Plate

Hot water leaks from here to crushed coffee

If you remove the lid of the coffee maker, you will find three things:

Internal view on top of coffee maker

	How coffee works

• There is a small bucket that is used to hold water (the right part) when pouring water into the coffee pot at the beginning of the coffee cooking process ). There is a hole at the bottom of the bucket. After a while, its function will appear.

• There is a black catheter used to import hot water into the drip area.

• There isDrip Area(That is, the left part of the image ). The water flow from the black hot water catheter to here, that is, from the small hole to the broken coffee.

After reading this picture, your first impression on the coffee maker is that this is not a high-tech device. If you remove the bottom of the coffee maker, you will find:

Internal view at the bottom of the coffee maker

The right concave part of the image is the bottom of the bucket, and the orange catheter in the middle is the hot water pipe (connected to the Black catheter shown above ), another orange catheter exports cold water from a small hole in the bucket. In addition, you can also see the power cord and the switch used to turn on and off the coffee maker.

Switch

HeaterIt is an aluminum forging product consisting of two parts: a durable heater and a guide pipe, as shown below:

Durable heaters and aluminum tubes used for boiling water

Durable HeaterIt's just a winding wire, like a filament in a light bulb or a heater in an electric oven, which can turn hot with just one power supply. In such a durable heater, the heating coil is embedded in plaster to make the surface more rough. The heater has two functions:

1. When you pour water into the coffee machine, the heater will boil the water.

2. After the coffee is cooked, the heater can keep the coffee warm.

In, you can see that the heater and the heating board are connected. The heater is close to the lower end of the heating board, and a white thermal grease paste can ensure effective heat transfer to the heating board. By the way, this layer of fat paste is very sticky (it is difficult to clean your fingers !). You can see the grease paste on a variety of devices, including the stereo amplifier, power supply equipment-almost all kinds of equipment to heat.

Coffee makerSwitchUsed to power on or off the heater. Three typesSolid State Temperature SensorAvailable, as shown in the following figure:

Simple Solid State Temperature Sensor cut off current when the temperature is too high

The device directly connected to the coil is the main temperature sensor. When it detects that the coil is overheated, it will cut off the current. Then, when the temperature drops, the current is re-connected, so that the coil can maintain a constant temperature. The other two devices are thermal fuses. If they sense a high temperature, the power supply is directly cut off. It is designed for security reasons and can be used in case the active sensor is broken.

In this coffee machine, an invisible part is the check valve door. The valve is either in a small hole in the bucket or in an aluminum heating tube. If there is no check valve, the possibility of boiling water flowing into the bucket is as high as that of black catheter. Check Valve let the cold water flow into the aluminum pipe, but let the boiling water bubble flow up the black catheter. If you blow to the catheter leading to the valve, the valve should open. If you inhale in the catheter, this check valve will block any intake.

Coffee

You can find that coffee machines are almost the simplest of household appliances! The following is how it works:

1. When you add the cold water, the water enters the orange catheter from the small hole at the bottom of the barrel.

2. The water flows from the Check Valve door to the heater's aluminum pipe, and then a part flows into the black catheter. Due to gravity, the entire process is well understood.

3. When you turn on the switch, the heater starts to heat the aluminum tube, and the water in the tube begins to boil.

4. When water is boiling, bubbles rise up in the black catheter. The next step is like the typical aquarium filter: the catheter is small, and the bubble is large, so that the bubble can hold a string of Water bars.

5. Water flows out of the other end of the Black catheter and drops onto the coffee.

By the way, such a boiling water pump, to some extent, works in the same way as a filtration coffee machine.

As you can see, there is no mechanical pump of any type here. In fact, there are no other moving parts except the moving parts of the check valve door, which makes the coffee machine extremely reliable.

What problems will occur?

The following are some of the most common problems that may cause failures in the drip coffee:

• The power cord or switch may be faulty. No matter what the problem occurs, it is best to ask a professional to replace or purchase a new coffee -- an improper replacement may cause a fire.

• The check valve may be blocked or cannot be closed. Generally, you can use your toothpicks to remove the problematic parts.

• The catheter may be blocked by calcium. Aluminum Heating Tubes are more prone to this problem. To solve this problem, the usual solution is to run the coffee once with vinegar, and then run twice with water to discharge the vinegar.

However, there are almost two problems that cannot be solved:

• One of the hot sensors fails.

• Heating Coil failure

Because it is almost impossible to replace parts, no matter which problem occurs on your machine, you may have to buy a new coffee.

Now, when you cook the coffee again tomorrow morning, you will have a brand new understanding of what happened in the coffee!

For more information about coffee maker, coffee, and related topics, see the next page.