Types of emptying pipes and valves in mixer kettles

The front emptying pipe is located in front of the kettle. It is positioned at the same height where the curved bottom parts start. This means that to have all the product emptied through the pipe, the kettle needs to be tilted to have the final part drained through the pipe.

The front emptying pipe is best suited for use where the kettle is only intermittently emptied through the pipe and, at other times, operated normally. The benefit of the front emptying pipes is that, if not needed, they cannot be used.

The bottom emptying pipe is located at the low part of the kettle's curved bottom - almost at the center of the kettle. The benefit is that all the products can be emptied without tilting the kettle. As a counterweight, the length of the pipe is longer; thus, during cooking, it needs to be plugged in to prevent ingredients from entering the pipe. 

As the bottom emptying pipe needs plugging every time cooking is done, it is more optimal for applications where food is emptied constantly through the pipe. Typical cases are when the kettle is connected to a mass pump that automatically portions the product from the kettle.

Echtermann-type valves

Echermann-type valves provides full pass-through with a 90-degree turn, slightly limiting the size of components that flow through and directing the flow downwards. These are typically selected for the front emptying pipe for intermittent emptying through the pipe to GN trays. 

The ball valve
The ball valve is based on a rotating ball with a hole through the center of the ball. The hole in the ball is turned either in the direction of the flow or against the flow. In the former case, the valve allows the flow, and in the latter ball prevents the flow.

The ball valve provides a full pass-through making it suitable for replacing the tilting of the kettle, but more often, it is used for applications where food is pumped through the emptying pipe. Ball valves can be used with both front and bottom emptying pipes.

The disadvantage of the ball valve is its relatively large size and longer cleaning process, so it is not optimal for intermittent use.

Butterfly valve   

The construction of a butterfly valve is relatively simple. The rotating disc in the center of the valve controls the flow through the valve. In the closed position, the disc blocks the valve, while in the open position, the disc is turned around on its axis and opens flow from both sides of the center axis. In the butterfly valve, the valve is never open for the full diameter of the emptying pipe.

Butterfly valves are the smallest, lightest, cheapest, and simplest-to-use valve type. It is typically selected with a front emptying pipe for application with intermittent use. It is commonly used with liquid products because it reduces the flow and limits the component size that can pass through the valve.

The arch valve
The arch valve's operating principle is similar to a ball valve, but the rotating element is an arch instead of a ball. Like the ball valve, it provides full pass-through making it another choice for pumping applications. 
Arch valves are also large and quite heavy, but they are generally considered easier to clean and more hygienic than ball valves.