In our First Session, About HPP Equipment we will cover the major components of a High Pressure Processing (HPP) Machine.
When learning about HPP equipment, there are 3 Major Component of the High Pressure Processing Machine you must talk about. The HPP Vessel, HPP Plugs, and HPP Yoke or Frame.
HPP Vessel #1
When learning about HPP Equipment, the Vessel depicted as #1, is the first major component of the HPP Machine. You can think of the vessel as a large tube of carbon steel. Because the vessel interior liner is stainless steel it meets food safety compliance. Therefore the vessel is two layers. The vessel holds tremendous pressure using miles of wire wrapped around the vessel like a golf ball. Stainless steel is used to wrap the vessel. To prevent corrosion of the wiring some companies use either oil or wax to coat the wiring. The vessel can be of various lengths and internal and external diameters. Since the vessel is a pressure component, most countries have strict certifications that must be followed. Such as ASME U3 in North America, CE in Europe, IBR in India and GOST in Russia. Countries such as China do not have such compliance.
HPP Plugs #3
Depiction #3 is the Plugs and they are the second major component of the HPP Machine. are two stainless steel plugs one for each side of the vessel. These plugs server many purposes. First, they maintain the seal with the wall so water doesn’t leak out of the vessel causing the vessel to lose pressure. Next, they allow low pressure and high pressure tubes to connect to the plugs to fill the vessel full of water while removing any residual air. These tubes also are connect to devices (pressure transducers) that monitor the pressure inside the vessel. Lastly, the high pressure tubes in the plugs serve as a way to release the pressure in the vessel (decompression). The plugs follow the same certifications as the vessel.
HPP Yoke or Frame (Frame) #4
When learning about HPP Equipment, Depiction #4 is the Frame and it is the third major component of the HPP Machine. The frame is what holds the plugs in place so that the vessel can be pressurized with the assistance of the wedges. Frame construction uses two different designs. The first design is to take many sheets of thick carbon steel and cut out the center for the plugs and vessel. Then create a lamented box. The second design uses the wire wound method used on the vessel by creating box out of blocks of carbon steel with a large hole in the center and then wrapping the outside of the box with miles of wire. Some designs coat with wire with oil or wax. And some systems have added air circulation between the stainless steel sleeve and the wiring to control condensation. The frame is sleeve in stainless steel.
Water Circulation Pump #5
The last piece depicted in this illustration is the Water Circulation Pump #5. The water circulation pump fills the vessel full of cold water. After the cycle is completed and the plugs are removed, it recaptures most of the water.
Wedges/Blocks #2
Depicted as #2 are the carbon steel blocks. Learning about HPP blocks is important as they keep the plugs in the vessel maintaining the seal during pressurization. The plugs are fully inserted into the vessel and then the vessel is positioned inside of the frame. There is a large gap between the back of the plug and the inside wall of the frame. The block fills the gap.
Hydraulic Valves #6
The hydraulic valves control the movements of the machine as depicted in #6. the hydraulic valves control the movements such as the plugs being inserted into the vessel, the vessel being moved into the frame, the blocks being moved into the gap between the vessel and frame.
Decompression Values #7
There are several different designs for depiction #7, decompression valves. These valves release the very high pressures that are generated by the water being pumped into the vessel. Once the vessel has held pressure for the desired amount of time, either hydraulic valves or pneumatic valves will open the decompression valves and release the water from the vessel. These decompression valves slow the water down very quickly and dump this hot water into a decompression tank before either releasing it down a drain or reintroducing it to the recirculation tank. Some systems use a looping tube system to slow the water down before the water enters the decompression tank.
Studs and Bolts #8
Depicted as #8 the studs and bolts are part of the lamented frame design and serve two purposes. The studs and bolts keep the lamented pieces from shifting during pressurization. The large studs on each end of the frame used for the transport and moving of the frame for installation and relocation.
Water Filtration System #9
Depicted in #9 is the water filtration system. The filtration uses 10 micron filtering system. Water in the vessel can become contaminated with packages and containers of product that leak out when pressurized. Also pieces of plastic from the containers can get in the water system. Since the systems want to conserve water and reuse it, the water filtration system makes this possible. Most HPP machines today utilize separate water systems for the intensifiers and the filling of the vessel.
Hydraulic Pumps and Intensifiers #10
Depicted as #10 the horsepower that drives the HPP machines. The hydraulic pumps are controlled by the hydraulic valves. In addition to providing the power that moves the vessel, plugs, blocks, the pumps provide the power that drives the intensifiers. These intensifiers are also known as superchargers.
So what is an intensifier? Well, an intensifier intensifies the low pressure water by forcing water into the vessel using what is called a plunger. The plungers come in both stainless steel and ceramic. How this works is that the intensifier has two components. The center of the component is a hydraulic cylinder with a piston that goes back and forth. This hydraulic cylinder’s diameter is 30 times bigger in inside diameter of the water cylinder. So when the hydraulic piston goes back and forth it causes the plunger to push water into the vessel at 30 times more pressure than the piston. To create the very high pressures of 87,000 psi/600 MPa, the hydraulic pump pressure is set at 3,000 psi/20 MPa. Coincidentally the waterside cylinders must be stainless steel.
What did you learn?
Hopefully you are learning about HPP and now you have a basic understanding of the major components that make up High Pressure Equipment for Cold Pressure Pasteurization. What you do with this new found knowledge is up to each individual reader.
What is Next?
The next module in this HPP Series will build upon what you just learned and apply it to the current HPP manufactures. We will introduce you to each company, the machines, and how the machines for different manufactures similar and what differentiates them. If you are in a hurry to learn more, make sure you sign up for the HPP Workshop coming in April 2019.