Gourmet cheese maker goes natural

Gourmet cheese maker goes natural


At the end of 2018, three Bitzer ammonia compressor packs were installed for gourmet cheesemaker Woerle in Austria. While this was Woerle’s first experience with ammonia, this natural refrigerant was the obvious choice as the company only uses natural ingredients in the production of its cheese. 

Au natural is tradition at Woerle: the company produces cheese from milk sourced from organic farmers in the region. The gourmet cheesemaker hadn’t had any experience with natural refrigerant ammonia but that has all changed: since the end of 2018, three Bitzer ammonia compressor packs (ACPs) have been ready to take charge of cooling liquid coolant to -12°C and ice water to +2°C for cold stores, ventilation systems and production at the Henndorf site near Salzburg (Austria).

Herzog Kälte-Klima based in Styria took on the job, delivering and installing the Bitzer ACPs. And with a length of over 2.2m, a width of 2.7m, a height of 2.3m and a weight of up to 7t per ACP, delivering them was anything but a simple task.

Image 2 BITZER HerzogAn art in itself: how heavyweights learn to fly. Image credit: Bitzer

An act of strength? Naturally!

Delivering three ACPs required the right planning, an effective team and the appropriate equipment – and then everything was straightforward. It took six employees to do all the heavy lifting: the crane operator, one crane banksman at the truck and another in the installation hall, and three installers for securing the lifting equipment and disconnecting the load. With a radius of up to 35m, a 220-tonne crane lifted the ACPs about 20m into the air before lowering them through the opening into the installation room, where they were pushed horizontally into their final position. The units were horizontally mounted and lifted using a vibration-reducing machine base and horizontally transported by five installers. The process also required heavy-duty castors, lifting cylinders and jacks for horizontal transport inside the installation room.

And that’s when the installation team comprising a welder, two pipe fitters and an electrician came into play. TÜV monitored pipe installation, which included a process inspection, design examination in accordance with the Pressure Equipment Directive, X-ray testing of weld seams and a safety-relevant pressure test with nitrogen as a pressure medium – all before the systems could be filled. Electrical mounting followed, with TÜV testing the safety technology and function control.

Image 3 BITZER HerzogA 220-tonne crane with a radius of 35m lowered the ACPs through the opening. Image credit: Bitzer

Neighbours helping neighbours

Project manager Herbert Khier, who oversaw the entire process, has been with Herzog Kälte-Klima for seven years, though the relationship with Bitzer goes back even further; he reports, “We at Herzog have been working with Bitzer products for 40 years. During that time, we’ve rarely had much to do with ammonia systems, but they’re becoming more and more common. Our customer Woerle was already familiar with the name Bitzer. It was ultimately the outstanding value for money that made the company opt for Bitzer ACPs. The ‘Made in Germany’ label also carries a lot of weight here in Austria.”

Image 4 BITZER HerzogThe Bitzer ACPs on the spot. Image credit: Bitzer

Bitzer manufactures its ammonia compressor packs in Rottenburg-Hailfingen in southern Germany; the screw compressors used there are provided by the manufacturing site in neighbouring Rottenburg-Ergenzingen. Each ACP contains one or two OSKA95 screw compressors as well as a three-stage horizontal OAHC oil separator and are all provided by the bitzer company. For this special customer case, Bitzer offered ACPs with just one compressor with the option to expand. The ACPs boast maximum efficiency thanks to frequency inverters and two double-pole high-speed motors, each with an output of 315kW and a maximum speed of 4 200rpm. 

The ACPs were to be commissioned in April 2019 and the ammonia will keep the cheese nice and cool.

Technical data

Planned for the final stage:
Liquid coolant to/tc –15°C/+36°C Qo 2 × 1 725kW Qw 2 × 484kW
Ice water to/tc –0.5°C Qo 3 053kW Qw 533kW

Image 5 BITZER HerzogEach of the three ACPs contains OSKA95 screw compressors and a three-stage horizontal OAHC oil separator. Image credit: Bitzer