Case Study:

Con­trol of the heat reco­very sys­tem

Logo Laundry Bauer

Intui­tively con­trol­led, sim­ply regu­la­ted

Washing, dry­ing, iro­ning – the laundry Bauer from Groß­wechsun­gen offers pro­fes­sio­nal tex­tile clea­ning for pri­vate house­holds and com­pa­nies. As a modern family busi­ness, the Thu­rin­gi­ans have been rely­ing on heat reco­very for a few years now. The heat reco­very sys­tem is con­trol­led by the mul­ti­func­tion con­trol­ler (MFC) from HESCH. The intel­li­gent con­trol­ler enab­les laundry experts to create com­plex auto­ma­tion sequen­ces them­sel­ves, even without PLC and pro­gramming know­ledge.

Using waste heat and genera­ting energy

Dry clea­ners and laund­ries have high energy requi­re­ments: on average, they spend a good 10 per­cent of their total costs on energy and water. This makes them one of the most energy-inten­sive sec­tors in the skil­led tra­des. The majo­rity – 85 to 90 per­cent – is requi­red for the genera­tion of ther­mal energy, for example to heat the washing lines, washing machi­nes, iro­ners and dry­ers, as well as for pro­ces­ses such as iro­ning and forming. This pro­du­ces waste heat that usually escapes unused into the open air – a waste of resour­ces that is neit­her good for the envi­ron­ment nor good for the wal­let. Because waste heat is valu­able energy.

 

With a heat reco­very sys­tem, it can be cap­tu­red and made usable again. This signi­fi­cantly redu­ces energy con­sump­tion and ope­ra­ting costs.

Con­trol of the heat reco­very sys­tem without PLC

The Bauer laundry in Groß­wechsun­gen on the sou­thern edge of the Harz Moun­tains also works con­ti­nuously to opti­mise pro­ces­ses and reduce costs. This modern family busi­ness collects, deli­vers and pro­ces­ses in-house and ren­tal linen for hotels, guest­houses, restau­rants, house­holds, public insti­tu­ti­ons, busi­nes­ses and nur­sing homes.

To incre­ase effi­ci­ency, the Thu­rin­gi­ans deci­ded some time ago to install a heat reco­very sys­tem. There were ple­nty of such sys­tems on the mar­ket. But vir­tually all manu­fac­tu­rers insis­ted on using their own pro­gramm­a­ble logic con­trol­ler (PLC).

Diese SPS waren für meine Zwe­cke aber zu teuer und unfle­xi­bel.

Lothar Bauer (owner)

Maid with freshly laundered towels
Washing, dry­ing, iro­ning - the laundry Bauer from Groß­wechsun­gen offers pro­fes­sio­nal tex­tile clea­ning for pri­vate house­holds and com­pa­nies.

As a trai­ned electri­cian, he is fami­liar with the sub­ject mat­ter, but has no spe­cial pro­gramming know­ledge – but without this you won’t get very far with a PLC.

„In mei­ner Wäsche­rei gibt es lau­fend Ver­bes­se­rungs­be­darf. Daher muss ich stän­dig erwei­tern, steu­ern, über­wa­chen und regeln kön­nen“

Lothar Bauer

“I would like to do this mys­elf without having to hire a PLC pro­grammer every time,” says Lothar Bauer.

So Bauer set out to find a plant manu­fac­tu­rer who would only sup­ply him with the heat reco­very tech­no­logy (without a PLC) and an intel­li­gent con­trol­ler that would give him the free­dom he wan­ted.

Less is more

During his Inter­net rese­arch, he came across the mul­ti­func­tion con­trol­ler (MFC) from the HESCH com­pany and was immedia­tely enthu­si­astic:

Mit dem MFC las­sen sich Ablauf­steue­run­gen selbst erstel­len, opti­mie­ren und über­wa­chen – und zwar ohne dass man ein Stu­dium als Pro­gram­mie­rer absol­viert haben muss.

Lothar Bauer

“This is exactly what I was loo­king for,” said Lothar Bauer.
The MFC is modu­larly expan­da­ble and offers simple com­mis­sio­ning, intui­tive ope­ra­tion and a wide range of com­mu­ni­ca­tion inter­faces (PROFINET, PROFIBUS, Mod­bus, CAN bus, HPR bus). In addi­tion, an exten­sive func­tion library with over 100 ready-made func­tions is avail­able. These can be assem­bled on the PC sim­ply by drag & drop to the desi­red pro­cess flow. Pro­gramming know­ledge is not requi­red. This saves time and costs.

Screenshot EasyTool MFC
In the gra­phi­cal edi­tor (Easy­Tool MFC), the user wires the finis­hed func­tion blocks without requi­ring any pro­gramming know­ledge.
Heating at the heat recovery unit
The mul­ti­func­tion con­trol­ler ensu­res that the two heat exch­an­gers work effi­ci­ently. For this pur­pose, it mea­su­res the tem­pe­ra­tures at several points in the pro­cess and con­trols (opens / clo­ses) the 3-way val­ves and cir­cu­la­tion pumps.

All-roun­der for all con­trol and moni­to­ring tasks

In the mean­time, the MFC from HESCH has been in use in the Groß­wechsun­gen laundry for over two years. There he con­trols and moni­tors the com­plete heat reco­very sys­tem.

 

It ensu­res that the two heat exch­an­gers work effi­ci­ently and ensu­res that there is always enough hot water for pro­duc­tion. In addi­tion, he mana­ges the sup­ply of hea­ting energy to other com­pany buil­dings (dining room, chan­ging rooms, offices) and the adja­cent resi­den­tial buil­ding. For this pur­pose, the MFC mea­su­res the tem­pe­ra­tures at several points in the pro­cess and con­trols (opens / clo­ses) the 3-way val­ves and cir­cu­la­tion pumps. The sys­tem pres­sure is also moni­to­red.

“The data log­ger func­tion is also very inte­res­ting for us,” Bauer reports. The MFC records the heat curve over the ent­ire pro­duc­tion day. The data can be saved locally and viewed and ana­ly­zed clearly in tabu­lar form.

„So habe ich jeder­zeit einen Über­blick über die Pro­zesse und kann auf Grund­lage der Daten wei­tere Opti­mie­run­gen vor­neh­men.“

Lothar Bauer

Thanks to its nume­rous com­mu­ni­ca­tion inter­faces, the MFC can be easily inte­gra­ted into all sys­tems and allows access to the data from any­where.

Buffer tank as part of the heat recovery system
In the Bauer laundry, the MFC from HESCH con­trols and moni­tors the com­plete heat reco­very sys­tem. Sur­plus heat is tem­pora­rily stored in the buf­fer tank

Taking the wheel into your own hands

The HESCH experts at the Bauer laundry were on hand from the very begin­ning to pro­vide sup­port and advice.

„Der tech­ni­sche Sup­port durch HESCH ist wirk­lich aus­ge­spro­chen gut“

Lothar Bauer

“After instal­ling the heat exch­an­gers, piping and wiring, we worked tog­e­ther to build the con­trol sys­tem piece by piece. Actually, we’re not really done with that even now. We have new sug­ges­ti­ons for impro­ve­ments all the time and are still in con­stant con­tact,” reports Bauer.

 

Ser­vice is a top prio­rity at HESCH. Detailed inst­ruc­tion in the func­tio­n­ing of the MFC as well as sup­port in “pro­gramming” are the­re­fore part of the scope of ser­vices for the auto­ma­tion spe­cia­list.

Control of the heat recovery system
The dis­play of the mul­ti­func­tion con­trol­ler gives an over­view of the cur­rent tem­pe­ra­tures. Set­tings can also be made here.

Modu­lar con­cept with many opti­ons – not only for con­trol­ling the heat reco­very sys­tem

Due to the local con­di­ti­ons, an exten­sion module is used in the Bauer laundry in addi­tion to the mul­ti­func­tion con­trol­ler. The Fiel­dbus Cou­p­ler HE 5813 con­nects the modu­lar Pro­cess I/O HIMOD Sys­tem with a Mod­bus RTU net­work and enab­les an app­li­ca­tion also out­side the con­trol cabi­net.

Thanks to its own intel­li­gence, the multi-chan­nel I/O module is able to pre-pro­cess the inco­m­ing signals from the tem­pe­ra­ture sen­sors. This relie­ves the sys­tem con­trol. The HIMOD exten­sion is instal­led in the pro­duc­tion area, the main con­trol sys­tem is loca­ted in the boi­ler house 100 meters away. Both are con­nec­ted via a data line.
“This intel­li­gent fiel­dbus sys­tem is of great advan­tage to us,” says Bauer. “It allows us to install all the con­trol relays in the pro­duc­tion area without having to run any more wires.” The multi-func­tion con­trol­ler from HESCH is not the first con­trol­ler in the Thu­rin­gian laundry. Several PLCs from dif­fe­rent manu­fac­tu­rers are already in use. But the MFC is the first con­trol­ler that has con­vin­ced Bauer all along the line:

„Er ist ein­fach und intui­tiv zu bedie­nen, intel­li­gent ver­netzt sowie jeder­zeit fle­xi­bel ver­än­der- und erwei­ter­bar. Das ist per­fekt für uns. Ich kann ihn jedem Wäsche­rei­be­trieb nur emp­feh­len.“

Lothar Bauer

There is also ano­t­her, posi­tive effect: Bauer reck­ons with a savings poten­tial of at least 20 per­cent in energy con­sump­tion.

Are you inte­res­ted in a pro­duct demons­tra­tion?

Write to us or give us a call. We will be happy to arrange an appoint­ment with you.

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